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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 "mongo/db/session/sessions_collection.h"
#include <functional>
#include <memory>
#include <vector>
#include "mongo/bson/bsonobjbuilder.h"
#include "mongo/client/dbclient_base.h"
#include "mongo/db/create_indexes_gen.h"
#include "mongo/db/ops/write_ops.h"
#include "mongo/db/repl/read_concern_args.h"
#include "mongo/db/session/logical_session_id.h"
#include "mongo/db/session/logical_session_id_helpers.h"
#include "mongo/rpc/get_status_from_command_result.h"
namespace mongo {
namespace {
// This batch size is chosen to ensure that we don't form requests larger than the 16mb limit.
// Especially for refreshes, the updates we send include the full user name (user@db), and user
// names can be quite large (we enforce a max 10k limit for usernames used with sessions).
//
// At 1000 elements, a 16mb payload gives us a budget of 16000 bytes per user, which we should
// comfortably be able to stay under, even with 10k user names.
constexpr size_t kMaxBatchSize = 1000;
// Used to refresh or remove items from the session collection with write
// concern majority
const WriteConcernOptions kMajorityWriteConcern{WriteConcernOptions::kMajority,
WriteConcernOptions::SyncMode::UNSET,
WriteConcernOptions::kWriteConcernTimeoutSystem};
BSONObj lsidQuery(const LogicalSessionId& lsid) {
return BSON(LogicalSessionRecord::kIdFieldName << lsid.toBSON());
}
BSONObj lsidQuery(const LogicalSessionRecord& record) {
return lsidQuery(record.getId());
}
BSONArray updateQuery(const LogicalSessionRecord& record) {
// [ { $set : { lastUse : $$NOW } } , { $set : { user: <user> } } ]
// Build our update doc.
BSONArrayBuilder updateBuilder;
updateBuilder << BSON("$set" << BSON(LogicalSessionRecord::kLastUseFieldName << "$$NOW"));
if (record.getUser()) {
updateBuilder << BSON("$set" << BSON(LogicalSessionRecord::kUserFieldName
<< BSON("name" << *record.getUser())));
}
return updateBuilder.arr();
}
template <typename TFactory, typename AddLineFn, typename SendFn, typename Container>
void runBulkGeneric(TFactory makeT, AddLineFn addLine, SendFn sendBatch, const Container& items) {
using T = decltype(makeT());
size_t i = 0;
boost::optional<T> thing;
auto setupBatch = [&] {
i = 0;
thing.emplace(makeT());
};
auto sendLocalBatch = [&] {
sendBatch(thing.value());
};
setupBatch();
for (const auto& item : items) {
addLine(*thing, item);
if (++i >= kMaxBatchSize) {
sendLocalBatch();
setupBatch();
}
}
if (i > 0) {
sendLocalBatch();
}
}
template <typename InitBatchFn, typename AddLineFn, typename SendBatchFn, typename Container>
void runBulkCmd(StringData label,
InitBatchFn&& initBatch,
AddLineFn&& addLine,
SendBatchFn&& sendBatch,
const Container& items) {
BufBuilder buf;
boost::optional<BSONObjBuilder> batchBuilder;
boost::optional<BSONArrayBuilder> entries;
auto makeBatch = [&] {
buf.reset();
batchBuilder.emplace(buf);
initBatch(&(batchBuilder.value()));
entries.emplace(batchBuilder->subarrayStart(label));
return &(entries.value());
};
auto sendLocalBatch = [&](BSONArrayBuilder*) {
entries->done();
sendBatch(batchBuilder->done());
};
runBulkGeneric(makeBatch, addLine, sendLocalBatch, items);
}
} // namespace
constexpr StringData SessionsCollection::kSessionsTTLIndex;
SessionsCollection::SessionsCollection() = default;
SessionsCollection::~SessionsCollection() = default;
SessionsCollection::SendBatchFn SessionsCollection::makeSendFnForBatchWrite(
const NamespaceString& ns, DBClientBase* client) {
auto send = [client, ns](BSONObj batch) {
BSONObj res;
if (!client->runCommand(ns.dbName(), batch, res)) {
uassertStatusOK(getStatusFromCommandResult(res));
}
};
return send;
}
SessionsCollection::SendBatchFn SessionsCollection::makeSendFnForCommand(const NamespaceString& ns,
DBClientBase* client) {
auto send = [client, ns](BSONObj cmd) {
BSONObj res;
if (!client->runCommand(ns.dbName(), cmd, res)) {
uassertStatusOK(getStatusFromCommandResult(res));
}
};
return send;
}
SessionsCollection::FindBatchFn SessionsCollection::makeFindFnForCommand(const NamespaceString& ns,
DBClientBase* client) {
auto send = [client, ns](BSONObj cmd) -> BSONObj {
BSONObj res;
if (!client->runCommand(ns.dbName(), cmd, res)) {
uassertStatusOK(getStatusFromCommandResult(res));
}
return res;
};
return send;
}
void SessionsCollection::_doRefresh(const NamespaceString& ns,
const std::vector<LogicalSessionRecord>& sessions,
SendBatchFn send) {
auto init = [ns](BSONObjBuilder* batch) {
batch->append("update", ns.coll());
batch->append("ordered", false);
batch->append(WriteConcernOptions::kWriteConcernField, kMajorityWriteConcern.toBSON());
};
auto add = [](BSONArrayBuilder* entries, const LogicalSessionRecord& record) {
entries->append(
BSON("q" << lsidQuery(record) << "u" << updateQuery(record) << "upsert" << true));
};
runBulkCmd("updates", init, add, send, sessions);
}
void SessionsCollection::_doRemove(const NamespaceString& ns,
const std::vector<LogicalSessionId>& sessions,
SendBatchFn send) {
auto init = [ns](BSONObjBuilder* batch) {
batch->append("delete", ns.coll());
batch->append("ordered", false);
batch->append(WriteConcernOptions::kWriteConcernField, kMajorityWriteConcern.toBSON());
};
auto add = [](BSONArrayBuilder* builder, const LogicalSessionId& lsid) {
builder->append(BSON("q" << lsidQuery(lsid) << "limit" << 0));
};
runBulkCmd("deletes", init, add, send, sessions);
}
LogicalSessionIdSet SessionsCollection::_doFindRemoved(
const NamespaceString& ns, const std::vector<LogicalSessionId>& sessions, FindBatchFn send) {
auto makeT = [] {
return std::vector<LogicalSessionId>{};
};
auto add = [](std::vector<LogicalSessionId>& batch, const LogicalSessionId& record) {
batch.push_back(record);
};
LogicalSessionIdSet removed{sessions.begin(), sessions.end()};
auto wrappedSend = [&](BSONObj batch) {
BSONObjBuilder batchWithReadConcernLocal(batch);
batchWithReadConcernLocal.append(repl::ReadConcernArgs::kReadConcernFieldName,
repl::ReadConcernArgs::kLocal);
auto swBatchResult = send(batchWithReadConcernLocal.obj());
auto result = SessionsCollectionFetchResult::parse(
IDLParserContext{"SessionsCollectionFetchResult"}, swBatchResult);
for (const auto& lsid : result.getCursor().getFirstBatch()) {
removed.erase(lsid.get_id());
}
};
auto sendLocal = [&](std::vector<LogicalSessionId>& batch) {
SessionsCollectionFetchRequest request;
request.setFind(ns.coll());
request.setFilter({});
request.getFilter().set_id({});
request.getFilter().get_id().setIn(batch);
request.setProjection({});
request.getProjection().set_id(1);
request.setBatchSize(batch.size());
request.setLimit(batch.size());
request.setSingleBatch(true);
wrappedSend(request.toBSON());
};
runBulkGeneric(makeT, add, sendLocal, sessions);
return removed;
}
BSONObj SessionsCollection::generateCreateIndexesCmd() {
NewIndexSpec index;
index.setKey(BSON("lastUse" << 1));
index.setName(kSessionsTTLIndex);
index.setExpireAfterSeconds(localLogicalSessionTimeoutMinutes * 60);
CreateIndexesCommand createIndexes(NamespaceString::kLogicalSessionsNamespace);
createIndexes.setIndexes({index.toBSON()});
return createIndexes.toBSON(BSON(WriteConcernOptions::kWriteConcernField
<< WriteConcernOptions::kInternalWriteDefault));
}
BSONObj SessionsCollection::generateCollModCmd() {
BSONObjBuilder collModCmdBuilder;
collModCmdBuilder << "collMod" << NamespaceString::kLogicalSessionsNamespace.coll();
BSONObjBuilder indexBuilder(collModCmdBuilder.subobjStart("index"));
indexBuilder << "name" << kSessionsTTLIndex;
indexBuilder << "expireAfterSeconds" << localLogicalSessionTimeoutMinutes * 60;
indexBuilder.done();
collModCmdBuilder.append(WriteConcernOptions::kWriteConcernField,
WriteConcernOptions::kInternalWriteDefault);
collModCmdBuilder.done();
return collModCmdBuilder.obj();
}
} // namespace mongo
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