gdata: Support mounting archive files in GData cache.

chrome/browser/chromeos/gdata/gdata_util.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/chromeos/gdata/gdata_util.h"
 
 #include <string>
 #include <vector>
 #include <utility>
 
@@ skipping 203 matching lines @@
       kReadOnlyFilePermissions));
   // TODO(tbarzic): When we start supporting openFile operation, we may have to
   // change permission for localy modified files to match handler's permissions.
   cache_paths->push_back(std::make_pair(
       file_system->GetCacheFilePath(resource_id, file_md5,
           GDataRootDirectory::CACHE_TYPE_PERSISTENT,
           GDataFileSystem::CACHED_FILE_LOCALLY_MODIFIED),
      kReadOnlyFilePermissions));
   cache_paths->push_back(std::make_pair(
       file_system->GetCacheFilePath(resource_id, file_md5,
+          GDataRootDirectory::CACHE_TYPE_PERSISTENT,
+          GDataFileSystem::CACHED_FILE_MOUNTED),
+     kReadOnlyFilePermissions));
+  cache_paths->push_back(std::make_pair(
+      file_system->GetCacheFilePath(resource_id, file_md5,
           GDataRootDirectory::CACHE_TYPE_TMP,
           GDataFileSystem::CACHED_FILE_FROM_SERVER),
       kReadOnlyFilePermissions));
 
 }
 
 void SetPermissionsForGDataCacheFiles(Profile* profile,
                                       int pid,
                                       const FilePath& path) {
   std::vector<std::pair<FilePath, int> > cache_paths;
@@ skipping 18 matching lines @@
 
   // Disable gdata if preference is set.  This can happen with commandline flag
   // --disable-gdata or enterprise policy, or probably with user settings too
   // in the future.
   if (profile->GetPrefs()->GetBoolean(prefs::kDisableGData))
     return false;
 
   return true;
 }
 
+void ParseCacheFilePath(const FilePath& path,
+                        std::string* resource_id,
+                        std::string* md5,
+                        std::string* extra_extension) {
+  DCHECK(resource_id);
+  DCHECK(md5);
+  DCHECK(extra_extension);
+
+  // Extract up to two extensions from the right.
+  FilePath base_name = path.BaseName();
+  const int kNumExtensionsToExtract = 2;
+  std::vector<FilePath::StringType> extensions;
+  for (int i = 0; i < kNumExtensionsToExtract; ++i) {
+    FilePath::StringType extension = base_name.Extension();
+    if (!extension.empty()) {
+      // FilePath::Extension returns ".", so strip it.
+      extension = GDataEntry::UnescapeUtf8FileName(extension.substr(1));
+      base_name = base_name.RemoveExtension();
+      extensions.push_back(extension);
+    } else {
+      break;
+    }
+  }
+
+  // The base_name here is already stripped of extensions in the loop above.
+  *resource_id = GDataEntry::UnescapeUtf8FileName(base_name.value());
+
+  // Assign the extracted extensions to md5 and extra_extension.
+  switch (extensions.size()) {

[tbarzic, 2012/04/23 18:03:22]

What do you think about this:
size_t extension_count = extensions.size();
if (extension_count > 0)
  *md5 = extensions[extension_count -1];
if (extension_count > 1)
  *extra_extension = extensions[extension_count - 2]; 

[hshi, 2012/04/23 20:45:47]

Done.

+    case 0:
+      // Only resource_id is present: "<resource_id>".
+      *md5 = std::string();
+      *extra_extension = std::string();
+      break;
+    case 1:
+      // Both resource_id and md5 are present: "<resource_id>.<md5>".
+      *md5 = extensions[0];
+      *extra_extension = std::string();
+      break;
+    case 2:
+      // All three parts are present: ""<resource_id>.<md5>.<extra_extension>".
+      *md5 = extensions[1];
+      *extra_extension = extensions[0];
+      break;
+    default:
+      NOTREACHED();
+  }
+}
+
 }  // namespace util
 }  // namespace gdata