gdata: Add comments about the threading model of GDataCache
Along the way, make |cache_paths_| const to make it clear that
they won't change.
BUG=131756
TEST=no change in behaviors
Review URL: https://chromiumcodereview.appspot.com/10537161
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@142082 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/chromeos/gdata/gdata_cache.h b/chrome/browser/chromeos/gdata/gdata_cache.h
index cde682a..63f37678 100644
--- a/chrome/browser/chromeos/gdata/gdata_cache.h
+++ b/chrome/browser/chromeos/gdata/gdata_cache.h
@@ -17,10 +17,16 @@
namespace gdata {
+// GDataCache is used to maintain cache states of GDataFileSystem.
+//
+// All non-static public member functions, unless mentioned otherwise (see
+// GetCacheFilePath() for example), should be called from the sequenced
+// worker pool with the sequence token set by CreateGDataCache(). This
+// threading model is enforced by AssertOnSequencedWorkerPool().
class GDataCache {
public:
// Enum defining GCache subdirectory location.
- // This indexes into |GDataFileSystem::cache_paths_| vector.
+ // This indexes into |GDataCache::cache_paths_| vector.
enum CacheSubDirectoryType {
CACHE_TYPE_META = 0, // Downloaded feeds.
CACHE_TYPE_PINNED, // Symlinks to files in persistent dir that are
@@ -122,9 +128,13 @@
// Returns the sub-directory under gdata cache directory for the given sub
// directory type. Example: <user_profile_dir>/GCache/v1/tmp
+ //
+ // Can be called on any thread.
FilePath GetCacheDirectoryPath(CacheSubDirectoryType sub_dir_type) const;
// Returns absolute path of the file if it were cached or to be cached.
+ //
+ // Can be called on any thread.
FilePath GetCacheFilePath(const std::string& resource_id,
const std::string& md5,
CacheSubDirectoryType sub_dir_type,
@@ -132,6 +142,8 @@
// Returns true if the given path is under gdata cache directory, i.e.
// <user_profile_dir>/GCache/v1
+ //
+ // Can be called on any thread.
bool IsUnderGDataCacheDirectory(const FilePath& path) const;
// TODO(hashimoto): Remove this method when crbug.com/131756 is fixed.
@@ -192,7 +204,7 @@
const FilePath cache_root_path_;
// Paths for all subdirectories of GCache, one for each
// GDataCache::CacheSubDirectoryType enum.
- std::vector<FilePath> cache_paths_;
+ const std::vector<FilePath> cache_paths_;
base::SequencedWorkerPool* pool_;
const base::SequencedWorkerPool::SequenceToken sequence_token_;
