1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140
|
// oplog.h - writing to and reading from oplog
/**
* Copyright (C) 2008 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/>.
*/
/*
local.oplog.$main is the default
*/
#pragma once
#include "pdfile.h"
#include "db.h"
#include "dbhelpers.h"
#include "clientcursor.h"
#include "../client/dbclient.h"
#include "../util/optime.h"
#include "../util/timer.h"
namespace mongo {
void createOplog();
void _logOpObjRS(const BSONObj& op);
/** Write operation to the log (local.oplog.$main)
@param opstr
"i" insert
"u" update
"d" delete
"c" db cmd
"n" no-op
"db" declares presence of a database (ns is set to the db name + '.')
See _logOp() in oplog.cpp for more details.
*/
void logOp(const char *opstr, const char *ns, const BSONObj& obj, BSONObj *patt = 0, bool *b = 0);
void logKeepalive();
/** puts obj in the oplog as a comment (a no-op). Just for diags.
convention is
{ msg : "text", ... }
*/
void logOpComment(const BSONObj& obj);
void oplogCheckCloseDatabase( Database * db );
extern int __findingStartInitialTimeout; // configurable for testing
class QueryPlan;
/** Implements an optimized procedure for finding the first op in the oplog. */
class FindingStartCursor {
public:
/**
* The cursor will attempt to find the first op in the oplog matching the
* 'ts' field of the qp's query.
*/
FindingStartCursor( const QueryPlan & qp );
/** @return true if the first matching op in the oplog has been found. */
bool done() const { return !_findingStart; }
/** @return cursor pointing to the first matching op, if done(). */
shared_ptr<Cursor> cursor() { verify( 14835, done() ); return _c; }
/** Iterate the cursor, to continue trying to find matching op. */
void next();
/** Yield cursor, if not done(). */
bool prepareToYield() {
if ( _findingStartCursor ) {
return _findingStartCursor->prepareToYield( _yieldData );
}
return false;
}
/** Recover from cursor yield. */
void recoverFromYield() {
if ( _findingStartCursor ) {
if ( !ClientCursor::recoverFromYield( _yieldData ) ) {
_findingStartCursor.reset( 0 );
msgassertedNoTrace( 15889, "FindingStartCursor::recoverFromYield() failed to recover" );
}
}
}
private:
enum FindingStartMode { Initial, FindExtent, InExtent };
const QueryPlan &_qp;
bool _findingStart;
FindingStartMode _findingStartMode;
auto_ptr< CoveredIndexMatcher > _matcher;
Timer _findingStartTimer;
ClientCursor::CleanupPointer _findingStartCursor;
shared_ptr<Cursor> _c;
ClientCursor::YieldData _yieldData;
DiskLoc extentFirstLoc( const DiskLoc &rec );
DiskLoc prevExtentFirstLoc( const DiskLoc &rec );
void createClientCursor( const DiskLoc &startLoc = DiskLoc() );
void destroyClientCursor() {
_findingStartCursor.reset( 0 );
}
void init();
bool firstDocMatchesOrEmpty() const;
};
void pretouchOperation(const BSONObj& op);
void pretouchN(vector<BSONObj>&, unsigned a, unsigned b);
/**
* take an op and apply locally
* used for applying from an oplog
* @param fromRepl really from replication or for testing/internal/command/etc...
* Returns if the op was an update that could not be applied (true on failure)
*/
bool applyOperation_inlock(const BSONObj& op , bool fromRepl = true );
/**
* If applyOperation_inlock should be called again after an update fails.
*/
bool shouldRetry(const BSONObj& op , const string& hn);
}
|