content/browser/indexed_db/indexed_db_dispatcher_host.h - chromium/src.git - 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.

 #ifndef CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DISPATCHER_HOST_H_
 #define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DISPATCHER_HOST_H_

 #include <stdint.h>

 #include <map>
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>

 #include "base/id_map.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "content/browser/blob_storage/chrome_blob_storage_context.h"
 #include "content/public/browser/browser_message_filter.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "storage/browser/blob/blob_data_handle.h"
 #include "storage/browser/quota/quota_manager.h"
 #include "storage/common/quota/quota_status_code.h"
 #include "url/gurl.h"

 struct IndexedDBDatabaseMetadata;
 struct IndexedDBHostMsg_DatabaseCount_Params;
 struct IndexedDBHostMsg_DatabaseCreateIndex_Params;
 struct IndexedDBHostMsg_DatabaseCreateObjectStore_Params;
 struct IndexedDBHostMsg_DatabaseCreateTransaction_Params;
 struct IndexedDBHostMsg_DatabaseDeleteRange_Params;
 struct IndexedDBHostMsg_DatabaseGet_Params;
 struct IndexedDBHostMsg_DatabaseGetAll_Params;
 struct IndexedDBHostMsg_DatabaseObserve_Params;
 struct IndexedDBHostMsg_DatabaseOpenCursor_Params;
 struct IndexedDBHostMsg_DatabasePut_Params;
 struct IndexedDBHostMsg_DatabaseSetIndexKeys_Params;
 struct IndexedDBHostMsg_FactoryDeleteDatabase_Params;
 struct IndexedDBHostMsg_FactoryGetDatabaseNames_Params;
 struct IndexedDBHostMsg_FactoryOpen_Params;
 struct IndexedDBMsg_Observation;
 struct IndexedDBMsg_ObserverChanges;

 namespace url {
 class Origin;
 }

 namespace content {
 class IndexedDBBlobInfo;
 class IndexedDBConnection;
 class IndexedDBContextImpl;
 class IndexedDBCursor;
 class IndexedDBKey;
 class IndexedDBKeyPath;
 class IndexedDBKeyRange;
 class IndexedDBObservation;
 class IndexedDBObserverChanges;
 struct IndexedDBDatabaseMetadata;

 // Handles all IndexedDB related messages from a particular renderer process.
 class IndexedDBDispatcherHost : public BrowserMessageFilter {
  public:
   // Only call the constructor from the UI thread.
   IndexedDBDispatcherHost(int ipc_process_id,
                           net::URLRequestContextGetter* request_context_getter,
                           IndexedDBContextImpl* indexed_db_context,
                           ChromeBlobStorageContext* blob_storage_context);

   static ::IndexedDBDatabaseMetadata ConvertMetadata(
       const content::IndexedDBDatabaseMetadata& metadata);
   static IndexedDBMsg_ObserverChanges ConvertObserverChanges(
       std::unique_ptr<IndexedDBObserverChanges> changes);
   static IndexedDBMsg_Observation ConvertObservation(
       const IndexedDBObservation* observation);

   // BrowserMessageFilter implementation.
   void OnChannelClosing() override;
   void OnDestruct() const override;
   base::TaskRunner* OverrideTaskRunnerForMessage(
       const IPC::Message& message) override;
   bool OnMessageReceived(const IPC::Message& message) override;

   void FinishTransaction(int64_t host_transaction_id, bool committed);

   // A shortcut for accessing our context.
   IndexedDBContextImpl* context() const { return indexed_db_context_.get(); }
   storage::BlobStorageContext* blob_storage_context() const {
     return blob_storage_context_->context();
   }

   // IndexedDBCallbacks call these methods to add the results into the
   // applicable map.  See below for more details.
   int32_t Add(IndexedDBCursor* cursor);
   int32_t Add(IndexedDBConnection* connection,
               int32_t ipc_thread_id,
               const url::Origin& origin);

   void RegisterTransactionId(int64_t host_transaction_id,
                              const url::Origin& origin);

   IndexedDBCursor* GetCursorFromId(int32_t ipc_cursor_id);

   // These are called to map a 32-bit front-end (renderer-specific) transaction
   // id to and from a back-end ("host") transaction id that encodes the process
   // id in the high 32 bits. The mapping is host-specific and ids are validated.
   int64_t HostTransactionId(int64_t transaction_id);
   int64_t RendererTransactionId(int64_t host_transaction_id);

   // These are called to decode a host transaction ID, for diagnostic purposes.
   static uint32_t TransactionIdToRendererTransactionId(
       int64_t host_transaction_id);
   static uint32_t TransactionIdToProcessId(int64_t host_transaction_id);

   std::string HoldBlobData(const IndexedDBBlobInfo& blob_info);

  private:
   // Friends to enable OnDestruct() delegation.
   friend class BrowserThread;
   friend class base::DeleteHelper<IndexedDBDispatcherHost>;

   // Used in nested classes.
   typedef std::map<int64_t, int64_t> TransactionIDToDatabaseIDMap;
   typedef std::map<int64_t, uint64_t> TransactionIDToSizeMap;
   typedef std::map<int64_t, url::Origin> TransactionIDToOriginMap;
   typedef std::map<int32_t, url::Origin> WebIDBObjectIDToOriginMap;

   // IDMap for RefCounted types
   template <typename RefCountedType>
   class RefIDMap {
    public:
     typedef int32_t KeyType;

     RefIDMap() {}
     ~RefIDMap() {}

     KeyType Add(RefCountedType* data) {
       return map_.Add(new scoped_refptr<RefCountedType>(data));
     }

     RefCountedType* Lookup(KeyType id) {
       scoped_refptr<RefCountedType>* ptr = map_.Lookup(id);
       if (ptr == NULL)
         return NULL;
       return ptr->get();
     }

     void Remove(KeyType id) { map_.Remove(id); }

     void set_check_on_null_data(bool value) {
       map_.set_check_on_null_data(value);
     }

    private:
     IDMap<scoped_refptr<RefCountedType>, IDMapOwnPointer> map_;

     DISALLOW_COPY_AND_ASSIGN(RefIDMap);
   };

   class DatabaseDispatcherHost {
    public:
     explicit DatabaseDispatcherHost(IndexedDBDispatcherHost* parent);
     ~DatabaseDispatcherHost();

     void CloseAll();
     bool OnMessageReceived(const IPC::Message& message);

     void OnCreateObjectStore(
         const IndexedDBHostMsg_DatabaseCreateObjectStore_Params& params);
     void OnDeleteObjectStore(int32_t ipc_database_id,
                              int64_t transaction_id,
                              int64_t object_store_id);
     void OnRenameObjectStore(int32_t ipc_database_id,
                              int64_t transaction_id,
                              int64_t object_store_id,
                              const base::string16& new_name);
     void OnCreateTransaction(
         const IndexedDBHostMsg_DatabaseCreateTransaction_Params&);
     void OnClose(int32_t ipc_database_id);
     void OnVersionChangeIgnored(int32_t ipc_database_id);
     void OnDestroyed(int32_t ipc_database_id);

     void OnObserve(const IndexedDBHostMsg_DatabaseObserve_Params&);
     void OnUnobserve(int32_t ipc_database_id,
                      const std::vector<int32_t>& observer_ids_to_remove);

     void OnGet(const IndexedDBHostMsg_DatabaseGet_Params& params);
     void OnGetAll(const IndexedDBHostMsg_DatabaseGetAll_Params& params);
     // OnPutWrapper starts on the IO thread so that it can grab BlobDataHandles
     // before posting to the IDB TaskRunner for the rest of the job.
     void OnPutWrapper(const IndexedDBHostMsg_DatabasePut_Params& params);
     void OnPut(const IndexedDBHostMsg_DatabasePut_Params& params,
                std::vector<std::unique_ptr<storage::BlobDataHandle>> handles);
     void OnSetIndexKeys(
         const IndexedDBHostMsg_DatabaseSetIndexKeys_Params& params);
     void OnSetIndexesReady(int32_t ipc_database_id,
                            int64_t transaction_id,
                            int64_t object_store_id,
                            const std::vector<int64_t>& ids);
     void OnOpenCursor(const IndexedDBHostMsg_DatabaseOpenCursor_Params& params);
     void OnCount(const IndexedDBHostMsg_DatabaseCount_Params& params);
     void OnDeleteRange(
         const IndexedDBHostMsg_DatabaseDeleteRange_Params& params);
     void OnClear(int32_t ipc_thread_id,
                  int32_t ipc_callbacks_id,
                  int32_t ipc_database_id,
                  int64_t transaction_id,
                  int64_t object_store_id);
     void OnCreateIndex(
         const IndexedDBHostMsg_DatabaseCreateIndex_Params& params);
     void OnDeleteIndex(int32_t ipc_database_id,
                        int64_t transaction_id,
                        int64_t object_store_id,
                        int64_t index_id);
     void OnRenameIndex(int32_t ipc_database_id,
                        int64_t transaction_id,
                        int64_t object_store_id,
                        int64_t index_id,
                        const base::string16& new_name);

     void OnAbort(int32_t ipc_database_id, int64_t transaction_id);
     void OnCommit(int32_t ipc_database_id, int64_t transaction_id);
     void OnGotUsageAndQuotaForCommit(int32_t ipc_database_id,
                                      int64_t transaction_id,
                                      storage::QuotaStatusCode status,
                                      int64_t usage,
                                      int64_t quota);

     IndexedDBDispatcherHost* parent_;
     IDMap<IndexedDBConnection, IDMapOwnPointer> map_;
     WebIDBObjectIDToOriginMap database_origin_map_;
     TransactionIDToSizeMap transaction_size_map_;
     TransactionIDToOriginMap transaction_origin_map_;
     TransactionIDToDatabaseIDMap transaction_database_map_;

     // Weak pointers are used when an asynchronous quota request is made, in
     // case the dispatcher is torn down before the response returns.
     base::WeakPtrFactory<DatabaseDispatcherHost> weak_factory_;

    private:
     DISALLOW_COPY_AND_ASSIGN(DatabaseDispatcherHost);
   };

   class CursorDispatcherHost {
    public:
     explicit CursorDispatcherHost(IndexedDBDispatcherHost* parent);
     ~CursorDispatcherHost();

     bool OnMessageReceived(const IPC::Message& message);

     void OnAdvance(int32_t ipc_object_store_id,
                    int32_t ipc_thread_id,
                    int32_t ipc_callbacks_id,
                    uint32_t count);
     void OnContinue(int32_t ipc_object_store_id,
                     int32_t ipc_thread_id,
                     int32_t ipc_callbacks_id,
                     const IndexedDBKey& key,
                     const IndexedDBKey& primary_key);
     void OnPrefetch(int32_t ipc_cursor_id,
                     int32_t ipc_thread_id,
                     int32_t ipc_callbacks_id,
                     int n);
     void OnPrefetchReset(int32_t ipc_cursor_id,
                          int used_prefetches,
                          int unused_prefetches);
     void OnDestroyed(int32_t ipc_cursor_id);

     IndexedDBDispatcherHost* parent_;
     RefIDMap<IndexedDBCursor> map_;

    private:
     DISALLOW_COPY_AND_ASSIGN(CursorDispatcherHost);
   };

   ~IndexedDBDispatcherHost() override;

   // Helper templates.
   template <class ReturnType>
   ReturnType* GetOrTerminateProcess(IDMap<ReturnType, IDMapOwnPointer>* map,
                                     int32_t ipc_return_object_id);
   template <class ReturnType>
   ReturnType* GetOrTerminateProcess(RefIDMap<ReturnType>* map,
                                     int32_t ipc_return_object_id);

   template <typename MapType>
   void DestroyObject(MapType* map, int32_t ipc_object_id);

   // Message processing. Most of the work is delegated to the dispatcher hosts
   // below.
   void OnIDBFactoryGetDatabaseNames(
       const IndexedDBHostMsg_FactoryGetDatabaseNames_Params& p);
   void OnIDBFactoryOpen(const IndexedDBHostMsg_FactoryOpen_Params& p);

   void OnIDBFactoryDeleteDatabase(
       const IndexedDBHostMsg_FactoryDeleteDatabase_Params& p);

   void OnAckReceivedBlobs(const std::vector<std::string>& uuids);
   void OnPutHelper(
       const IndexedDBHostMsg_DatabasePut_Params& params,
       std::vector<std::unique_ptr<storage::BlobDataHandle>> handles);

   void ResetDispatcherHosts();
   void DropBlobData(const std::string& uuid);

   scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
   scoped_refptr<IndexedDBContextImpl> indexed_db_context_;
   scoped_refptr<ChromeBlobStorageContext> blob_storage_context_;

   // Maps blob uuid to a pair (handle, ref count). Entry is added and/or count
   // is incremented in HoldBlobData(), and count is decremented and/or entry
   // removed in DropBlobData().
   std::map<std::string,
            std::pair<std::unique_ptr<storage::BlobDataHandle>, int>>
       blob_data_handle_map_;

   // Only access on IndexedDB thread.
   std::unique_ptr<DatabaseDispatcherHost> database_dispatcher_host_;
   std::unique_ptr<CursorDispatcherHost> cursor_dispatcher_host_;

   // Used to set file permissions for blob storage.
   int ipc_process_id_;

   DISALLOW_IMPLICIT_CONSTRUCTORS(IndexedDBDispatcherHost);
 };

 }  // namespace content

 #endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DISPATCHER_HOST_H_
	// 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.

	#ifndef CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DISPATCHER_HOST_H_
	#define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DISPATCHER_HOST_H_

	#include <stdint.h>

	#include <map>
	#include <memory>
	#include <string>
	#include <utility>
	#include <vector>

	#include "base/id_map.h"
	#include "base/macros.h"
	#include "base/memory/ref_counted.h"
	#include "base/memory/weak_ptr.h"
	#include "content/browser/blob_storage/chrome_blob_storage_context.h"
	#include "content/public/browser/browser_message_filter.h"
	#include "net/url_request/url_request_context_getter.h"
	#include "storage/browser/blob/blob_data_handle.h"
	#include "storage/browser/quota/quota_manager.h"
	#include "storage/common/quota/quota_status_code.h"
	#include "url/gurl.h"

	struct IndexedDBDatabaseMetadata;
	struct IndexedDBHostMsg_DatabaseCount_Params;
	struct IndexedDBHostMsg_DatabaseCreateIndex_Params;
	struct IndexedDBHostMsg_DatabaseCreateObjectStore_Params;
	struct IndexedDBHostMsg_DatabaseCreateTransaction_Params;
	struct IndexedDBHostMsg_DatabaseDeleteRange_Params;
	struct IndexedDBHostMsg_DatabaseGet_Params;
	struct IndexedDBHostMsg_DatabaseGetAll_Params;
	struct IndexedDBHostMsg_DatabaseObserve_Params;
	struct IndexedDBHostMsg_DatabaseOpenCursor_Params;
	struct IndexedDBHostMsg_DatabasePut_Params;
	struct IndexedDBHostMsg_DatabaseSetIndexKeys_Params;
	struct IndexedDBHostMsg_FactoryDeleteDatabase_Params;
	struct IndexedDBHostMsg_FactoryGetDatabaseNames_Params;
	struct IndexedDBHostMsg_FactoryOpen_Params;
	struct IndexedDBMsg_Observation;
	struct IndexedDBMsg_ObserverChanges;

	namespace url {
	class Origin;
	}

	namespace content {
	class IndexedDBBlobInfo;
	class IndexedDBConnection;
	class IndexedDBContextImpl;
	class IndexedDBCursor;
	class IndexedDBKey;
	class IndexedDBKeyPath;
	class IndexedDBKeyRange;
	class IndexedDBObservation;
	class IndexedDBObserverChanges;
	struct IndexedDBDatabaseMetadata;

	// Handles all IndexedDB related messages from a particular renderer process.
	class IndexedDBDispatcherHost : public BrowserMessageFilter {
	public:
	// Only call the constructor from the UI thread.
	IndexedDBDispatcherHost(int ipc_process_id,
	net::URLRequestContextGetter* request_context_getter,
	IndexedDBContextImpl* indexed_db_context,
	ChromeBlobStorageContext* blob_storage_context);

	static ::IndexedDBDatabaseMetadata ConvertMetadata(
	const content::IndexedDBDatabaseMetadata& metadata);
	static IndexedDBMsg_ObserverChanges ConvertObserverChanges(
	std::unique_ptr<IndexedDBObserverChanges> changes);
	static IndexedDBMsg_Observation ConvertObservation(
	const IndexedDBObservation* observation);

	// BrowserMessageFilter implementation.
	void OnChannelClosing() override;
	void OnDestruct() const override;
	base::TaskRunner* OverrideTaskRunnerForMessage(
	const IPC::Message& message) override;
	bool OnMessageReceived(const IPC::Message& message) override;

	void FinishTransaction(int64_t host_transaction_id, bool committed);

	// A shortcut for accessing our context.
	IndexedDBContextImpl* context() const { return indexed_db_context_.get(); }
	storage::BlobStorageContext* blob_storage_context() const {
	return blob_storage_context_->context();
	}

	// IndexedDBCallbacks call these methods to add the results into the
	// applicable map. See below for more details.
	int32_t Add(IndexedDBCursor* cursor);
	int32_t Add(IndexedDBConnection* connection,
	int32_t ipc_thread_id,
	const url::Origin& origin);

	void RegisterTransactionId(int64_t host_transaction_id,
	const url::Origin& origin);

	IndexedDBCursor* GetCursorFromId(int32_t ipc_cursor_id);

	// These are called to map a 32-bit front-end (renderer-specific) transaction
	// id to and from a back-end ("host") transaction id that encodes the process
	// id in the high 32 bits. The mapping is host-specific and ids are validated.
	int64_t HostTransactionId(int64_t transaction_id);
	int64_t RendererTransactionId(int64_t host_transaction_id);

	// These are called to decode a host transaction ID, for diagnostic purposes.
	static uint32_t TransactionIdToRendererTransactionId(
	int64_t host_transaction_id);
	static uint32_t TransactionIdToProcessId(int64_t host_transaction_id);

	std::string HoldBlobData(const IndexedDBBlobInfo& blob_info);

	private:
	// Friends to enable OnDestruct() delegation.
	friend class BrowserThread;
	friend class base::DeleteHelper<IndexedDBDispatcherHost>;

	// Used in nested classes.
	typedef std::map<int64_t, int64_t> TransactionIDToDatabaseIDMap;
	typedef std::map<int64_t, uint64_t> TransactionIDToSizeMap;
	typedef std::map<int64_t, url::Origin> TransactionIDToOriginMap;
	typedef std::map<int32_t, url::Origin> WebIDBObjectIDToOriginMap;

	// IDMap for RefCounted types
	template <typename RefCountedType>
	class RefIDMap {
	public:
	typedef int32_t KeyType;

	RefIDMap() {}
	~RefIDMap() {}

	KeyType Add(RefCountedType* data) {
	return map_.Add(new scoped_refptr<RefCountedType>(data));
	}

	RefCountedType* Lookup(KeyType id) {
	scoped_refptr<RefCountedType>* ptr = map_.Lookup(id);
	if (ptr == NULL)
	return NULL;
	return ptr->get();
	}

	void Remove(KeyType id) { map_.Remove(id); }

	void set_check_on_null_data(bool value) {
	map_.set_check_on_null_data(value);
	}

	private:
	IDMap<scoped_refptr<RefCountedType>, IDMapOwnPointer> map_;

	DISALLOW_COPY_AND_ASSIGN(RefIDMap);
	};

	class DatabaseDispatcherHost {
	public:
	explicit DatabaseDispatcherHost(IndexedDBDispatcherHost* parent);
	~DatabaseDispatcherHost();

	void CloseAll();
	bool OnMessageReceived(const IPC::Message& message);

	void OnCreateObjectStore(
	const IndexedDBHostMsg_DatabaseCreateObjectStore_Params& params);
	void OnDeleteObjectStore(int32_t ipc_database_id,
	int64_t transaction_id,
	int64_t object_store_id);
	void OnRenameObjectStore(int32_t ipc_database_id,
	int64_t transaction_id,
	int64_t object_store_id,
	const base::string16& new_name);
	void OnCreateTransaction(
	const IndexedDBHostMsg_DatabaseCreateTransaction_Params&);
	void OnClose(int32_t ipc_database_id);
	void OnVersionChangeIgnored(int32_t ipc_database_id);
	void OnDestroyed(int32_t ipc_database_id);

	void OnObserve(const IndexedDBHostMsg_DatabaseObserve_Params&);
	void OnUnobserve(int32_t ipc_database_id,
	const std::vector<int32_t>& observer_ids_to_remove);

	void OnGet(const IndexedDBHostMsg_DatabaseGet_Params& params);
	void OnGetAll(const IndexedDBHostMsg_DatabaseGetAll_Params& params);
	// OnPutWrapper starts on the IO thread so that it can grab BlobDataHandles
	// before posting to the IDB TaskRunner for the rest of the job.
	void OnPutWrapper(const IndexedDBHostMsg_DatabasePut_Params& params);
	void OnPut(const IndexedDBHostMsg_DatabasePut_Params& params,
	std::vector<std::unique_ptr<storage::BlobDataHandle>> handles);
	void OnSetIndexKeys(
	const IndexedDBHostMsg_DatabaseSetIndexKeys_Params& params);
	void OnSetIndexesReady(int32_t ipc_database_id,
	int64_t transaction_id,
	int64_t object_store_id,
	const std::vector<int64_t>& ids);
	void OnOpenCursor(const IndexedDBHostMsg_DatabaseOpenCursor_Params& params);
	void OnCount(const IndexedDBHostMsg_DatabaseCount_Params& params);
	void OnDeleteRange(
	const IndexedDBHostMsg_DatabaseDeleteRange_Params& params);
	void OnClear(int32_t ipc_thread_id,
	int32_t ipc_callbacks_id,
	int32_t ipc_database_id,
	int64_t transaction_id,
	int64_t object_store_id);
	void OnCreateIndex(
	const IndexedDBHostMsg_DatabaseCreateIndex_Params& params);
	void OnDeleteIndex(int32_t ipc_database_id,
	int64_t transaction_id,
	int64_t object_store_id,
	int64_t index_id);
	void OnRenameIndex(int32_t ipc_database_id,
	int64_t transaction_id,
	int64_t object_store_id,
	int64_t index_id,
	const base::string16& new_name);

	void OnAbort(int32_t ipc_database_id, int64_t transaction_id);
	void OnCommit(int32_t ipc_database_id, int64_t transaction_id);
	void OnGotUsageAndQuotaForCommit(int32_t ipc_database_id,
	int64_t transaction_id,
	storage::QuotaStatusCode status,
	int64_t usage,
	int64_t quota);

	IndexedDBDispatcherHost* parent_;
	IDMap<IndexedDBConnection, IDMapOwnPointer> map_;
	WebIDBObjectIDToOriginMap database_origin_map_;
	TransactionIDToSizeMap transaction_size_map_;
	TransactionIDToOriginMap transaction_origin_map_;
	TransactionIDToDatabaseIDMap transaction_database_map_;

	// Weak pointers are used when an asynchronous quota request is made, in
	// case the dispatcher is torn down before the response returns.
	base::WeakPtrFactory<DatabaseDispatcherHost> weak_factory_;

	private:
	DISALLOW_COPY_AND_ASSIGN(DatabaseDispatcherHost);
	};

	class CursorDispatcherHost {
	public:
	explicit CursorDispatcherHost(IndexedDBDispatcherHost* parent);
	~CursorDispatcherHost();

	bool OnMessageReceived(const IPC::Message& message);

	void OnAdvance(int32_t ipc_object_store_id,
	int32_t ipc_thread_id,
	int32_t ipc_callbacks_id,
	uint32_t count);
	void OnContinue(int32_t ipc_object_store_id,
	int32_t ipc_thread_id,
	int32_t ipc_callbacks_id,
	const IndexedDBKey& key,
	const IndexedDBKey& primary_key);
	void OnPrefetch(int32_t ipc_cursor_id,
	int32_t ipc_thread_id,
	int32_t ipc_callbacks_id,
	int n);
	void OnPrefetchReset(int32_t ipc_cursor_id,
	int used_prefetches,
	int unused_prefetches);
	void OnDestroyed(int32_t ipc_cursor_id);

	IndexedDBDispatcherHost* parent_;
	RefIDMap<IndexedDBCursor> map_;

	private:
	DISALLOW_COPY_AND_ASSIGN(CursorDispatcherHost);
	};

	~IndexedDBDispatcherHost() override;

	// Helper templates.
	template <class ReturnType>
	ReturnType* GetOrTerminateProcess(IDMap<ReturnType, IDMapOwnPointer>* map,
	int32_t ipc_return_object_id);
	template <class ReturnType>
	ReturnType* GetOrTerminateProcess(RefIDMap<ReturnType>* map,
	int32_t ipc_return_object_id);

	template <typename MapType>
	void DestroyObject(MapType* map, int32_t ipc_object_id);

	// Message processing. Most of the work is delegated to the dispatcher hosts
	// below.
	void OnIDBFactoryGetDatabaseNames(
	const IndexedDBHostMsg_FactoryGetDatabaseNames_Params& p);
	void OnIDBFactoryOpen(const IndexedDBHostMsg_FactoryOpen_Params& p);

	void OnIDBFactoryDeleteDatabase(
	const IndexedDBHostMsg_FactoryDeleteDatabase_Params& p);

	void OnAckReceivedBlobs(const std::vector<std::string>& uuids);
	void OnPutHelper(
	const IndexedDBHostMsg_DatabasePut_Params& params,
	std::vector<std::unique_ptr<storage::BlobDataHandle>> handles);

	void ResetDispatcherHosts();
	void DropBlobData(const std::string& uuid);

	scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
	scoped_refptr<IndexedDBContextImpl> indexed_db_context_;
	scoped_refptr<ChromeBlobStorageContext> blob_storage_context_;

	// Maps blob uuid to a pair (handle, ref count). Entry is added and/or count
	// is incremented in HoldBlobData(), and count is decremented and/or entry
	// removed in DropBlobData().
	std::map<std::string,
	std::pair<std::unique_ptr<storage::BlobDataHandle>, int>>
	blob_data_handle_map_;

	// Only access on IndexedDB thread.
	std::unique_ptr<DatabaseDispatcherHost> database_dispatcher_host_;
	std::unique_ptr<CursorDispatcherHost> cursor_dispatcher_host_;

	// Used to set file permissions for blob storage.
	int ipc_process_id_;

	DISALLOW_IMPLICIT_CONSTRUCTORS(IndexedDBDispatcherHost);
	};

	} // namespace content

	#endif // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DISPATCHER_HOST_H_