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 uint64_t ntpts = ((unsigned long long)(stAndrodTp.tv_sec + 2208988800UL) << 32) +
34 (unsigned long long)(stAndrodTp.tv_usec / 1e6 * 4294967296.);
35
36 pstNtpTime.m_uiNtpHigh32Bits = (ntpts >> 32);
37 pstNtpTime.m_uiNtpLow32Bits = ntpts;
38 }
39 }
40
Srand()41 RtpDt_Void RtpOsUtil::Srand()
42 {
43 struct timeval stSysTime;
44 gettimeofday(&stSysTime, nullptr);
45 RtpDt_UInt32 uiSeed = stSysTime.tv_usec * 1000;
46 srand(uiSeed);
47 }
48
Rand()49 RtpDt_UInt32 RtpOsUtil::Rand()
50 {
51 RtpOsUtil::Srand();
52 return rand();
53 }
54
Ntohl(RtpDt_UInt32 uiNetlong)55 RtpDt_UInt32 RtpOsUtil::Ntohl(RtpDt_UInt32 uiNetlong)
56 {
57 return ntohl(uiNetlong);
58 }
59
RRand()60 RtpDt_Double RtpOsUtil::RRand()
61 {
62 tRTP_NTP_TIME stNtpTs = {0, 0};
63 RtpOsUtil::Srand();
64 RtpDt_Double dRandNum = static_cast<RtpDt_Double>(rand()) / static_cast<RtpDt_Double>(RAND_MAX);
65 RtpOsUtil::GetNtpTime(stNtpTs);
66 RtpDt_Double dTemp = ((dRandNum * stNtpTs.m_uiNtpHigh32Bits) +
67 (stNtpTs.m_uiNtpLow32Bits / static_cast<RtpDt_Double>(RTP_MILLISEC_MICRO)));
68
69 if (dTemp > RTP_ZERO)
70 {
71 return 1.0 / dTemp;
72 }
73 else
74 {
75 return 1.0;
76 }
77 }
78