register/handlers: remove context manager

Signed-off-by: Stephen J Day <stephen.day@docker.com>

registry/handlers/context.go

@@ -3,7 +3,6 @@ package handlers
 import (
 	"fmt"
 	"net/http"
-	"sync"
 
 	"github.com/docker/distribution"
 	ctxu "github.com/docker/distribution/context"
@@ -91,62 +90,3 @@ func getUserName(ctx context.Context, r *http.Request) string {
 
 	return username
 }
-
-// contextManager allows us to associate net/context.Context instances with a
-// request, based on the memory identity of http.Request. This prepares http-
-// level context, which is not application specific. If this is called,
-// (*contextManager).release must be called on the context when the request is
-// completed.
-//
-// Providing this circumvents a lot of necessity for dispatchers with the
-// benefit of instantiating the request context much earlier.
-//
-// TODO(stevvooe): Consider making this facility a part of the context package.
-type contextManager struct {
-	contexts map[*http.Request]context.Context
-	mu       sync.Mutex
-}
-
-// defaultContextManager is just a global instance to register request contexts.
-var defaultContextManager = newContextManager()
-
-func newContextManager() *contextManager {
-	return &contextManager{
-		contexts: make(map[*http.Request]context.Context),
-	}
-}
-
-// context either returns a new context or looks it up in the manager.
-func (cm *contextManager) context(parent context.Context, w http.ResponseWriter, r *http.Request) context.Context {
-	cm.mu.Lock()
-	defer cm.mu.Unlock()
-
-	ctx, ok := cm.contexts[r]
-	if ok {
-		return ctx
-	}
-
-	if parent == nil {
-		parent = ctxu.Background()
-	}
-
-	ctx = ctxu.WithRequest(parent, r)
-	ctx, w = ctxu.WithResponseWriter(ctx, w)
-	ctx = ctxu.WithLogger(ctx, ctxu.GetRequestLogger(ctx))
-	cm.contexts[r] = ctx
-
-	return ctx
-}
-
-// releases frees any associated with resources from request.
-func (cm *contextManager) release(ctx context.Context) {
-	cm.mu.Lock()
-	defer cm.mu.Unlock()
-
-	r, err := ctxu.GetRequest(ctx)
-	if err != nil {
-		ctxu.GetLogger(ctx).Errorf("no request found in context during release")
-		return
-	}
-	delete(cm.contexts, r)
-}