Aleksey Shakhmatov
6b1941fce7
Introduce the core building blocks for the httpx library: - middleware.Middleware type and Chain() composer - Error struct with sentinel errors (ErrRetryExhausted, ErrCircuitOpen, ErrNoHealthy) - internal/clock package with Clock interface and MockClock for deterministic testing
30 lines
1017 B
Go
30 lines
1017 B
Go
package middleware
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import "net/http"
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// Middleware wraps an http.RoundTripper to add behavior.
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// This is the fundamental building block of the httpx library.
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type Middleware func(http.RoundTripper) http.RoundTripper
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// Chain composes middlewares so that Chain(A, B, C)(base) == A(B(C(base))).
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// Middlewares are applied from right to left: C wraps base first, then B wraps
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// the result, then A wraps last. This means A is the outermost layer and sees
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// every request first.
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func Chain(mws ...Middleware) Middleware {
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return func(rt http.RoundTripper) http.RoundTripper {
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for i := len(mws) - 1; i >= 0; i-- {
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rt = mws[i](rt)
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}
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return rt
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}
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}
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// RoundTripperFunc is an adapter to allow the use of ordinary functions as
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// http.RoundTripper. It works exactly like http.HandlerFunc for handlers.
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type RoundTripperFunc func(*http.Request) (*http.Response, error)
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// RoundTrip implements http.RoundTripper.
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func (f RoundTripperFunc) RoundTrip(req *http.Request) (*http.Response, error) {
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return f(req)
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}
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