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/* Copyright 2009 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects
* for all of the code used other than as permitted herein. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you do not
* wish to do so, delete this exception statement from your version. If you
* delete this exception statement from all source files in the program,
* then also delete it in the license file.
*/
#pragma once
#include "mongo/base/data_view.h"
#include "mongo/bson/util/builder.h"
#include "mongo/util/assert_util.h"
#include "mongo/util/time_support.h"
namespace mongo {
class BSONObj;
/**
* Timestamp: A combination of a count of seconds since the POSIX epoch plus an ordinal value.
*/
class Timestamp {
public:
// Timestamp to signal that the storage engine should take unstable checkpoints.
static const Timestamp kAllowUnstableCheckpointsSentinel;
// Maximum Timestamp value.
static Timestamp max();
// Returns the minimum timestamp. Used in the context of selecting and ordering storage engine
// snapshots.
static Timestamp min() {
return Timestamp();
}
/**
* DEPRECATED Constructor that builds a Timestamp from a Date_t by using the
* high-order 4 bytes of "date" for the "secs" field and the low-order 4 bytes
* for the "i" field.
*/
explicit Timestamp(Date_t date) : Timestamp(date.toULL()) {}
/**
* DEPRECATED Constructor that builds a Timestamp from a 64-bit unsigned integer by using
* the high-order 4 bytes of "v" for the "secs" field and the low-order 4 bytes for the "i"
* field.
*/
explicit Timestamp(unsigned long long v) : Timestamp(v >> 32, v) {}
Timestamp(Seconds s, unsigned increment) : Timestamp(s.count(), increment) {}
Timestamp(unsigned a, unsigned b) : i(b), secs(a) {}
Timestamp() = default;
unsigned getSecs() const {
return secs;
}
unsigned getInc() const {
return i;
}
unsigned long long asULL() const {
unsigned long long result = secs;
result <<= 32;
result |= i;
return result;
}
long long asLL() const {
return static_cast<long long>(asULL());
}
bool isNull() const {
return secs == 0;
}
std::string toStringPretty() const;
std::string toString() const;
bool operator==(const Timestamp& r) const {
return tie() == r.tie();
}
bool operator!=(const Timestamp& r) const {
return tie() != r.tie();
}
bool operator<(const Timestamp& r) const {
return tie() < r.tie();
}
bool operator<=(const Timestamp& r) const {
return tie() <= r.tie();
}
bool operator>(const Timestamp& r) const {
return tie() > r.tie();
}
bool operator>=(const Timestamp& r) const {
return tie() >= r.tie();
}
// Append the BSON representation of this Timestamp to the given BufBuilder with the given
// name. This lives here because Timestamp manages its own serialization format.
void append(BufBuilder& builder, const StringData& fieldName) const;
BSONObj toBSON() const;
private:
std::tuple<unsigned, unsigned> tie() const {
return std::tie(secs, i);
}
unsigned i = 0;
unsigned secs = 0;
};
} // namespace mongo
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