Avoid fragmenting the heap too much while reconstructing the index.

net/disk_cache/simple/simple_index_file.h

Index: net/disk_cache/simple/simple_index_file.h
diff --git a/net/disk_cache/simple/simple_index_file.h b/net/disk_cache/simple/simple_index_file.h
index b536df9a1e72cbaaa8a32f01ef33e82fa6f915d3..3c33de3f5ad0509f20b93872494f4b2a00aa1e88 100644
--- a/net/disk_cache/simple/simple_index_file.h
+++ b/net/disk_cache/simple/simple_index_file.h
@@ -97,6 +97,9 @@ class NET_EXPORT_PRIVATE SimpleIndexFile {
  private:
   friend class WrappedSimpleIndexFile;
 
+  // Used for cache directory traversal.
+  typedef base::Callback<void (const base::FilePath&)> EntryFileCallback;
+
   // When loading the entries from disk, add this many extra hash buckets to
   // prevent reallocation on the IO thread when merging in new live entries.
   static const int kExtraSizeForMerge = 512;
@@ -120,9 +123,19 @@ class NET_EXPORT_PRIVATE SimpleIndexFile {
 
   // Given the contents of an index file |data| of length |data_len|, returns
   // the corresponding EntrySet. Returns NULL on error.
-  static void Deserialize(const char* data, int data_len,
+  static void Deserialize(const char* data,
+                          int data_len,

[gavinp, 2013/08/21 15:31:58]

Nit: don't do this change. It's acceptable for closely related parameters to be
on the same line.

[Philippe, 2013/08/21 15:37:50]

Done.

                           SimpleIndexLoadResult* out_result);
 
+  // Implemented either in simple_index_file_posix.cc or
+  // simple_index_file_win.cc. base::FileEnumerator turned out to be very
+  // expensive in terms of memory usage therefore it's used only on non-POSIX
+  // environments for convenience (for now). Returns whether the traversal
+  // succeeded.
+  static bool TraverseCacheDirectory(
+      const base::FilePath& cache_path,
+      const EntryFileCallback& entry_file_callback);
+
   // Scan the index directory for entries, returning an EntrySet of all entries
   // found.
   static void SyncRestoreFromDisk(const base::FilePath& cache_directory,
@@ -144,9 +157,6 @@ class NET_EXPORT_PRIVATE SimpleIndexFile {
   const base::FilePath index_file_;
   const base::FilePath temp_index_file_;
 
-  static const char kIndexFileName[];
-  static const char kTempIndexFileName[];
-
   DISALLOW_COPY_AND_ASSIGN(SimpleIndexFile);
 };