blob: d71f57cdb6462924b4c573f7b473c5cfc02301fd [file] [log] [blame]
// 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 "base/basictypes.h"
#include "net/base/completion_callback.h"
#include "net/base/net_export.h"
namespace net {
class IOBuffer;
class UploadBytesElementReader;
class UploadFileElementReader;
// An interface to read an upload data element.
class NET_EXPORT UploadElementReader {
UploadElementReader() {}
virtual ~UploadElementReader() {}
// Returns this instance's pointer as UploadBytesElementReader when possible,
// otherwise returns NULL.
virtual const UploadBytesElementReader* AsBytesReader() const;
// Returns this instance's pointer as UploadFileElementReader when possible,
// otherwise returns NULL.
virtual const UploadFileElementReader* AsFileReader() const;
// Initializes the instance synchronously when possible, otherwise does
// initialization aynschronously, returns ERR_IO_PENDING and runs callback.
// Calling this method again after a Init() success results in resetting the
// state.
virtual int Init(const CompletionCallback& callback) = 0;
// Returns the byte-length of the element. For files that do not exist, 0
// is returned. This is done for consistency with Mozilla.
virtual uint64 GetContentLength() const = 0;
// Returns the number of bytes remaining to read.
virtual uint64 BytesRemaining() const = 0;
// Returns true if the upload element is entirely in memory.
// The default implementation returns false.
virtual bool IsInMemory() const;
// Reads up to |buf_length| bytes synchronously and returns the number of
// bytes read or error code when possible, otherwise, returns ERR_IO_PENDING
// and runs |callback| with the result. |buf_length| must be greater than 0.
virtual int Read(IOBuffer* buf,
int buf_length,
const CompletionCallback& callback) = 0;
} // namespace net