file.h revision a1401311d1ab56c4ed0a474bd38c108f75cb0cd9
15c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved. 25c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)// found in the LICENSE file. 45c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 55c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)// See net/disk_cache/disk_cache.h for the public interface of the cache. 65c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 75c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#ifndef NET_DISK_CACHE_BLOCKFILE_FILE_H_ 85c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#define NET_DISK_CACHE_BLOCKFILE_FILE_H_ 95c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 105c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#include "base/memory/ref_counted.h" 115c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#include "base/platform_file.h" 125c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#include "net/base/net_export.h" 135c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 145c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)namespace base { 155c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)class FilePath; 165c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)} 175c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 185c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)namespace disk_cache { 195c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 205c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)// This interface is used to support asynchronous ReadData and WriteData calls. 215c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)class FileIOCallback { 225c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) public: 2351b2906e11752df6c18351cf520e30522d3b53a1Torne (Richard Coles) // Notified of the actual number of bytes read or written. This value is 247757ec2eadfa2dd8ac2aeed0a4399e9b07ec38cbBen Murdoch // negative if an error occurred. 257757ec2eadfa2dd8ac2aeed0a4399e9b07ec38cbBen Murdoch virtual void OnFileIOComplete(int bytes_copied) = 0; 267757ec2eadfa2dd8ac2aeed0a4399e9b07ec38cbBen Murdoch 275c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) protected: 28c1847b1379d12d0e05df27436bf19a9b1bf12deaTorne (Richard Coles) virtual ~FileIOCallback() {} 295c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)}; 305c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 315c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)// Simple wrapper around a file that allows asynchronous operations. 325c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)class NET_EXPORT_PRIVATE File : public base::RefCounted<File> { 335c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) friend class base::RefCounted<File>; 345c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) public: 355c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) File(); 365c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // mixed_mode set to true enables regular synchronous operations for the file. 375c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) explicit File(bool mixed_mode); 385c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 395c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Initializes the object to use the passed in file instead of opening it with 405c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // the Init() call. No asynchronous operations can be performed with this 415c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // object. 425c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) explicit File(base::PlatformFile file); 435c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 445c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Initializes the object to point to a given file. The file must aready exist 455c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // on disk, and allow shared read and write. 465c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) bool Init(const base::FilePath& name); 475c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 485c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Returns the handle or file descriptor. 495c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) base::PlatformFile platform_file() const; 505c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 5151b2906e11752df6c18351cf520e30522d3b53a1Torne (Richard Coles) // Returns true if the file was opened properly. 525c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) bool IsValid() const; 535c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 545c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Performs synchronous IO. 555c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) bool Read(void* buffer, size_t buffer_len, size_t offset); 565c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) bool Write(const void* buffer, size_t buffer_len, size_t offset); 575c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 5802772c6a72f1ee0b226341a4f4439970c29fc861Ben Murdoch // Performs asynchronous IO. callback will be called when the IO completes, 595c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // as an APC on the thread that queued the operation. 605c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) bool Read(void* buffer, size_t buffer_len, size_t offset, 615c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) FileIOCallback* callback, bool* completed); 625c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) bool Write(const void* buffer, size_t buffer_len, size_t offset, 635c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) FileIOCallback* callback, bool* completed); 645c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 655c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Sets the file's length. The file is truncated or extended with zeros to 665c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // the new length. 675c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) bool SetLength(size_t length); 685c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) size_t GetLength(); 695c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 705c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Blocks until |num_pending_io| IO operations complete. 715c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) static void WaitForPendingIO(int* num_pending_io); 725c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 735c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Drops current pending operations without waiting for them to complete. 745c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) static void DropPendingIO(); 7553e740f4a82e17f3ae59772501622dc354e42336Torne (Richard Coles) 7651b2906e11752df6c18351cf520e30522d3b53a1Torne (Richard Coles) protected: 7751b2906e11752df6c18351cf520e30522d3b53a1Torne (Richard Coles) virtual ~File(); 7853e740f4a82e17f3ae59772501622dc354e42336Torne (Richard Coles) 795c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) private: 805c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // Performs the actual asynchronous write. If notify is set and there is no 815c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // callback, the call will be re-synchronized. 82 bool AsyncWrite(const void* buffer, size_t buffer_len, size_t offset, 83 FileIOCallback* callback, bool* completed); 84 85 // Infrastructure for async IO. 86 int DoRead(void* buffer, size_t buffer_len, size_t offset); 87 int DoWrite(const void* buffer, size_t buffer_len, size_t offset); 88 void OnOperationComplete(FileIOCallback* callback, int result); 89 90 bool init_; 91 bool mixed_; 92 base::PlatformFile platform_file_; // Regular, asynchronous IO handle. 93 base::PlatformFile sync_platform_file_; // Synchronous IO handle. 94 95 DISALLOW_COPY_AND_ASSIGN(File); 96}; 97 98} // namespace disk_cache 99 100#endif // NET_DISK_CACHE_BLOCKFILE_FILE_H_ 101