From 1a57267a17c2fc17fb6e104846fabc3e363c326c Mon Sep 17 00:00:00 2001 From: Emile Date: Fri, 16 Aug 2024 19:50:26 +0200 Subject: initial commit --- .../felixge/httpsnoop/capture_metrics.go | 86 ++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 vendor/github.com/felixge/httpsnoop/capture_metrics.go (limited to 'vendor/github.com/felixge/httpsnoop/capture_metrics.go') diff --git a/vendor/github.com/felixge/httpsnoop/capture_metrics.go b/vendor/github.com/felixge/httpsnoop/capture_metrics.go new file mode 100644 index 0000000..b77cc7c --- /dev/null +++ b/vendor/github.com/felixge/httpsnoop/capture_metrics.go @@ -0,0 +1,86 @@ +package httpsnoop + +import ( + "io" + "net/http" + "time" +) + +// Metrics holds metrics captured from CaptureMetrics. +type Metrics struct { + // Code is the first http response code passed to the WriteHeader func of + // the ResponseWriter. If no such call is made, a default code of 200 is + // assumed instead. + Code int + // Duration is the time it took to execute the handler. + Duration time.Duration + // Written is the number of bytes successfully written by the Write or + // ReadFrom function of the ResponseWriter. ResponseWriters may also write + // data to their underlaying connection directly (e.g. headers), but those + // are not tracked. Therefor the number of Written bytes will usually match + // the size of the response body. + Written int64 +} + +// CaptureMetrics wraps the given hnd, executes it with the given w and r, and +// returns the metrics it captured from it. +func CaptureMetrics(hnd http.Handler, w http.ResponseWriter, r *http.Request) Metrics { + return CaptureMetricsFn(w, func(ww http.ResponseWriter) { + hnd.ServeHTTP(ww, r) + }) +} + +// CaptureMetricsFn wraps w and calls fn with the wrapped w and returns the +// resulting metrics. This is very similar to CaptureMetrics (which is just +// sugar on top of this func), but is a more usable interface if your +// application doesn't use the Go http.Handler interface. +func CaptureMetricsFn(w http.ResponseWriter, fn func(http.ResponseWriter)) Metrics { + m := Metrics{Code: http.StatusOK} + m.CaptureMetrics(w, fn) + return m +} + +// CaptureMetrics wraps w and calls fn with the wrapped w and updates +// Metrics m with the resulting metrics. This is similar to CaptureMetricsFn, +// but allows one to customize starting Metrics object. +func (m *Metrics) CaptureMetrics(w http.ResponseWriter, fn func(http.ResponseWriter)) { + var ( + start = time.Now() + headerWritten bool + hooks = Hooks{ + WriteHeader: func(next WriteHeaderFunc) WriteHeaderFunc { + return func(code int) { + next(code) + + if !headerWritten { + m.Code = code + headerWritten = true + } + } + }, + + Write: func(next WriteFunc) WriteFunc { + return func(p []byte) (int, error) { + n, err := next(p) + + m.Written += int64(n) + headerWritten = true + return n, err + } + }, + + ReadFrom: func(next ReadFromFunc) ReadFromFunc { + return func(src io.Reader) (int64, error) { + n, err := next(src) + + headerWritten = true + m.Written += n + return n, err + } + }, + } + ) + + fn(Wrap(w, hooks)) + m.Duration += time.Since(start) +} -- cgit 1.4.1