webkit/blob/blob_storage_controller.cc - chromium - Git at Google

 // 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 "webkit/blob/blob_storage_controller.h"

 #include "base/logging.h"
 #include "googleurl/src/gurl.h"
 #include "webkit/blob/blob_data.h"

 namespace webkit_blob {

 namespace {

 // We can't use GURL directly for these hash fragment manipulations
 // since it doesn't have specific knowlege of the BlobURL format. GURL
 // treats BlobURLs as if they were PathURLs which don't support hash
 // fragments.

 bool BlobUrlHasRef(const GURL& url) {
   return url.spec().find('#') != std::string::npos;
 }

 GURL ClearBlobUrlRef(const GURL& url) {
   size_t hash_pos = url.spec().find('#');
   if (hash_pos == std::string::npos)
     return url;
   return GURL(url.spec().substr(0, hash_pos));
 }

 static const int64 kMaxMemoryUsage = 1024 * 1024 * 1024;  // 1G

 }  // namespace

 BlobStorageController::BlobStorageController()
     : memory_usage_(0) {
 }

 BlobStorageController::~BlobStorageController() {
 }

 void BlobStorageController::StartBuildingBlob(const GURL& url) {
   DCHECK(url.SchemeIs("blob"));
   DCHECK(!BlobUrlHasRef(url));
   BlobData* blob_data = new BlobData;
   unfinalized_blob_map_[url.spec()] = blob_data;
   IncrementBlobDataUsage(blob_data);
 }

 void BlobStorageController::AppendBlobDataItem(
     const GURL& url, const BlobData::Item& item) {
   DCHECK(url.SchemeIs("blob"));
   DCHECK(!BlobUrlHasRef(url));
   BlobMap::iterator found = unfinalized_blob_map_.find(url.spec());
   if (found == unfinalized_blob_map_.end())
     return;
   BlobData* target_blob_data = found->second;
   DCHECK(target_blob_data);

   memory_usage_ -= target_blob_data->GetMemoryUsage();

   // The blob data is stored in the "canonical" way. That is, it only contains a
   // list of Data and File items.
   // 1) The Data item is denoted by the raw data and the range.
   // 2) The File item is denoted by the file path, the range and the expected
   //    modification time.
   // 3) The FileSystem File item is denoted by the FileSystem URL, the range
   //    and the expected modification time.
   // All the Blob items in the passing blob data are resolved and expanded into
   // a set of Data and File items.

   DCHECK(item.length() > 0);
   switch (item.type()) {
     case BlobData::Item::TYPE_BYTES:
       DCHECK(!item.offset());
       target_blob_data->AppendData(item.bytes(), item.length());
       break;
     case BlobData::Item::TYPE_FILE:
       AppendFileItem(target_blob_data,
                      item.path(),
                      item.offset(),
                      item.length(),
                      item.expected_modification_time());
       break;
     case BlobData::Item::TYPE_FILE_FILESYSTEM:
       AppendFileSystemFileItem(target_blob_data,
                                item.url(),
                                item.offset(),
                                item.length(),
                                item.expected_modification_time());
       break;
     case BlobData::Item::TYPE_BLOB: {
       BlobData* src_blob_data = GetBlobDataFromUrl(item.url());
       DCHECK(src_blob_data);
       if (src_blob_data)
         AppendStorageItems(target_blob_data,
                            src_blob_data,
                            item.offset(),
                            item.length());
       break;
     }
     default:
       NOTREACHED();
       break;
   }

   memory_usage_ += target_blob_data->GetMemoryUsage();

   // If we're using too much memory, drop this blob.
   // TODO(michaeln): Blob memory storage does not yet spill over to disk,
   // until it does, we'll prevent memory usage over a max amount.
   if (memory_usage_ > kMaxMemoryUsage)
     RemoveBlob(url);
 }

 void BlobStorageController::FinishBuildingBlob(
     const GURL& url, const std::string& content_type) {
   DCHECK(url.SchemeIs("blob"));
   DCHECK(!BlobUrlHasRef(url));
   BlobMap::iterator found = unfinalized_blob_map_.find(url.spec());
   if (found == unfinalized_blob_map_.end())
     return;
   found->second->set_content_type(content_type);
   blob_map_[url.spec()] = found->second;
   unfinalized_blob_map_.erase(found);
 }

 void BlobStorageController::AddFinishedBlob(const GURL& url,
                                             const BlobData* data) {
   StartBuildingBlob(url);
   for (std::vector<BlobData::Item>::const_iterator iter =
            data->items().begin();
        iter != data->items().end(); ++iter) {
     AppendBlobDataItem(url, *iter);
   }
   FinishBuildingBlob(url, data->content_type());
 }

 void BlobStorageController::CloneBlob(
     const GURL& url, const GURL& src_url) {
   DCHECK(url.SchemeIs("blob"));
   DCHECK(!BlobUrlHasRef(url));

   BlobData* blob_data = GetBlobDataFromUrl(src_url);
   DCHECK(blob_data);
   if (!blob_data)
     return;

   blob_map_[url.spec()] = blob_data;
   IncrementBlobDataUsage(blob_data);
 }

 void BlobStorageController::RemoveBlob(const GURL& url) {
   DCHECK(url.SchemeIs("blob"));
   DCHECK(!BlobUrlHasRef(url));

   if (!RemoveFromMapHelper(&unfinalized_blob_map_, url))
     RemoveFromMapHelper(&blob_map_, url);
 }

 bool BlobStorageController::RemoveFromMapHelper(
     BlobMap* map, const GURL& url) {
   BlobMap::iterator found = map->find(url.spec());
   if (found == map->end())
     return false;
   if (DecrementBlobDataUsage(found->second))
     memory_usage_ -= found->second->GetMemoryUsage();
   map->erase(found);
   return true;
 }


 BlobData* BlobStorageController::GetBlobDataFromUrl(const GURL& url) {
   BlobMap::iterator found = blob_map_.find(
       BlobUrlHasRef(url) ? ClearBlobUrlRef(url).spec() : url.spec());
   return (found != blob_map_.end()) ? found->second : NULL;
 }

 void BlobStorageController::AppendStorageItems(
     BlobData* target_blob_data, BlobData* src_blob_data,
     uint64 offset, uint64 length) {
   DCHECK(target_blob_data && src_blob_data &&
          length != static_cast<uint64>(-1));

   std::vector<BlobData::Item>::const_iterator iter =
       src_blob_data->items().begin();
   if (offset) {
     for (; iter != src_blob_data->items().end(); ++iter) {
       if (offset >= iter->length())
         offset -= iter->length();
       else
         break;
     }
   }

   for (; iter != src_blob_data->items().end() && length > 0; ++iter) {
     uint64 current_length = iter->length() - offset;
     uint64 new_length = current_length > length ? length : current_length;
     if (iter->type() == BlobData::Item::TYPE_BYTES) {
       target_blob_data->AppendData(
           iter->bytes() + static_cast<size_t>(iter->offset() + offset),
           static_cast<uint32>(new_length));
     } else {
       DCHECK(iter->type() == BlobData::Item::TYPE_FILE);
       AppendFileItem(target_blob_data,
                      iter->path(),
                      iter->offset() + offset,
                      new_length,
                      iter->expected_modification_time());
     }
     length -= new_length;
     offset = 0;
   }
 }

 void BlobStorageController::AppendFileItem(
     BlobData* target_blob_data,
     const FilePath& file_path, uint64 offset, uint64 length,
     const base::Time& expected_modification_time) {
   target_blob_data->AppendFile(file_path, offset, length,
                                expected_modification_time);

   // It may be a temporary file that should be deleted when no longer needed.
   scoped_refptr<ShareableFileReference> shareable_file =
       ShareableFileReference::Get(file_path);
   if (shareable_file)
     target_blob_data->AttachShareableFileReference(shareable_file);
 }

 void BlobStorageController::AppendFileSystemFileItem(
     BlobData* target_blob_data,
     const GURL& url, uint64 offset, uint64 length,
     const base::Time& expected_modification_time) {
   target_blob_data->AppendFileSystemFile(url, offset, length,
                                          expected_modification_time);
 }

 void BlobStorageController::IncrementBlobDataUsage(BlobData* blob_data) {
   blob_data_usage_count_[blob_data] += 1;
 }

 bool BlobStorageController::DecrementBlobDataUsage(BlobData* blob_data) {
   BlobDataUsageMap::iterator found = blob_data_usage_count_.find(blob_data);
   DCHECK(found != blob_data_usage_count_.end());
   if (--(found->second))
     return false;  // Still in use
   blob_data_usage_count_.erase(found);
   return true;
 }

 }  // namespace webkit_blob
	// 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 "webkit/blob/blob_storage_controller.h"

	#include "base/logging.h"
	#include "googleurl/src/gurl.h"
	#include "webkit/blob/blob_data.h"

	namespace webkit_blob {

	namespace {

	// We can't use GURL directly for these hash fragment manipulations
	// since it doesn't have specific knowlege of the BlobURL format. GURL
	// treats BlobURLs as if they were PathURLs which don't support hash
	// fragments.

	bool BlobUrlHasRef(const GURL& url) {
	return url.spec().find('#') != std::string::npos;
	}

	GURL ClearBlobUrlRef(const GURL& url) {
	size_t hash_pos = url.spec().find('#');
	if (hash_pos == std::string::npos)
	return url;
	return GURL(url.spec().substr(0, hash_pos));
	}

	static const int64 kMaxMemoryUsage = 1024 * 1024 * 1024; // 1G

	} // namespace

	BlobStorageController::BlobStorageController()
	: memory_usage_(0) {
	}

	BlobStorageController::~BlobStorageController() {
	}

	void BlobStorageController::StartBuildingBlob(const GURL& url) {
	DCHECK(url.SchemeIs("blob"));
	DCHECK(!BlobUrlHasRef(url));
	BlobData* blob_data = new BlobData;
	unfinalized_blob_map_[url.spec()] = blob_data;
	IncrementBlobDataUsage(blob_data);
	}

	void BlobStorageController::AppendBlobDataItem(
	const GURL& url, const BlobData::Item& item) {
	DCHECK(url.SchemeIs("blob"));
	DCHECK(!BlobUrlHasRef(url));
	BlobMap::iterator found = unfinalized_blob_map_.find(url.spec());
	if (found == unfinalized_blob_map_.end())
	return;
	BlobData* target_blob_data = found->second;
	DCHECK(target_blob_data);

	memory_usage_ -= target_blob_data->GetMemoryUsage();

	// The blob data is stored in the "canonical" way. That is, it only contains a
	// list of Data and File items.
	// 1) The Data item is denoted by the raw data and the range.
	// 2) The File item is denoted by the file path, the range and the expected
	// modification time.
	// 3) The FileSystem File item is denoted by the FileSystem URL, the range
	// and the expected modification time.
	// All the Blob items in the passing blob data are resolved and expanded into
	// a set of Data and File items.

	DCHECK(item.length() > 0);
	switch (item.type()) {
	case BlobData::Item::TYPE_BYTES:
	DCHECK(!item.offset());
	target_blob_data->AppendData(item.bytes(), item.length());
	break;
	case BlobData::Item::TYPE_FILE:
	AppendFileItem(target_blob_data,
	item.path(),
	item.offset(),
	item.length(),
	item.expected_modification_time());
	break;
	case BlobData::Item::TYPE_FILE_FILESYSTEM:
	AppendFileSystemFileItem(target_blob_data,
	item.url(),
	item.offset(),
	item.length(),
	item.expected_modification_time());
	break;
	case BlobData::Item::TYPE_BLOB: {
	BlobData* src_blob_data = GetBlobDataFromUrl(item.url());
	DCHECK(src_blob_data);
	if (src_blob_data)
	AppendStorageItems(target_blob_data,
	src_blob_data,
	item.offset(),
	item.length());
	break;
	}
	default:
	NOTREACHED();
	break;
	}

	memory_usage_ += target_blob_data->GetMemoryUsage();

	// If we're using too much memory, drop this blob.
	// TODO(michaeln): Blob memory storage does not yet spill over to disk,
	// until it does, we'll prevent memory usage over a max amount.
	if (memory_usage_ > kMaxMemoryUsage)
	RemoveBlob(url);
	}

	void BlobStorageController::FinishBuildingBlob(
	const GURL& url, const std::string& content_type) {
	DCHECK(url.SchemeIs("blob"));
	DCHECK(!BlobUrlHasRef(url));
	BlobMap::iterator found = unfinalized_blob_map_.find(url.spec());
	if (found == unfinalized_blob_map_.end())
	return;
	found->second->set_content_type(content_type);
	blob_map_[url.spec()] = found->second;
	unfinalized_blob_map_.erase(found);
	}

	void BlobStorageController::AddFinishedBlob(const GURL& url,
	const BlobData* data) {
	StartBuildingBlob(url);
	for (std::vector<BlobData::Item>::const_iterator iter =
	data->items().begin();
	iter != data->items().end(); ++iter) {
	AppendBlobDataItem(url, *iter);
	}
	FinishBuildingBlob(url, data->content_type());
	}

	void BlobStorageController::CloneBlob(
	const GURL& url, const GURL& src_url) {
	DCHECK(url.SchemeIs("blob"));
	DCHECK(!BlobUrlHasRef(url));

	BlobData* blob_data = GetBlobDataFromUrl(src_url);
	DCHECK(blob_data);
	if (!blob_data)
	return;

	blob_map_[url.spec()] = blob_data;
	IncrementBlobDataUsage(blob_data);
	}

	void BlobStorageController::RemoveBlob(const GURL& url) {
	DCHECK(url.SchemeIs("blob"));
	DCHECK(!BlobUrlHasRef(url));

	if (!RemoveFromMapHelper(&unfinalized_blob_map_, url))
	RemoveFromMapHelper(&blob_map_, url);
	}

	bool BlobStorageController::RemoveFromMapHelper(
	BlobMap* map, const GURL& url) {
	BlobMap::iterator found = map->find(url.spec());
	if (found == map->end())
	return false;
	if (DecrementBlobDataUsage(found->second))
	memory_usage_ -= found->second->GetMemoryUsage();
	map->erase(found);
	return true;
	}


	BlobData* BlobStorageController::GetBlobDataFromUrl(const GURL& url) {
	BlobMap::iterator found = blob_map_.find(
	BlobUrlHasRef(url) ? ClearBlobUrlRef(url).spec() : url.spec());
	return (found != blob_map_.end()) ? found->second : NULL;
	}

	void BlobStorageController::AppendStorageItems(
	BlobData* target_blob_data, BlobData* src_blob_data,
	uint64 offset, uint64 length) {
	DCHECK(target_blob_data && src_blob_data &&
	length != static_cast<uint64>(-1));

	std::vector<BlobData::Item>::const_iterator iter =
	src_blob_data->items().begin();
	if (offset) {
	for (; iter != src_blob_data->items().end(); ++iter) {
	if (offset >= iter->length())
	offset -= iter->length();
	else
	break;
	}
	}

	for (; iter != src_blob_data->items().end() && length > 0; ++iter) {
	uint64 current_length = iter->length() - offset;
	uint64 new_length = current_length > length ? length : current_length;
	if (iter->type() == BlobData::Item::TYPE_BYTES) {
	target_blob_data->AppendData(
	iter->bytes() + static_cast<size_t>(iter->offset() + offset),
	static_cast<uint32>(new_length));
	} else {
	DCHECK(iter->type() == BlobData::Item::TYPE_FILE);
	AppendFileItem(target_blob_data,
	iter->path(),
	iter->offset() + offset,
	new_length,
	iter->expected_modification_time());
	}
	length -= new_length;
	offset = 0;
	}
	}

	void BlobStorageController::AppendFileItem(
	BlobData* target_blob_data,
	const FilePath& file_path, uint64 offset, uint64 length,
	const base::Time& expected_modification_time) {
	target_blob_data->AppendFile(file_path, offset, length,
	expected_modification_time);

	// It may be a temporary file that should be deleted when no longer needed.
	scoped_refptr<ShareableFileReference> shareable_file =
	ShareableFileReference::Get(file_path);
	if (shareable_file)
	target_blob_data->AttachShareableFileReference(shareable_file);
	}

	void BlobStorageController::AppendFileSystemFileItem(
	BlobData* target_blob_data,
	const GURL& url, uint64 offset, uint64 length,
	const base::Time& expected_modification_time) {
	target_blob_data->AppendFileSystemFile(url, offset, length,
	expected_modification_time);
	}

	void BlobStorageController::IncrementBlobDataUsage(BlobData* blob_data) {
	blob_data_usage_count_[blob_data] += 1;
	}

	bool BlobStorageController::DecrementBlobDataUsage(BlobData* blob_data) {
	BlobDataUsageMap::iterator found = blob_data_usage_count_.find(blob_data);
	DCHECK(found != blob_data_usage_count_.end());
	if (--(found->second))
	return false; // Still in use
	blob_data_usage_count_.erase(found);
	return true;
	}

	} // namespace webkit_blob