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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 <string>
#include "mongo/base/status.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/catalog/collection.h"
#include "mongo/db/commands/plan_cache_commands.h"
#include "mongo/db/db_raii.h"
#include "mongo/db/matcher/extensions_callback_real.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/query/collection_query_info.h"
#include "mongo/db/query/plan_cache_callbacks.h"
#include "mongo/db/query/plan_cache_key_factory.h"
#include "mongo/db/query/plan_ranker.h"
#include "mongo/db/query/query_utils.h"
#include "mongo/db/query/sbe_plan_cache.h"
#include "mongo/logv2/log.h"
#define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kCommand
namespace mongo {
namespace {
PlanCache* getPlanCache(OperationContext* opCtx, const CollectionPtr& collection) {
invariant(collection);
PlanCache* planCache = CollectionQueryInfo::get(collection).getPlanCache();
invariant(planCache);
return planCache;
}
/**
* Clears collection's plan cache. If query shape is provided, clears plans for that single query
* shape only.
*/
Status clear(OperationContext* opCtx,
const CollectionPtr& collection,
PlanCache* planCache,
const std::string& ns,
const BSONObj& cmdObj) {
invariant(planCache);
// According to the specification, the planCacheClear command runs in two modes:
// - clear all query shapes; or
// - clear plans for single query shape when a query shape is described in the
// command arguments.
if (cmdObj.hasField("query")) {
auto statusWithCQ = plan_cache_commands::canonicalize(opCtx, ns, cmdObj);
if (!statusWithCQ.isOK()) {
return statusWithCQ.getStatus();
}
auto cq = std::move(statusWithCQ.getValue());
// Based on a query shape only, we cannot be sure whether a query with the given query shape
// can be executed with the SBE engine or not. Therefore, we try to clean the plan caches in
// both cases.
stdx::unordered_set<uint32_t> planCacheCommandKeys = {canonical_query_encoder::computeHash(
canonical_query_encoder::encodeForPlanCacheCommand(*cq))};
plan_cache_commands::removePlanCacheEntriesByPlanCacheCommandKeys(planCacheCommandKeys,
planCache);
plan_cache_commands::removePlanCacheEntriesByPlanCacheCommandKeys(
planCacheCommandKeys, collection->uuid(), &sbe::getPlanCache(opCtx));
return Status::OK();
}
// If query is not provided, make sure sort, projection, and collation are not in arguments.
// We do not want to clear the entire cache inadvertently when the user
// forgets to provide a value for "query".
if (cmdObj.hasField("sort") || cmdObj.hasField("projection") || cmdObj.hasField("collation")) {
return Status(ErrorCodes::BadValue,
"sort, projection, or collation provided without query");
}
planCache->clear();
auto version = CollectionQueryInfo::get(collection).getPlanCacheInvalidatorVersion();
sbe::clearPlanCacheEntriesWith(opCtx->getServiceContext(),
collection->uuid(),
version,
false /*matchSecondaryCollections*/);
LOGV2_DEBUG(
23908, 1, "{namespace}: Cleared plan cache", "Cleared plan cache", "namespace"_attr = ns);
return Status::OK();
}
} // namespace
/**
* The 'planCacheClear' command can be used to clear all entries from a collection's plan cache, or
* to delete a particular plan cache entry. In the latter case, the plan cache entry to delete is
* specified with an example query, like so:
*
* {
* planCacheClear: <collection>,
* query: <query>,
* sort: <sort>,
* projection: <projection>
* }
*/
class PlanCacheClearCommand final : public BasicCommand {
public:
PlanCacheClearCommand() : BasicCommand("planCacheClear") {}
bool run(OperationContext* opCtx,
const DatabaseName& dbName,
const BSONObj& cmdObj,
BSONObjBuilder& result) override;
bool supportsWriteConcern(const BSONObj& cmd) const override {
return false;
}
AllowedOnSecondary secondaryAllowed(ServiceContext*) const override {
return AllowedOnSecondary::kOptIn;
}
Status checkAuthForOperation(OperationContext* opCtx,
const DatabaseName& dbName,
const BSONObj& cmdObj) const override;
std::string help() const override {
return "Drops one or all plan cache entries in a collection.";
}
} planCacheClearCommand;
Status PlanCacheClearCommand::checkAuthForOperation(OperationContext* opCtx,
const DatabaseName& dbName,
const BSONObj& cmdObj) const {
AuthorizationSession* authzSession = AuthorizationSession::get(opCtx->getClient());
ResourcePattern pattern = parseResourcePattern(dbName, cmdObj);
if (authzSession->isAuthorizedForActionsOnResource(pattern, ActionType::planCacheWrite)) {
return Status::OK();
}
return Status(ErrorCodes::Unauthorized, "unauthorized");
}
bool PlanCacheClearCommand::run(OperationContext* opCtx,
const DatabaseName& dbName,
const BSONObj& cmdObj,
BSONObjBuilder& result) {
const NamespaceString nss(CommandHelpers::parseNsCollectionRequired(dbName, cmdObj));
// This is a read lock. The query cache is owned by the collection.
AutoGetCollectionForReadCommand ctx(opCtx, nss);
if (!ctx.getCollection()) {
// Clearing a non-existent collection always succeeds.
return true;
}
auto planCache = getPlanCache(opCtx, ctx.getCollection());
uassertStatusOK(clear(opCtx, ctx.getCollection(), planCache, nss.ns(), cmdObj));
return true;
}
} // namespace mongo
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