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/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#ifndef FD_BUFFER_H
#define FD_BUFFER_H
#include <android/util/EncodedBuffer.h>
#include <utils/Errors.h>
using namespace android;
using namespace android::util;
using namespace std;
/**
* Reads data from fd into a buffer, fd must be closed explicitly.
*/
class FdBuffer {
public:
FdBuffer();
~FdBuffer();
/**
* Read the data until the timeout is hit or we hit eof.
* Returns NO_ERROR if there were no errors or if we timed out.
* Will mark the file O_NONBLOCK.
*/
status_t read(int fd, int64_t timeoutMs);
/**
* Read processed results by streaming data to a parsing process, e.g. incident helper.
* The parsing process provides IO fds which are 'toFd' and 'fromFd'. The function
* reads original data in 'fd' and writes to parsing process through 'toFd', then it reads
* and stores the processed data from 'fromFd' in memory for later usage.
* This function behaves in a streaming fashion in order to save memory usage.
* Returns NO_ERROR if there were no errors or if we timed out.
*
* Poll will return POLLERR if fd is from sysfs, handle this edge case.
*/
status_t readProcessedDataInStream(int fd, int toFd, int fromFd, int64_t timeoutMs,
const bool isSysfs = false);
/**
* Whether we timed out.
*/
bool timedOut() const { return mTimedOut; }
/**
* If more than 4 MB is read, we truncate the data and return success.
* Downstream tools must handle truncated incident reports as best as possible
* anyway because they could be cut off for a lot of reasons and it's best
* to get as much useful information out of the system as possible. If this
* happens, truncated() will return true so it can be marked. If the data is
* exactly 4 MB, truncated is still set. Sorry.
*/
bool truncated() const { return mTruncated; }
/**
* How much data was read.
*/
size_t size() const;
/**
* How long the read took in milliseconds.
*/
int64_t durationMs() const { return mFinishTime - mStartTime; }
/**
* Reader API for data stored in FdBuffer
*/
EncodedBuffer::iterator data() const;
/**
* Return the internal buffer, don't call unless you are familiar with EncodedBuffer.
*/
EncodedBuffer* getInternalBuffer() { return &mBuffer; }
private:
EncodedBuffer mBuffer;
int64_t mStartTime;
int64_t mFinishTime;
bool mTimedOut;
bool mTruncated;
};
#endif // FD_BUFFER_H