1 files changed, 93 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/rs/xhandler/chain.go b/Godeps/_workspace/src/github.com/rs/xhandler/chain.go
new file mode 100644
index 000000000..ffac67e8a
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/rs/xhandler/chain.go
@@ -0,0 +1,93 @@
+package xhandler
+
+import (
+	"net/http"
+
+	"github.com/ethereum/go-ethereum/Godeps/_workspace/src/golang.org/x/net/context"
+)
+
+// Chain is an helper to chain middleware handlers together for an easier
+// management.
+type Chain []func(next HandlerC) HandlerC
+
+// UseC appends a context-aware handler to the middleware chain.
+func (c *Chain) UseC(f func(next HandlerC) HandlerC) {
+	*c = append(*c, f)
+}
+
+// Use appends a standard http.Handler to the middleware chain without
+// lossing track of the context when inserted between two context aware handlers.
+//
+// Caveat: the f function will be called on each request so you are better to put
+// any initialization sequence outside of this function.
+func (c *Chain) Use(f func(next http.Handler) http.Handler) {
+	xf := func(next HandlerC) HandlerC {
+		return HandlerFuncC(func(ctx context.Context, w http.ResponseWriter, r *http.Request) {
+			n := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				next.ServeHTTPC(ctx, w, r)
+			})
+			f(n).ServeHTTP(w, r)
+		})
+	}
+	*c = append(*c, xf)
+}
+
+// Handler wraps the provided final handler with all the middleware appended to
+// the chain and return a new standard http.Handler instance.
+// The context.Background() context is injected automatically.
+func (c Chain) Handler(xh HandlerC) http.Handler {
+	ctx := context.Background()
+	return c.HandlerCtx(ctx, xh)
+}
+
+// HandlerFC is an helper to provide a function (HandlerFuncC) to Handler().
+//
+// HandlerFC is equivalent to:
+//  c.Handler(xhandler.HandlerFuncC(xhc))
+func (c Chain) HandlerFC(xhf HandlerFuncC) http.Handler {
+	ctx := context.Background()
+	return c.HandlerCtx(ctx, HandlerFuncC(xhf))
+}
+
+// HandlerH is an helper to provide a standard http handler (http.HandlerFunc)
+// to Handler(). Your final handler won't have access the context though.
+func (c Chain) HandlerH(h http.Handler) http.Handler {
+	ctx := context.Background()
+	return c.HandlerCtx(ctx, HandlerFuncC(func(ctx context.Context, w http.ResponseWriter, r *http.Request) {
+		h.ServeHTTP(w, r)
+	}))
+}
+
+// HandlerF is an helper to provide a standard http handler function
+// (http.HandlerFunc) to Handler(). Your final handler won't have access
+// the context though.
+func (c Chain) HandlerF(hf http.HandlerFunc) http.Handler {
+	ctx := context.Background()
+	return c.HandlerCtx(ctx, HandlerFuncC(func(ctx context.Context, w http.ResponseWriter, r *http.Request) {
+		hf(w, r)
+	}))
+}
+
+// HandlerCtx wraps the provided final handler with all the middleware appended to
+// the chain and return a new standard http.Handler instance.
+func (c Chain) HandlerCtx(ctx context.Context, xh HandlerC) http.Handler {
+	return New(ctx, c.HandlerC(xh))
+}
+
+// HandlerC wraps the provided final handler with all the middleware appended to
+// the chain and returns a HandlerC instance.
+func (c Chain) HandlerC(xh HandlerC) HandlerC {
+	for i := len(c) - 1; i >= 0; i-- {
+		xh = c[i](xh)
+	}
+	return xh
+}
+
+// HandlerCF wraps the provided final handler func with all the middleware appended to
+// the chain and returns a HandlerC instance.
+//
+// HandlerCF is equivalent to:
+//  c.HandlerC(xhandler.HandlerFuncC(xhc))
+func (c Chain) HandlerCF(xhc HandlerFuncC) HandlerC {
+	return c.HandlerC(HandlerFuncC(xhc))
+}