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
17#ifndef FD_BUFFER_H
18#define FD_BUFFER_H
19
20#include "Reporter.h"
21
22#include <utils/Errors.h>
23
24#include <set>
25#include <vector>
26
27using namespace android;
28using namespace std;
29
30/**
31 * Reads a file into a buffer, and then writes that data to an FdSet.
32 */
33class FdBuffer
34{
35public:
36    FdBuffer();
37    ~FdBuffer();
38
39    /**
40     * Read the data until the timeout is hit or we hit eof.
41     * Returns NO_ERROR if there were no errors or if we timed out.
42     * Will mark the file O_NONBLOCK.
43     */
44    status_t read(int fd, int64_t timeoutMs);
45
46    /**
47     * Whether we timed out.
48     */
49    bool timedOut() { return mTimedOut; }
50
51    /**
52     * If more than 4 MB is read, we truncate the data and return success.
53     * Downstream tools must handle truncated incident reports as best as possible
54     * anyway because they could be cut off for a lot of reasons and it's best
55     * to get as much useful information out of the system as possible. If this
56     * happens, truncated() will return true so it can be marked. If the data is
57     * exactly 4 MB, truncated is still set. Sorry.
58     */
59    bool truncated() { return mTruncated; }
60
61    /**
62     * How much data was read.
63     */
64    size_t size();
65
66    /**
67     * Write the data that we recorded to the fd given.
68     */
69    status_t write(ReportRequestSet* requests);
70
71    /**
72     * How long the read took in milliseconds.
73     */
74    int64_t durationMs() { return mFinishTime - mStartTime; }
75
76private:
77    vector<uint8_t*> mBuffers;
78    int64_t mStartTime;
79    int64_t mFinishTime;
80    ssize_t mCurrentWritten;
81    bool mTimedOut;
82    bool mTruncated;
83};
84
85
86#endif // FD_BUFFER_H
87