From 38ee83e45b4de7edf89bf9f0ef629eb4c6ad0fa8 Mon Sep 17 00:00:00 2001 From: Christopher Speller Date: Thu, 12 May 2016 23:56:07 -0400 Subject: Moving to glide --- vendor/github.com/golang/groupcache/http.go | 227 ++++++++++++++++++++++++++++ 1 file changed, 227 insertions(+) create mode 100644 vendor/github.com/golang/groupcache/http.go (limited to 'vendor/github.com/golang/groupcache/http.go') diff --git a/vendor/github.com/golang/groupcache/http.go b/vendor/github.com/golang/groupcache/http.go new file mode 100644 index 000000000..14eb345a8 --- /dev/null +++ b/vendor/github.com/golang/groupcache/http.go @@ -0,0 +1,227 @@ +/* +Copyright 2013 Google Inc. + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +*/ + +package groupcache + +import ( + "bytes" + "fmt" + "io" + "net/http" + "net/url" + "strings" + "sync" + + "github.com/golang/groupcache/consistenthash" + pb "github.com/golang/groupcache/groupcachepb" + "github.com/golang/protobuf/proto" +) + +const defaultBasePath = "/_groupcache/" + +const defaultReplicas = 50 + +// HTTPPool implements PeerPicker for a pool of HTTP peers. +type HTTPPool struct { + // Context optionally specifies a context for the server to use when it + // receives a request. + // If nil, the server uses a nil Context. + Context func(*http.Request) Context + + // Transport optionally specifies an http.RoundTripper for the client + // to use when it makes a request. + // If nil, the client uses http.DefaultTransport. + Transport func(Context) http.RoundTripper + + // this peer's base URL, e.g. "https://example.net:8000" + self string + + // opts specifies the options. + opts HTTPPoolOptions + + mu sync.Mutex // guards peers and httpGetters + peers *consistenthash.Map + httpGetters map[string]*httpGetter // keyed by e.g. "http://10.0.0.2:8008" +} + +// HTTPPoolOptions are the configurations of a HTTPPool. +type HTTPPoolOptions struct { + // BasePath specifies the HTTP path that will serve groupcache requests. + // If blank, it defaults to "/_groupcache/". + BasePath string + + // Replicas specifies the number of key replicas on the consistent hash. + // If blank, it defaults to 50. + Replicas int + + // HashFn specifies the hash function of the consistent hash. + // If blank, it defaults to crc32.ChecksumIEEE. + HashFn consistenthash.Hash +} + +// NewHTTPPool initializes an HTTP pool of peers, and registers itself as a PeerPicker. +// For convenience, it also registers itself as an http.Handler with http.DefaultServeMux. +// The self argument be a valid base URL that points to the current server, +// for example "http://example.net:8000". +func NewHTTPPool(self string) *HTTPPool { + p := NewHTTPPoolOpts(self, nil) + http.Handle(p.opts.BasePath, p) + return p +} + +var httpPoolMade bool + +// NewHTTPPoolOpts initializes an HTTP pool of peers with the given options. +// Unlike NewHTTPPool, this function does not register the created pool as an HTTP handler. +// The returned *HTTPPool implements http.Handler and must be registered using http.Handle. +func NewHTTPPoolOpts(self string, o *HTTPPoolOptions) *HTTPPool { + if httpPoolMade { + panic("groupcache: NewHTTPPool must be called only once") + } + httpPoolMade = true + + p := &HTTPPool{ + self: self, + httpGetters: make(map[string]*httpGetter), + } + if o != nil { + p.opts = *o + } + if p.opts.BasePath == "" { + p.opts.BasePath = defaultBasePath + } + if p.opts.Replicas == 0 { + p.opts.Replicas = defaultReplicas + } + p.peers = consistenthash.New(p.opts.Replicas, p.opts.HashFn) + + RegisterPeerPicker(func() PeerPicker { return p }) + return p +} + +// Set updates the pool's list of peers. +// Each peer value should be a valid base URL, +// for example "http://example.net:8000". +func (p *HTTPPool) Set(peers ...string) { + p.mu.Lock() + defer p.mu.Unlock() + p.peers = consistenthash.New(p.opts.Replicas, p.opts.HashFn) + p.peers.Add(peers...) + p.httpGetters = make(map[string]*httpGetter, len(peers)) + for _, peer := range peers { + p.httpGetters[peer] = &httpGetter{transport: p.Transport, baseURL: peer + p.opts.BasePath} + } +} + +func (p *HTTPPool) PickPeer(key string) (ProtoGetter, bool) { + p.mu.Lock() + defer p.mu.Unlock() + if p.peers.IsEmpty() { + return nil, false + } + if peer := p.peers.Get(key); peer != p.self { + return p.httpGetters[peer], true + } + return nil, false +} + +func (p *HTTPPool) ServeHTTP(w http.ResponseWriter, r *http.Request) { + // Parse request. + if !strings.HasPrefix(r.URL.Path, p.opts.BasePath) { + panic("HTTPPool serving unexpected path: " + r.URL.Path) + } + parts := strings.SplitN(r.URL.Path[len(p.opts.BasePath):], "/", 2) + if len(parts) != 2 { + http.Error(w, "bad request", http.StatusBadRequest) + return + } + groupName := parts[0] + key := parts[1] + + // Fetch the value for this group/key. + group := GetGroup(groupName) + if group == nil { + http.Error(w, "no such group: "+groupName, http.StatusNotFound) + return + } + var ctx Context + if p.Context != nil { + ctx = p.Context(r) + } + + group.Stats.ServerRequests.Add(1) + var value []byte + err := group.Get(ctx, key, AllocatingByteSliceSink(&value)) + if err != nil { + http.Error(w, err.Error(), http.StatusInternalServerError) + return + } + + // Write the value to the response body as a proto message. + body, err := proto.Marshal(&pb.GetResponse{Value: value}) + if err != nil { + http.Error(w, err.Error(), http.StatusInternalServerError) + return + } + w.Header().Set("Content-Type", "application/x-protobuf") + w.Write(body) +} + +type httpGetter struct { + transport func(Context) http.RoundTripper + baseURL string +} + +var bufferPool = sync.Pool{ + New: func() interface{} { return new(bytes.Buffer) }, +} + +func (h *httpGetter) Get(context Context, in *pb.GetRequest, out *pb.GetResponse) error { + u := fmt.Sprintf( + "%v%v/%v", + h.baseURL, + url.QueryEscape(in.GetGroup()), + url.QueryEscape(in.GetKey()), + ) + req, err := http.NewRequest("GET", u, nil) + if err != nil { + return err + } + tr := http.DefaultTransport + if h.transport != nil { + tr = h.transport(context) + } + res, err := tr.RoundTrip(req) + if err != nil { + return err + } + defer res.Body.Close() + if res.StatusCode != http.StatusOK { + return fmt.Errorf("server returned: %v", res.Status) + } + b := bufferPool.Get().(*bytes.Buffer) + b.Reset() + defer bufferPool.Put(b) + _, err = io.Copy(b, res.Body) + if err != nil { + return fmt.Errorf("reading response body: %v", err) + } + err = proto.Unmarshal(b.Bytes(), out) + if err != nil { + return fmt.Errorf("decoding response body: %v", err) + } + return nil +} -- cgit v1.2.3-1-g7c22