path: root/src/mongo/db/storage/durable_catalog.h

/**
 *    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.
 */

#pragma once

#include "mongo/base/string_data.h"
#include "mongo/db/catalog/collection_options.h"
#include "mongo/db/catalog/import_options.h"
#include "mongo/db/index/index_descriptor.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/storage/bson_collection_catalog_entry.h"
#include "mongo/db/storage/durable_catalog_entry.h"
#include "mongo/db/storage/storage_engine.h"

namespace mongo {
/**
 * An interface to modify the on-disk catalog metadata.
 */
class DurableCatalog {
    DurableCatalog(const DurableCatalog&) = delete;
    DurableCatalog& operator=(const DurableCatalog&) = delete;
    DurableCatalog(DurableCatalog&&) = delete;
    DurableCatalog& operator=(DurableCatalog&&) = delete;

protected:
    DurableCatalog() = default;

public:
    static constexpr auto kIsFeatureDocumentFieldName = "isFeatureDoc"_sd;

    /**
     * `Entry` ties together the common identifiers of a single `_mdb_catalog` document.
     */
    struct EntryIdentifier {
        EntryIdentifier() {}
        EntryIdentifier(RecordId catalogId, std::string ident, NamespaceString nss)
            : catalogId(std::move(catalogId)), ident(std::move(ident)), nss(std::move(nss)) {}
        RecordId catalogId;
        std::string ident;
        NamespaceString nss;
    };

    virtual ~DurableCatalog() {}

    static DurableCatalog* get(OperationContext* opCtx) {
        return opCtx->getServiceContext()->getStorageEngine()->getCatalog();
    }

    /**
     *  Allows featureDocuments to be checked with older versions.
     */
    static bool isFeatureDocument(const BSONObj& obj) {
        BSONElement firstElem = obj.firstElement();
        if (firstElem.fieldNameStringData() == kIsFeatureDocumentFieldName) {
            return firstElem.booleanSafe();
        }
        return false;
    }

    /**
     * Gets the parsed namespace from a raw BSON catalog entry.
     */
    static NamespaceString getNamespaceFromCatalogEntry(const BSONObj& catalogEntry) {
        return NamespaceString::parseFromStringExpectTenantIdInMultitenancyMode(
            catalogEntry["ns"].checkAndGetStringData());
    }

    /**
     * Gets the metadata as BSON from a raw BSON catalog entry.
     */
    static BSONObj getMetadataFromCatalogEntry(const BSONObj& catalogEntry) {
        return catalogEntry["md"].Obj();
    }

    virtual void init(OperationContext* opCtx) = 0;

    virtual std::vector<EntryIdentifier> getAllCatalogEntries(OperationContext* opCtx) const = 0;

    /**
     * Scans the persisted catalog until an entry is found matching 'nss'.
     */
    virtual boost::optional<DurableCatalogEntry> scanForCatalogEntryByNss(
        OperationContext* opCtx, const NamespaceString& nss) const = 0;

    /**
     * Scans the persisted catalog until an entry is found matching 'uuid'.
     */
    virtual boost::optional<DurableCatalogEntry> scanForCatalogEntryByUUID(
        OperationContext* opCtx, const UUID& uuid) const = 0;

    virtual EntryIdentifier getEntry(const RecordId& catalogId) const = 0;

    virtual std::string getIndexIdent(OperationContext* opCtx,
                                      const RecordId& id,
                                      StringData idxName) const = 0;

    virtual std::vector<std::string> getIndexIdents(OperationContext* opCtx,
                                                    const RecordId& id) const = 0;

    /**
     * Get a raw catalog entry for catalogId as BSON.
     */
    virtual BSONObj getCatalogEntry(OperationContext* opCtx, const RecordId& catalogId) const = 0;

    /**
     * Like 'getCatalogEntry' above but parses the catalog entry to common types.
     */
    virtual boost::optional<DurableCatalogEntry> getParsedCatalogEntry(
        OperationContext* opCtx, const RecordId& catalogId) const = 0;

    /**
     * Parses the passed in catalog entry object.
     */
    virtual DurableCatalogEntry getParsedCatalogEntry(OperationContext* opCtx,
                                                      const RecordId& catalogId,
                                                      const BSONObj& obj) const = 0;

    /**
     * Like 'getParsedCatalogEntry' above but only extracts the metadata component.
     */
    virtual std::shared_ptr<BSONCollectionCatalogEntry::MetaData> getMetaData(
        OperationContext* opCtx, const RecordId& id) const = 0;

    /**
     * Updates the catalog entry for the collection 'nss' with the fields specified in 'md'. If
     * 'md.indexes' contains a new index entry, then this method generates a new index ident and
     * adds it to the catalog entry.
     */
    virtual void putMetaData(OperationContext* opCtx,
                             const RecordId& id,
                             BSONCollectionCatalogEntry::MetaData& md) = 0;

    virtual std::vector<std::string> getAllIdents(OperationContext* opCtx) const = 0;

    virtual bool isUserDataIdent(StringData ident) const = 0;

    virtual bool isInternalIdent(StringData ident) const = 0;

    virtual bool isCollectionIdent(StringData ident) const = 0;


    virtual RecordStore* getRecordStore() = 0;

    /**
     * Create an entry in the catalog for an orphaned collection found in the
     * storage engine. Return the generated ns of the collection.
     * Note that this function does not recreate the _id index on the for non-clustered collections
     * because it does not have access to index catalog.
     */
    virtual StatusWith<std::string> newOrphanedIdent(OperationContext* opCtx,
                                                     std::string ident,
                                                     const CollectionOptions& optionsWithUUID) = 0;

    virtual std::string getFilesystemPathForDb(const std::string& dbName) const = 0;

    /**
     * Generate an internal ident name.
     */
    virtual std::string newInternalIdent() = 0;

    /**
     * Generates a new unique identifier for a new "thing".
     * @param nss - the containing namespace
     * @param kind - what this "thing" is, likely collection or index
     *
     * Warning: It's only unique as far as we know without checking every file on disk, but it is
     * possible that this ident collides with an existing one.
     */
    virtual std::string generateUniqueIdent(NamespaceString nss, const char* kind) = 0;

    /**
     * Generate an internal resumable index build ident name.
     */
    virtual std::string newInternalResumableIndexBuildIdent() = 0;

    /**
     * On success, returns the RecordId which identifies the new record store in the durable catalog
     * in addition to ownership of the new RecordStore.
     */
    virtual StatusWith<std::pair<RecordId, std::unique_ptr<RecordStore>>> createCollection(
        OperationContext* opCtx,
        const NamespaceString& nss,
        const CollectionOptions& options,
        bool allocateDefaultSpace) = 0;

    virtual Status createIndex(OperationContext* opCtx,
                               const RecordId& catalogId,
                               const NamespaceString& nss,
                               const CollectionOptions& collOptions,
                               const IndexDescriptor* spec) = 0;

    /**
     * Import a collection by inserting the given metadata into the durable catalog and instructing
     * the storage engine to import the corresponding idents. The metadata object should be a valid
     * catalog entry and contain the following fields:
     * "md": A document representing the BSONCollectionCatalogEntry::MetaData of the collection.
     * "idxIdent": A document containing {<index_name>: <index_ident>} pairs for all indexes.
     * "nss": NamespaceString of the collection being imported.
     * "ident": Ident of the collection file.
     *
     * On success, returns an ImportResult structure containing the RecordId which identifies the
     * new record store in the durable catalog, ownership of the new RecordStore and the UUID of the
     * collection imported.
     *
     * The collection must be locked in MODE_X when calling this function.
     */
    struct ImportResult {
        ImportResult(RecordId catalogId, std::unique_ptr<RecordStore> rs, UUID uuid)
            : catalogId(std::move(catalogId)), rs(std::move(rs)), uuid(uuid) {}
        RecordId catalogId;
        std::unique_ptr<RecordStore> rs;
        UUID uuid;
    };

    virtual StatusWith<ImportResult> importCollection(OperationContext* opCtx,
                                                      const NamespaceString& nss,
                                                      const BSONObj& metadata,
                                                      const BSONObj& storageMetadata,
                                                      const ImportOptions& importOptions) = 0;

    virtual Status renameCollection(OperationContext* opCtx,
                                    const RecordId& catalogId,
                                    const NamespaceString& toNss,
                                    BSONCollectionCatalogEntry::MetaData& md) = 0;

    /**
     * Deletes the persisted collection catalog entry identified by 'catalogId'.
     *
     * Expects (invariants) that all of the index catalog entries have been removed already via
     * removeIndex.
     */
    virtual Status dropCollection(OperationContext* opCtx, const RecordId& catalogId) = 0;

    /**
     * Drops the provided ident and recreates it as empty for use in resuming an index build.
     */
    virtual Status dropAndRecreateIndexIdentForResume(OperationContext* opCtx,
                                                      const NamespaceString& nss,
                                                      const CollectionOptions& collOptions,
                                                      const IndexDescriptor* spec,
                                                      StringData ident) = 0;

    virtual int getTotalIndexCount(OperationContext* opCtx, const RecordId& catalogId) const = 0;

    virtual void getReadyIndexes(OperationContext* opCtx,
                                 RecordId catalogId,
                                 StringSet* names) const = 0;

    virtual bool isIndexPresent(OperationContext* opCtx,
                                const RecordId& catalogId,
                                StringData indexName) const = 0;

    virtual bool isIndexReady(OperationContext* opCtx,
                              const RecordId& catalogId,
                              StringData indexName) const = 0;

    /**
     * Returns true if the index identified by 'indexName' is multikey, and returns false otherwise.
     *
     * If the 'multikeyPaths' pointer is non-null, then it must point to an empty vector. If this
     * index type supports tracking path-level multikey information in the catalog, then this
     * function sets 'multikeyPaths' as the path components that cause this index to be multikey.
     *
     * In particular, if this function returns false and the index supports tracking path-level
     * multikey information, then 'multikeyPaths' is initialized as a vector with size equal to the
     * number of elements in the index key pattern of empty sets.
     */
    virtual bool isIndexMultikey(OperationContext* opCtx,
                                 const RecordId& catalogId,
                                 StringData indexName,
                                 MultikeyPaths* multikeyPaths) const = 0;

    virtual void setRand_forTest(const std::string& rand) = 0;

    virtual std::string getRand_forTest() const = 0;
};
}  // namespace mongo