Break large blobs into multiple ipcs during creation.

webkit/blob/blob_storage_controller.h

Index: webkit/blob/blob_storage_controller.h
===================================================================
--- webkit/blob/blob_storage_controller.h	(revision 103169)
+++ webkit/blob/blob_storage_controller.h	(working copy)
@@ -5,9 +5,13 @@
 #ifndef WEBKIT_BLOB_BLOB_STORAGE_CONTROLLER_H_
 #define WEBKIT_BLOB_BLOB_STORAGE_CONTROLLER_H_
 
+#include <map>
+#include <string>
+
 #include "base/hash_tables.h"
 #include "base/memory/ref_counted.h"
 #include "base/process.h"
+#include "webkit/blob/blob_data.h"
 
 class GURL;
 class FilePath;
@@ -21,17 +25,18 @@
 
 namespace webkit_blob {
 
-class BlobData;
-
 // This class handles the logistics of blob Storage within the browser process.
 class BlobStorageController {
  public:
   BlobStorageController();
   ~BlobStorageController();
 
-  void RegisterBlobUrl(const GURL& url, const BlobData* blob_data);
-  void RegisterBlobUrlFrom(const GURL& url, const GURL& src_url);
-  void UnregisterBlobUrl(const GURL& url);
+  void StartBuildingBlob(const GURL& url);
+  void AppendBlobDataItem(const GURL& url, const BlobData::Item& data_item);
+  void FinishBuildingBlob(const GURL& url, const std::string& content_type);
+  void AddFinishedBlob(const GURL& url, const BlobData* blob_data);

[jianli, 2011/09/30 00:59:34]

Probably BuildBlob sounds better? This seems to be used for testing purpose.
Perhaps we should add the comment to warn this.

+  void CloneBlob(const GURL& url, const GURL& src_url);
+  void RemoveBlob(const GURL& url);
   BlobData* GetBlobDataFromUrl(const GURL& url);
 
   // If there is any blob reference in the upload data, it will get resolved
@@ -41,6 +46,9 @@
  private:
   friend class ViewBlobInternalsJob;
 
+  typedef base::hash_map<std::string, scoped_refptr<BlobData> > BlobMap;
+  typedef std::map<BlobData*, int> BlobDataUsageMap;
+
   void AppendStorageItems(BlobData* target_blob_data,
                           BlobData* src_blob_data,
                           uint64 offset,
@@ -49,9 +57,24 @@
                       const FilePath& file_path, uint64 offset, uint64 length,
                       const base::Time& expected_modification_time);
 
-  typedef base::hash_map<std::string, scoped_refptr<BlobData> > BlobMap;
+  bool RemoveFromMapHelper(BlobMap* map, const GURL& url);
+
+  void IncrementBlobDataUsage(BlobData* blob_data);
+  // Returns true if no longer in use.
+  bool DecrementBlobDataUsage(BlobData* blob_data);
+
   BlobMap blob_map_;
+  BlobMap unfinalized_blob_map_;
 
+  // Used to keep track of how much memory is being utitlized for blob data,
+  // we count only the items of TYPE_DATA which are held in memory and not
+  // items of TYPE_FILE.
+  int64 memory_usage_;
+
+  // Multiple urls can refer to the same blob data, this map keeps track of
+  // how many urls refer to a BlobData.
+  BlobDataUsageMap blob_data_usage_count_;
+
   DISALLOW_COPY_AND_ASSIGN(BlobStorageController);
 };