Create packages client/internal/ retry and lhttp.

client/isolatedclient/isolatedclient.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package isolatedclient
 
 import (
+        "errors"
         "io"
         "io/ioutil"
         "net/http"
         "strconv"
+        "strings"
 
-        "github.com/luci/luci-go/client/internal/common"
+        "github.com/luci/luci-go/client/internal/lhttp"
+        "github.com/luci/luci-go/client/internal/retry"
         "github.com/luci/luci-go/client/internal/tracer"
         "github.com/luci/luci-go/common/isolated"
 )
 
 // IsolateServer is the low-level client interface to interact with an Isolate
 // server.
 type IsolateServer interface {
         ServerCapabilities() (*isolated.ServerCapabilities, error)
         // Contains looks up cache presence on the server of multiple items.
         //
         // The returned list is in the same order as 'items', with entries nil for
         // items that were present.
         Contains(items []*isolated.DigestItem) ([]*PushState, error)
         Push(state *PushState, src io.Reader) error
 }
 
 // PushState is per-item state passed from IsolateServer.Contains() to
 // IsolateServer.Push().
 //
 // Its content is implementation specific.
 type PushState struct {
         status    isolated.PreuploadStatus
         size      int64
         uploaded  bool
         finalized bool
 }
 
 // New returns a new IsolateServer client.
-func New(url, namespace string) IsolateServer {
+func New(host, namespace string) IsolateServer {
         i := &isolateServer{
-                url:       url,
+                url:       strings.TrimRight(host, "/"),
                 namespace: namespace,
         }
-        tracer.NewTID(i, nil, url)
+        tracer.NewTID(i, nil, i.url)
         return i
 }
 
 // Private details.
 
 type isolateServer struct {
         url       string
         namespace string
 }
 
+func (i *isolateServer) postJSON(resource string, in, out interface{}) error {
+        if len(resource) == 0 || resource[0] != '/' {
+                return errors.New("resource must start with '/'")
+        }
+        return lhttp.PostJSON(retry.Default, http.DefaultClient, i.url+resource, in, out)

[Vadim Sh., 2015/05/13 21:54:48]

let's put http.Client and retry.Config into isolateServer instead of using
defaults here. Same for Swarming below.

+}
+
 func (i *isolateServer) ServerCapabilities() (*isolated.ServerCapabilities, error) {
-        url := i.url + "/_ah/api/isolateservice/v1/server_details"
         out := &isolated.ServerCapabilities{}
-        if _, err := common.PostJSON(nil, url, nil, out); err != nil {
+        if err := i.postJSON("/_ah/api/isolateservice/v1/server_details", map[string]string{}, out); err != nil {
                 return nil, err
         }
         return out, nil
 }
 
 func (i *isolateServer) Contains(items []*isolated.DigestItem) (out []*PushState, err error) {
         end := tracer.Span(i, "contains", strconv.Itoa(len(items)), nil)
         defer func() { end(tracer.Args{"err": err}) }()
         in := isolated.DigestCollection{Items: items}
         in.Namespace.Namespace = i.namespace
         data := &isolated.UrlCollection{}
-        url := i.url + "/_ah/api/isolateservice/v1/preupload"
-        if _, err = common.PostJSON(nil, url, in, data); err != nil {
+        if err = i.postJSON("/_ah/api/isolateservice/v1/preupload", in, data); err != nil {
                 return nil, err
         }
         out = make([]*PushState, len(items))
         for _, e := range data.Items {
                 index := int(e.Index)
                 out[index] = &PushState{
                         status: e,
                         size:   items[index].Size,
                 }
         }
@@ skipping 13 matching lines @@
 
         // Optionally notify the server that it's done.
         if state.status.GSUploadURL != "" {
                 end := tracer.Span(i, "finalize", "finalize", nil)
                 defer func() { end(tracer.Args{"err": err}) }()
                 // TODO(vadimsh): Calculate MD5 or CRC32C sum while uploading a file and
                 // send it to isolated server. That way isolate server can verify that
                 // the data safely reached Google Storage (GS provides MD5 and CRC32C of
                 // stored files).
                 in := isolated.FinalizeRequest{state.status.UploadTicket}
-                url := i.url + "/_ah/api/isolateservice/v1/finalize_gs_upload"
-                _, err = common.PostJSON(nil, url, in, nil)
-                if err != nil {
+                if err = i.postJSON("/_ah/api/isolateservice/v1/finalize_gs_upload", in, nil); err != nil {
                         return
                 }
         }
         state.finalized = true
         return
 }
 
 func (i *isolateServer) doPush(state *PushState, src io.Reader) (err error) {
         end := tracer.Span(i, "push", strconv.FormatInt(state.size, 10), nil)
         defer func() { end(tracer.Args{"err": err}) }()
@@ skipping 11 matching lines @@
         }()
         defer func() {
                 err4 := <-c
                 if err == nil {
                         err = err4
                 }
         }()
 
         // DB upload.
         if state.status.GSUploadURL == "" {
-                url := i.url + "/_ah/api/isolateservice/v1/store_inline"
                 content, err2 := ioutil.ReadAll(reader)
                 if err2 != nil {
                         return err2
                 }
                 in := &isolated.StorageRequest{state.status.UploadTicket, content}
-                _, err = common.PostJSON(nil, url, in, nil)
-                return
+                return i.postJSON("/_ah/api/isolateservice/v1/store_inline", in, nil)
         }
 
         // Upload to GCS.
         client := &http.Client{}
         request, err5 := http.NewRequest("PUT", state.status.GSUploadURL, reader)
         if err5 != nil {
                 return err5
         }
         request.Header.Set("Content-Type", "application/octet-stream")
         // TODO(maruel): For relatively small file, set request.ContentLength so the
         // TCP connection can be reused.
         resp, err6 := client.Do(request)
         if err6 != nil {
                 return err6
         }
         _, err = io.Copy(ioutil.Discard, resp.Body)
         resp.Body.Close()
         return
 }