Files
MultiforaDB/src/commands.zig
Aleksey Shakhmatov 9390021b1e index/commands: stream whole-index scans; add a reverse leaf iterator
A whole-index read used to materialize every candidate before the caller saw
the first one. At the tens-of-GB target that is a list of every offset in the
collection -- ~160 MB for a countDocuments({}) over 20 million documents --
which defeats the point of moving storage to disk. Cursors are M1, but
*streaming a scan* has to exist now.

`Candidates` is the one loop candidates arrive through, whatever produced them:
a plan's materialized lookups, or the index read end to end. That keeps this
file's governing invariant -- an index only generates candidates, the full
filter is re-applied to every one -- in a single place. A narrowed plan still
materializes, because its multikey/$in dedupe genuinely needs the whole set and
is bounded by selectivity.

`RevIter` walks `Node.prev`, which has always been maintained and which nothing
had ever read: a descending scan materialized the whole index and reversed the
list. `find({}).sort({_id:-1}).limit(20)` becomes O(20).

The unfiltered fallback now walks the _id_ index instead of the docs map. That
is ordered rather than hash-ordered, and it does not depend on a structure that
is about to be deleted.

`Plan.full_scan()` refuses multikey indexes, since one document contributes
several entries there and a stream cannot dedupe what `search` did. The check is
currently redundant -- the planner refuses to order a multikey index anyway --
and is kept because the two guards protect different things. Stated precisely
in both places after checking: the commands.zig test reddens only when *both*
guards are removed, which is what that test actually pins.

--

This also broke e2e6's compaction check, and the fix there is the more
interesting half.

The check required peak/final > 1.4 and got 1.28. The final size was identical
to the byte (2,398,065 vs 2,398,064) -- compaction reclaimed exactly as before
-- and only the peak moved. Isolated to one variable: changing just the order
updateMany({}) walks its matches moves peak/final between 1.65 and 1.28, because
compaction can also fire from the once-per-second TTL monitor and whether one
lands inside the batch shifts the peak a long way while leaving the outcome
unchanged. The threshold was measuring the schedule.

Replaced with `peak > final`, which measures the shape instead: an append-only
log grows monotonically, so its maximum *is* its final size, and a file that
was ever larger than it ended can only have been rewritten.

Worth recording why the obvious alternative does not work. An absolute size
bound cannot distinguish a working compactor here: the payload is one repeated
character, so ~48 MB of records LZ4-compress to ~3 MB whether or not anything is
reclaimed -- with compaction disabled entirely the file still ends at 3.1 MB. I
first wrote the comment claiming that bound was the strong one, then measured it
and found the opposite; `peak > final` is what goes red.
2026-08-03 20:05:38 +03:00

2768 lines
129 KiB
Zig

//! MongoDB command dispatch. Each command fills `reply` with its result;
//! unknown commands and failures produce error replies with real codes.
const std = @import("std");
const builtin = @import("builtin");
const bson = @import("bson.zig");
const wire = @import("wire.zig");
const db = @import("db.zig");
const Collection = db.Collection;
const query = @import("query.zig");
const update = @import("update.zig");
const index = @import("index.zig");
// Always active, including in the default ReleaseFast build -- see assert.zig.
const assert = @import("assert.zig").assert;
const assert_msg = @import("assert.zig").assert_msg;
pub const Context = struct {
gpa: std.mem.Allocator,
io: std.Io,
oid_gen: *bson.ObjectIdGen,
connection_id: u32,
client_desc: []const u8,
engine: *db.Engine,
server_start: std.Io.Timestamp,
};
pub const ErrorCode = enum(i32) {
command_not_found = 59,
bad_value = 2,
invalid_argument = 72,
namespace_not_found = 26,
index_not_found = 27,
duplicate_key = 11000,
namespace_exists = 48,
failed_to_parse = 9,
internal_error = 1,
invalid_pipeline_operator = 40324,
index_options_conflict = 85,
cannot_create_index = 67,
invalid_index_specification_option = 197,
};
/// Which lock (if any) a command needs on the engine. Contract: only
/// `.write` commands may call engine mutation functions (insert, replace,
/// remove, drop*, get_or_create_collection, compact); `.read` commands may
/// only read (`get_collection`, `database_names`, `collection_names`);
/// `.none` commands must not touch the engine at all.
const CommandKind = enum { none, read, write };
/// Lock shape for one command, acquired by dispatch: the catalog lock mode
/// and whether the command's target collection is locked (shared for reads,
/// exclusive for writes/DDL). The target collection is the message field
/// named after the command (find/count/insert/...), which every
/// collection-targeting command uses.
const LockShape = struct {
catalog: enum { none, shared, exclusive } = .none,
coll: enum { none, shared, exclusive } = .none,
};
const Command = struct {
name: []const u8,
kind: CommandKind,
locks: LockShape = .{},
handler: *const fn (*Context, *wire.Message, *wire.Reply) anyerror!void,
};
/// The one place a command exists: name, lock class, and handler declared
/// together so a new command cannot be given a handler but no lock.
const command_table = [_]Command{
// Handshake, admin info, no-ops: never touch the engine.
.{ .name = "hello", .kind = .none, .handler = cmd_hello },
.{ .name = "isMaster", .kind = .none, .handler = cmd_is_master },
.{ .name = "ismaster", .kind = .none, .handler = cmd_is_master },
.{ .name = "ping", .kind = .none, .handler = cmd_ping },
.{ .name = "buildInfo", .kind = .none, .handler = cmd_build_info },
.{ .name = "getParameter", .kind = .none, .handler = cmd_get_parameter },
.{ .name = "whatsmyuri", .kind = .none, .handler = cmd_whatsmyuri },
.{ .name = "hostInfo", .kind = .none, .handler = cmd_host_info },
.{ .name = "getCmdLineOpts", .kind = .none, .handler = cmd_get_cmd_line_opts },
.{ .name = "serverStatus", .kind = .none, .handler = cmd_server_status },
.{ .name = "endSessions", .kind = .none, .handler = cmd_end_sessions },
.{ .name = "connectionStatus", .kind = .none, .handler = cmd_connection_status },
.{ .name = "getMore", .kind = .none, .handler = cmd_get_more },
.{ .name = "killCursors", .kind = .none, .handler = cmd_kill_cursors },
// Read-only: scan the engine without mutating it.
.{ .name = "find", .kind = .read, .locks = .{ .catalog = .shared, .coll = .shared }, .handler = cmd_find },
.{ .name = "count", .kind = .read, .locks = .{ .catalog = .shared, .coll = .shared }, .handler = cmd_count },
.{ .name = "aggregate", .kind = .read, .locks = .{ .catalog = .shared, .coll = .shared }, .handler = cmd_aggregate },
.{ .name = "listDatabases", .kind = .read, .locks = .{ .catalog = .shared }, .handler = cmd_list_databases },
.{ .name = "listCollections", .kind = .read, .locks = .{ .catalog = .shared }, .handler = cmd_list_collections },
// Writes: the target collection exclusively; create/drop take the
// catalog exclusively (they mutate the maps).
.{ .name = "create", .kind = .write, .locks = .{ .catalog = .exclusive, .coll = .exclusive }, .handler = cmd_create },
.{ .name = "drop", .kind = .write, .locks = .{ .catalog = .exclusive, .coll = .exclusive }, .handler = cmd_drop },
.{ .name = "dropDatabase", .kind = .write, .locks = .{ .catalog = .exclusive }, .handler = cmd_drop_database },
.{ .name = "createIndexes", .kind = .write, .locks = .{ .catalog = .shared, .coll = .exclusive }, .handler = cmd_create_indexes },
.{ .name = "dropIndexes", .kind = .write, .locks = .{ .catalog = .shared, .coll = .exclusive }, .handler = cmd_drop_indexes },
.{ .name = "insert", .kind = .write, .locks = .{ .catalog = .shared, .coll = .exclusive }, .handler = cmd_insert },
.{ .name = "update", .kind = .write, .locks = .{ .catalog = .shared, .coll = .exclusive }, .handler = cmd_update },
.{ .name = "delete", .kind = .write, .locks = .{ .catalog = .shared, .coll = .exclusive }, .handler = cmd_delete },
.{ .name = "findAndModify", .kind = .write, .locks = .{ .catalog = .shared, .coll = .exclusive }, .handler = cmd_find_and_modify },
.{ .name = "listIndexes", .kind = .read, .locks = .{ .catalog = .shared, .coll = .shared }, .handler = cmd_list_indexes },
};
/// Command name to its index in `command_table`, resolved at comptime so a
/// request costs one hash instead of a walk down the whole table comparing
/// strings.
const command_index = blk: {
var kvs: [command_table.len]struct { []const u8, usize } = undefined;
for (&command_table, 0..) |c, i| kvs[i] = .{ c.name, i };
break :blk std.StaticStringMap(usize).initComptime(kvs);
};
pub fn dispatch(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const name = msg.command_name();
const cmd = if (command_index.get(name)) |i| &command_table[i] else {
var buf: [256]u8 = undefined;
const errmsg = try std.fmt.bufPrint(&buf, "no such command: '{s}'", .{name});
return reply.put_error(@intFromEnum(ErrorCode.command_not_found), "CommandNotFound", errmsg);
};
// Lock the catalog (shared for most commands, exclusive for DDL), then
// the target collection, then run the handler. The collection lock is
// taken while the catalog lock is held, so a concurrent drop can never
// free the collection out from under us.
// Resolve the namespace *before* taking any lock. It used to happen after
// the catalog lock, with `orelse return` on both parts -- and a plain
// `return` is not an error return, so it ran neither the errdefer below nor
// the explicit unlocks after the handler. The catalog lock was simply
// leaked, shared, forever.
//
// A database-level command reaches it: `db.aggregate(...)` sends
// `{aggregate: 1}`, whose value is not a string, so str_arg returns null.
// The symptom was baffling because a leaked *shared* lock is invisible to
// readers -- ping and listDatabases kept answering in microseconds -- while
// the next write that needs the catalog exclusive to create a collection
// blocks forever. It presented as an unrelated client-side timeout one
// command later.
var ns: ?struct { db: []const u8, coll: []const u8 } = null;
if (cmd.locks.coll != .none) {
const db_name = msg.db_name() orelse
return bad_value(reply, "command requires a $db");
const coll_name = str_arg(msg.body.get(name)) orelse
return bad_value(reply, "command requires a collection name");
ns = .{ .db = db_name, .coll = coll_name };
}
switch (cmd.locks.catalog) {
.none => {},
.shared => try ctx.engine.lock_catalog(false),
.exclusive => try ctx.engine.lock_catalog(true),
}
var catalog_held = cmd.locks.catalog != .none;
var coll: ?*Collection = null;
errdefer {
if (coll) |c| ctx.engine.unlock_collection(c, cmd.locks.coll == .exclusive);
if (catalog_held) ctx.engine.unlock_catalog(cmd.locks.catalog == .exclusive);
}
if (ns) |n| {
// Write commands may create the collection on first use; the catalog
// lock is upgraded to exclusive for that, then restored to shared.
const create = cmd.kind == .write and cmd.locks.catalog == .shared;
if (try ctx.engine.lock_collection(n.db, n.coll, cmd.locks.coll == .exclusive, create)) |c| {
coll = c;
}
}
const result = cmd.handler(ctx, msg, reply);
// Release the collection and catalog locks before the commit: the
// commit may block on other writers' appends, and must never do so
// while holding a collection lock.
if (coll) |c| ctx.engine.unlock_collection(c, cmd.locks.coll == .exclusive);
coll = null;
if (catalog_held) ctx.engine.unlock_catalog(cmd.locks.catalog == .exclusive);
catalog_held = false;
if (cmd.locks.coll == .exclusive) {
// Durability (seal + fsync) coalesces across concurrent writers. A
// commit error deliberately wins over the handler's captured `result`:
// whether the write reached disk matters more to the client than why
// the write itself was unhappy.
// commit() asserts its own postcondition (committed_seq >= this
// command's seq) internally. Re-checking it here is not possible
// without the log lock, and taking it just to assert would add a real
// race in exchange for a weaker check than the one already made.
try ctx.engine.commit();
// The write is durable by now, so a compaction failure is a maintenance
// problem and not the client's. Report it and hand the request back
// rather than turning an applied write into an error the client retries.
if (ctx.engine.take_compact()) {
ctx.engine.compact() catch |err| {
std.debug.print("multiforadb: compaction failed: {s}\n", .{@errorName(err)});
ctx.engine.request_compact();
};
}
}
return result;
}
// ---------------------------------------------------------------------------
// Handshake / administration
// ---------------------------------------------------------------------------
fn add_server_info(ctx: *Context, reply: *wire.Reply) !void {
try reply.put("isWritablePrimary", .{ .bool = true });
try reply.put("maxBsonObjectSize", .{ .int32 = wire.max_bson_object_size });
try reply.put("maxMessageSizeBytes", .{ .int32 = 48000000 });
try reply.put("maxWriteBatchSize", .{ .int32 = 100000 });
const now = std.Io.Timestamp.now(ctx.io, .real);
try reply.put("localTime", .{ .datetime = now.toMilliseconds() });
try reply.put("logicalSessionTimeoutMinutes", .{ .int32 = 30 });
try reply.put("connectionId", .{ .int32 = @intCast(ctx.connection_id) });
try reply.put("minWireVersion", .{ .int32 = 0 });
try reply.put("maxWireVersion", .{ .int32 = 8 });
try reply.put("readOnly", .{ .bool = false });
// Deliberately no `topologyVersion`. A driver treats its presence as
// "this server supports the streaming (awaitable) hello protocol" and
// switches monitoring to an exhaust hello: it sends one hello with
// maxAwaitTimeMS and the OP_MSG exhaustAllowed flag, then expects a
// stream of unsolicited replies each carrying moreToCome. We answer
// once with moreToCome clear and go back to reading, so the driver
// fails the heartbeat ("Server ended moreToCome unexpectedly"), drops
// the connection and resets its pool — a connect/disconnect loop once
// per heartbeat, which is what MongoDB Compass showed. Omitting the
// field keeps monitoring on the polling path, which we do implement,
// and matches maxWireVersion 8: streaming hello arrived in wire 9.
}
fn cmd_hello(ctx: *Context, _: *wire.Message, reply: *wire.Reply) !void {
try add_server_info(ctx, reply);
try reply.put_ok();
}
fn cmd_is_master(ctx: *Context, _: *wire.Message, reply: *wire.Reply) !void {
try add_server_info(ctx, reply);
try reply.put("ismaster", .{ .bool = true });
try reply.put("helloOk", .{ .bool = true });
try reply.put_ok();
}
fn cmd_ping(_: *Context, _: *wire.Message, reply: *wire.Reply) !void {
try reply.put_ok();
}
fn cmd_build_info(_: *Context, _: *wire.Message, reply: *wire.Reply) !void {
try reply.put("version", .{ .string = "4.4.0" });
try reply.put("gitVersion", .{ .string = "multiforadb" });
try reply.put("versionArray", .{ .array = try int_array(reply, &.{ 4, 4, 0, 0 }) });
try reply.put("openssl", .{ .doc = &.{} });
try reply.put("loaderFlags", .{ .string = "" });
try reply.put("compilerInfo", .{ .string = "zig 0.16.0" });
try reply.put("allocator", .{ .string = "system" });
try reply.put("javascriptEngine", .{ .string = "none" });
try reply.put("bits", .{ .int32 = 64 });
try reply.put("debug", .{ .bool = false });
try reply.put("maxBsonObjectSize", .{ .int32 = wire.max_bson_object_size });
try reply.put("storageEngines", .{ .array = try str_array(reply, &.{"wiredTiger"}) });
try reply.put_ok();
}
fn cmd_get_parameter(_: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
// mongosh probes featureCompatibilityVersion; respond per requested key.
const params = doc_arg(msg.body.get("getParameter")) orelse
return invalid_arg(reply, "getParameter requires a document");
if (bson.get_pair(params, "featureCompatibilityVersion") == null) {
return invalid_arg(reply, "no option found to get");
}
const fcv = try reply.arena_alloc().alloc(bson.Pair, 1);
fcv[0] = .{ .key = "version", .value = .{ .string = "4.4" } };
try reply.put("featureCompatibilityVersion", .{ .doc = fcv });
try reply.put_ok();
}
fn cmd_whatsmyuri(ctx: *Context, _: *wire.Message, reply: *wire.Reply) !void {
try reply.put("you", .{ .string = ctx.client_desc });
try reply.put_ok();
}
fn cmd_host_info(ctx: *Context, _: *wire.Message, reply: *wire.Reply) !void {
const now = std.Io.Timestamp.now(ctx.io, .real);
const cpu_count: usize = std.Thread.getCpuCount() catch 1;
const system = try reply.arena_alloc().alloc(bson.Pair, 6);
system[0] = .{ .key = "currentTime", .value = .{ .datetime = now.toMilliseconds() } };
system[1] = .{ .key = "hostname", .value = .{ .string = "localhost" } };
system[2] = .{ .key = "cpuAddrSize", .value = .{ .int32 = 64 } };
system[3] = .{ .key = "memSizeMB", .value = .{ .int32 = 0 } };
system[4] = .{ .key = "numCores", .value = .{ .int32 = @intCast(cpu_count) } };
system[5] = .{ .key = "cpuArch", .value = .{ .string = @tagName(builtin.cpu.arch) } };
try reply.put("system", .{ .doc = system });
const os = try reply.arena_alloc().alloc(bson.Pair, 3);
os[0] = .{ .key = "type", .value = .{ .string = @tagName(builtin.os.tag) } };
os[1] = .{ .key = "name", .value = .{ .string = @tagName(builtin.os.tag) } };
os[2] = .{ .key = "version", .value = .{ .string = "unknown" } };
try reply.put("os", .{ .doc = os });
try reply.put("extra", .{ .doc = &.{} });
try reply.put_ok();
}
fn cmd_get_cmd_line_opts(_: *Context, _: *wire.Message, reply: *wire.Reply) !void {
const argv = try reply.arena_alloc().alloc(bson.Pair, 2);
argv[0] = .{ .key = "dbpath", .value = .{ .string = "multiforadb.log" } };
argv[1] = .{ .key = "port", .value = .{ .int32 = 27017 } };
try reply.put("argv", .{ .array = &.{} });
try reply.put("parsed", .{ .doc = argv });
try reply.put_ok();
}
fn cmd_server_status(ctx: *Context, _: *wire.Message, reply: *wire.Reply) !void {
const now = std.Io.Timestamp.now(ctx.io, .real);
const uptime: i64 = std.Io.Timestamp.durationTo(ctx.server_start, now).toSeconds();
try reply.put("host", .{ .string = "localhost" });
try reply.put("version", .{ .string = "4.4.0" });
try reply.put("process", .{ .string = "mongod" });
try reply.put("uptime", .{ .double = @floatFromInt(uptime) });
try reply.put("localTime", .{ .datetime = now.toMilliseconds() });
const connections = try reply.arena_alloc().alloc(bson.Pair, 1);
connections[0] = .{ .key = "current", .value = .{ .int32 = @intCast(ctx.connection_id) } };
try reply.put("connections", .{ .doc = connections });
try reply.put_ok();
}
fn cmd_end_sessions(_: *Context, _: *wire.Message, reply: *wire.Reply) !void {
try reply.put_ok();
}
fn cmd_connection_status(_: *Context, _: *wire.Message, reply: *wire.Reply) !void {
const auth_info = try reply.arena_alloc().alloc(bson.Pair, 2);
auth_info[0] = .{ .key = "authenticatedUsers", .value = .{ .array = &.{} } };
auth_info[1] = .{ .key = "authenticatedUserRoles", .value = .{ .array = &.{} } };
try reply.put("authInfo", .{ .doc = auth_info });
try reply.put_ok();
}
fn cmd_list_databases(ctx: *Context, _: *wire.Message, reply: *wire.Reply) !void {
var names: std.ArrayListUnmanaged([]const u8) = .empty;
defer names.deinit(ctx.gpa);
try ctx.engine.database_names(&names);
const values = try reply.arena_alloc().alloc(bson.Value, names.items.len);
for (names.items, 0..) |n, i| {
const entry = try reply.arena_alloc().alloc(bson.Pair, 3);
entry[0] = .{ .key = "name", .value = .{ .string = try reply.arena_alloc().dupe(u8, n) } };
entry[1] = .{ .key = "sizeOnDisk", .value = .{ .double = 0 } };
entry[2] = .{ .key = "empty", .value = .{ .bool = true } };
values[i] = .{ .doc = entry };
}
try reply.put("databases", .{ .array = values });
try reply.put("totalSize", .{ .int32 = 0 });
try reply.put("totalSizeMb", .{ .int32 = 0 });
try reply.put_ok();
}
fn cmd_list_collections(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "listCollections requires $db");
var names: std.ArrayListUnmanaged([]const u8) = .empty;
defer names.deinit(ctx.gpa);
try ctx.engine.collection_names(db_name, &names);
const values = try reply.arena_alloc().alloc(bson.Value, names.items.len);
for (names.items, 0..) |n, i| {
const entry = try reply.arena_alloc().alloc(bson.Pair, 3);
entry[0] = .{ .key = "name", .value = .{ .string = try reply.arena_alloc().dupe(u8, n) } };
entry[1] = .{ .key = "type", .value = .{ .string = "collection" } };
entry[2] = .{ .key = "options", .value = .{ .doc = &.{} } };
values[i] = .{ .doc = entry };
}
try reply.put("cursor", .{ .doc = try cursor_doc(reply, 0, try format_namespace(reply, db_name, ""), "firstBatch", values) });
try reply.put_ok();
}
fn cmd_create(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "create requires $db");
const coll_name = str_arg(msg.body.get("create")) orelse return bad_value(reply, "create requires a collection name");
_ = try ctx.engine.get_or_create_collection(db_name, coll_name);
try reply.put_ok();
}
fn cmd_drop(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "drop requires $db");
const coll_name = str_arg(msg.body.get("drop")) orelse return bad_value(reply, "drop requires a collection name");
if (!try ctx.engine.drop_collection(db_name, coll_name)) {
return reply.put_error(@intFromEnum(ErrorCode.namespace_not_found), "NamespaceNotFound", "ns not found");
}
try reply.put_ok();
}
fn cmd_drop_database(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "dropDatabase requires $db");
_ = try ctx.engine.drop_database(db_name);
try reply.put("dropped", .{ .string = try reply.arena_alloc().dupe(u8, db_name) });
try reply.put_ok();
}
// ---------------------------------------------------------------------------
// Indexes
// ---------------------------------------------------------------------------
fn cmd_create_indexes(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "createIndexes requires $db");
const coll_name = str_arg(msg.body.get("createIndexes")) orelse return bad_value(reply, "createIndexes requires a collection name");
const indexes = switch (msg.body.get("indexes") orelse return bad_value(reply, "createIndexes requires indexes")) {
.array => |a| a,
else => return bad_value(reply, "indexes must be an array"),
};
const existed = ctx.engine.get_collection(db_name, coll_name) != null;
const coll = try ctx.engine.get_or_create_collection(db_name, coll_name);
const num_before: i32 = @intCast(coll.indexes.items.len + 1); // + the _id_ index
for (indexes) |spec_v| {
const spec = switch (spec_v) {
.doc => |p| p,
else => return bad_value(reply, "indexes must be documents"),
};
const key_value = bson.get_pair(spec, "key") orelse return bad_value(reply, "index spec requires key");
const key_pairs = switch (key_value) {
.doc => |p| p,
else => return bad_value(reply, "key must be a document"),
};
if (key_pairs.len == 0) return bad_value(reply, "cannot create index with an empty key");
// {_id: 1} is the implicit index: an idempotent no-op. Any other
// secondary index touching _id is rejected.
var has_id = false;
for (key_pairs) |p| {
if (std.mem.eql(u8, p.key, "_id")) has_id = true;
}
if (has_id) {
const only = key_pairs[0].value;
const is_id_index = key_pairs.len == 1 and ((only == .int32 and only.int32 == 1) or
(only == .int64 and only.int64 == 1) or
(only == .double and only.double == 1.0));
if (is_id_index) {
// The no-op must not swallow options that would change what
// the index does — MongoDB rejects a TTL _id index rather
// than quietly ignoring the expiry.
if (bson.get_pair(spec, "expireAfterSeconds") != null) {
return reply.put_error(
@intFromEnum(ErrorCode.invalid_index_specification_option),
"InvalidIndexSpecificationOption",
"the field 'expireAfterSeconds' is not valid for an _id " ++
"index specification",
);
}
continue;
}
return bad_value(reply, "cannot create a secondary index on the _id field");
}
const name = bson.get_pair(spec, "name") orelse bson.Value.null;
if (name == .string and std.mem.eql(u8, name.string, "_id_")) {
return bad_value(reply, "cannot create index with name '_id_'");
}
const spec_doc = bson.Document{ .arena = undefined, .pairs = spec };
_ = ctx.engine.create_index(db_name, coll_name, &spec_doc) catch |err| switch (err) {
error.InvalidIndexSpec => return bad_value(reply, "invalid index spec"),
error.TtlOnCompoundIndex => return reply.put_error(
@intFromEnum(ErrorCode.cannot_create_index),
"CannotCreateIndex",
"TTL indexes are single-field indexes, compound indexes do not support TTL",
),
error.InvalidExpireAfterSeconds => return reply.put_error(
@intFromEnum(ErrorCode.cannot_create_index),
"CannotCreateIndex",
"TTL index 'expireAfterSeconds' option must be a whole number " ++
"between 0 and 2147483647",
),
error.IndexOptionsConflict => return reply.put_error(@intFromEnum(ErrorCode.index_options_conflict), "IndexOptionsConflict", "index already exists with a different specification"),
error.DuplicateKeyIndex => {
const ix_name = if (name == .string) name.string else "index";
const msg_text = try e11000_message(reply, db_name, coll_name, ix_name, try render_spec_key(reply, key_pairs));
return reply.put_error(@intFromEnum(ErrorCode.duplicate_key), "DuplicateKey", msg_text);
},
error.ParallelArrays => return bad_value(reply, "cannot index parallel arrays"),
else => return err,
};
}
try reply.put("createdCollectionAutomatically", .{ .bool = !existed });
try reply.put("numIndexesBefore", .{ .int32 = num_before });
try reply.put("numIndexesAfter", .{ .int32 = @intCast(coll.indexes.items.len + 1) });
try reply.put_ok();
}
fn cmd_list_indexes(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "listIndexes requires $db");
const coll_name = str_arg(msg.body.get("listIndexes")) orelse return bad_value(reply, "listIndexes requires a collection name");
const coll = ctx.engine.get_collection(db_name, coll_name) orelse
return reply.put_error(@intFromEnum(ErrorCode.namespace_not_found), "NamespaceNotFound", "ns not found");
// The _id_ index first, then the secondaries.
const n = coll.indexes.items.len + 1;
const values = try reply.arena_alloc().alloc(bson.Value, n);
const id_pairs = try reply.arena_alloc().alloc(bson.Pair, 2);
id_pairs[0] = .{ .key = "v", .value = .{ .int32 = 2 } };
id_pairs[1] = .{ .key = "key", .value = .{ .doc = &.{.{ .key = "_id", .value = .{ .int32 = 1 } }} } };
values[0] = .{ .doc = try index_pairs_append(reply, id_pairs, "_id_") };
for (coll.indexes.items, 0..) |ix, i| {
// The pairs live in the reply arena (freed with it); the values
// array below references them.
var pairs: std.ArrayListUnmanaged(bson.Pair) = .empty;
try ix.spec_pairs(reply.arena_alloc(), &pairs);
values[1 + i] = .{ .doc = pairs.items };
}
try reply.put("cursor", .{ .doc = try cursor_doc(reply, 0, try format_namespace(reply, db_name, coll_name), "firstBatch", values) });
try reply.put_ok();
}
/// The _id_ index entry: {v, key: {_id: 1}, name: "_id_"}.
fn index_pairs_append(
reply: *wire.Reply,
pairs: []const bson.Pair,
name: []const u8,
) ![]const bson.Pair {
const arena = reply.arena_alloc();
const with_name = try arena.alloc(bson.Pair, pairs.len + 1);
@memcpy(with_name[0..pairs.len], pairs);
with_name[pairs.len] = .{ .key = "name", .value = .{ .string = try arena.dupe(u8, name) } };
return with_name;
}
fn cmd_drop_indexes(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "dropIndexes requires $db");
const coll_name = str_arg(msg.body.get("dropIndexes")) orelse return bad_value(reply, "dropIndexes requires a collection name");
const coll = ctx.engine.get_collection(db_name, coll_name) orelse
return reply.put_error(@intFromEnum(ErrorCode.namespace_not_found), "NamespaceNotFound", "ns not found");
const n_indexes_was: i32 = @intCast(coll.indexes.items.len + 1);
const arg = msg.body.get("index") orelse return bad_value(reply, "dropIndexes requires index");
if (arg == .string and std.mem.eql(u8, arg.string, "*")) {
// Drop every secondary index. Copy the names first: each drop
// mutates the collection's index list.
var names: std.ArrayListUnmanaged([]const u8) = .empty;
defer names.deinit(ctx.gpa);
for (coll.indexes.items) |ix| try names.append(ctx.gpa, ix.name);
for (names.items) |nm| _ = try ctx.engine.drop_index(db_name, coll_name, nm);
} else if (arg == .string) {
if (std.mem.eql(u8, arg.string, "_id_")) {
return invalid_arg(reply, "cannot drop the _id index");
}
if (!try ctx.engine.drop_index(db_name, coll_name, arg.string)) {
return reply.put_error(@intFromEnum(ErrorCode.index_not_found), "IndexNotFound", "index not found with name");
}
} else if (arg == .doc) {
// A key document: drop the index with a matching key pattern.
const key_value = bson.get_pair(arg.doc, "key") orelse bson.Value{ .doc = arg.doc };
const key_pairs = switch (key_value) {
.doc => |p| p,
else => return bad_value(reply, "dropIndexes index must be a name, key document, or '*'"),
};
const target = index.find_by_key_pattern(coll.indexes.items, key_pairs) orelse
return reply.put_error(@intFromEnum(ErrorCode.index_not_found), "IndexNotFound", "index not found with key pattern");
_ = try ctx.engine.drop_index(db_name, coll_name, target.name);
} else {
return bad_value(reply, "dropIndexes index must be a name, key document, or '*'");
}
try reply.put("nIndexesWas", .{ .int32 = n_indexes_was });
try reply.put_ok();
}
/// The E11000 text drivers parse. One definition for both create-time and
/// write-time conflicts; they differ only in how the dup key is rendered.
fn e11000_message(
reply: *wire.Reply,
db_name: []const u8,
coll_name: []const u8,
index_name: []const u8,
key_text: []const u8,
) ![]const u8 {
return std.fmt.allocPrint(
reply.arena_alloc(),
"E11000 duplicate key error collection: {s}.{s} index: {s} dup key: {s}",
.{ db_name, coll_name, index_name, key_text },
);
}
/// Render the key pattern with placeholder values for a createIndexes
/// duplicate-key error (no specific document is involved).
fn render_spec_key(reply: *wire.Reply, key_pairs: []const bson.Pair) ![]const u8 {
const arena = reply.arena_alloc();
var out: std.ArrayListUnmanaged(u8) = .empty;
defer out.deinit(arena);
try out.append(arena, '{');
for (key_pairs, 0..) |p, i| {
if (i > 0) try out.appendSlice(arena, ", ");
try out.appendSlice(arena, p.key);
try out.appendSlice(arena, ": ?");
}
try out.append(arena, '}');
return out.toOwnedSlice(arena);
}
// ---------------------------------------------------------------------------
// CRUD
// ---------------------------------------------------------------------------
fn cmd_insert(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "insert requires $db");
const coll_name = str_arg(msg.body.get("insert")) orelse return bad_value(reply, "insert requires a collection name");
const docs = try batch_arg(msg, reply, "insert", "documents") orelse return;
var inserted: i64 = 0;
var write_errors: std.ArrayListUnmanaged(bson.Value) = .empty;
defer write_errors.deinit(reply.arena_alloc());
// Group commit: one fsync for the whole batch instead of one per document.
// Nothing to open or close here -- appends never sync, and the dispatch
// epilogue is the single commit point. It runs on every return path, so a
// failed doc (writeErrors) or a hard error still syncs what was appended,
// and does it after the collection lock is released.
for (docs, 0..) |*doc, i| {
if (ctx.engine.insert(db_name, coll_name, doc, ctx.oid_gen)) |_| {
inserted += 1;
} else |err| {
switch (err) {
error.DuplicateKey, error.DuplicateKeyIndex => {
const e = try reply.arena_alloc().alloc(bson.Pair, 3);
e[0] = .{ .key = "index", .value = .{ .int32 = @intCast(i) } };
e[1] = .{ .key = "code", .value = .{ .int32 = @intFromEnum(ErrorCode.duplicate_key) } };
e[2] = .{ .key = "errmsg", .value = .{ .string = try duplicate_key_message(ctx, reply, db_name, coll_name, doc) } };
try write_errors.append(reply.arena_alloc(), .{ .doc = e });
},
else => return err,
}
}
}
try reply.put("n", .{ .int32 = @intCast(inserted) });
if (write_errors.items.len > 0) {
// Copy into the reply arena: write_errors is freed when this command
// returns, before the reply is serialized.
const arr = try reply.arena_alloc().alloc(bson.Value, write_errors.items.len);
@memcpy(arr, write_errors.items);
try reply.put("writeErrors", .{ .array = arr });
}
try reply.put_ok();
}
fn cmd_find(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "find requires $db");
const coll_name = str_arg(msg.body.get("find")) orelse return bad_value(reply, "find requires a collection name");
const filter = doc_arg(msg.body.get("filter")) orelse return bad_value(reply, "filter must be a document");
const sort_keys = try parse_sort_keys(reply, msg.body.get("sort"));
const proj_pairs = doc_arg(msg.body.get("projection"));
const skip: u64 = int_arg(msg.body.get("skip")) orelse 0;
// A negative limit means "return this many in a single batch"; we always
// reply with one batch, so only the magnitude matters.
const limit: usize = @abs(int_value(msg.body.get("limit")) orelse 0);
var matched: std.ArrayListUnmanaged(u64) = .empty;
defer matched.deinit(ctx.gpa);
// Documents needed to fill the page, counting the skipped prefix; 0
// means unbounded.
const page_end: usize = if (limit == 0) 0 else blk: {
const skip_usize = std.math.cast(usize, skip) orelse break :blk 0;
break :blk skip_usize +| limit;
};
// An index whose order already is the requested one lets the scan stop
// at the page boundary and skip sorting entirely. Otherwise a sort has
// to see every match before it can tell which ones the page contains.
var index_sorted = false;
_ = try scan_sorted(ctx, db_name, coll_name, filter, page_end, &matched, sort_keys, &index_sorted);
// Sorting and emitting need the documents as trees; materialize the
// matched page into the reply arena (the slab itself is never copied).
// A find on a namespace that does not exist is an empty cursor, not an
// error and not a reply missing `ok`: the scan above matched nothing, so
// falling through to the emit at the end of this function says exactly
// that without a second exit path to keep in step with it.
const coll = ctx.engine.get_collection(db_name, coll_name);
// The scan above ran against this same collection with the catalog lock
// held, so a missing collection means nothing matched. Asserted rather than
// left implicit: if that ever stops holding, the loop below silently emits
// an empty page for a query that did match, which is the hardest kind of
// wrong answer to notice.
if (coll == null) assert_msg(matched.items.len == 0, "find matched documents in a collection that does not exist");
// Lives in the reply arena; freed with it.
var tree_docs: std.ArrayListUnmanaged(*const bson.Document) = .empty;
const arena = reply.arena_alloc();
if (coll) |c| {
for (matched.items) |off| {
try tree_docs.append(arena, try doc_tree(arena, c, off));
}
}
if (sort_keys.len > 0 and !index_sorted) {
// Selecting the page is much cheaper than ordering everything when
// the page is a small fraction of the matches. Above that fraction
// the heap's bookkeeping stops paying for itself.
if (page_end > 0 and page_end *| 4 <= tree_docs.items.len) {
try query.sort_docs_top_k(arena, tree_docs.items, sort_keys, page_end);
} else {
try query.sort_docs(arena, tree_docs.items, sort_keys);
}
}
const rest = if (skip < tree_docs.items.len) tree_docs.items[skip..] else &.{};
const page = if (limit > 0 and limit < rest.len) rest[0..limit] else rest;
try emit_docs_tree(reply, db_name, coll_name, proj_pairs, page);
try reply.put_ok();
}
/// Collect the documents in `db_name.coll_name` matching `filter`, stopping
/// after `limit` matches (0 = unlimited). Returns the number matched; `out`
/// may be null when only the count is wanted. Every command that scans a
/// collection goes through here, so an index only needs this one call site.
///
/// Candidate generation order: the _id_ fast path (docs map lookup), then a
/// secondary-index plan, then a plain scan. Every candidate is re-checked
/// with the unchanged filter, so an index that over-approximates is merely
/// slow — never wrong. With no index created and no usable _id clause, the
/// plain-scan path is the only one reached.
fn scan_matching(
ctx: *Context,
db_name: []const u8,
coll_name: []const u8,
filter: []const bson.Pair,
limit: usize,
out: ?*std.ArrayListUnmanaged(u64),
) !usize {
return scan_sorted(ctx, db_name, coll_name, filter, limit, out, &.{}, null);
}
/// `scan_matching` plus the option of having an index produce the ordering.
/// When `sorted` is given it reports whether the candidates came out in
/// `sort` order, in which case the caller must not sort them again — and
/// `limit` is then a genuine early stop rather than an arbitrary subset.
fn scan_sorted(
ctx: *Context,
db_name: []const u8,
coll_name: []const u8,
filter: []const bson.Pair,
limit: usize,
out: ?*std.ArrayListUnmanaged(u64),
sort: []const query.SortKey,
sorted: ?*bool,
) !usize {
if (sorted) |flag| flag.* = false;
// Stopping early is only meaningful when the candidates come out in the
// order the caller asked for. Without a sort any subset of that size is
// a valid page; with one, the limit is honoured only if an index turns
// out to supply the ordering.
var lim: usize = if (sort.len == 0) limit else 0;
const coll = ctx.engine.get_collection(db_name, coll_name) orelse return 0;
var n: usize = 0;
// Index plan (the implicit _id_ index first, then the secondaries):
// candidates in index order, re-filtered. A candidate *is* a slab offset
// now, so the map lookup that used to translate an id into one is gone --
// and so is the accidental safety net it provided: a stale entry used to be
// dropped silently by `orelse continue`, where now it resolves to
// superseded-but-parseable bytes that the re-applied filter might accept.
// Loud beats silent: a wrong answer a test can see beats a missing
// candidate nothing can.
// Candidates arrive as a stream so that a whole-index read never
// materializes: at the tens-of-GB target a `countDocuments({})` would
// otherwise build a list of every offset in the collection before the
// first one is examined. A narrowed plan still materializes, because its
// multikey/$in dedupe genuinely needs the whole set, and it is bounded by
// selectivity.
var offs: std.ArrayListUnmanaged(u64) = .empty;
defer offs.deinit(ctx.gpa);
var cands: index.Candidates = undefined;
var plan_opt = try index.plan(ctx.gpa, &coll.id_index, coll.indexes.items, filter, sort);
defer if (plan_opt) |*p| p.deinit(ctx.gpa);
if (plan_opt) |*plan| {
if (sorted) |flag| flag.* = plan.provides_sort;
if (plan.provides_sort) lim = limit;
if (plan.full_scan()) {
cands = if (plan.backward)
.{ .scan_rev = plan.index.iter_reverse() }
else
.{ .scan = plan.index.iter() };
} else {
try plan.search(ctx.gpa, &offs);
cands = .{ .list = .{ .items = offs.items } };
}
} else {
// No usable predicate: every document, in _id order. The docs map was
// the fallback here, and its iteration order was the hash's; walking
// the _id_ index instead is ordered, streams, and does not depend on a
// structure that is going away.
cands = .{ .scan = coll.id_index.iter() };
}
while (cands.next()) |off| {
if (!try query.matches_bytes(ctx.gpa, filter, coll.doc_bytes(off))) continue;
if (out) |list| try list.append(ctx.gpa, off);
n += 1;
if (lim != 0 and n >= lim) break;
}
return n;
}
/// A stored document (a slab offset) materialized as a borrowed spine in
/// `arena`: keys and leaf values point into the slab's stable bytes, only
/// the pair/value skeleton is allocated. The arena owns the skeleton, so
/// the result is never deinit'd — the reply arena frees it with the reply.
fn doc_tree(arena: std.mem.Allocator, coll: *const Collection, off: u64) !*const bson.Document {
const doc = try arena.create(bson.Document);
doc.* = bson.Document{ .arena = undefined, .pairs = try bson.spine(arena, coll.doc_bytes(off)) };
return doc;
}
fn emit_docs_tree(
reply: *wire.Reply,
db_name: []const u8,
coll_name: []const u8,
proj_pairs: ?[]const bson.Pair,
docs: []const *const bson.Document,
) !void {
const values = try reply.arena_alloc().alloc(bson.Value, docs.len);
for (docs, 0..) |d, i| {
values[i] = try project_doc(reply, d, proj_pairs);
}
try reply.put("cursor", .{ .doc = try cursor_doc(reply, 0, try format_namespace(reply, db_name, coll_name), "firstBatch", values) });
}
/// Project a stored doc (or deep-copy it) into the reply arena.
fn project_doc(
reply: *wire.Reply,
doc: *const bson.Document,
proj_pairs: ?[]const bson.Pair,
) !bson.Value {
if (proj_pairs) |pp| {
var out: std.ArrayListUnmanaged(bson.Pair) = .empty;
errdefer out.deinit(reply.arena_alloc());
try query.project(reply.arena_alloc(), doc, &.{ .arena = undefined, .pairs = pp }, &out);
return .{ .doc = out.items };
}
return .{ .doc = try bson.copy_pairs(reply.arena_alloc(), doc.pairs) };
}
fn cmd_update(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "update requires $db");
const coll_name = str_arg(msg.body.get("update")) orelse return bad_value(reply, "update requires a collection name");
const specs = try batch_arg(msg, reply, "update", "updates") orelse return;
var n_matched: i64 = 0;
var n_modified: i64 = 0;
var upserted: std.ArrayListUnmanaged(bson.Pair) = .empty;
defer upserted.deinit(reply.arena_alloc());
var write_errors: std.ArrayListUnmanaged(bson.Value) = .empty;
defer write_errors.deinit(reply.arena_alloc());
// Group commit for multi-document updates: one fsync per command, issued
// by the dispatch epilogue once the collection lock is released.
for (specs, 0..) |*spec, si| {
const q = doc_arg(spec.get("q")) orelse return bad_value(reply, "update spec requires q");
const u_doc = doc_arg(spec.get("u")) orelse return bad_value(reply, "update spec requires u");
const multi = bool_arg(spec.get("multi")) orelse false;
const upsert = bool_arg(spec.get("upsert")) orelse false;
var matched: std.ArrayListUnmanaged(u64) = .empty;
defer matched.deinit(ctx.gpa);
_ = try scan_matching(ctx, db_name, coll_name, q, if (multi) 0 else 1, &matched);
if (matched.items.len == 0) {
if (upsert) {
const new_doc = try build_upsert_doc(reply, q, u_doc);
ctx.engine.insert(db_name, coll_name, new_doc, ctx.oid_gen) catch |err| switch (err) {
error.DuplicateKey, error.DuplicateKeyIndex => return duplicate_key_error(ctx, reply, db_name, coll_name, new_doc),
else => return err,
};
const id = new_doc.get("_id") orelse bson.Value.null;
const u = try reply.arena_alloc().alloc(bson.Pair, 2);
u[0] = .{ .key = "index", .value = .{ .int32 = @intCast(si) } };
u[1] = .{ .key = "_id", .value = try bson.copy_value(reply.arena_alloc(), id) };
try upserted.append(reply.arena_alloc(), .{ .key = "u", .value = .{ .doc = u } });
n_matched += 1;
}
continue;
}
n_matched += @intCast(matched.items.len);
const coll = ctx.engine.get_collection(db_name, coll_name) orelse return;
for (matched.items) |off| {
// Work on a copy: the log write must precede any visible change,
// and a rejected update must not corrupt the stored document.
const doc = try doc_tree(reply.arena_alloc(), coll, off);
const copy = try clone_doc(reply, doc);
update.apply(copy, &.{ .arena = undefined, .pairs = u_doc }) catch |err| switch (err) {
error.ImmutableId, error.InvalidUpdate => return bad_value(reply, "bad update"),
else => return err,
};
ctx.engine.replace(db_name, coll_name, copy, ctx.oid_gen) catch |err| switch (err) {
error.DuplicateKey, error.DuplicateKeyIndex => {
const e = try reply.arena_alloc().alloc(bson.Pair, 3);
e[0] = .{ .key = "index", .value = .{ .int32 = @intCast(si) } };
e[1] = .{ .key = "code", .value = .{ .int32 = @intFromEnum(ErrorCode.duplicate_key) } };
e[2] = .{ .key = "errmsg", .value = .{ .string = try duplicate_key_message(ctx, reply, db_name, coll_name, copy) } };
try write_errors.append(reply.arena_alloc(), .{ .doc = e });
continue;
},
else => return err,
};
n_modified += 1;
}
}
try reply.put("n", .{ .int32 = @intCast(n_matched) });
try reply.put("nModified", .{ .int32 = @intCast(n_modified) });
if (write_errors.items.len > 0) {
const arr = try reply.arena_alloc().alloc(bson.Value, write_errors.items.len);
@memcpy(arr, write_errors.items);
try reply.put("writeErrors", .{ .array = arr });
}
if (upserted.items.len > 0) {
const arr = try reply.arena_alloc().alloc(bson.Value, upserted.items.len);
for (upserted.items, 0..) |u, i| arr[i] = u.value;
try reply.put("upserted", .{ .array = arr });
}
try reply.put_ok();
}
fn cmd_delete(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "delete requires $db");
const coll_name = str_arg(msg.body.get("delete")) orelse return bad_value(reply, "delete requires a collection name");
const specs = try batch_arg(msg, reply, "delete", "deletes") orelse return;
var n_deleted: i64 = 0;
// Group commit for multi-document deletes: one fsync per command, issued
// by the dispatch epilogue once the collection lock is released.
for (specs) |*spec| {
const q = doc_arg(spec.get("q")) orelse return bad_value(reply, "delete spec requires q");
const limit = int_value(spec.get("limit")) orelse 1;
var matched: std.ArrayListUnmanaged(u64) = .empty;
defer matched.deinit(ctx.gpa);
_ = try scan_matching(ctx, db_name, coll_name, q, if (limit == 1) 1 else 0, &matched);
if (ctx.engine.get_collection(db_name, coll_name)) |coll| {
var id_arena = std.heap.ArenaAllocator.init(ctx.gpa);
defer id_arena.deinit();
for (matched.items) |off| {
const id = (try bson.get_at(id_arena.allocator(), coll.doc_bytes(off), "_id")) orelse continue;
if (try ctx.engine.remove_by_id(db_name, coll_name, id)) n_deleted += 1;
}
}
}
try reply.put("n", .{ .int32 = @intCast(n_deleted) });
try reply.put_ok();
}
fn cmd_find_and_modify(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "findAndModify requires $db");
const coll_name = str_arg(msg.body.get("findAndModify")) orelse return bad_value(reply, "findAndModify requires a collection name");
const q = doc_arg(msg.body.get("query")) orelse &.{};
const sort_keys = try parse_sort_keys(reply, msg.body.get("sort"));
const remove = bool_arg(msg.body.get("remove")) orelse false;
const do_update = msg.body.get("update") != null;
const upsert = bool_arg(msg.body.get("upsert")) orelse false;
const ret_new = bool_arg(msg.body.get("new")) orelse false;
const proj_pairs = doc_arg(msg.body.get("fields"));
if (remove and do_update) return bad_value(reply, "remove and update are mutually exclusive");
if (!remove and !do_update) return bad_value(reply, "must specify update or remove");
var matched: std.ArrayListUnmanaged(u64) = .empty;
defer matched.deinit(ctx.gpa);
// Without a sort, only the first match is ever used.
_ = try scan_matching(ctx, db_name, coll_name, q, if (sort_keys.len > 0) 0 else 1, &matched);
const arena = reply.arena_alloc();
const coll = ctx.engine.get_collection(db_name, coll_name) orelse return;
// findAndModify reads and rewrites the document, so materialize the
// (usually tiny) match set as trees in the reply arena.
var matched_docs: std.ArrayListUnmanaged(*const bson.Document) = .empty;
for (matched.items) |off| try matched_docs.append(arena, try doc_tree(arena, coll, off));
if (sort_keys.len > 0) {
try query.sort_docs(arena, matched_docs.items, sort_keys);
}
const target = if (matched_docs.items.len > 0) matched_docs.items[0] else null;
// Each branch decides what the reply says; the tail below emits it once.
var n: i32 = 0;
var updated_existing = false;
var upserted_id: ?bson.Value = null;
var value: bson.Value = .null;
if (target == null and do_update and upsert) {
const u_doc = doc_arg(msg.body.get("update")) orelse return bad_value(reply, "update must be a document");
const new_doc = try build_upsert_doc(reply, q, u_doc);
ctx.engine.insert(db_name, coll_name, new_doc, ctx.oid_gen) catch |err| switch (err) {
error.DuplicateKey, error.DuplicateKeyIndex => return duplicate_key_error(ctx, reply, db_name, coll_name, new_doc),
else => return err,
};
n = 1;
upserted_id = try bson.copy_value(arena, new_doc.get("_id") orelse bson.Value.null);
if (ret_new) value = try project_doc(reply, new_doc, proj_pairs);
} else if (target != null and remove) {
n = 1;
// Project before removing: this reads the stored document.
value = try project_doc(reply, target.?, proj_pairs);
_ = try ctx.engine.remove_by_id(db_name, coll_name, target.?.get("_id") orelse unreachable);
} else if (target != null and do_update) {
const u_doc = doc_arg(msg.body.get("update")) orelse return bad_value(reply, "update must be a document");
const before = try bson.copy_pairs(arena, target.?.pairs);
const copy = try clone_doc(reply, target.?);
update.apply(copy, &.{ .arena = undefined, .pairs = u_doc }) catch |err| switch (err) {
error.ImmutableId, error.InvalidUpdate => return bad_value(reply, "bad update"),
else => return err,
};
try ctx.engine.replace(db_name, coll_name, copy, ctx.oid_gen);
n = 1;
updated_existing = true;
value = if (ret_new) try project_doc(reply, copy, proj_pairs) else .{ .doc = before };
} // else: no match and no upsert — an empty result
var leo: std.ArrayListUnmanaged(bson.Pair) = .empty;
defer leo.deinit(arena);
try leo.append(arena, .{ .key = "n", .value = .{ .int32 = n } });
try leo.append(arena, .{ .key = "updatedExisting", .value = .{ .bool = updated_existing } });
if (upserted_id) |id| try leo.append(arena, .{ .key = "upserted", .value = id });
try reply.put("value", value);
try reply.put("lastErrorObject", .{ .doc = try leo.toOwnedSlice(arena) });
try reply.put_ok();
}
fn cmd_count(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "count requires $db");
const coll_name = str_arg(msg.body.get("count")) orelse return bad_value(reply, "count requires a collection name");
const q = doc_arg(msg.body.get("query")) orelse &.{};
const n = try scan_matching(ctx, db_name, coll_name, q, 0, null);
try reply.put("n", .{ .int32 = @intCast(n) });
try reply.put_ok();
}
fn cmd_aggregate(ctx: *Context, msg: *wire.Message, reply: *wire.Reply) !void {
const db_name = msg.db_name() orelse return invalid_arg(reply, "aggregate requires $db");
const coll_name = str_arg(msg.body.get("aggregate")) orelse return bad_value(reply, "aggregate requires a collection name");
const pipeline_value = msg.body.get("pipeline") orelse return bad_value(reply, "aggregate requires pipeline");
var stages = switch (pipeline_value) {
.array => |a| a,
else => return bad_value(reply, "pipeline must be an array"),
};
// countDocuments() reaches us as [{$match: F}?, {$group: {_id: <literal>,
// n: {$sum: 1}}}]. The general path answers that by materializing every
// matching document and then throwing them all away, so recognize the
// shape and answer it from a counting scan instead.
if (try count_only_pipeline(reply, stages)) |shape| {
const n = try scan_matching(ctx, db_name, coll_name, shape.filter, 0, null);
// No documents means no groups at all, not a group holding zero —
// same as the general path, which builds groups per document.
var docs: []const *const bson.Document = &.{};
if (n > 0) {
const arena = reply.arena_alloc();
const pairs = try arena.alloc(bson.Pair, 1 + shape.accs.len);
pairs[0] = .{ .key = "_id", .value = try bson.copy_value(arena, shape.id_value) };
for (shape.accs, 0..) |acc, i| {
// Mirrors run_group's coercion exactly: an integral sum in
// int32 range comes back as int32, otherwise a double.
const sum: f64 = @as(f64, @floatFromInt(n)) * acc.term;
pairs[1 + i] = .{
.key = acc.key,
.value = if (sum == @floor(sum) and sum <= 2_147_483_647 and sum >= -2_147_483_648)
.{ .int32 = @intFromFloat(sum) }
else
.{ .double = sum },
};
}
const doc = try arena.create(bson.Document);
doc.* = bson.Document{ .arena = undefined, .pairs = pairs };
const one = try arena.alloc(*const bson.Document, 1);
one[0] = doc;
docs = one;
}
try emit_docs_tree(reply, db_name, coll_name, null, docs);
return reply.put_ok();
}
// The pipeline operates on a stream of documents; each stage transforms
// the current window [start, end). Before $group the stream holds slab
// offsets (matched in place, never materialized); $group replaces it
// with generated group documents, so the stream flips to tree form.
var offs: std.ArrayListUnmanaged(u64) = .empty;
defer offs.deinit(ctx.gpa);
var trees: std.ArrayListUnmanaged(*const bson.Document) = .empty;
defer trees.deinit(ctx.gpa);
var in_trees = false;
// No such collection is an empty result, not an absent one. A bare
// `return` here sent a reply with no `ok` field at all, which the driver
// reports as the uninformative `MongoServerError: n/a` -- and it is what
// `db.aggregate(...)` hits, because a database-level aggregate names no
// collection. MongoDB answers an aggregate over a missing collection with
// an empty cursor.
const coll = ctx.engine.get_collection(db_name, coll_name) orelse {
try emit_docs_tree(reply, db_name, coll_name, null, &.{});
return reply.put_ok();
};
// A leading $match is pushed down into an indexed candidate scan; the
// stage is then dropped from the pipeline so it is not applied twice.
if (stages.len > 0 and stages[0] == .doc and stages[0].doc.len > 0 and std.mem.eql(u8, stages[0].doc[0].key, "$match")) {
const filter = doc_arg(stages[0].doc[0].value) orelse return bad_value(reply, "$match requires a document");
_ = try scan_matching(ctx, db_name, coll_name, filter, 0, &offs);
stages = stages[1..];
} else {
// Every document, in _id order. A pipeline materializes its stream
// anyway (stages need random access to the window), so this one stays a
// list -- but it comes from the _id_ index rather than the docs map,
// which is ordered and does not depend on a structure that is going
// away. Streaming the whole pipeline is M1's cursor work.
var it = coll.id_index.iter();
while (it.next()) |e| try offs.append(ctx.gpa, e.off);
}
var start: usize = 0;
var end: usize = offs.items.len;
var count_stage: ?[]const u8 = null;
var proj_pairs: ?[]const bson.Pair = null;
for (stages) |stage_v| {
const stage = switch (stage_v) {
.doc => |pairs| pairs,
else => return bad_value(reply, "pipeline stages must be documents"),
};
if (stage.len == 0) continue;
const stage_name = stage[0].key;
if (std.mem.eql(u8, stage_name, "$match")) {
const filter = doc_arg(stage[0].value) orelse return bad_value(reply, "$match requires a document");
if (!in_trees) {
var kept: std.ArrayListUnmanaged(u64) = .empty;
defer kept.deinit(ctx.gpa);
for (offs.items[start..end]) |off| {
if (try query.matches_bytes(ctx.gpa, filter, coll.doc_bytes(off))) {
try kept.append(ctx.gpa, off);
}
}
offs.deinit(ctx.gpa);
offs = kept;
kept = .empty;
} else {
var kept: std.ArrayListUnmanaged(*const bson.Document) = .empty;
defer kept.deinit(ctx.gpa);
for (trees.items[start..end]) |d| {
if (try query.matches(ctx.gpa, &.{ .arena = undefined, .pairs = filter }, d)) {
try kept.append(ctx.gpa, d);
}
}
trees.deinit(ctx.gpa);
trees = kept;
kept = .empty;
}
start = 0;
end = (if (in_trees) trees.items.len else offs.items.len);
} else if (std.mem.eql(u8, stage_name, "$sort")) {
const keys = try parse_sort_keys(reply, stage[0].value);
if (keys.len > 0) {
const arena = reply.arena_alloc();
if (!in_trees) {
// Sorting needs the values; materialize and switch the
// stream to tree form for the rest of the pipeline.
//
// The list buffer must come from `ctx.gpa`, because that is
// what frees it: ownership moves to `trees`, and `trees` is
// released by this function's `defer trees.deinit(ctx.gpa)`
// and by the $match branch above. Building it from the
// reply arena instead handed a gpa-free an arena-owned
// pointer -- a remote, client-triggerable invalid free that
// macOS malloc turns into SIGTRAP with no panic text, so it
// read as "the connection closed". Any pipeline with $sort
// and no preceding $group reached it.
//
// The *documents* stay in the arena on purpose: it outlives
// the command, and only the ArrayList's own allocator has
// to match its deinit.
var all: std.ArrayListUnmanaged(*const bson.Document) = .empty;
errdefer all.deinit(ctx.gpa);
for (offs.items) |off| try all.append(ctx.gpa, try doc_tree(arena, coll, off));
trees.deinit(ctx.gpa);
trees = all;
all = .empty;
in_trees = true;
}
try query.sort_docs(arena, trees.items[start..end], keys);
}
} else if (std.mem.eql(u8, stage_name, "$skip")) {
const n = try stage_count(reply, stage[0].value, "$skip") orelse return;
start = @min(start + n, end);
} else if (std.mem.eql(u8, stage_name, "$limit")) {
const n = try stage_count(reply, stage[0].value, "$limit") orelse return;
end = @min(end, start + n);
} else if (std.mem.eql(u8, stage_name, "$project")) {
proj_pairs = doc_arg(stage[0].value);
} else if (std.mem.eql(u8, stage_name, "$group")) {
const gp = doc_arg(stage[0].value) orelse return bad_value(reply, "$group requires a document");
const grouped_opt = try run_group(ctx, reply, coll, gp, offs.items[start..end]);
var grouped = grouped_opt orelse return;
// Group results replace the stream: later stages see groups.
offs.deinit(ctx.gpa);
offs = .empty;
trees.deinit(ctx.gpa);
trees = grouped;
grouped = .empty;
in_trees = true;
start = 0;
end = trees.items.len;
} else if (std.mem.eql(u8, stage_name, "$count")) {
count_stage = switch (stage[0].value) {
.string => |s| s,
else => return bad_value(reply, "$count requires a string"),
};
} else {
const msg_text = try std.fmt.allocPrint(reply.arena_alloc(), "Unrecognized pipeline stage name: '{s}'", .{stage_name});
return reply.put_error(@intFromEnum(ErrorCode.invalid_pipeline_operator), "InvalidPipelineOperator", msg_text);
}
}
if (count_stage) |name| {
const len = if (in_trees) trees.items[start..end].len else offs.items[start..end].len;
const c = try reply.arena_alloc().alloc(bson.Pair, 1);
c[0] = .{ .key = try reply.arena_alloc().dupe(u8, name), .value = .{ .int32 = @intCast(len) } };
const values = try reply.arena_alloc().alloc(bson.Value, 1);
values[0] = .{ .doc = c };
try reply.put("cursor", .{ .doc = try cursor_doc(reply, 0, try format_namespace(reply, db_name, coll_name), "firstBatch", values) });
} else {
const arena = reply.arena_alloc();
if (in_trees) {
try emit_docs_tree(reply, db_name, coll_name, proj_pairs, trees.items[start..end]);
} else {
var page: std.ArrayListUnmanaged(*const bson.Document) = .empty;
for (offs.items[start..end]) |off| try page.append(arena, try doc_tree(arena, coll, off));
try emit_docs_tree(reply, db_name, coll_name, proj_pairs, page.items);
}
}
try reply.put_ok();
}
/// A pipeline whose whole answer is the number of matching documents.
const CountShape = struct {
filter: []const bson.Pair,
/// The literal every document groups under.
id_value: bson.Value,
accs: []const Acc,
const Acc = struct { key: []const u8, term: f64 };
};
/// Recognize `[{$match: F}?, {$group: {_id: <literal>, k: {$sum: <number>}}}]`
/// — the shape a driver sends for countDocuments().
///
/// Deliberately conservative: a `_id` of `"$field"`, an accumulator over a
/// field, or any other stage needs the documents themselves, so anything
/// that is not exactly this shape returns null and takes the general path.
fn count_only_pipeline(reply: *wire.Reply, stages: []const bson.Value) !?CountShape {
if (stages.len == 0 or stages.len > 2) return null;
var filter: []const bson.Pair = &.{};
if (stages.len == 2) {
const first = switch (stages[0]) {
.doc => |p| p,
else => return null,
};
if (first.len != 1 or !std.mem.eql(u8, first[0].key, "$match")) return null;
filter = doc_arg(first[0].value) orelse return null;
}
const last = switch (stages[stages.len - 1]) {
.doc => |p| p,
else => return null,
};
if (last.len != 1 or !std.mem.eql(u8, last[0].key, "$group")) return null;
const gp = doc_arg(last[0].value) orelse return null;
const id_value = bson.get_pair(gp, "_id") orelse return null;
switch (id_value) {
// A field path or a computed id groups per document.
.string => |s| if (s.len > 0 and s[0] == '$') return null,
.doc, .array => return null,
else => {},
}
var accs: std.ArrayListUnmanaged(CountShape.Acc) = .empty;
for (gp) |p| {
if (std.mem.eql(u8, p.key, "_id")) continue;
const spec = switch (p.value) {
.doc => |d| d,
else => return null,
};
if (spec.len != 1 or !std.mem.eql(u8, spec[0].key, "$sum")) return null;
const term: f64 = switch (spec[0].value) {
.int32 => |i| @floatFromInt(i),
.int64 => |i| @floatFromInt(i),
.double => |d| d,
// $sum over a field depends on the documents.
else => return null,
};
try accs.append(reply.arena_alloc(), .{ .key = p.key, .term = term });
}
return .{ .filter = filter, .id_value = id_value, .accs = accs.items };
}
/// Minimal $group: supports `_id` of null/literal/"$field" and `$sum`
/// accumulators (constant or "$field").
fn run_group(
ctx: *Context,
reply: *wire.Reply,
coll: *const Collection,
group_pairs: []const bson.Pair,
docs: []const u64,
) !?std.ArrayListUnmanaged(*const bson.Document) {
const arena = reply.arena_alloc();
const id_expr = bson.get_pair(group_pairs, "_id") orelse {
try bad_value(reply, "$group requires _id");
return null;
};
var accs: std.ArrayListUnmanaged(bson.Pair) = .empty;
defer accs.deinit(arena);
for (group_pairs) |p| {
if (std.mem.eql(u8, p.key, "_id")) continue;
try accs.append(arena, p);
}
const Group = struct {
id_value: bson.Value,
sums: []f64,
};
var groups: std.StringHashMapUnmanaged(Group) = .empty;
defer groups.deinit(ctx.gpa);
// StringHashMapUnmanaged does not copy keys; keep them alive until done.
var keys_owned: std.ArrayListUnmanaged([]u8) = .empty;
defer {
for (keys_owned.items) |k| ctx.gpa.free(k);
keys_owned.deinit(ctx.gpa);
}
var id_key_buf: std.ArrayListUnmanaged(u8) = .empty;
defer id_key_buf.deinit(ctx.gpa);
// Byte-walk materializations (nested group keys) live here.
var walk_arena = std.heap.ArenaAllocator.init(ctx.gpa);
defer walk_arena.deinit();
for (docs) |off| {
const doc = coll.doc_bytes(off);
const id_value: bson.Value = switch (id_expr) {
.string => |s| if (s.len > 0 and s[0] == '$') (try query_path_value_bytes(walk_arena.allocator(), doc, s[1..])) orelse .null else id_expr,
else => id_expr,
};
id_key_buf.clearRetainingCapacity();
try bson.write_value(id_value, ctx.gpa, &id_key_buf);
const gop = try groups.getOrPut(ctx.gpa, id_key_buf.items);
if (!gop.found_existing) {
// Only a new group needs an owned copy of the key; the map
// borrows it, so keys_owned keeps it alive until we are done.
const key = try ctx.gpa.dupe(u8, id_key_buf.items);
try keys_owned.append(ctx.gpa, key);
gop.key_ptr.* = key;
const sums = try ctx.gpa.alloc(f64, accs.items.len);
@memset(sums, 0);
gop.value_ptr.* = .{ .id_value = id_value, .sums = sums };
}
for (accs.items, 0..) |acc, i| {
var expr = acc.value;
// Unwrap {$sum: <expr>} accumulator documents.
if (expr == .doc) {
if (bson.get_pair(expr.doc, "$sum")) |inner| {
expr = inner;
} else continue;
}
const term: f64 = switch (expr) {
.int32 => |n| @floatFromInt(n),
.int64 => |n| @floatFromInt(n),
.double => |n| n,
.string => |s| if (s.len > 0 and s[0] == '$')
switch ((try query_path_value_bytes(walk_arena.allocator(), doc, s[1..])) orelse .null) {
.int32 => |n| @floatFromInt(n),
.int64 => |n| @floatFromInt(n),
.double => |n| n,
else => 0,
}
else
0,
else => 0,
};
gop.value_ptr.sums[i] += term;
}
}
var out: std.ArrayListUnmanaged(*const bson.Document) = .empty;
errdefer out.deinit(ctx.gpa);
var it = groups.iterator();
// free sum arrays
defer {
var git = groups.iterator();
while (git.next()) |e| ctx.gpa.free(e.value_ptr.sums);
}
while (it.next()) |entry| {
const npairs = 1 + accs.items.len;
const pairs = try arena.alloc(bson.Pair, npairs);
pairs[0] = .{ .key = "_id", .value = try bson.copy_value(arena, entry.value_ptr.id_value) };
for (accs.items, 0..) |acc, i| {
const sum: f64 = entry.value_ptr.sums[i];
const sum_value: bson.Value = if (sum == @floor(sum) and sum <= 2_147_483_647 and sum >= -2_147_483_648)
.{ .int32 = @intFromFloat(sum) }
else
.{ .double = sum };
pairs[1 + i] = .{ .key = acc.key, .value = sum_value };
}
const doc = try arena.create(bson.Document);
doc.* = bson.Document{ .arena = undefined, .pairs = pairs };
try out.append(ctx.gpa, doc);
}
return out;
}
/// Resolve a simple "$field" path expression inside a document.
fn query_path_value_bytes(
gpa: std.mem.Allocator,
bytes: []const u8,
path: []const u8,
) !?bson.Value {
var cur: bson.Value = undefined;
var it = std.mem.splitScalar(u8, path, '.');
const first = it.next() orelse return null;
cur = (try bson.get_at(gpa, bytes, first)) orelse return null;
while (it.next()) |seg| {
cur = switch (cur) {
.doc => |pairs| bson.get_pair(pairs, seg) orelse return null,
else => return null,
};
}
return cur;
}
fn cmd_get_more(_: *Context, _: *wire.Message, reply: *wire.Reply) !void {
// Cursors are never left open, so getMore always yields an empty batch.
try reply.put("cursor", .{ .doc = try cursor_doc(reply, 0, "test.$cmd", "nextBatch", &.{}) });
try reply.put_ok();
}
fn cmd_kill_cursors(_: *Context, _: *wire.Message, reply: *wire.Reply) !void {
try reply.put("cursorsKilled", .{ .array = &.{} });
try reply.put("cursorsNotFound", .{ .array = &.{} });
try reply.put("cursorsAlive", .{ .array = &.{} });
try reply.put_ok();
}
// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------
/// Deep-copy a stored document into the reply arena so updates can be
/// applied off the live doc.
fn clone_doc(reply: *wire.Reply, doc: *const bson.Document) !*bson.Document {
const arena = reply.arena_alloc();
const owned = try arena.create(bson.Document);
owned.* = .{
.arena = std.heap.ArenaAllocator.init(arena),
.pairs = try bson.copy_pairs(arena, doc.pairs),
};
return owned;
}
/// Build the document for an upsert: equality fields from the filter, then
/// the update operators applied. Owned by the reply arena.
fn build_upsert_doc(
reply: *wire.Reply,
q: []const bson.Pair,
u_doc: []const bson.Pair,
) !*bson.Document {
const arena = reply.arena_alloc();
var pairs: std.ArrayListUnmanaged(bson.Pair) = .empty;
defer pairs.deinit(arena);
for (q) |p| {
const is_operator = p.key.len > 0 and p.key[0] == '$';
const is_embedded_operator = p.value == .doc and query.all_operator_keys(p.value.doc);
if (!is_operator and !is_embedded_operator) {
try pairs.append(arena, .{ .key = try arena.dupe(u8, p.key), .value = try bson.copy_value(arena, p.value) });
}
}
const owned = try arena.create(bson.Document);
owned.* = bson.Document{ .arena = std.heap.ArenaAllocator.init(arena), .pairs = try pairs.toOwnedSlice(arena) };
// Apply update operators to build the final doc; _id handled by insert.
update.apply(owned, &.{ .arena = undefined, .pairs = u_doc }) catch |err| switch (err) {
error.ImmutableId, error.InvalidUpdate => return error.InvalidUpdate,
else => return err,
};
return owned;
}
fn parse_sort_keys(reply: *wire.Reply, value: ?bson.Value) ![]const query.SortKey {
const pairs = doc_arg(value) orelse return &.{};
const out = try reply.arena_alloc().alloc(query.SortKey, pairs.len);
for (pairs, 0..) |p, i| {
const descending = switch (p.value) {
.int32 => |n| n < 0,
.int64 => |n| n < 0,
.double => |n| n < 0,
.string => |s| std.mem.eql(u8, s, "desc"),
else => false,
};
out[i] = .{
.path = try reply.arena_alloc().dupe(u8, p.key),
.descending = descending,
};
}
return out;
}
fn doc_arg(v: ?bson.Value) ?[]const bson.Pair {
return switch (v orelse return null) {
.doc => |pairs| pairs,
else => null,
};
}
fn str_arg(v: ?bson.Value) ?[]const u8 {
return switch (v orelse return null) {
.string => |s| s,
else => null,
};
}
fn bool_arg(v: ?bson.Value) ?bool {
return switch (v orelse return null) {
.bool => |b| b,
.int32 => |i| i != 0,
else => null,
};
}
fn int_arg(v: ?bson.Value) ?u64 {
const i = int_value(v) orelse return null;
return if (i < 0) null else @intCast(i);
}
/// Numeric argument as a signed integer, with no clamping — callers that care
/// about the sign (find's limit, delete's limit, $skip) apply their own rule.
fn int_value(v: ?bson.Value) ?i64 {
return switch (v orelse return null) {
.int32 => |i| i,
.int64 => |i| i,
// lossyCast saturates instead of trapping on out-of-range doubles.
.double => |d| std.math.lossyCast(i64, d),
else => null,
};
}
/// A `$skip`/`$limit` stage operand: a non-negative document count. Writes
/// the error reply and returns null when the operand is not a number.
fn stage_count(reply: *wire.Reply, v: bson.Value, stage: []const u8) !?usize {
const n = int_value(v) orelse {
const text = try std.fmt.allocPrint(reply.arena_alloc(), "{s} requires a number", .{stage});
try bad_value(reply, text);
return null;
};
return @intCast(@max(0, n));
}
/// Fetch a batch argument, writing the standard error reply and returning
/// null when it is missing or malformed.
fn batch_arg(
msg: *wire.Message,
reply: *wire.Reply,
cmd: []const u8,
name: []const u8,
) !?[]const bson.Document {
return msg.batch(name) catch |err| {
const arena = reply.arena_alloc();
const text = switch (err) {
error.MissingBatch => try std.fmt.allocPrint(arena, "{s} requires {s}", .{ cmd, name }),
error.BatchNotArray => try std.fmt.allocPrint(arena, "{s} must be an array", .{name}),
error.BatchElementNotDoc => try std.fmt.allocPrint(arena, "{s} must be documents", .{name}),
error.OutOfMemory => return error.OutOfMemory,
};
try bad_value(reply, text);
return null;
};
}
fn invalid_arg(reply: *wire.Reply, msg: []const u8) !void {
return reply.put_error(@intFromEnum(ErrorCode.invalid_argument), "InvalidArgument", msg);
}
fn bad_value(reply: *wire.Reply, msg: []const u8) !void {
return reply.put_error(@intFromEnum(ErrorCode.bad_value), "BadValue", msg);
}
/// The E11000 text, shared by the top-level error reply and the per-document
/// `writeErrors` entries of a batch insert. Uses the collection's
/// dup_index (set by a rejected unique-index write) when the conflict came
/// from a secondary index; otherwise it is the _id_ index. Per-collection
/// so concurrent writers on other collections cannot clobber it.
fn duplicate_key_message(
ctx: *Context,
reply: *wire.Reply,
db_name: []const u8,
coll_name: []const u8,
doc: *const bson.Document,
) ![]const u8 {
var index_name: []const u8 = "_id_";
var key_text: []const u8 = undefined;
const coll = ctx.engine.get_collection(db_name, coll_name);
if (coll) |c| {
if (c.dup_index) |name| {
index_name = name;
key_text = try render_dup_key(ctx, reply, db_name, coll_name, name, doc);
return e11000_message(reply, db_name, coll_name, index_name, key_text);
}
}
key_text = try serialize_value_compact(reply, doc.get("_id") orelse bson.Value.null);
return e11000_message(reply, db_name, coll_name, index_name, key_text);
}
/// Render the dup key of a secondary index from the offending document: the
/// document's values for the index key pattern.
fn render_dup_key(
ctx: *Context,
reply: *wire.Reply,
db_name: []const u8,
coll_name: []const u8,
index_name: []const u8,
doc: *const bson.Document,
) ![]const u8 {
const arena = reply.arena_alloc();
const coll = ctx.engine.get_collection(db_name, coll_name) orelse
// Index not found (defensive): fall back to the document's _id.
return serialize_value_compact(reply, doc.get("_id") orelse bson.Value.null);
const ix = coll.find_index(index_name) orelse
return serialize_value_compact(reply, doc.get("_id") orelse bson.Value.null);
var out: std.ArrayListUnmanaged(u8) = .empty;
defer out.deinit(arena);
try out.append(arena, '{');
for (ix.keys, 0..) |k, i| {
if (i > 0) try out.appendSlice(arena, ", ");
try out.appendSlice(arena, k.path);
try out.appendSlice(arena, ": ");
var values: std.ArrayListUnmanaged(bson.Value) = .empty;
defer values.deinit(arena);
try query.collect_values(arena, doc.pairs, k.path, &values, 0);
const v: bson.Value = if (values.items.len > 0) values.items[0] else .null;
try out.appendSlice(arena, try serialize_value_compact(reply, v));
}
try out.append(arena, '}');
return out.toOwnedSlice(arena);
}
fn duplicate_key_error(
ctx: *Context,
reply: *wire.Reply,
db_name: []const u8,
coll_name: []const u8,
doc: *const bson.Document,
) !void {
const msg_text = try duplicate_key_message(ctx, reply, db_name, coll_name, doc);
return reply.put_error(@intFromEnum(ErrorCode.duplicate_key), "DuplicateKey", msg_text);
}
/// Compact extended-JSON-ish rendering of a value for error messages.
fn serialize_value_compact(reply: *wire.Reply, v: bson.Value) ![]const u8 {
const arena = reply.arena_alloc();
return switch (v) {
.int32 => |i| try std.fmt.allocPrint(arena, "{d}", .{i}),
.int64 => |i| try std.fmt.allocPrint(arena, "{d}", .{i}),
.double => |d| try std.fmt.allocPrint(arena, "{d}", .{d}),
.string => |s| try std.fmt.allocPrint(arena, "'{s}'", .{s}),
.bool => |b| try std.fmt.allocPrint(arena, "{}", .{b}),
.object_id => |oid| blk: {
const hex = std.fmt.bytesToHex(oid[0..], .lower);
break :blk try std.fmt.allocPrint(arena, "ObjectId('{s}')", .{hex});
},
else => "{ ... }",
};
}
/// Build a { id: <n>, ns: "...", <batch_key>: [...] } cursor document.
pub fn cursor_doc(
reply: *wire.Reply,
cursor_id: i64,
ns: []const u8,
batch_key: []const u8,
docs: []const bson.Value,
) ![]const bson.Pair {
const c = try reply.arena_alloc().alloc(bson.Pair, 3);
c[0] = .{ .key = "id", .value = .{ .int64 = cursor_id } };
c[1] = .{ .key = "ns", .value = .{ .string = ns } };
c[2] = .{ .key = batch_key, .value = .{ .array = docs } };
return c;
}
fn format_namespace(reply: *wire.Reply, db_name: []const u8, coll_name: []const u8) ![]const u8 {
return std.fmt.allocPrint(reply.arena_alloc(), "{s}.{s}", .{ db_name, coll_name });
}
fn int_array(reply: *wire.Reply, values: []const i32) ![]const bson.Value {
const out = try reply.arena_alloc().alloc(bson.Value, values.len);
for (values, 0..) |v, i| out[i] = .{ .int32 = v };
return out;
}
fn str_array(reply: *wire.Reply, values: []const []const u8) ![]const bson.Value {
const out = try reply.arena_alloc().alloc(bson.Value, values.len);
for (values, 0..) |v, i| out[i] = .{ .string = try reply.arena_alloc().dupe(u8, v) };
return out;
}
// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------
const testing = std.testing;
/// Temp-log-backed engine plus the Context a command test dispatches with.
const TestDb = struct {
tmp: std.testing.TmpDir,
path: []u8,
engine: db.Engine,
gen: bson.ObjectIdGen,
fn init(io: std.Io) !TestDb {
const tmp = std.testing.tmpDir(.{});
const path = try std.fmt.allocPrint(testing.allocator, ".zig-cache/tmp/{s}/cmd.log", .{tmp.sub_path});
return .{
.tmp = tmp,
.path = path,
.engine = try db.Engine.open(testing.allocator, io, path),
.gen = bson.ObjectIdGen.init(io),
};
}
fn deinit(self: *TestDb) void {
self.engine.deinit();
self.tmp.cleanup();
testing.allocator.free(self.path);
}
fn ctx(self: *TestDb, io: std.Io) Context {
return test_ctx(io, &self.engine, &self.gen, 1);
}
};
fn test_ctx(io: std.Io, engine: *db.Engine, gen: *bson.ObjectIdGen, connection_id: u32) Context {
return .{
.gpa = testing.allocator,
.io = io,
.oid_gen = gen,
.connection_id = connection_id,
.client_desc = "127.0.0.1:0",
.engine = engine,
.server_start = std.Io.Timestamp.now(io, .real),
};
}
test "ping and hello replies parse" {
var threaded: std.Io.Threaded = .init_single_threaded;
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
var ctx = tdb.ctx(io);
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
var msg = try parse_fake_msg("ping", .null, &.{});
defer msg.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(f64, 1.0), reply.pairs.items[0].value.double);
var reply2 = wire.Reply.init(testing.allocator);
defer reply2.deinit();
var msg2 = try parse_fake_msg("hello", .null, &.{});
defer msg2.deinit();
try dispatch(&ctx, &msg2, &reply2);
const ok = bson.get_pair(reply2.pairs.items, "ok").?;
try testing.expectEqual(@as(f64, 1.0), ok.double);
const primary = bson.get_pair(reply2.pairs.items, "isWritablePrimary").?;
try testing.expect(primary.bool);
try testing.expectEqual(@as(i32, 8), bson.get_pair(reply2.pairs.items, "maxWireVersion").?.int32);
}
test "handshake does not advertise the streaming hello protocol" {
// `topologyVersion` in a hello/isMaster reply tells the driver it may
// monitor with an exhaust hello and expect moreToCome replies we never
// send; the driver then kills the connection every heartbeat.
var threaded: std.Io.Threaded = .init_single_threaded;
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
var ctx = tdb.ctx(io);
for ([_][]const u8{ "hello", "isMaster", "ismaster" }) |cmd| {
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
var msg = try parse_fake_msg(cmd, .null, &.{});
defer msg.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(f64, 1.0), bson.get_pair(reply.pairs.items, "ok").?.double);
try testing.expect(bson.get_pair(reply.pairs.items, "topologyVersion") == null);
}
}
test "unknown command gives CommandNotFound" {
var threaded: std.Io.Threaded = .init_single_threaded;
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
var ctx = tdb.ctx(io);
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
var msg = try parse_fake_msg("nonsenseCmd", .null, &.{});
defer msg.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(f64, 0.0), bson.get_pair(reply.pairs.items, "ok").?.double);
try testing.expectEqual(@as(i32, 59), bson.get_pair(reply.pairs.items, "code").?.int32);
try testing.expectEqualStrings("CommandNotFound", bson.get_pair(reply.pairs.items, "codeName").?.string);
}
test "getParameter responds for featureCompatibilityVersion" {
var threaded: std.Io.Threaded = .init_single_threaded;
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
var ctx = tdb.ctx(io);
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
var fcv_doc = try testing.allocator.alloc(bson.Pair, 1);
defer testing.allocator.free(fcv_doc);
fcv_doc[0] = .{ .key = "featureCompatibilityVersion", .value = .{ .int32 = 1 } };
var msg = try parse_fake_msg("getParameter", .{ .doc = fcv_doc }, &.{});
defer msg.deinit();
try dispatch(&ctx, &msg, &reply);
const fcv = bson.get_pair(reply.pairs.items, "featureCompatibilityVersion").?;
try testing.expectEqualStrings("4.4", fcv.doc[0].value.string);
}
test "insert counts only successful inserts" {
var threaded: std.Io.Threaded = .init_single_threaded;
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
var ctx = tdb.ctx(io);
// documents: [{_id:1}, {_id:1} (dup), {_id:2}] → n: 2 + one writeError.
const docs = [_]bson.Value{
.{ .doc = &.{.{ .key = "_id", .value = .{ .int32 = 1 } }} },
.{ .doc = &.{.{ .key = "_id", .value = .{ .int32 = 1 } }} },
.{ .doc = &.{.{ .key = "_id", .value = .{ .int32 = 2 } }} },
};
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
var msg = try parse_fake_msg("insert", .{ .string = "users" }, &.{
.{ .key = "documents", .value = .{ .array = &docs } },
});
defer msg.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(i64, 2), bson.get_pair(reply.pairs.items, "n").?.int32);
const errors = bson.get_pair(reply.pairs.items, "writeErrors").?;
try testing.expectEqual(@as(usize, 1), errors.array.len);
const first = errors.array[0].doc[0];
try testing.expectEqualStrings("index", first.key);
try testing.expectEqual(@as(i64, 1), first.value.int32);
}
fn parse_fake_msg(name: []const u8, value: bson.Value, extra: []const bson.Pair) !wire.Message {
var out: std.ArrayListUnmanaged(u8) = .empty;
defer out.deinit(testing.allocator);
const pairs = try testing.allocator.alloc(bson.Pair, 2 + extra.len);
defer testing.allocator.free(pairs);
pairs[0] = .{ .key = name, .value = value };
pairs[1] = .{ .key = "$db", .value = .{ .string = "test" } };
@memcpy(pairs[2..], extra);
try bson.write_doc(pairs, testing.allocator, &out);
var msg: std.ArrayListUnmanaged(u8) = .empty;
defer msg.deinit(testing.allocator);
try msg.appendSlice(testing.allocator, &[_]u8{ 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0xDD, 0x07, 0, 0, 0, 0, 0, 0 });
try msg.append(testing.allocator, 0x00);
try msg.appendSlice(testing.allocator, out.items);
std.mem.writeInt(u32, msg.items[0..4], @intCast(msg.items.len), .little);
std.mem.writeInt(i32, msg.items[12..16], wire.op_code_msg, .little);
return wire.Message.parse(testing.allocator, msg.items);
}
test "concurrent insert/find commands on a threaded Io" {
// Exercises dispatch's lock classification end-to-end: writer fibers run
// `insert` under the exclusive lock, reader fibers run `count`/`find`
// under the shared lock. Every committed insert must be visible once all
// writers finish, and no reader may observe more docs than can exist.
var threaded: std.Io.Threaded = .init(testing.allocator, .{});
defer threaded.deinit();
const io = threaded.io();
var gen = bson.ObjectIdGen.init(io);
var tmp = std.testing.tmpDir(.{});
defer tmp.cleanup();
const path = try std.fmt.allocPrint(testing.allocator, ".zig-cache/tmp/{s}/conc.log", .{tmp.sub_path});
defer testing.allocator.free(path);
var engine = try db.Engine.open(testing.allocator, io, path);
defer engine.deinit();
const writers = 4;
const readers = 4;
const per_writer: i32 = 150;
const total: i32 = writers * per_writer;
var next_id = std.atomic.Value(i32).init(1);
var remaining = std.atomic.Value(usize).init(@intCast(total));
const Worker = struct {
fn writer(
iow: std.Io,
eng: *db.Engine,
id_counter: *std.atomic.Value(i32),
pending: *std.atomic.Value(usize),
fiber_id: u32,
total_writes: i32,
) error{Canceled}!void {
var wgen = bson.ObjectIdGen.init(iow);
var ctx = test_ctx(iow, eng, &wgen, fiber_id);
while (true) {
const id = id_counter.fetchAdd(1, .monotonic);
if (id > total_writes) return;
const docs = [_]bson.Value{.{ .doc = &.{.{ .key = "_id", .value = .{ .int32 = id } }} }};
var msg = parse_fake_msg("insert", .{ .string = "users" }, &.{
.{ .key = "documents", .value = .{ .array = &docs } },
}) catch return error.Canceled;
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
dispatch(&ctx, &msg, &reply) catch return error.Canceled;
_ = pending.fetchSub(1, .monotonic);
}
}
fn reader(
iow: std.Io,
eng: *db.Engine,
pending: *std.atomic.Value(usize),
fiber_id: u32,
total_writes: i32,
) error{Canceled}!void {
var rgen = bson.ObjectIdGen.init(iow);
var ctx = test_ctx(iow, eng, &rgen, fiber_id);
while (pending.load(.acquire) > 0) {
var msg = parse_fake_msg("count", .{ .string = "users" }, &.{}) catch return error.Canceled;
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
dispatch(&ctx, &msg, &reply) catch return error.Canceled;
const n = bson.get_pair(reply.pairs.items, "n") orelse return error.Canceled;
if (n.int32 > total_writes) return error.Canceled;
}
}
};
var group: std.Io.Group = .init;
defer group.cancel(io);
for (0..readers) |i| group.async(io, Worker.reader, .{ io, &engine, &remaining, @intCast(i + 1), total });
for (0..writers) |i| group.async(io, Worker.writer, .{ io, &engine, &next_id, &remaining, @intCast(i + 1), total });
try group.await(io);
var ctx = test_ctx(io, &engine, &gen, 0);
var msg = try parse_fake_msg("count", .{ .string = "users" }, &.{});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(total, bson.get_pair(reply.pairs.items, "n").?.int32);
}
// -- index command tests ----------------------------------------------------
/// Dispatch an insert of the given documents (each a bson.Value .doc).
fn dispatch_insert(
tdb: *TestDb,
io: std.Io,
coll_name: []const u8,
docs: []const bson.Value,
) !void {
var ctx = tdb.ctx(io);
var msg = try parse_fake_msg("insert", .{ .string = coll_name }, &.{
.{ .key = "documents", .value = .{ .array = docs } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(f64, 1.0), bson.get_pair(reply.pairs.items, "ok").?.double);
// `ok: 1` is not success for an insert batch: a rejected document comes
// back as a writeError alongside it. Asserting only `ok` let a corpus
// silently shrink -- when _id_ became a unique index, the mixed-type
// corpus below lost its int64 1 document and every test over it still
// passed, over nine documents instead of ten.
if (bson.get_pair(reply.pairs.items, "writeErrors")) |we| {
std.debug.print("dispatch_insert: unexpected writeErrors: {any}\n", .{we});
return error.TestUnexpectedResult;
}
try testing.expectEqual(@as(i32, @intCast(docs.len)), bson.get_pair(reply.pairs.items, "n").?.int32);
}
/// Dispatch createIndexes for one spec.
fn dispatch_create_index(tdb: *TestDb, io: std.Io, coll_name: []const u8, spec: bson.Value) !void {
var ctx = tdb.ctx(io);
const specs = [_]bson.Value{spec};
var msg = try parse_fake_msg("createIndexes", .{ .string = coll_name }, &.{
.{ .key = "indexes", .value = .{ .array = &specs } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(f64, 1.0), bson.get_pair(reply.pairs.items, "ok").?.double);
}
/// Dispatch find and append the serialized _id of every result to `out`.
fn dispatch_find_ids(
tdb: *TestDb,
io: std.Io,
coll_name: []const u8,
filter: []const bson.Pair,
out: *std.ArrayListUnmanaged([]u8),
) !void {
var ctx = tdb.ctx(io);
var msg = try parse_fake_msg("find", .{ .string = coll_name }, &.{
.{ .key = "filter", .value = .{ .doc = filter } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(f64, 1.0), bson.get_pair(reply.pairs.items, "ok").?.double);
const cursor = bson.get_pair(reply.pairs.items, "cursor") orelse return error.TestUnexpectedResult;
const batch = switch (bson.get_pair(cursor.doc, "firstBatch") orelse return error.TestUnexpectedResult) {
.array => |a| a,
else => return error.TestUnexpectedResult,
};
for (batch) |d| {
const idv = bson.get_pair(d.doc, "_id") orelse continue;
try out.append(testing.allocator, try bson.serialize_value(testing.allocator, idv));
}
std.mem.sort([]u8, out.items, {}, less_u8);
}
fn less_u8(_: void, a: []u8, b: []u8) bool {
return std.mem.order(u8, a, b) == .lt;
}
test "createIndexes, listIndexes, dropIndexes, and idempotent re-create" {
var threaded: std.Io.Threaded = .init_single_threaded;
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
// createIndexes builds the index immediately.
{
var ctx = tdb.ctx(io);
const specs = [_]bson.Value{.{ .doc = &.{
.{ .key = "key", .value = .{ .doc = &.{.{ .key = "email", .value = .{ .int32 = 1 } }} } },
.{ .key = "name", .value = .{ .string = "email_1" } },
} }};
var msg = try parse_fake_msg("createIndexes", .{ .string = "users" }, &.{
.{ .key = "indexes", .value = .{ .array = &specs } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(f64, 1.0), bson.get_pair(reply.pairs.items, "ok").?.double);
try testing.expectEqual(@as(i64, 1), bson.get_pair(reply.pairs.items, "numIndexesBefore").?.int32);
try testing.expectEqual(@as(i64, 2), bson.get_pair(reply.pairs.items, "numIndexesAfter").?.int32);
}
// Idempotent re-create of the same spec.
try dispatch_create_index(&tdb, io, "users", .{ .doc = &.{
.{ .key = "key", .value = .{ .doc = &.{.{ .key = "email", .value = .{ .int32 = 1 } }} } },
.{ .key = "name", .value = .{ .string = "email_1" } },
} });
// listIndexes: _id_ first, then the secondary.
{
var ctx = tdb.ctx(io);
var msg = try parse_fake_msg("listIndexes", .{ .string = "users" }, &.{});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(f64, 1.0), bson.get_pair(reply.pairs.items, "ok").?.double);
const cursor = bson.get_pair(reply.pairs.items, "cursor").?;
const batch = bson.get_pair(cursor.doc, "firstBatch").?.array;
try testing.expectEqual(@as(usize, 2), batch.len);
try testing.expectEqualStrings("_id_", bson.get_pair(batch[0].doc, "name").?.string);
try testing.expectEqualStrings("email_1", bson.get_pair(batch[1].doc, "name").?.string);
const key_pairs = bson.get_pair(batch[1].doc, "key").?.doc;
try testing.expect(bson.get_pair(key_pairs, "email") != null);
}
// listIndexes on a missing collection: NamespaceNotFound.
{
var ctx = tdb.ctx(io);
var msg = try parse_fake_msg("listIndexes", .{ .string = "nope" }, &.{});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(i32, 26), bson.get_pair(reply.pairs.items, "code").?.int32);
}
// dropIndexes("*") removes the secondary but keeps _id_.
{
var ctx = tdb.ctx(io);
var msg = try parse_fake_msg("dropIndexes", .{ .string = "users" }, &.{
.{ .key = "index", .value = .{ .string = "*" } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(f64, 1.0), bson.get_pair(reply.pairs.items, "ok").?.double);
try testing.expectEqual(@as(i64, 2), bson.get_pair(reply.pairs.items, "nIndexesWas").?.int32);
}
try testing.expectEqual(@as(usize, 0), tdb.engine.get_collection("test", "users").?.indexes.items.len);
// dropIndexes("_id_") errors.
{
var ctx = tdb.ctx(io);
var msg = try parse_fake_msg("dropIndexes", .{ .string = "users" }, &.{
.{ .key = "index", .value = .{ .string = "_id_" } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(i32, 72), bson.get_pair(reply.pairs.items, "code").?.int32);
}
}
test "TTL index round-trips through createIndexes/listIndexes; bad specs give 67" {
var threaded: std.Io.Threaded = .init_single_threaded;
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
// A driver sends expireAfterSeconds as a double.
try dispatch_create_index(&tdb, io, "sessions", .{ .doc = &.{
.{
.key = "key",
.value = .{ .doc = &.{
.{ .key = "expireAt", .value = .{ .int32 = 1 } },
} },
},
.{ .key = "name", .value = .{ .string = "expireAt_1" } },
.{ .key = "expireAfterSeconds", .value = .{ .double = 60.0 } },
} });
try testing.expectEqual(@as(?i64, 60), tdb.engine.get_collection("test", "sessions").?.indexes.items[0].ttl);
// listIndexes reports it back.
{
var ctx = tdb.ctx(io);
var msg = try parse_fake_msg("listIndexes", .{ .string = "sessions" }, &.{});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
const cursor = bson.get_pair(reply.pairs.items, "cursor").?;
const batch = bson.get_pair(cursor.doc, "firstBatch").?.array;
try testing.expectEqual(@as(usize, 2), batch.len);
try testing.expectEqual(@as(i32, 60), bson.get_pair(batch[1].doc, "expireAfterSeconds").?.int32);
// The _id_ entry never carries one.
try testing.expect(bson.get_pair(batch[0].doc, "expireAfterSeconds") == null);
}
// Same name and key, different expiry: IndexOptionsConflict, as in
// MongoDB (changing it is a collMod, which this server does not have).
const bad = [_]struct { spec: bson.Value, code: i32 }{
.{ .code = 85, .spec = .{ .doc = &.{
.{ .key = "key", .value = .{ .doc = &.{.{ .key = "expireAt", .value = .{ .int32 = 1 } }} } },
.{ .key = "name", .value = .{ .string = "expireAt_1" } },
.{ .key = "expireAfterSeconds", .value = .{ .int32 = 90 } },
} } },
// TTL on a compound key.
.{ .code = 67, .spec = .{ .doc = &.{
.{ .key = "key", .value = .{ .doc = &.{
.{ .key = "a", .value = .{ .int32 = 1 } },
.{ .key = "b", .value = .{ .int32 = 1 } },
} } },
.{ .key = "expireAfterSeconds", .value = .{ .int32 = 60 } },
} } },
// Negative and non-numeric expiries.
.{ .code = 67, .spec = .{ .doc = &.{
.{ .key = "key", .value = .{ .doc = &.{.{ .key = "a", .value = .{ .int32 = 1 } }} } },
.{ .key = "expireAfterSeconds", .value = .{ .int32 = -1 } },
} } },
.{ .code = 67, .spec = .{ .doc = &.{
.{ .key = "key", .value = .{ .doc = &.{.{ .key = "a", .value = .{ .int32 = 1 } }} } },
.{ .key = "expireAfterSeconds", .value = .{ .string = "60" } },
} } },
// Past MongoDB's 2147483647 bound.
.{ .code = 67, .spec = .{ .doc = &.{
.{ .key = "key", .value = .{ .doc = &.{.{ .key = "a", .value = .{ .int32 = 1 } }} } },
.{ .key = "expireAfterSeconds", .value = .{ .int64 = index.max_expire_after_seconds + 1 } },
} } },
// {_id: 1} is otherwise an idempotent no-op, but an expiry on it
// would be silently dropped, so it is rejected instead.
.{ .code = 197, .spec = .{ .doc = &.{
.{ .key = "key", .value = .{ .doc = &.{.{ .key = "_id", .value = .{ .int32 = 1 } }} } },
.{ .key = "expireAfterSeconds", .value = .{ .int32 = 60 } },
} } },
};
for (bad) |case| {
var ctx = tdb.ctx(io);
const specs = [_]bson.Value{case.spec};
var msg = try parse_fake_msg("createIndexes", .{ .string = "sessions" }, &.{
.{ .key = "indexes", .value = .{ .array = &specs } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(case.code, bson.get_pair(reply.pairs.items, "code").?.int32);
}
// Nothing partial was registered by the rejected specs.
try testing.expectEqual(@as(usize, 1), tdb.engine.get_collection("test", "sessions").?.indexes.items.len);
}
test "unique index constraint returns 11000 through insert and update" {
var threaded: std.Io.Threaded = .init_single_threaded;
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
try dispatch_create_index(&tdb, io, "users", .{ .doc = &.{
.{ .key = "key", .value = .{ .doc = &.{.{ .key = "email", .value = .{ .int32 = 1 } }} } },
.{ .key = "name", .value = .{ .string = "email_1" } },
.{ .key = "unique", .value = .{ .bool = true } },
} });
const docs = [_]bson.Value{
.{ .doc = &.{ .{ .key = "_id", .value = .{ .int32 = 1 } }, .{ .key = "email", .value = .{ .string = "a@x.io" } } } },
.{ .doc = &.{ .{ .key = "_id", .value = .{ .int32 = 2 } }, .{ .key = "email", .value = .{ .string = "a@x.io" } } } },
.{ .doc = &.{ .{ .key = "_id", .value = .{ .int32 = 3 } }, .{ .key = "email", .value = .{ .string = "b@x.io" } } } },
};
var ctx = tdb.ctx(io);
var msg = try parse_fake_msg("insert", .{ .string = "users" }, &.{
.{ .key = "documents", .value = .{ .array = &docs } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
// 2 inserted, 1 writeError with code 11000 naming the index.
try testing.expectEqual(@as(i64, 2), bson.get_pair(reply.pairs.items, "n").?.int32);
const errors = bson.get_pair(reply.pairs.items, "writeErrors").?.array;
try testing.expectEqual(@as(usize, 1), errors.len);
try testing.expectEqual(@as(i64, 11000), bson.get_pair(errors[0].doc, "code").?.int32);
const errmsg = bson.get_pair(errors[0].doc, "errmsg").?.string;
try testing.expect(std.mem.indexOf(u8, errmsg, "email_1") != null);
try testing.expect(std.mem.indexOf(u8, errmsg, "E11000") != null);
// An update that collides is reported as a writeError with code 11000.
const updates = [_]bson.Value{.{ .doc = &.{
.{ .key = "q", .value = .{ .doc = &.{.{ .key = "_id", .value = .{ .int32 = 3 } }} } },
.{ .key = "u", .value = .{ .doc = &.{.{ .key = "$set", .value = .{ .doc = &.{.{ .key = "email", .value = .{ .string = "a@x.io" } }} } }} } },
} }};
var msg2 = try parse_fake_msg("update", .{ .string = "users" }, &.{
.{ .key = "updates", .value = .{ .array = &updates } },
});
defer msg2.deinit();
var reply2 = wire.Reply.init(testing.allocator);
defer reply2.deinit();
try dispatch(&ctx, &msg2, &reply2);
try testing.expectEqual(@as(f64, 1.0), bson.get_pair(reply2.pairs.items, "ok").?.double);
try testing.expectEqual(@as(i64, 0), bson.get_pair(reply2.pairs.items, "nModified").?.int32);
const up_errs = bson.get_pair(reply2.pairs.items, "writeErrors").?.array;
try testing.expectEqual(@as(usize, 1), up_errs.len);
try testing.expectEqual(@as(i64, 11000), bson.get_pair(up_errs[0].doc, "code").?.int32);
}
/// Free a list of serialized ids (each element is gpa-owned).
fn free_id_list(gpa: std.mem.Allocator, list: *std.ArrayListUnmanaged([]u8)) void {
for (list.items) |id| gpa.free(id);
list.deinit(gpa);
}
/// Free the serialized ids and reset the list, keeping capacity.
fn clear_id_list(gpa: std.mem.Allocator, list: *std.ArrayListUnmanaged([]u8)) void {
for (list.items) |id| gpa.free(id);
list.clearRetainingCapacity();
}
test "aggregate $sort without a preceding $group sorts and frees correctly" {
// Regression test for a remote, client-triggerable invalid free: the
// $sort stage materialized its document list from the reply arena and
// handed it to `trees`, which is freed with the gpa. Two things made it
// survive for so long, and this test is shaped to close both:
//
// - every existing aggregate test sorts *after* a $group, which leaves
// the stream already materialized so the guilty branch never runs.
// So this pipeline must have $sort with NO $group before it.
// - the symptom was allocator-dependent (macOS malloc aborted; other
// allocators may not notice). testing.allocator detects an invalid
// free itself, which is what gives this teeth in every mode.
//
// Mutation check: change the `all.append(ctx.gpa, ...)` back to
// `all.append(arena, ...)` in cmd_aggregate and this goes red.
var threaded = std.Io.Threaded.init(testing.allocator, .{});
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
// Insert out of order so a missing sort is visible, not coincidental.
try dispatch_insert(&tdb, io, "agg", &.{
.{ .doc = &.{ .{ .key = "_id", .value = .{ .int32 = 1 } }, .{ .key = "x", .value = .{ .int32 = 30 } } } },
.{ .doc = &.{ .{ .key = "_id", .value = .{ .int32 = 2 } }, .{ .key = "x", .value = .{ .int32 = 10 } } } },
.{ .doc = &.{ .{ .key = "_id", .value = .{ .int32 = 3 } }, .{ .key = "x", .value = .{ .int32 = 20 } } } },
});
const sort_stage = bson.Value{ .doc = &.{.{ .key = "$sort", .value = .{ .doc = &.{.{ .key = "x", .value = .{ .int32 = 1 } }} } }} };
const stages = [_]bson.Value{sort_stage};
var ctx = tdb.ctx(io);
var msg = try parse_fake_msg("aggregate", .{ .string = "agg" }, &.{
.{ .key = "pipeline", .value = .{ .array = &stages } },
.{ .key = "cursor", .value = .{ .doc = &.{} } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(f64, 1.0), bson.get_pair(reply.pairs.items, "ok").?.double);
const cursor = bson.get_pair(reply.pairs.items, "cursor") orelse return error.TestUnexpectedResult;
const batch = switch (bson.get_pair(cursor.doc, "firstBatch") orelse return error.TestUnexpectedResult) {
.array => |a| a,
else => return error.TestUnexpectedResult,
};
try testing.expectEqual(@as(usize, 3), batch.len);
// Ascending by x means _id order 2, 3, 1.
const want = [_]i32{ 2, 3, 1 };
for (batch, want) |d, id| {
try testing.expectEqual(id, bson.get_pair(d.doc, "_id").?.int32);
}
}
test "count_only_pipeline accepts only shapes a count can answer" {
// The fast path skips materializing documents, so mis-accepting a
// pipeline would silently return a wrong aggregate rather than a slow
// one. Pin exactly which shapes it claims.
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
const group_count = bson.Value{ .doc = &.{.{ .key = "$group", .value = .{ .doc = &.{
.{ .key = "_id", .value = .null },
.{ .key = "n", .value = .{ .doc = &.{.{ .key = "$sum", .value = .{ .int32 = 1 } }} } },
} } }} };
const match_k = bson.Value{ .doc = &.{.{ .key = "$match", .value = .{ .doc = &.{.{ .key = "k", .value = .{ .int32 = 2 } }} } }} };
// Accepted: the two shapes countDocuments() produces.
try testing.expect(try count_only_pipeline(&reply, &.{group_count}) != null);
const with_match = try count_only_pipeline(&reply, &.{ match_k, group_count });
try testing.expect(with_match != null);
try testing.expectEqual(@as(usize, 1), with_match.?.filter.len);
try testing.expectEqualStrings("k", with_match.?.filter[0].key);
// Rejected: grouping by a field value needs the documents.
try testing.expect(try count_only_pipeline(&reply, &.{.{ .doc = &.{.{ .key = "$group", .value = .{ .doc = &.{
.{ .key = "_id", .value = .{ .string = "$k" } },
.{ .key = "n", .value = .{ .doc = &.{.{ .key = "$sum", .value = .{ .int32 = 1 } }} } },
} } }} }}) == null);
// Rejected: summing a field, not a constant.
try testing.expect(try count_only_pipeline(&reply, &.{.{ .doc = &.{.{ .key = "$group", .value = .{ .doc = &.{
.{ .key = "_id", .value = .null },
.{ .key = "t", .value = .{ .doc = &.{.{ .key = "$sum", .value = .{ .string = "$x" } }} } },
} } }} }}) == null);
// Rejected: an accumulator we do not model at all.
try testing.expect(try count_only_pipeline(&reply, &.{.{ .doc = &.{.{ .key = "$group", .value = .{ .doc = &.{
.{ .key = "_id", .value = .null },
.{ .key = "m", .value = .{ .doc = &.{.{ .key = "$max", .value = .{ .string = "$x" } }} } },
} } }} }}) == null);
// Rejected: any extra stage, since it could reshape the result.
try testing.expect(try count_only_pipeline(&reply, &.{ match_k, group_count, .{ .doc = &.{.{ .key = "$limit", .value = .{ .int32 = 1 } }} } }) == null);
// Rejected: a leading stage that is not $match.
try testing.expect(try count_only_pipeline(&reply, &.{ .{ .doc = &.{.{ .key = "$sort", .value = .{ .doc = &.{.{ .key = "k", .value = .{ .int32 = 1 } }} } }} }, group_count }) == null);
// Rejected: empty pipeline.
try testing.expect(try count_only_pipeline(&reply, &.{}) == null);
}
test "a sorted full scan over a multikey index returns each document once" {
// scan_sorted streams a whole-index read instead of materializing it, which
// is what keeps a countDocuments({}) from building a list of every offset in
// the collection. But one document contributes several entries to a multikey
// index, so walking that index end to end yields it once per array element.
// The materializing path deduped; a stream cannot, so Plan.full_scan()
// refuses multikey indexes and this shape keeps materializing.
//
// The shape is `find({}).sort({tags: 1})`: no filter, so the only reason to
// use an index at all is that it supplies the order.
//
// Mutation check, and it is worth stating precisely because the obvious
// version of it does nothing: two independent guards refuse this, so
// removing either one alone leaves the test green. `index_provides_sort`
// returns null for a multikey index, and `Plan.full_scan` refuses one
// again. Remove *both* and each document comes back three times. So this
// test pins the pair, not either guard -- which is the useful property,
// since it is the behaviour that matters rather than which check delivers
// it.
var threaded: std.Io.Threaded = .init_single_threaded;
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
try dispatch_insert(&tdb, io, "mk", &.{
.{ .doc = &.{
.{ .key = "_id", .value = .{ .int32 = 1 } },
.{ .key = "tags", .value = .{ .array = &.{ .{ .int32 = 1 }, .{ .int32 = 2 }, .{ .int32 = 3 } } } },
} },
.{ .doc = &.{
.{ .key = "_id", .value = .{ .int32 = 2 } },
.{ .key = "tags", .value = .{ .array = &.{ .{ .int32 = 4 }, .{ .int32 = 5 }, .{ .int32 = 6 } } } },
} },
});
try dispatch_create_index(&tdb, io, "mk", .{ .doc = &.{
.{ .key = "key", .value = .{ .doc = &.{.{ .key = "tags", .value = .{ .int32 = 1 } }} } },
.{ .key = "name", .value = .{ .string = "tags_1" } },
} });
var ctx = tdb.ctx(io);
var msg = try parse_fake_msg("find", .{ .string = "mk" }, &.{
.{ .key = "filter", .value = .{ .doc = &.{} } },
.{ .key = "sort", .value = .{ .doc = &.{.{ .key = "tags", .value = .{ .int32 = 1 } }} } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
try testing.expectEqual(@as(f64, 1.0), bson.get_pair(reply.pairs.items, "ok").?.double);
const cursor = bson.get_pair(reply.pairs.items, "cursor") orelse return error.TestUnexpectedResult;
const batch = switch (bson.get_pair(cursor.doc, "firstBatch") orelse return error.TestUnexpectedResult) {
.array => |arr| arr,
else => return error.TestUnexpectedResult,
};
// Two documents, not six.
try testing.expectEqual(@as(usize, 2), batch.len);
}
test "a command with no collection name errors and holds no lock" {
// Regression for a leaked catalog lock. dispatch resolved the namespace
// *after* taking the catalog lock, with `orelse return` -- and a plain
// return runs neither the errdefer nor the explicit unlocks, so the lock
// was held shared forever. `db.aggregate(...)` sends {aggregate: 1}, whose
// value is not a string, so it reached exactly that path.
//
// Two assertions, because the first alone would have passed before the fix
// for the wrong reason: the reply must be a real error (it used to be an
// empty document, which a driver reports as the useless "n/a"), and a
// subsequent write that has to take the catalog exclusive to create a
// collection must still complete. The second is the lock check.
//
// Mutation check: restore the `orelse return` pair after the lock
// acquisition and this test hangs on the insert rather than failing -- the
// suite times out. That is a deadlock, so it cannot be asserted more
// politely from a single fiber; the e2e suite covers the same sequence
// where a hang surfaces as a client timeout instead.
var threaded: std.Io.Threaded = .init_single_threaded;
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
{
var ctx = tdb.ctx(io);
// {aggregate: 1} -- a database-level aggregate, no collection named.
var msg = try parse_fake_msg("aggregate", .{ .int32 = 1 }, &.{
.{ .key = "pipeline", .value = .{ .array = &.{} } },
.{ .key = "cursor", .value = .{ .doc = &.{} } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
// A proper error, not an empty reply.
try testing.expectEqual(@as(f64, 0.0), bson.get_pair(reply.pairs.items, "ok").?.double);
try testing.expectEqual(
@as(i32, @intFromEnum(ErrorCode.bad_value)),
bson.get_pair(reply.pairs.items, "code").?.int32,
);
}
// The lock assertion: this insert creates a collection, which upgrades the
// catalog lock to exclusive. With the lock leaked it never returns.
try dispatch_insert(&tdb, io, "after", &.{
.{ .doc = &.{.{ .key = "_id", .value = .{ .int32 = 1 } }} },
});
}
test "compare-equal _id encodings collide under the unique _id_ index" {
// _id uniqueness moved from a docs-map probe keyed on serialize_value to
// the _id_ B+tree, keyed on the canonical bson.encode_key (PLAN A3/A4).
// That changes observable behavior, in MongoDB's direction: int32 1,
// int64 1 and double 1.0 are one _id, not three.
//
// Mutation check: setting `unique = false` back on id_index makes these
// collisions vanish (this test and "insert counts only successful inserts"
// both go red).
//
// The other half of the change is covered elsewhere, which is worth
// knowing so nobody re-checks it here: passing `id_key` instead of null as
// check_unique's exclude on the insert path is caught by "insert counts
// only successful inserts", not by this test. Two documents with the
// *same* encoding share an id_key, so exclude-self hides the collision;
// int32 1 and int64 1 have different id_keys, so this test survives that
// mutation. The two tests are complementary, not redundant.
var threaded: std.Io.Threaded = .init_single_threaded;
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
try dispatch_insert(&tdb, io, "ids", &.{
.{ .doc = &.{.{ .key = "_id", .value = .{ .int32 = 1 } }} },
});
// Each of these is the same _id as int32 1.
for ([_]bson.Value{
.{ .doc = &.{.{ .key = "_id", .value = .{ .int64 = 1 } }} },
.{ .doc = &.{.{ .key = "_id", .value = .{ .double = 1.0 } }} },
}) |dup| {
var ctx = tdb.ctx(io);
const one = [_]bson.Value{dup};
var msg = try parse_fake_msg("insert", .{ .string = "ids" }, &.{
.{ .key = "documents", .value = .{ .array = &one } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
const we = bson.get_pair(reply.pairs.items, "writeErrors") orelse return error.TestUnexpectedResult;
const first = we.array[0];
try testing.expectEqual(@as(i32, 11000), bson.get_pair(first.doc, "code").?.int32);
// The index named in the message is the one MongoDB names.
const errmsg = bson.get_pair(first.doc, "errmsg").?.string;
try testing.expect(std.mem.indexOf(u8, errmsg, "_id_") != null);
}
// A different rank is a different _id: "1" is not 1.
try dispatch_insert(&tdb, io, "ids", &.{
.{ .doc = &.{.{ .key = "_id", .value = .{ .string = "1" } }} },
});
// And the collision is not merely rejection: a lookup by any of the
// equivalent encodings finds the one stored document.
for ([_]bson.Value{ .{ .int32 = 1 }, .{ .int64 = 1 }, .{ .double = 1.0 } }) |probe| {
var ids: std.ArrayListUnmanaged([]u8) = .empty;
defer {
for (ids.items) |id| testing.allocator.free(id);
ids.deinit(testing.allocator);
}
try dispatch_find_ids(&tdb, io, "ids", &.{.{ .key = "_id", .value = probe }}, &ids);
try testing.expectEqual(@as(usize, 1), ids.items.len);
}
}
test "indexed queries are equivalent to scans over a mixed corpus" {
var threaded: std.Io.Threaded = .init_single_threaded;
defer threaded.deinit();
const io = threaded.io();
var tdb = try TestDb.init(io);
defer tdb.deinit();
// Corpus deliberately mixes numeric _id encodings, arrays, nested docs,
// missing fields, explicit nulls, and duplicate values.
//
// It used to carry int32 1 and int64 1 as two documents, to exercise the
// old docs-map fast path (they compare equal but serialize differently).
// _id_ is a unique index now, keyed on the canonical bson.encode_key, so
// those two *are* the same _id and the second is rejected -- which is
// MongoDB's behavior. The int64 encoding still appears below, on a
// distinct value; the collision itself is asserted in "compare-equal _id
// encodings collide under the unique _id_ index".
const corpus = [_]bson.Value{
.{ .doc = &.{
.{ .key = "_id", .value = .{ .int32 = 1 } },
.{ .key = "a", .value = .{ .int32 = 10 } },
.{ .key = "b", .value = .{ .string = "x" } },
.{ .key = "tags", .value = .{ .array = &.{ .{ .string = "a" }, .{ .string = "b" } } } },
} },
.{ .doc = &.{
.{ .key = "_id", .value = .{ .int64 = 2 } },
.{ .key = "a", .value = .{ .int32 = 20 } },
.{ .key = "b", .value = .{ .string = "y" } },
.{ .key = "tags", .value = .{ .array = &.{} } },
} },
.{ .doc = &.{
.{ .key = "_id", .value = .{ .int32 = 3 } },
.{ .key = "a", .value = .{ .double = 30.0 } },
.{ .key = "b", .value = .null },
.{ .key = "tags", .value = .{ .array = &.{.{ .string = "a" }} } },
} },
.{ .doc = &.{
.{ .key = "_id", .value = .{ .string = "s4" } },
.{ .key = "a", .value = .{ .int32 = 10 } },
.{ .key = "b", .value = .{ .string = "z" } },
.{ .key = "tags", .value = .{ .array = &.{ .{ .int32 = 10 }, .{ .int32 = 20 } } } },
} },
.{ .doc = &.{
.{ .key = "_id", .value = .{ .int32 = 5 } },
.{ .key = "a", .value = .null },
.{ .key = "b", .value = .{ .string = "x" } },
} },
.{ .doc = &.{
.{ .key = "_id", .value = .{ .int32 = 6 } },
.{ .key = "a", .value = .{ .doc = &.{.{ .key = "n", .value = .{ .int32 = 1 } }} } },
.{ .key = "b", .value = .{ .string = "w" } },
} },
.{ .doc = &.{
.{ .key = "_id", .value = .{ .int32 = 7 } },
.{ .key = "a", .value = .{ .array = &.{ .{ .int32 = 1 }, .{ .int32 = 2 } } } },
.{ .key = "b", .value = .{ .string = "q" } },
} },
.{ .doc = &.{
.{ .key = "_id", .value = .{ .int32 = 8 } },
.{ .key = "c", .value = .{ .int32 = 99 } },
} },
.{ .doc = &.{
.{ .key = "_id", .value = .{ .int32 = 9 } },
.{ .key = "a", .value = .{ .int32 = 40 } },
.{ .key = "b", .value = .{ .array = &.{ .{ .int32 = 5 }, .{ .int32 = 6 } } } },
} },
};
try dispatch_insert(&tdb, io, "eq", &corpus);
const filters = [_]struct { pairs: []const bson.Pair }{
.{ .pairs = &.{} },
.{ .pairs = &.{.{ .key = "a", .value = .{ .int32 = 10 } }} },
.{ .pairs = &.{.{ .key = "a", .value = .{ .doc = &.{.{ .key = "$eq", .value = .{ .int32 = 20 } }} } }} },
.{ .pairs = &.{.{ .key = "a", .value = .{ .doc = &.{.{ .key = "$gt", .value = .{ .int32 = 15 } }} } }} },
.{ .pairs = &.{.{ .key = "a", .value = .{ .doc = &.{.{ .key = "$gte", .value = .{ .int32 = 20 } }} } }} },
.{ .pairs = &.{.{ .key = "a", .value = .{ .doc = &.{.{ .key = "$lt", .value = .{ .int32 = 30 } }} } }} },
.{ .pairs = &.{.{ .key = "a", .value = .{ .doc = &.{.{ .key = "$lte", .value = .{ .int32 = 30 } }} } }} },
.{ .pairs = &.{.{ .key = "a", .value = .{ .doc = &.{.{ .key = "$in", .value = .{ .array = &.{ .{ .int32 = 10 }, .{ .int32 = 30 } } } }} } }} },
.{ .pairs = &.{.{ .key = "a", .value = .{ .doc = &.{ .{ .key = "$gt", .value = .{ .int32 = 5 } }, .{ .key = "$lt", .value = .{ .int32 = 25 } } } } }} },
.{ .pairs = &.{.{ .key = "b", .value = .{ .string = "x" } }} },
.{ .pairs = &.{.{ .key = "b", .value = .null }} },
.{ .pairs = &.{ .{ .key = "a", .value = .{ .int32 = 10 } }, .{ .key = "b", .value = .{ .string = "x" } } } },
.{ .pairs = &.{.{ .key = "tags", .value = .{ .string = "a" } }} },
.{ .pairs = &.{.{ .key = "tags", .value = .{ .array = &.{ .{ .string = "a" }, .{ .string = "b" } } } }} },
.{ .pairs = &.{.{ .key = "tags", .value = .{ .doc = &.{.{ .key = "$all", .value = .{ .array = &.{.{ .string = "a" }} } }} } }} },
.{ .pairs = &.{.{ .key = "a", .value = .{ .doc = &.{.{ .key = "$regex", .value = .{ .string = "^1" } }} } }} },
.{ .pairs = &.{.{ .key = "c", .value = .{ .doc = &.{.{ .key = "$exists", .value = .{ .bool = false } }} } }} },
.{ .pairs = &.{.{ .key = "a", .value = .null }} },
.{ .pairs = &.{.{ .key = "_id", .value = .{ .int32 = 1 } }} },
.{ .pairs = &.{.{ .key = "_id", .value = .{ .string = "s4" } }} },
.{ .pairs = &.{.{ .key = "_id", .value = .{ .doc = &.{.{ .key = "$in", .value = .{ .array = &.{ .{ .int32 = 1 }, .{ .string = "s4" } } } }} } }} },
.{ .pairs = &.{.{ .key = "$and", .value = .{ .array = &.{
.{ .doc = &.{.{ .key = "a", .value = .{ .doc = &.{.{ .key = "$gte", .value = .{ .int32 = 10 } }} } }} },
.{ .doc = &.{.{ .key = "a", .value = .{ .doc = &.{.{ .key = "$lte", .value = .{ .int32 = 30 } }} } }} },
} } }} },
.{ .pairs = &.{.{ .key = "a", .value = .{ .array = &.{ .{ .int32 = 1 }, .{ .int32 = 2 } } } }} },
.{ .pairs = &.{.{ .key = "a", .value = .{ .doc = &.{.{ .key = "$gt", .value = .{ .int32 = 100 } }} } }} },
.{ .pairs = &.{.{ .key = "$or", .value = .{ .array = &.{
.{ .doc = &.{.{ .key = "a", .value = .{ .int32 = 10 } }} },
.{ .doc = &.{.{ .key = "b", .value = .{ .string = "y" } }} },
} } }} },
.{ .pairs = &.{.{ .key = "a", .value = .{ .doc = &.{.{ .key = "$gt", .value = .null }} } }} },
.{ .pairs = &.{ .{ .key = "a", .value = .{ .int32 = 10 } }, .{ .key = "tags", .value = .{ .int32 = 10 } } } },
};
// First with a compound (a, b) index, then after dropping it — and the
// _id fast path is exercised by the _id filters in both runs.
try dispatch_create_index(&tdb, io, "eq", .{ .doc = &.{
.{ .key = "key", .value = .{ .doc = &.{
.{ .key = "a", .value = .{ .int32 = 1 } },
.{ .key = "b", .value = .{ .int32 = 1 } },
} } },
.{ .key = "name", .value = .{ .string = "a_1_b_1" } },
} });
// Run every filter through the index (the (a, b) plan plus the _id fast
// path), then drop the index and require identical results from the
// scan. The corpus's int32/int64 _id pair exercises the fast-path guard
// (numbers fall back to a scan in both runs).
var indexed_results: std.ArrayListUnmanaged(std.ArrayListUnmanaged([]u8)) = .empty;
defer {
for (indexed_results.items) |*l| free_id_list(testing.allocator, l);
indexed_results.deinit(testing.allocator);
}
for (filters) |f| {
var list: std.ArrayListUnmanaged([]u8) = .empty;
errdefer free_id_list(testing.allocator, &list);
try dispatch_find_ids(&tdb, io, "eq", f.pairs, &list);
try indexed_results.append(testing.allocator, list);
}
{
var ctx = tdb.ctx(io);
var msg = try parse_fake_msg("dropIndexes", .{ .string = "eq" }, &.{
.{ .key = "index", .value = .{ .string = "*" } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
}
var scanned: std.ArrayListUnmanaged([]u8) = .empty;
defer free_id_list(testing.allocator, &scanned);
for (filters, 0..) |f, fi| {
clear_id_list(testing.allocator, &scanned);
try dispatch_find_ids(&tdb, io, "eq", f.pairs, &scanned);
const indexed = indexed_results.items[fi];
try testing.expectEqual(scanned.items.len, indexed.items.len);
for (scanned.items, indexed.items) |a, b| try testing.expectEqualSlices(u8, a, b);
}
// Same corpus with a sparse (a, b) index: the sparse/null bail keeps
// {a: null} and null-range filters correct.
try dispatch_create_index(&tdb, io, "eq", .{ .doc = &.{
.{ .key = "key", .value = .{ .doc = &.{
.{ .key = "a", .value = .{ .int32 = 1 } },
.{ .key = "b", .value = .{ .int32 = 1 } },
} } },
.{ .key = "name", .value = .{ .string = "a_1_b_1_sparse" } },
.{ .key = "sparse", .value = .{ .bool = true } },
} });
for (indexed_results.items) |*l| free_id_list(testing.allocator, l);
indexed_results.clearRetainingCapacity();
for (filters) |f| {
var list: std.ArrayListUnmanaged([]u8) = .empty;
errdefer free_id_list(testing.allocator, &list);
try dispatch_find_ids(&tdb, io, "eq", f.pairs, &list);
try indexed_results.append(testing.allocator, list);
}
{
var ctx = tdb.ctx(io);
var msg = try parse_fake_msg("dropIndexes", .{ .string = "eq" }, &.{
.{ .key = "index", .value = .{ .string = "*" } },
});
defer msg.deinit();
var reply = wire.Reply.init(testing.allocator);
defer reply.deinit();
try dispatch(&ctx, &msg, &reply);
}
for (filters, 0..) |f, fi| {
clear_id_list(testing.allocator, &scanned);
try dispatch_find_ids(&tdb, io, "eq", f.pairs, &scanned);
const indexed = indexed_results.items[fi];
try testing.expectEqual(scanned.items.len, indexed.items.len);
for (scanned.items, indexed.items) |a, b| try testing.expectEqualSlices(u8, a, b);
}
}