1 /**
2 * Copyright (C) 2022 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 #include <sys/time.h>
18 #include <stdlib.h>
19 #include <netinet/in.h>
20 #include <RtpOsUtil.h>
21
RtpOsUtil()22 RtpOsUtil::RtpOsUtil() {}
23
~RtpOsUtil()24 RtpOsUtil::~RtpOsUtil() {}
25
GetNtpTime(tRTP_NTP_TIME & pstNtpTime)26 RtpDt_Void RtpOsUtil::GetNtpTime(tRTP_NTP_TIME& pstNtpTime)
27 {
28 struct timeval stAndrodTp;
29
30 if (gettimeofday(&stAndrodTp, nullptr) != -1)
31 {
32 // To convert a UNIX timestamp (seconds since 1970) to NTP time, add 2,208,988,800 seconds
33 pstNtpTime.m_uiNtpHigh32Bits = stAndrodTp.tv_sec + 2208988800UL;
34 pstNtpTime.m_uiNtpLow32Bits = (RtpDt_UInt32)(stAndrodTp.tv_usec * 4294UL);
35 }
36 }
37
Srand()38 RtpDt_Void RtpOsUtil::Srand()
39 {
40 struct timeval stSysTime;
41 gettimeofday(&stSysTime, nullptr);
42 RtpDt_UInt32 uiSeed = stSysTime.tv_usec * 1000;
43 srand(uiSeed);
44 }
45
Rand()46 RtpDt_UInt32 RtpOsUtil::Rand()
47 {
48 RtpOsUtil::Srand();
49 return rand();
50 }
51
Ntohl(RtpDt_UInt32 uiNetlong)52 RtpDt_UInt32 RtpOsUtil::Ntohl(RtpDt_UInt32 uiNetlong)
53 {
54 return ntohl(uiNetlong);
55 }
56
RRand()57 RtpDt_Double RtpOsUtil::RRand()
58 {
59 tRTP_NTP_TIME stNtpTs = {0, 0};
60 RtpOsUtil::Srand();
61 RtpDt_Double dRandNum = static_cast<RtpDt_Double>(rand()) / static_cast<RtpDt_Double>(RAND_MAX);
62 RtpOsUtil::GetNtpTime(stNtpTs);
63 RtpDt_Double dTemp = ((dRandNum * stNtpTs.m_uiNtpHigh32Bits) +
64 (stNtpTs.m_uiNtpLow32Bits / static_cast<RtpDt_Double>(RTP_MILLISEC_MICRO)));
65
66 if (dTemp > RTP_ZERO)
67 {
68 return 1.0 / dTemp;
69 }
70 else
71 {
72 return 1.0;
73 }
74 }
75