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/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* 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
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* 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 Server Side 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.
*/
#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kStorage
#include "mongo/platform/basic.h"
#include "mongo/db/storage/wiredtiger/wiredtiger_cursor.h"
#include "mongo/db/storage/recovery_unit.h"
#include "mongo/db/storage/wiredtiger/wiredtiger_util.h"
#include "mongo/logv2/log.h"
#include "mongo/util/log.h"
namespace mongo {
WiredTigerCursor::WiredTigerCursor(const std::string& uri,
uint64_t tableID,
bool allowOverwrite,
OperationContext* opCtx) {
_tableID = tableID;
_ru = WiredTigerRecoveryUnit::get(opCtx);
_session = _ru->getSession();
_readOnce = _ru->getReadOnce();
_isCheckpoint =
(_ru->getTimestampReadSource() == WiredTigerRecoveryUnit::ReadSource::kCheckpoint);
str::stream builder;
if (_readOnce) {
builder << "read_once=true,";
}
if (_isCheckpoint) {
// Type can be "lsm" or "file".
std::string type, sourceURI;
WiredTigerUtil::fetchTypeAndSourceURI(opCtx, uri, &type, &sourceURI);
uassert(ErrorCodes::InvalidOptions,
str::stream() << "LSM does not support opening cursors by checkpoint",
type != "lsm");
builder << "checkpoint=WiredTigerCheckpoint,";
}
// Add this option last to avoid needing a trailing comma. This enables an optimization in
// WiredTiger to skip parsing the config string. See SERVER-43232 for details.
if (!allowOverwrite) {
builder << "overwrite=false";
}
const std::string config = builder;
try {
if (_readOnce || _isCheckpoint) {
_cursor = _session->getNewCursor(uri, config.c_str());
} else {
_cursor = _session->getCachedCursor(uri, tableID, config.c_str());
}
} catch (const ExceptionFor<ErrorCodes::CursorNotFound>& ex) {
// A WiredTiger table will not be available in the latest checkpoint if the checkpoint
// thread hasn't ran after the initial WiredTiger table was created.
if (!_isCheckpoint) {
LOGV2_ERROR(23719, "{ex}", "ex"_attr = ex);
fassertFailedNoTrace(50883);
}
throw;
}
}
WiredTigerCursor::~WiredTigerCursor() {
dassert(_ru->getReadOnce() == _readOnce);
dassert(_isCheckpoint ==
(_ru->getTimestampReadSource() == WiredTigerRecoveryUnit::ReadSource::kCheckpoint));
// Read-once and checkpoint cursors will never take cursors from the cursor cache, and
// should never release cursors into the cursor cache.
if (_readOnce || _isCheckpoint) {
_session->closeCursor(_cursor);
} else {
_session->releaseCursor(_tableID, _cursor);
}
}
void WiredTigerCursor::reset() {
invariantWTOK(_cursor->reset(_cursor));
}
} // namespace mongo
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