1 files changed, 94 insertions, 0 deletions
diff --git a/vendor/github.com/alexedwards/stack/stack.go b/vendor/github.com/alexedwards/stack/stack.go
new file mode 100644
index 0000000..47c42b2
--- /dev/null
+++ b/vendor/github.com/alexedwards/stack/stack.go
@@ -0,0 +1,94 @@
+package stack
+
+import "net/http"
+
+type chainHandler func(*Context) http.Handler
+type chainMiddleware func(*Context, http.Handler) http.Handler
+
+type Chain struct {
+	mws []chainMiddleware
+	h   chainHandler
+}
+
+func New(mws ...chainMiddleware) Chain {
+	return Chain{mws: mws}
+}
+
+func (c Chain) Append(mws ...chainMiddleware) Chain {
+	newMws := make([]chainMiddleware, len(c.mws)+len(mws))
+	copy(newMws[:len(c.mws)], c.mws)
+	copy(newMws[len(c.mws):], mws)
+	c.mws = newMws
+	return c
+}
+
+func (c Chain) Then(chf func(ctx *Context, w http.ResponseWriter, r *http.Request)) HandlerChain {
+	c.h = adaptContextHandlerFunc(chf)
+	return newHandlerChain(c)
+}
+
+func (c Chain) ThenHandler(h http.Handler) HandlerChain {
+	c.h = adaptHandler(h)
+	return newHandlerChain(c)
+}
+
+func (c Chain) ThenHandlerFunc(fn func(http.ResponseWriter, *http.Request)) HandlerChain {
+	c.h = adaptHandlerFunc(fn)
+	return newHandlerChain(c)
+}
+
+type HandlerChain struct {
+	context *Context
+	Chain
+}
+
+func newHandlerChain(c Chain) HandlerChain {
+	return HandlerChain{context: NewContext(), Chain: c}
+}
+
+func (hc HandlerChain) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	// Always take a copy of context (i.e. pointing to a brand new memory location)
+	ctx := hc.context.copy()
+
+	final := hc.h(ctx)
+	for i := len(hc.mws) - 1; i >= 0; i-- {
+		final = hc.mws[i](ctx, final)
+	}
+	final.ServeHTTP(w, r)
+}
+
+func Inject(hc HandlerChain, key string, val interface{}) HandlerChain {
+	hc.context = hc.context.copy().Put(key, val)
+	return hc
+}
+
+// Adapt third party middleware with the signature
+// func(http.Handler) http.Handler into chainMiddleware
+func Adapt(fn func(http.Handler) http.Handler) chainMiddleware {
+	return func(ctx *Context, h http.Handler) http.Handler {
+		return fn(h)
+	}
+}
+
+// Adapt http.Handler into a chainHandler
+func adaptHandler(h http.Handler) chainHandler {
+	return func(ctx *Context) http.Handler {
+		return h
+	}
+}
+
+// Adapt a function with the signature
+// func(http.ResponseWriter, *http.Request) into a chainHandler
+func adaptHandlerFunc(fn func(w http.ResponseWriter, r *http.Request)) chainHandler {
+	return adaptHandler(http.HandlerFunc(fn))
+}
+
+// Adapt a function with the signature
+// func(Context, http.ResponseWriter, *http.Request) into a chainHandler
+func adaptContextHandlerFunc(fn func(ctx *Context, w http.ResponseWriter, r *http.Request)) chainHandler {
+	return func(ctx *Context) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			fn(ctx, w, r)
+		})
+	}
+}