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// optime.h - OpTime class
/* Copyright 2009 10gen Inc.
*
* 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.
*/
#pragma once
#include "../db/concurrency.h"
namespace mongo {
/* Operation sequence #. A combination of current second plus an ordinal value.
*/
#pragma pack(4)
class OpTime {
unsigned i;
unsigned secs;
static OpTime last;
public:
unsigned getSecs() const {
return secs;
}
OpTime(unsigned long long date) {
reinterpret_cast<unsigned long long&>(*this) = date;
}
OpTime(unsigned a, unsigned b) {
secs = a;
i = b;
}
OpTime() {
secs = 0;
i = 0;
}
static OpTime now() {
unsigned t = (unsigned) time(0);
// DEV assertInWriteLock();
if ( t < last.secs ){
log() << "clock skew detected prev: " << last.secs << " now: " << t << " trying to handle..." << endl;
t = last.secs;
}
if ( last.secs == t ) {
last.i++;
return last;
}
last = OpTime(t, 1);
return last;
}
/* We store OpTime's in the database as BSON Date datatype -- we needed some sort of
64 bit "container" for these values. While these are not really "Dates", that seems a
better choice for now than say, Number, which is floating point. Note the BinData type
is perhaps the cleanest choice, lacking a true unsigned64 datatype, but BinData has 5
bytes of overhead.
*/
unsigned long long asDate() const {
return *((unsigned long long *) &i);
}
// unsigned long long& asDate() { return *((unsigned long long *) &i); }
bool isNull() {
return secs == 0;
}
string toStringLong() const {
char buf[64];
time_t_to_String(secs, buf);
stringstream ss;
ss << buf << ' ';
ss << hex << secs << ':' << i;
return ss.str();
}
string toString() const {
stringstream ss;
ss << hex << secs << ':' << i;
return ss.str();
}
operator string() const { return toString(); }
bool operator==(const OpTime& r) const {
return i == r.i && secs == r.secs;
}
bool operator!=(const OpTime& r) const {
return !(*this == r);
}
bool operator<(const OpTime& r) const {
if ( secs != r.secs )
return secs < r.secs;
return i < r.i;
}
};
#pragma pack()
} // namespace mongo
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