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/*
* Copyright 2013, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SNTP_CLIENT_H_
#define SNTP_CLIENT_H_
#include <media/stagefright/foundation/ABase.h>
#include <utils/Errors.h>
namespace android {
// Implementation of the SNTP (Simple Network Time Protocol)
struct SNTPClient {
SNTPClient();
status_t requestTime(const char *host);
// given a time obtained from ALooper::GetNowUs()
// return the number of us elapsed since Jan 1 1970 00:00:00 (UTC).
int64_t adjustTimeUs(int64_t timeUs) const;
private:
enum {
kNTPPort = 123,
kNTPPacketSize = 48,
kNTPModeClient = 3,
kNTPVersion = 3,
kNTPTransmitTimeOffset = 40,
kNTPOriginateTimeOffset = 24,
kNTPReceiveTimeOffset = 32,
};
uint64_t mTimeReferenceNTP;
int64_t mTimeReferenceUs;
int64_t mRoundTripTimeNTP;
static void writeTimeStamp(uint8_t *dst, uint64_t ntpTime);
static uint64_t readTimeStamp(const uint8_t *dst);
static uint64_t getNowNTP();
static uint64_t makeNTP(uint64_t deltaUs);
DISALLOW_EVIL_CONSTRUCTORS(SNTPClient);
};
} // namespace android
#endif // SNTP_CLIENT_H_
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