1 /*
2  * Copyright (C) 2012-2014 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 _LOGD_LOG_BUFFER_ELEMENT_H__
18 #define _LOGD_LOG_BUFFER_ELEMENT_H__
19 
20 #include <stdatomic.h>
21 #include <stdlib.h>
22 #include <sys/types.h>
23 
24 #include <sysutils/SocketClient.h>
25 #include <log/log.h>
26 #include <log/log_read.h>
27 
28 class LogBuffer;
29 
30 #define EXPIRE_HOUR_THRESHOLD 24 // Only expire chatty UID logs to preserve
31                                  // non-chatty UIDs less than this age in hours
32 #define EXPIRE_THRESHOLD 10      // A smaller expire count is considered too
33                                  // chatty for the temporal expire messages
34 #define EXPIRE_RATELIMIT 10      // maximum rate in seconds to report expiration
35 
36 class LogBufferElement {
37 
38     friend LogBuffer;
39 
40     const log_id_t mLogId;
41     const uid_t mUid;
42     const pid_t mPid;
43     const pid_t mTid;
44     char *mMsg;
45     union {
46         const unsigned short mMsgLen; // mMSg != NULL
47         unsigned short mDropped;      // mMsg == NULL
48     };
49     const uint64_t mSequence;
50     log_time mRealTime;
51     static atomic_int_fast64_t sequence;
52 
53     // assumption: mMsg == NULL
54     size_t populateDroppedMessage(char *&buffer,
55                                   LogBuffer *parent);
56 
57 public:
58     LogBufferElement(log_id_t log_id, log_time realtime,
59                      uid_t uid, pid_t pid, pid_t tid,
60                      const char *msg, unsigned short len);
61     virtual ~LogBufferElement();
62 
getLogId()63     log_id_t getLogId() const { return mLogId; }
getUid(void)64     uid_t getUid(void) const { return mUid; }
getPid(void)65     pid_t getPid(void) const { return mPid; }
getTid(void)66     pid_t getTid(void) const { return mTid; }
getDropped(void)67     unsigned short getDropped(void) const { return mMsg ? 0 : mDropped; }
setDropped(unsigned short value)68     unsigned short setDropped(unsigned short value) {
69         if (mMsg) {
70             delete [] mMsg;
71             mMsg = NULL;
72         }
73         return mDropped = value;
74     }
getMsgLen()75     unsigned short getMsgLen() const { return mMsg ? mMsgLen : 0; }
getSequence(void)76     uint64_t getSequence(void) const { return mSequence; }
getCurrentSequence(void)77     static uint64_t getCurrentSequence(void) { return sequence.load(memory_order_relaxed); }
getRealTime(void)78     log_time getRealTime(void) const { return mRealTime; }
79 
80     uint32_t getTag(void) const;
81 
82     static const uint64_t FLUSH_ERROR;
83     uint64_t flushTo(SocketClient *writer, LogBuffer *parent, bool privileged);
84 };
85 
86 #endif
87