Add a package listing API to cipd.

go/src/infra/tools/cipd/client.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 cipd implements client side of Chrome Infra Package Deployer.
 
 TODO: write more.
 
 Binary package file format (in free form representation):
@@ skipping 149 matching lines @@
         // processed" responses.
         AttachTagsWhenReady(pin common.Pin, tags []string) error
 
         // FetchInstance downloads package instance file from the repository.
         FetchInstance(pin common.Pin, output io.WriteSeeker) error
 
         // FetchAndDeployInstance fetches the package instance and deploys it into
         // the site root. It doesn't check whether the instance is already deployed.
         FetchAndDeployInstance(pin common.Pin) error
 
+        // ListPackages returns a list of strings of package names.
+        ListPackages(prefix string) ([]string, error)
+
         // ProcessEnsureFile parses text file that describes what should be installed
         // by EnsurePackages function. It is a text file where each line has a form:
         // <package name> <desired version>. Whitespaces are ignored. Lines that start
         // with '#' are ignored. Version can be specified as instance ID, tag or ref.
         // Will resolve tags and refs to concrete instance IDs by calling the backend.
         ProcessEnsureFile(r io.Reader) ([]common.Pin, error)
 
         // EnsurePackages is high-level interface for installation, removal and update
         // of packages inside the installation site root. Given a description of
         // what packages (and versions) should be installed it will do all necessary
@@ skipping 91 matching lines @@
 }
 
 func (client *clientImpl) FetchACL(packagePath string) ([]PackageACL, error) {
         return client.remote.fetchACL(packagePath)
 }
 
 func (client *clientImpl) ModifyACL(packagePath string, changes []PackageACLChange) error {
         return client.remote.modifyACL(packagePath, changes)
 }
 
+func (client *clientImpl) ListPackages(prefix string) ([]string, error) {
+        return client.remote.listPackages(prefix)
+}
+
 func (client *clientImpl) UploadToCAS(sha1 string, data io.ReadSeeker, session *UploadSession) error {
         // Open new upload session if an existing is not provided.
         var err error
         if session == nil {
                 client.Logger.Infof("cipd: uploading %s: initiating", sha1)
                 session, err = client.remote.initiateUpload(sha1)
                 if err != nil {
                         client.Logger.Warningf("cipd: can't upload %s - %s", sha1, err)
                         return err
                 }
@@ skipping 298 matching lines @@
         modifyACL(packagePath string, changes []PackageACLChange) error
 
         resolveVersion(packageName, version string) (common.Pin, error)
 
         initiateUpload(sha1 string) (*UploadSession, error)
         finalizeUpload(sessionID string) (bool, error)
         registerInstance(pin common.Pin) (*registerInstanceResponse, error)
 
         attachTags(pin common.Pin, tags []string) error
         fetchInstance(pin common.Pin) (*fetchInstanceResponse, error)
+
+        listPackages(prefix string) ([]string, error)
 }
 
 type storage interface {
         upload(url string, data io.ReadSeeker) error
         download(url string, output io.WriteSeeker) error
 }
 
 type registerInstanceResponse struct {
         uploadSession     *UploadSession
         alreadyRegistered bool
@@ skipping 36 matching lines @@
 }
 
 // buildInstanceIDMap builds mapping {package name -> instance ID}.
 func buildInstanceIDMap(pins []common.Pin) map[string]string {
         out := map[string]string{}
         for _, p := range pins {
                 out[p.PackageName] = p.InstanceID
         }
         return out
 }