Dynamic Configuration Refactoring

old/middlewares/accesslog/save_backend.go

@@ -0,0 +1,64 @@
+package accesslog
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/urfave/negroni"
+	"github.com/vulcand/oxy/utils"
+)
+
+// SaveBackend sends the backend name to the logger.
+// These are always used with a corresponding SaveFrontend handler.
+type SaveBackend struct {
+	next        http.Handler
+	backendName string
+}
+
+// NewSaveBackend creates a SaveBackend handler.
+func NewSaveBackend(next http.Handler, backendName string) http.Handler {
+	return &SaveBackend{next, backendName}
+}
+
+func (sb *SaveBackend) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
+	serveSaveBackend(rw, r, sb.backendName, func(crw *captureResponseWriter) {
+		sb.next.ServeHTTP(crw, r)
+	})
+}
+
+// SaveNegroniBackend sends the backend name to the logger.
+type SaveNegroniBackend struct {
+	next        negroni.Handler
+	backendName string
+}
+
+// NewSaveNegroniBackend creates a SaveBackend handler.
+func NewSaveNegroniBackend(next negroni.Handler, backendName string) negroni.Handler {
+	return &SaveNegroniBackend{next, backendName}
+}
+
+func (sb *SaveNegroniBackend) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+	serveSaveBackend(rw, r, sb.backendName, func(crw *captureResponseWriter) {
+		sb.next.ServeHTTP(crw, r, next)
+	})
+}
+
+func serveSaveBackend(rw http.ResponseWriter, r *http.Request, backendName string, apply func(*captureResponseWriter)) {
+	table := GetLogDataTable(r)
+	table.Core[BackendName] = backendName
+	table.Core[BackendURL] = r.URL // note that this is *not* the original incoming URL
+	table.Core[BackendAddr] = r.URL.Host
+
+	crw := &captureResponseWriter{rw: rw}
+	start := time.Now().UTC()
+
+	apply(crw)
+
+	// use UTC to handle switchover of daylight saving correctly
+	table.Core[OriginDuration] = time.Now().UTC().Sub(start)
+	table.Core[OriginStatus] = crw.Status()
+	// make copy of headers so we can ensure there is no subsequent mutation during response processing
+	table.OriginResponse = make(http.Header)
+	utils.CopyHeaders(table.OriginResponse, crw.Header())
+	table.Core[OriginContentSize] = crw.Size()
+}