storage/browser/blob/blob_storage_context.cc - chromium/src - Git at Google

 // Copyright (c) 2013 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 "storage/browser/blob/blob_storage_context.h"

 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "storage/browser/blob/blob_data_handle.h"
 #include "storage/common/blob/blob_data.h"
 #include "url/gurl.h"

 namespace storage {

 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));
 }

 // TODO(michaeln): use base::SysInfo::AmountOfPhysicalMemoryMB() in some
 // way to come up with a better limit.
 static const int64 kMaxMemoryUsage = 500 * 1024 * 1024;  // Half a gig.

 }  // namespace

 BlobStorageContext::BlobMapEntry::BlobMapEntry()
     : refcount(0), flags(0) {
 }

 BlobStorageContext::BlobMapEntry::BlobMapEntry(
     int refcount, int flags, BlobData* data)
     : refcount(refcount), flags(flags), data(data) {
 }

 BlobStorageContext::BlobMapEntry::~BlobMapEntry() {
 }

 BlobStorageContext::BlobStorageContext()
     : memory_usage_(0) {
 }

 BlobStorageContext::~BlobStorageContext() {
 }

 scoped_ptr<BlobDataHandle> BlobStorageContext::GetBlobDataFromUUID(
     const std::string& uuid) {
   scoped_ptr<BlobDataHandle> result;
   BlobMap::iterator found = blob_map_.find(uuid);
   if (found == blob_map_.end())
     return result.Pass();
   if (found->second.flags & EXCEEDED_MEMORY)
     return result.Pass();
   DCHECK(!(found->second.flags & BEING_BUILT));
   result.reset(new BlobDataHandle(
       found->second.data.get(), this, base::MessageLoopProxy::current().get()));
   return result.Pass();
 }

 scoped_ptr<BlobDataHandle> BlobStorageContext::GetBlobDataFromPublicURL(
     const GURL& url) {
   BlobURLMap::iterator found = public_blob_urls_.find(
       BlobUrlHasRef(url) ? ClearBlobUrlRef(url) : url);
   if (found == public_blob_urls_.end())
     return scoped_ptr<BlobDataHandle>();
   return GetBlobDataFromUUID(found->second);
 }

 scoped_ptr<BlobDataHandle> BlobStorageContext::AddFinishedBlob(
     const BlobData* data) {
   StartBuildingBlob(data->uuid());
   for (std::vector<BlobData::Item>::const_iterator iter =
            data->items().begin();
        iter != data->items().end(); ++iter) {
     AppendBlobDataItem(data->uuid(), *iter);
   }
   FinishBuildingBlob(data->uuid(), data->content_type());
   scoped_ptr<BlobDataHandle> handle = GetBlobDataFromUUID(data->uuid());
   DecrementBlobRefCount(data->uuid());
   return handle.Pass();
 }

 bool BlobStorageContext::RegisterPublicBlobURL(
     const GURL& blob_url, const std::string& uuid) {
   DCHECK(!BlobUrlHasRef(blob_url));
   DCHECK(IsInUse(uuid));
   DCHECK(!IsUrlRegistered(blob_url));
   if (!IsInUse(uuid) || IsUrlRegistered(blob_url))
     return false;
   IncrementBlobRefCount(uuid);
   public_blob_urls_[blob_url] = uuid;
   return true;
 }

 void BlobStorageContext::RevokePublicBlobURL(const GURL& blob_url) {
   DCHECK(!BlobUrlHasRef(blob_url));
   if (!IsUrlRegistered(blob_url))
     return;
   DecrementBlobRefCount(public_blob_urls_[blob_url]);
   public_blob_urls_.erase(blob_url);
 }

 void BlobStorageContext::StartBuildingBlob(const std::string& uuid) {
   DCHECK(!IsInUse(uuid) && !uuid.empty());
   blob_map_[uuid] = BlobMapEntry(1, BEING_BUILT, new BlobData(uuid));
 }

 void BlobStorageContext::AppendBlobDataItem(
     const std::string& uuid, const BlobData::Item& item) {
   DCHECK(IsBeingBuilt(uuid));
   BlobMap::iterator found = blob_map_.find(uuid);
   if (found == blob_map_.end())
     return;
   if (found->second.flags & EXCEEDED_MEMORY)
     return;
   BlobData* target_blob_data = found->second.data.get();
   DCHECK(target_blob_data);

   bool exceeded_memory = false;

   // The blob data is stored in the canonical way which only contains a
   // list of Data, File, and FileSystem items. Aggregated TYPE_BLOB items
   // are expanded into the primitive constituent types.
   // 1) The Data item is denoted by the raw data and length.
   // 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.
   // 4) The Blob items are expanded.
   // TODO(michaeln): Would be nice to avoid copying Data items when expanding.

   DCHECK(item.length() > 0);
   switch (item.type()) {
     case BlobData::Item::TYPE_BYTES:
       DCHECK(!item.offset());
       exceeded_memory = !AppendBytesItem(target_blob_data,
                                          item.bytes(),
                                          static_cast<int64>(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.filesystem_url(),
                                item.offset(),
                                item.length(),
                                item.expected_modification_time());
       break;
     case BlobData::Item::TYPE_BLOB: {
       scoped_ptr<BlobDataHandle> src = GetBlobDataFromUUID(item.blob_uuid());
       if (src)
         exceeded_memory = !ExpandStorageItems(target_blob_data,
                                               src->data(),
                                               item.offset(),
                                               item.length());
       break;
     }
     default:
       NOTREACHED();
       break;
   }

   // If we're using too much memory, drop this blob's data.
   // TODO(michaeln): Blob memory storage does not yet spill over to disk,
   // as a stop gap, we'll prevent memory usage over a max amount.
   if (exceeded_memory) {
     memory_usage_ -= target_blob_data->GetMemoryUsage();
     found->second.flags |= EXCEEDED_MEMORY;
     found->second.data = new BlobData(uuid);
     return;
   }
 }

 void BlobStorageContext::FinishBuildingBlob(
     const std::string& uuid, const std::string& content_type) {
   DCHECK(IsBeingBuilt(uuid));
   BlobMap::iterator found = blob_map_.find(uuid);
   if (found == blob_map_.end())
     return;
   found->second.data->set_content_type(content_type);
   found->second.flags &= ~BEING_BUILT;
 }

 void BlobStorageContext::CancelBuildingBlob(const std::string& uuid) {
   DCHECK(IsBeingBuilt(uuid));
   DecrementBlobRefCount(uuid);
 }

 void BlobStorageContext::IncrementBlobRefCount(const std::string& uuid) {
   BlobMap::iterator found = blob_map_.find(uuid);
   if (found == blob_map_.end()) {
     DCHECK(false);
     return;
   }
   ++(found->second.refcount);
 }

 void BlobStorageContext::DecrementBlobRefCount(const std::string& uuid) {
   BlobMap::iterator found = blob_map_.find(uuid);
   if (found == blob_map_.end())
     return;
   DCHECK_EQ(found->second.data->uuid(), uuid);
   if (--(found->second.refcount) == 0) {
     memory_usage_ -= found->second.data->GetMemoryUsage();
     blob_map_.erase(found);
   }
 }

 bool BlobStorageContext::ExpandStorageItems(
     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) {
       if (!AppendBytesItem(
               target_blob_data,
               iter->bytes() + static_cast<size_t>(iter->offset() + offset),
               static_cast<int64>(new_length))) {
         return false;  // exceeded memory
       }
     } else if (iter->type() == BlobData::Item::TYPE_FILE) {
       AppendFileItem(target_blob_data,
                      iter->path(),
                      iter->offset() + offset,
                      new_length,
                      iter->expected_modification_time());
     } else {
       DCHECK(iter->type() == BlobData::Item::TYPE_FILE_FILESYSTEM);
       AppendFileSystemFileItem(target_blob_data,
                                iter->filesystem_url(),
                                iter->offset() + offset,
                                new_length,
                                iter->expected_modification_time());
     }
     length -= new_length;
     offset = 0;
   }
   return true;
 }

 bool BlobStorageContext::AppendBytesItem(
     BlobData* target_blob_data, const char* bytes, int64 length) {
   if (length < 0) {
     DCHECK(false);
     return false;
   }
   if (memory_usage_ + length > kMaxMemoryUsage)
     return false;
   target_blob_data->AppendData(bytes, static_cast<size_t>(length));
   memory_usage_ += length;
   return true;
 }

 void BlobStorageContext::AppendFileItem(
     BlobData* target_blob_data,
     const base::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.get())
     target_blob_data->AttachShareableFileReference(shareable_file.get());
 }

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

 bool BlobStorageContext::IsInUse(const std::string& uuid) {
   return blob_map_.find(uuid) != blob_map_.end();
 }

 bool BlobStorageContext::IsBeingBuilt(const std::string& uuid) {
   BlobMap::iterator found = blob_map_.find(uuid);
   if (found == blob_map_.end())
     return false;
   return found->second.flags & BEING_BUILT;
 }

 bool BlobStorageContext::IsUrlRegistered(const GURL& blob_url) {
   return public_blob_urls_.find(blob_url) != public_blob_urls_.end();
 }

 }  // namespace storage
	// Copyright (c) 2013 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 "storage/browser/blob/blob_storage_context.h"

	#include "base/bind.h"
	#include "base/location.h"
	#include "base/logging.h"
	#include "base/message_loop/message_loop_proxy.h"
	#include "storage/browser/blob/blob_data_handle.h"
	#include "storage/common/blob/blob_data.h"
	#include "url/gurl.h"

	namespace storage {

	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));
	}

	// TODO(michaeln): use base::SysInfo::AmountOfPhysicalMemoryMB() in some
	// way to come up with a better limit.
	static const int64 kMaxMemoryUsage = 500 * 1024 * 1024; // Half a gig.

	} // namespace

	BlobStorageContext::BlobMapEntry::BlobMapEntry()
	: refcount(0), flags(0) {
	}

	BlobStorageContext::BlobMapEntry::BlobMapEntry(
	int refcount, int flags, BlobData* data)
	: refcount(refcount), flags(flags), data(data) {
	}

	BlobStorageContext::BlobMapEntry::~BlobMapEntry() {
	}

	BlobStorageContext::BlobStorageContext()
	: memory_usage_(0) {
	}

	BlobStorageContext::~BlobStorageContext() {
	}

	scoped_ptr<BlobDataHandle> BlobStorageContext::GetBlobDataFromUUID(
	const std::string& uuid) {
	scoped_ptr<BlobDataHandle> result;
	BlobMap::iterator found = blob_map_.find(uuid);
	if (found == blob_map_.end())
	return result.Pass();
	if (found->second.flags & EXCEEDED_MEMORY)
	return result.Pass();
	DCHECK(!(found->second.flags & BEING_BUILT));
	result.reset(new BlobDataHandle(
	found->second.data.get(), this, base::MessageLoopProxy::current().get()));
	return result.Pass();
	}

	scoped_ptr<BlobDataHandle> BlobStorageContext::GetBlobDataFromPublicURL(
	const GURL& url) {
	BlobURLMap::iterator found = public_blob_urls_.find(
	BlobUrlHasRef(url) ? ClearBlobUrlRef(url) : url);
	if (found == public_blob_urls_.end())
	return scoped_ptr<BlobDataHandle>();
	return GetBlobDataFromUUID(found->second);
	}

	scoped_ptr<BlobDataHandle> BlobStorageContext::AddFinishedBlob(
	const BlobData* data) {
	StartBuildingBlob(data->uuid());
	for (std::vector<BlobData::Item>::const_iterator iter =
	data->items().begin();
	iter != data->items().end(); ++iter) {
	AppendBlobDataItem(data->uuid(), *iter);
	}
	FinishBuildingBlob(data->uuid(), data->content_type());
	scoped_ptr<BlobDataHandle> handle = GetBlobDataFromUUID(data->uuid());
	DecrementBlobRefCount(data->uuid());
	return handle.Pass();
	}

	bool BlobStorageContext::RegisterPublicBlobURL(
	const GURL& blob_url, const std::string& uuid) {
	DCHECK(!BlobUrlHasRef(blob_url));
	DCHECK(IsInUse(uuid));
	DCHECK(!IsUrlRegistered(blob_url));
	if (!IsInUse(uuid) \|\| IsUrlRegistered(blob_url))
	return false;
	IncrementBlobRefCount(uuid);
	public_blob_urls_[blob_url] = uuid;
	return true;
	}

	void BlobStorageContext::RevokePublicBlobURL(const GURL& blob_url) {
	DCHECK(!BlobUrlHasRef(blob_url));
	if (!IsUrlRegistered(blob_url))
	return;
	DecrementBlobRefCount(public_blob_urls_[blob_url]);
	public_blob_urls_.erase(blob_url);
	}

	void BlobStorageContext::StartBuildingBlob(const std::string& uuid) {
	DCHECK(!IsInUse(uuid) && !uuid.empty());
	blob_map_[uuid] = BlobMapEntry(1, BEING_BUILT, new BlobData(uuid));
	}

	void BlobStorageContext::AppendBlobDataItem(
	const std::string& uuid, const BlobData::Item& item) {
	DCHECK(IsBeingBuilt(uuid));
	BlobMap::iterator found = blob_map_.find(uuid);
	if (found == blob_map_.end())
	return;
	if (found->second.flags & EXCEEDED_MEMORY)
	return;
	BlobData* target_blob_data = found->second.data.get();
	DCHECK(target_blob_data);

	bool exceeded_memory = false;

	// The blob data is stored in the canonical way which only contains a
	// list of Data, File, and FileSystem items. Aggregated TYPE_BLOB items
	// are expanded into the primitive constituent types.
	// 1) The Data item is denoted by the raw data and length.
	// 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.
	// 4) The Blob items are expanded.
	// TODO(michaeln): Would be nice to avoid copying Data items when expanding.

	DCHECK(item.length() > 0);
	switch (item.type()) {
	case BlobData::Item::TYPE_BYTES:
	DCHECK(!item.offset());
	exceeded_memory = !AppendBytesItem(target_blob_data,
	item.bytes(),
	static_cast<int64>(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.filesystem_url(),
	item.offset(),
	item.length(),
	item.expected_modification_time());
	break;
	case BlobData::Item::TYPE_BLOB: {
	scoped_ptr<BlobDataHandle> src = GetBlobDataFromUUID(item.blob_uuid());
	if (src)
	exceeded_memory = !ExpandStorageItems(target_blob_data,
	src->data(),
	item.offset(),
	item.length());
	break;
	}
	default:
	NOTREACHED();
	break;
	}

	// If we're using too much memory, drop this blob's data.
	// TODO(michaeln): Blob memory storage does not yet spill over to disk,
	// as a stop gap, we'll prevent memory usage over a max amount.
	if (exceeded_memory) {
	memory_usage_ -= target_blob_data->GetMemoryUsage();
	found->second.flags \|= EXCEEDED_MEMORY;
	found->second.data = new BlobData(uuid);
	return;
	}
	}

	void BlobStorageContext::FinishBuildingBlob(
	const std::string& uuid, const std::string& content_type) {
	DCHECK(IsBeingBuilt(uuid));
	BlobMap::iterator found = blob_map_.find(uuid);
	if (found == blob_map_.end())
	return;
	found->second.data->set_content_type(content_type);
	found->second.flags &= ~BEING_BUILT;
	}

	void BlobStorageContext::CancelBuildingBlob(const std::string& uuid) {
	DCHECK(IsBeingBuilt(uuid));
	DecrementBlobRefCount(uuid);
	}

	void BlobStorageContext::IncrementBlobRefCount(const std::string& uuid) {
	BlobMap::iterator found = blob_map_.find(uuid);
	if (found == blob_map_.end()) {
	DCHECK(false);
	return;
	}
	++(found->second.refcount);
	}

	void BlobStorageContext::DecrementBlobRefCount(const std::string& uuid) {
	BlobMap::iterator found = blob_map_.find(uuid);
	if (found == blob_map_.end())
	return;
	DCHECK_EQ(found->second.data->uuid(), uuid);
	if (--(found->second.refcount) == 0) {
	memory_usage_ -= found->second.data->GetMemoryUsage();
	blob_map_.erase(found);
	}
	}

	bool BlobStorageContext::ExpandStorageItems(
	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) {
	if (!AppendBytesItem(
	target_blob_data,
	iter->bytes() + static_cast<size_t>(iter->offset() + offset),
	static_cast<int64>(new_length))) {
	return false; // exceeded memory
	}
	} else if (iter->type() == BlobData::Item::TYPE_FILE) {
	AppendFileItem(target_blob_data,
	iter->path(),
	iter->offset() + offset,
	new_length,
	iter->expected_modification_time());
	} else {
	DCHECK(iter->type() == BlobData::Item::TYPE_FILE_FILESYSTEM);
	AppendFileSystemFileItem(target_blob_data,
	iter->filesystem_url(),
	iter->offset() + offset,
	new_length,
	iter->expected_modification_time());
	}
	length -= new_length;
	offset = 0;
	}
	return true;
	}

	bool BlobStorageContext::AppendBytesItem(
	BlobData* target_blob_data, const char* bytes, int64 length) {
	if (length < 0) {
	DCHECK(false);
	return false;
	}
	if (memory_usage_ + length > kMaxMemoryUsage)
	return false;
	target_blob_data->AppendData(bytes, static_cast<size_t>(length));
	memory_usage_ += length;
	return true;
	}

	void BlobStorageContext::AppendFileItem(
	BlobData* target_blob_data,
	const base::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.get())
	target_blob_data->AttachShareableFileReference(shareable_file.get());
	}

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

	bool BlobStorageContext::IsInUse(const std::string& uuid) {
	return blob_map_.find(uuid) != blob_map_.end();
	}

	bool BlobStorageContext::IsBeingBuilt(const std::string& uuid) {
	BlobMap::iterator found = blob_map_.find(uuid);
	if (found == blob_map_.end())
	return false;
	return found->second.flags & BEING_BUILT;
	}

	bool BlobStorageContext::IsUrlRegistered(const GURL& blob_url) {
	return public_blob_urls_.find(blob_url) != public_blob_urls_.end();
	}

	} // namespace storage