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(); 39 40 /** 41 * Read the data until the timeout is hit or we hit eof. 42 * Returns NO_ERROR if there were no errors or if we timed out. 43 * Will mark the file O_NONBLOCK. 44 */ 45 status_t read(int fd, int64_t timeoutMs); 46 47 /** 48 * Read the data until we hit eof. 49 * Returns NO_ERROR if there were no errors. 50 */ 51 status_t readFully(int fd); 52 53 /** 54 * Read processed results by streaming data to a parsing process, e.g. incident helper. 55 * The parsing process provides IO fds which are 'toFd' and 'fromFd'. The function 56 * reads original data in 'fd' and writes to parsing process through 'toFd', then it reads 57 * and stores the processed data from 'fromFd' in memory for later usage. 58 * This function behaves in a streaming fashion in order to save memory usage. 59 * Returns NO_ERROR if there were no errors or if we timed out. 60 * 61 * Poll will return POLLERR if fd is from sysfs, handle this edge case. 62 */ 63 status_t readProcessedDataInStream(int fd, unique_fd toFd, unique_fd fromFd, int64_t timeoutMs, 64 const bool isSysfs = false); 65 66 /** 67 * Write by hand into the buffer. 68 */ 69 status_t write(uint8_t const* buf, size_t size); 70 71 /** 72 * Write all the data from a ProtoReader into our internal buffer. 73 */ 74 status_t write(const sp<ProtoReader>& data); 75 76 /** 77 * Write size bytes of data from a ProtoReader into our internal buffer. 78 */ 79 status_t write(const sp<ProtoReader>& data, size_t size); 80 81 /** 82 * Whether we timed out. 83 */ timedOut()84 bool timedOut() const { return mTimedOut; } 85 86 /** 87 * If more than 4 MB is read, we truncate the data and return success. 88 * Downstream tools must handle truncated incident reports as best as possible 89 * anyway because they could be cut off for a lot of reasons and it's best 90 * to get as much useful information out of the system as possible. If this 91 * happens, truncated() will return true so it can be marked. If the data is 92 * exactly 4 MB, truncated is still set. Sorry. 93 */ truncated()94 bool truncated() const { return mTruncated; } 95 96 /** 97 * How much data was read. 98 */ 99 size_t size() const; 100 101 /** 102 * How long the read took in milliseconds. 103 */ durationMs()104 int64_t durationMs() const { return mFinishTime - mStartTime; } 105 106 /** 107 * Get the EncodedBuffer inside. 108 */ 109 sp<EncodedBuffer> data() const; 110 111 private: 112 sp<EncodedBuffer> mBuffer; 113 int64_t mStartTime; 114 int64_t mFinishTime; 115 bool mTimedOut; 116 bool mTruncated; 117 }; 118 119 } // namespace incidentd 120 } // namespace os 121 } // namespace android 122 123 #endif // FD_BUFFER_H 124