Disk cache: First pass to add support for sparse entries....

net/disk_cache/entry_impl.cc

Index: net/disk_cache/entry_impl.cc
===================================================================
--- net/disk_cache/entry_impl.cc	(revision 18456)
+++ net/disk_cache/entry_impl.cc	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2009 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.
 
@@ -10,8 +10,10 @@
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/disk_cache/backend_impl.h"
+#include "net/disk_cache/bitmap.h"
 #include "net/disk_cache/cache_util.h"
 #include "net/disk_cache/histogram_macros.h"
+#include "net/disk_cache/sparse_control.h"
 
 using base::Time;
 using base::TimeDelta;
@@ -91,6 +93,9 @@
 // data related to a previous cache entry because the range was not fully
 // written before).
 EntryImpl::~EntryImpl() {
+  // Save the sparse info to disk before deleting this entry.
+  sparse_.reset();
+
   if (doomed_) {
     DeleteEntryData(true);
   } else {
@@ -353,16 +358,32 @@
 
 int EntryImpl::ReadSparseData(int64 offset, net::IOBuffer* buf, int buf_len,
                               net::CompletionCallback* completion_callback) {
-  return net::ERR_CACHE_OPERATION_NOT_SUPPORTED;
+  DCHECK(node_.Data()->dirty);
+  int result = InitSparseData();
+  if (net::OK != result)
+    return result;
+
+  return sparse_->StartIO(SparseControl::kReadOperation, offset, buf, buf_len,
+                          completion_callback);
 }
 
 int EntryImpl::WriteSparseData(int64 offset, net::IOBuffer* buf, int buf_len,
                                net::CompletionCallback* completion_callback) {
-  return net::ERR_CACHE_OPERATION_NOT_SUPPORTED;
+  DCHECK(node_.Data()->dirty);
+  int result = InitSparseData();
+  if (net::OK != result)
+    return result;
+
+  return sparse_->StartIO(SparseControl::kWriteOperation, offset, buf, buf_len,
+                          completion_callback);
 }
 
 int EntryImpl::GetAvailableRange(int64 offset, int len, int64* start) {
-  return net::ERR_CACHE_OPERATION_NOT_SUPPORTED;
+  int result = InitSparseData();
+  if (net::OK != result)
+    return result;
+
+  return sparse_->GetAvailableRange(offset, len, start);
 }
 
 uint32 EntryImpl::GetHash() {
@@ -813,6 +834,17 @@
   return true;
 }
 
+int EntryImpl::InitSparseData() {
+  if (sparse_.get())
+    return net::OK;
+
+  sparse_.reset(new SparseControl(this));
+  int result = sparse_->Init();
+  if (net::OK != result)
+    sparse_.reset();
+  return result;
+}
+
 void EntryImpl::Log(const char* msg) {
   void* pointer = NULL;
   int dirty = 0;