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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.
*/
#include "mongo/platform/basic.h"
#include <type_traits>
#include "mongo/db/write_concern_options.h"
#include "mongo/base/status.h"
#include "mongo/base/string_data.h"
#include "mongo/bson/util/bson_extract.h"
#include "mongo/db/field_parser.h"
#include "mongo/db/repl/repl_set_config.h"
#include "mongo/idl/basic_types_gen.h"
#include "mongo/util/str.h"
namespace mongo {
using std::string;
namespace {
/**
* Controls how much a client cares about writes and serves as initializer for the pre-defined
* write concern options.
*
* Default is NORMAL.
*/
enum WriteConcern { W_NONE = 0, W_NORMAL = 1 };
constexpr StringData kJFieldName = "j"_sd;
constexpr StringData kFSyncFieldName = "fsync"_sd;
constexpr StringData kWFieldName = "w"_sd;
constexpr StringData kWTimeoutFieldName = "wtimeout"_sd;
constexpr StringData kGetLastErrorFieldName = "getLastError"_sd;
constexpr StringData kWOpTimeFieldName = "wOpTime"_sd;
constexpr StringData kWElectionIdFieldName = "wElectionId"_sd;
} // namespace
constexpr Milliseconds WriteConcernOptions::kNoTimeout;
constexpr Milliseconds WriteConcernOptions::kNoWaiting;
constexpr StringData WriteConcernOptions::kWriteConcernField;
const char WriteConcernOptions::kMajority[] = "majority";
const BSONObj WriteConcernOptions::Default = BSONObj();
const BSONObj WriteConcernOptions::Acknowledged(BSON("w" << W_NORMAL));
const BSONObj WriteConcernOptions::Unacknowledged(BSON("w" << W_NONE));
const BSONObj WriteConcernOptions::Majority(BSON("w" << WriteConcernOptions::kMajority));
// The "kInternalWriteDefault" write concern, used by internal operations, is deliberately empty (no
// 'w' or 'wtimeout' specified). This allows internal operations to specify a write concern, while
// still allowing it to be either w:1 or automatically upconverted to w:majority on configsvrs.
const BSONObj WriteConcernOptions::kInternalWriteDefault;
constexpr Seconds WriteConcernOptions::kWriteConcernTimeoutSystem;
constexpr Seconds WriteConcernOptions::kWriteConcernTimeoutMigration;
constexpr Seconds WriteConcernOptions::kWriteConcernTimeoutSharding;
constexpr Seconds WriteConcernOptions::kWriteConcernTimeoutUserCommand;
WriteConcernOptions::WriteConcernOptions(int numNodes, SyncMode sync, Milliseconds timeout)
: w{numNodes},
syncMode{sync},
wTimeout(durationCount<Milliseconds>(timeout)),
usedDefaultConstructedWC{false},
notExplicitWValue{false} {}
WriteConcernOptions::WriteConcernOptions(const std::string& mode,
SyncMode sync,
Milliseconds timeout)
: w{mode},
syncMode{sync},
wTimeout(durationCount<Milliseconds>(timeout)),
usedDefaultConstructedWC{false},
notExplicitWValue{false} {}
StatusWith<WriteConcernOptions> WriteConcernOptions::parse(const BSONObj& obj) try {
if (obj.isEmpty()) {
return Status(ErrorCodes::FailedToParse, "write concern object cannot be empty");
}
auto writeConcernIdl = WriteConcernIdl::parse({"WriteConcernOptions"}, obj);
auto parsedW = writeConcernIdl.getWriteConcernW();
WriteConcernOptions writeConcern;
writeConcern.usedDefaultConstructedWC = !parsedW && !writeConcernIdl.getJ() &&
!writeConcernIdl.getFsync() && writeConcernIdl.getWtimeout() == 0;
if (parsedW) {
writeConcern.notExplicitWValue = false;
writeConcern.w = *parsedW;
}
auto j = writeConcernIdl.getJ();
auto fsync = writeConcernIdl.getFsync();
if (j && fsync && *j && *fsync) {
// If j and fsync are both set to true
return Status{ErrorCodes::FailedToParse, "fsync and j options cannot be used together"};
}
if (j && *j) {
writeConcern.syncMode = SyncMode::JOURNAL;
} else if (fsync && *fsync) {
writeConcern.syncMode = SyncMode::FSYNC;
} else if (j) {
// j has been set to false
writeConcern.syncMode = SyncMode::NONE;
}
writeConcern.wTimeout = Milliseconds{writeConcernIdl.getWtimeout()};
if (auto source = writeConcernIdl.getSource()) {
writeConcern._provenance = ReadWriteConcernProvenance(*source);
}
return writeConcern;
} catch (const DBException& ex) {
return ex.toStatus();
}
WriteConcernOptions WriteConcernOptions::deserializerForIDL(const BSONObj& obj) {
if (!obj.isEmpty()) {
return uassertStatusOK(parse(obj));
}
return WriteConcernOptions();
}
StatusWith<WriteConcernOptions> WriteConcernOptions::extractWCFromCommand(const BSONObj& cmdObj) {
// Return the default write concern if no write concern is provided. We check for the existence
// of the write concern field up front in order to avoid the expense of constructing an error
// status in bsonExtractTypedField() below.
if (!cmdObj.hasField(kWriteConcernField)) {
return WriteConcernOptions();
}
BSONElement writeConcernElement;
Status wcStatus =
bsonExtractTypedField(cmdObj, kWriteConcernField, Object, &writeConcernElement);
if (!wcStatus.isOK()) {
return wcStatus;
}
BSONObj writeConcernObj = writeConcernElement.Obj();
// Empty write concern is interpreted to default.
if (writeConcernObj.isEmpty()) {
return WriteConcernOptions();
}
return parse(writeConcernObj);
}
BSONObj WriteConcernOptions::toBSON() const {
BSONObjBuilder builder;
serializeWriteConcernW(w, "w", &builder);
if (syncMode == SyncMode::FSYNC) {
builder.append("fsync", true);
} else if (syncMode == SyncMode::JOURNAL) {
builder.append("j", true);
} else if (syncMode == SyncMode::NONE) {
builder.append("j", false);
}
// Historically we have serialized this as a int32_t, even though it is defined as an
// int64_t in our IDL format.
builder.append("wtimeout", static_cast<int32_t>(durationCount<Milliseconds>(wTimeout)));
_provenance.serialize(&builder);
return builder.obj();
}
bool WriteConcernOptions::needToWaitForOtherNodes() const {
return stdx::holds_alternative<std::string>(w) || stdx::holds_alternative<WTags>(w) ||
(stdx::holds_alternative<std::int64_t>(w) && stdx::get<std::int64_t>(w) > 1);
}
bool WriteConcernOptions::operator==(const WriteConcernOptions& other) const {
return w == other.w && syncMode == other.syncMode && wDeadline == other.wDeadline &&
wTimeout == other.wTimeout && _provenance == other._provenance;
}
} // namespace mongo
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