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// 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_DATA_STREAM_H_
#define NET_BASE_UPLOAD_DATA_STREAM_H_
#include <stdint.h>
#include <memory>
#include <vector>
#include "base/macros.h"
#include "net/base/completion_callback.h"
#include "net/base/net_export.h"
#include "net/base/upload_progress.h"
#include "net/log/net_log_with_source.h"
namespace net {
class DrainableIOBuffer;
class IOBuffer;
class UploadElementReader;
// A class for retrieving all data to be sent as a request body. Supports both
// chunked and non-chunked uploads.
class NET_EXPORT UploadDataStream {
public:
// |identifier| identifies a particular upload instance, which is used by the
// cache to formulate a cache key. This value should be unique across browser
// sessions. A value of 0 is used to indicate an unspecified identifier.
UploadDataStream(bool is_chunked, int64_t identifier);
virtual ~UploadDataStream();
// Initializes the stream. This function must be called before calling any
// other method. It is not valid to call any method (other than the
// destructor) if Init() fails. This method can be called multiple times.
// Calling this method after an Init() success results in resetting the
// state (i.e. the stream is rewound).
//
// Does the initialization synchronously and returns the result if possible,
// otherwise returns ERR_IO_PENDING and runs the callback with the result.
//
// Returns OK on success. Returns ERR_UPLOAD_FILE_CHANGED if the expected
// file modification time is set (usually not set, but set for sliced
// files) and the target file is changed.
int Init(const CompletionCallback& callback, const NetLogWithSource& net_log);
// When possible, reads up to |buf_len| bytes synchronously from the upload
// data stream to |buf| and returns the number of bytes read; otherwise,
// returns ERR_IO_PENDING and calls |callback| with the number of bytes read.
// Partial reads are allowed. Zero is returned on a call to Read when there
// are no remaining bytes in the stream, and IsEof() will return true
// hereafter.
//
// If there's less data to read than we initially observed (i.e. the actual
// upload data is smaller than size()), zeros are padded to ensure that
// size() bytes can be read, which can happen for TYPE_FILE payloads.
//
// TODO(mmenke): Investigate letting reads fail.
int Read(IOBuffer* buf, int buf_len, const CompletionCallback& callback);
// Returns the total size of the data stream and the current position.
// When the data is chunked, always returns zero. Must always return the same
// value after each call to Initialize().
uint64_t size() const { return total_size_; }
uint64_t position() const { return current_position_; }
// See constructor for description.
int64_t identifier() const { return identifier_; }
bool is_chunked() const { return is_chunked_; }
// Returns true if all data has been consumed from this upload data
// stream. For chunked uploads, returns false until the first read attempt.
// This makes some state machines a little simpler.
bool IsEOF() const;
// Cancels all pending callbacks, and resets state. Any IOBuffer currently
// being read to is not safe for future use, as it may be in use on another
// thread.
void Reset();
// Returns true if the upload data in the stream is entirely in memory, and
// all read requests will succeed synchronously. Expected to return false for
// chunked requests.
virtual bool IsInMemory() const;
// Returns a list of element readers owned by |this|, if it has any.
virtual const std::vector<std::unique_ptr<UploadElementReader>>*
GetElementReaders() const;
// Returns the upload progress. If the stream was not initialized
// successfully, or has been reset and not yet re-initialized, returns an
// empty UploadProgress.
virtual UploadProgress GetUploadProgress() const;
protected:
// Must be called by subclasses when InitInternal and ReadInternal complete
// asynchronously.
void OnInitCompleted(int result);
void OnReadCompleted(int result);
// Must be called before InitInternal completes, for non-chunked uploads.
// Must not be called for chunked uploads.
void SetSize(uint64_t size);
// Must be called for chunked uploads before the final ReadInternal call
// completes. Must not be called for non-chunked uploads.
void SetIsFinalChunk();
private:
// See Init(). If it returns ERR_IO_PENDING, OnInitCompleted must be called
// once it completes. If the upload is not chunked, SetSize must be called
// before it completes.
virtual int InitInternal(const NetLogWithSource& net_log) = 0;
// See Read(). For chunked uploads, must call SetIsFinalChunk if this is the
// final chunk. For non-chunked uploads, the UploadDataStream determins which
// read is the last based on size. Must read 1 or more bytes on every call,
// though the final chunk may be 0 bytes, for chunked requests. If it returns
// ERR_IO_PENDING, OnInitCompleted must be called once it completes. Must not
// return any error, other than ERR_IO_PENDING.
virtual int ReadInternal(IOBuffer* buf, int buf_len) = 0;
// Resets state and cancels any pending callbacks. Guaranteed to be called
// before all but the first call to InitInternal.
virtual void ResetInternal() = 0;
uint64_t total_size_;
uint64_t current_position_;
const int64_t identifier_;
const bool is_chunked_;
// True if the initialization was successful.
bool initialized_successfully_;
bool is_eof_;
CompletionCallback callback_;
NetLogWithSource net_log_;
DISALLOW_COPY_AND_ASSIGN(UploadDataStream);
};
} // namespace net
#endif // NET_BASE_UPLOAD_DATA_STREAM_H_