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/**
* Copyright (C) 2019-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/base/init.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/commands.h"
#include "mongo/db/commands/test_commands_enabled.h"
#include "mongo/db/cursor_manager.h"
#include "mongo/db/db_raii.h"
#include "mongo/db/exec/sbe/parser/parser.h"
#include "mongo/db/exec/sbe/stages/stages.h"
#include "mongo/db/query/cursor_request.h"
#include "mongo/db/query/cursor_response.h"
#include "mongo/db/query/find_common.h"
#include "mongo/db/query/plan_executor_factory.h"
namespace mongo {
/**
* A command for manually constructing a SBE query tree and running it.
*
* db.runCommand({sbe: "sbe query text"})
*
* This command is only for testing/experimentation, and requires the 'enableTestCommands' flag to
* be turned on.
*/
class SBECommand final : public BasicCommand {
public:
SBECommand() : BasicCommand("sbe") {}
AllowedOnSecondary secondaryAllowed(ServiceContext* context) const override {
return AllowedOnSecondary::kOptIn;
}
bool supportsWriteConcern(const BSONObj& cmd) const override {
return false;
}
bool run(OperationContext* opCtx,
const std::string& dbname,
const BSONObj& cmdObj,
BSONObjBuilder& result) override {
CommandHelpers::handleMarkKillOnClientDisconnect(opCtx);
// If SBE is disabled, then also disallow the SBE command.
uassert(5772200,
"the SBE command requires the SBE engine to be enabled",
!internalQueryForceClassicEngine.load());
// The SBE command may read from multiple collections, but no logic is in place to acquire
// locks on all of the necessary collections and databases. Therefore, its implementation
// depends on lock free reads being enabled (which is the case by default).
uassert(5772201,
"the SBE command requires lock free reads",
!storageGlobalParams.disableLockFreeReads);
long long batchSize;
uassertStatusOK(CursorRequest::parseCommandCursorOptions(
cmdObj, query_request_helper::kDefaultBatchSize, &batchSize));
// Acquire the global lock, acquire a snapshot, and stash our version of the collection
// catalog. The is necessary because SBE plan executors currently use the external lock
// policy. Note that this must be done before parsing because the parser may look up
// collections in the stashed catalog.
//
// Unlike the similar 'AutoGetCollection*' variants of this db_raii object, this will not
// handle re-establishing a view of the catalog which is consistent with the new storage
// snapshot after a yield. For this reason, the SBE command cannot yield.
//
// Also, this will not handle all read concerns. This is ok because the SBE command is
// experimental and need not support the various read concerns.
AutoGetDbForReadLockFree autoGet{opCtx, dbname};
auto env = std::make_unique<sbe::RuntimeEnvironment>();
sbe::Parser parser(env.get());
auto root = parser.parse(opCtx, dbname, cmdObj["sbe"].String());
auto [resultSlot, recordIdSlot] = parser.getTopLevelSlots();
std::unique_ptr<PlanExecutor, PlanExecutor::Deleter> exec;
BSONArrayBuilder firstBatch;
// Create a trivial cannonical query for the 'sbe' command execution.
NamespaceString nss{dbname};
auto statusWithCQ =
CanonicalQuery::canonicalize(opCtx, std::make_unique<FindCommandRequest>(nss));
std::unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
stage_builder::PlanStageData data{std::move(env)};
if (resultSlot) {
data.outputs.set(stage_builder::PlanStageSlots::kResult, *resultSlot);
}
if (recordIdSlot) {
data.outputs.set(stage_builder::PlanStageSlots::kRecordId, *recordIdSlot);
}
root->attachToOperationContext(opCtx);
exec = uassertStatusOK(plan_executor_factory::make(opCtx,
std::move(cq),
nullptr,
{std::move(root), std::move(data)},
{},
&CollectionPtr::null,
false, /* returnOwnedBson */
nss,
nullptr));
for (long long objCount = 0; objCount < batchSize; objCount++) {
BSONObj next;
PlanExecutor::ExecState state = exec->getNext(&next, nullptr);
if (state == PlanExecutor::IS_EOF) {
break;
}
invariant(state == PlanExecutor::ADVANCED);
// If we can't fit this result inside the current batch, then we stash it for later.
if (!FindCommon::haveSpaceForNext(next, objCount, firstBatch.len())) {
exec->enqueue(next);
break;
}
firstBatch.append(next);
}
if (exec->isEOF()) {
appendCursorResponseObject(0LL, nss.ns(), firstBatch.arr(), &result);
return true;
}
exec->saveState();
exec->detachFromOperationContext();
const auto pinnedCursor = CursorManager::get(opCtx)->registerCursor(
opCtx,
{std::move(exec),
nss,
AuthorizationSession::get(opCtx->getClient())->getAuthenticatedUserNames(),
APIParameters::get(opCtx),
opCtx->getWriteConcern(),
repl::ReadConcernArgs::get(opCtx),
ReadPreferenceSetting::get(opCtx),
cmdObj,
{}});
appendCursorResponseObject(
pinnedCursor.getCursor()->cursorid(), nss.ns(), firstBatch.arr(), &result);
return true;
}
// This is a test-only command so shouldn't be enabled in production, but we try to require
// auth on new test commands anyway, just in case someone enables them by mistake.
Status checkAuthForOperation(OperationContext* opCtx,
const std::string& dbname,
const BSONObj& cmdObj) const override {
auto authSession = AuthorizationSession::get(opCtx->getClient());
if (!authSession->isAuthorizedForAnyActionOnAnyResourceInDB(dbname)) {
return Status(ErrorCodes::Unauthorized, "Unauthorized");
}
return Status::OK();
}
};
MONGO_REGISTER_TEST_COMMAND(SBECommand);
} // namespace mongo
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