text: // 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 NET_BASE_UPLOAD_FILE_ELEMENT_READER_H_
  #define NET_BASE_UPLOAD_FILE_ELEMENT_READER_H_
  
  #include "base/compiler_specific.h"
  #include "base/files/file_path.h"
  #include "base/gtest_prod_util.h"
  #include "base/memory/ref_counted.h"
  #include "base/memory/scoped_ptr.h"
  #include "base/memory/weak_ptr.h"
  #include "base/time/time.h"
  #include "net/base/upload_element_reader.h"
  
  namespace base {
  class TaskRunner;
  }
  
  namespace net {
  
  class FileStream;
  
  // An UploadElementReader implementation for file.
  class NET_EXPORT UploadFileElementReader : public UploadElementReader {
   public:
    // |task_runner| is used to perform file operations. It must not be NULL.
    UploadFileElementReader(base::TaskRunner* task_runner,
                            const base::FilePath& path,
                            uint64 range_offset,
                            uint64 range_length,
                            const base::Time& expected_modification_time);
    virtual ~UploadFileElementReader();
  
    const base::FilePath& path() const { return path_; }
    uint64 range_offset() const { return range_offset_; }
    uint64 range_length() const { return range_length_; }
    const base::Time& expected_modification_time() const {
      return expected_modification_time_;
    }
  
    // UploadElementReader overrides:
    virtual const UploadFileElementReader* AsFileReader() const OVERRIDE;
    virtual int Init(const CompletionCallback& callback) OVERRIDE;
    virtual uint64 GetContentLength() const OVERRIDE;
    virtual uint64 BytesRemaining() const OVERRIDE;
    virtual int Read(IOBuffer* buf,
                     int buf_length,
                     const CompletionCallback& callback) OVERRIDE;
  
   private:
    // Deletes FileStream with |task_runner| to avoid blocking the IO thread.
    // This class is used as a template argument of scoped_ptr.
    class FileStreamDeleter {
     public:
      explicit FileStreamDeleter(base::TaskRunner* task_runner);
      ~FileStreamDeleter();
      void operator() (FileStream* file_stream) const;
  
     private:
      scoped_refptr<base::TaskRunner> task_runner_;
    };
  
    typedef scoped_ptr<FileStream, FileStreamDeleter> ScopedFileStreamPtr;
  
    FRIEND_TEST_ALL_PREFIXES(UploadDataStreamTest, FileSmallerThanLength);
    FRIEND_TEST_ALL_PREFIXES(HttpNetworkTransactionTest,
                             UploadFileSmallerThanLength);
    FRIEND_TEST_ALL_PREFIXES(HttpNetworkTransactionSpdy2Test,
                             UploadFileSmallerThanLength);
    FRIEND_TEST_ALL_PREFIXES(HttpNetworkTransactionSpdy3Test,
                             UploadFileSmallerThanLength);
  
    // Resets this instance to the uninitialized state.
    void Reset();
  
    // This method is used to implement Init().
    void OnInitCompleted(ScopedFileStreamPtr* file_stream,
                         uint64* content_length,
                         const CompletionCallback& callback,
                         int result);
  
    // This method is used to implement Read().
    void OnReadCompleted(ScopedFileStreamPtr file_stream,
                         const CompletionCallback& callback,
                         int result);
  
    // Sets an value to override the result for GetContentLength().
    // Used for tests.
    struct NET_EXPORT_PRIVATE ScopedOverridingContentLengthForTests {
      ScopedOverridingContentLengthForTests(uint64 value);
      ~ScopedOverridingContentLengthForTests();
    };
  
    scoped_refptr<base::TaskRunner> task_runner_;
    const base::FilePath path_;
    const uint64 range_offset_;
    const uint64 range_length_;
    const base::Time expected_modification_time_;
    ScopedFileStreamPtr file_stream_;
    uint64 content_length_;
    uint64 bytes_remaining_;
    base::WeakPtrFactory<UploadFileElementReader> weak_ptr_factory_;
  
    DISALLOW_COPY_AND_ASSIGN(UploadFileElementReader);
  };
  
  // An UploadElementReader implementation for file which performs file operation
  // synchronously.
  // Use this class only if the thread is IO allowed.
  class NET_EXPORT UploadFileElementReaderSync : public UploadElementReader {
   public:
    UploadFileElementReaderSync(const base::FilePath& path,
                                uint64 range_offset,
                                uint64 range_length,
                                const base::Time& expected_modification_time);
    virtual ~UploadFileElementReaderSync();
  
    // UploadElementReader overrides:
    virtual int Init(const CompletionCallback& callback) OVERRIDE;
    virtual uint64 GetContentLength() const OVERRIDE;
    virtual uint64 BytesRemaining() const OVERRIDE;
    virtual int Read(IOBuffer* buf,
                     int buf_length,
                     const CompletionCallback& callback) OVERRIDE;
  
   private:
    const base::FilePath path_;
    const uint64 range_offset_;
    const uint64 range_length_;
    const base::Time expected_modification_time_;
    scoped_ptr<FileStream> file_stream_;
    uint64 content_length_;
    uint64 bytes_remaining_;
  
    DISALLOW_COPY_AND_ASSIGN(UploadFileElementReaderSync);
  };
  
  }  // namespace net
  
  #endif  // NET_BASE_UPLOAD_FILE_ELEMENT_READER_H_
  