1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 #pragma once 17 18 #ifndef FD_BUFFER_H 19 #define FD_BUFFER_H 20 21 #include <android-base/unique_fd.h> 22 #include <android/util/EncodedBuffer.h> 23 #include <utils/Errors.h> 24 25 namespace android { 26 namespace os { 27 namespace incidentd { 28 29 using namespace android::base; 30 using namespace android::util; 31 32 /** 33 * Reads data from fd into a buffer, fd must be closed explicitly. 34 */ 35 class FdBuffer { 36 public: 37 FdBuffer(); 38 FdBuffer(sp<EncodedBuffer> buffer, bool isBufferPooled = false); 39 ~FdBuffer(); 40 41 /** 42 * Read the data until the timeout is hit or we hit eof. 43 * Returns NO_ERROR if there were no errors or if we timed out. 44 * Will mark the file O_NONBLOCK. 45 */ 46 status_t read(int fd, int64_t timeoutMs); 47 48 /** 49 * Read the data until we hit eof. 50 * Returns NO_ERROR if there were no errors. 51 */ 52 status_t readFully(int fd); 53 54 /** 55 * Read processed results by streaming data to a parsing process, e.g. incident helper. 56 * The parsing process provides IO fds which are 'toFd' and 'fromFd'. The function 57 * reads original data in 'fd' and writes to parsing process through 'toFd', then it reads 58 * and stores the processed data from 'fromFd' in memory for later usage. 59 * This function behaves in a streaming fashion in order to save memory usage. 60 * Returns NO_ERROR if there were no errors or if we timed out. 61 * 62 * Poll will return POLLERR if fd is from sysfs, handle this edge case. 63 */ 64 status_t readProcessedDataInStream(int fd, unique_fd toFd, unique_fd fromFd, int64_t timeoutMs, 65 const bool isSysfs = false); 66 67 /** 68 * Write by hand into the buffer. 69 */ 70 status_t write(uint8_t const* buf, size_t size); 71 72 /** 73 * Write all the data from a ProtoReader into our internal buffer. 74 */ 75 status_t write(const sp<ProtoReader>& data); 76 77 /** 78 * Write size bytes of data from a ProtoReader into our internal buffer. 79 */ 80 status_t write(const sp<ProtoReader>& data, size_t size); 81 82 /** 83 * Whether we timed out. 84 */ timedOut()85 bool timedOut() const { return mTimedOut; } 86 87 /** 88 * If more than 4 MB is read, we truncate the data and return success. 89 * Downstream tools must handle truncated incident reports as best as possible 90 * anyway because they could be cut off for a lot of reasons and it's best 91 * to get as much useful information out of the system as possible. If this 92 * happens, truncated() will return true so it can be marked. If the data is 93 * exactly 4 MB, truncated is still set. Sorry. 94 */ truncated()95 bool truncated() const { return mTruncated; } 96 97 /** 98 * How much data was read. 99 */ 100 size_t size() const; 101 102 /** 103 * How long the read took in milliseconds. 104 */ durationMs()105 int64_t durationMs() const { return mFinishTime - mStartTime; } 106 107 /** 108 * Get the EncodedBuffer inside. 109 */ 110 sp<EncodedBuffer> data() const; 111 112 private: 113 sp<EncodedBuffer> mBuffer; 114 int64_t mStartTime; 115 int64_t mFinishTime; 116 bool mTimedOut; 117 bool mTruncated; 118 bool mIsBufferPooled; 119 }; 120 121 } // namespace incidentd 122 } // namespace os 123 } // namespace android 124 125 #endif // FD_BUFFER_H 126