Exemple #1
0
        /// <summary>
        /// Rename a collection (do not support transactions)
        /// </summary>
        public async Task <bool> RenameCollectionAsync(string collection, string newName)
        {
            if (collection.IsNullOrWhiteSpace())
            {
                throw new ArgumentNullException(nameof(collection));
            }
            if (newName.IsNullOrWhiteSpace())
            {
                throw new ArgumentNullException(nameof(newName));
            }

            // rename collection is possible only in exclusive transaction for this
            if (_transaction != null)
            {
                throw LiteException.AlreadyExistsTransaction();
            }

            // check for collection name
            if (collection.Equals(newName, StringComparison.OrdinalIgnoreCase))
            {
                throw LiteException.InvalidCollectionName(newName, "New name must be different from current name");
            }

            // checks if newName are compatible
            CollectionService.CheckName(newName, _header);

            return(await this.AutoTransaction(async transaction =>
            {
                var currentSnapshot = await transaction.CreateSnapshot(LockMode.Write, collection, false);
                var newSnapshot = await transaction.CreateSnapshot(LockMode.Write, newName, false);

                if (currentSnapshot.CollectionPage == null)
                {
                    return false;
                }

                // checks if do not already exists this collection name
                if (_header.GetCollectionPageID(newName) != uint.MaxValue)
                {
                    throw LiteException.AlreadyExistsCollectionName(newName);
                }

                // rename collection and set page as dirty (there is no need to set IsDirty in HeaderPage)
                transaction.Pages.Commit += (h) =>
                {
                    h.RenameCollection(collection, newName);
                };

                return true;
            }));
        }
Exemple #2
0
        public Snapshot(LockMode mode, string collectionName, HeaderPage header, uint transactionID, TransactionPages transPages, LockService locker, WalIndexService walIndex, DiskReader reader, bool addIfNotExists)
        {
            _mode           = mode;
            _collectionName = collectionName;
            _header         = header;
            _transactionID  = transactionID;
            _transPages     = transPages;
            _locker         = locker;
            _walIndex       = walIndex;
            _reader         = reader;

            // enter in lock mode according initial mode
            if (mode == LockMode.Read)
            {
                _locker.EnterRead(_collectionName);
            }
            else
            {
                _locker.EnterReserved(_collectionName);
            }

            // get lastest read version from wal-index
            _readVersion = _walIndex.CurrentReadVersion;

            var srv = new CollectionService(_header, this, _transPages);

            // read collection (create if new - load virtual too)
            srv.Get(_collectionName, addIfNotExists, ref _collectionPage);

            // clear local pages (will clear _collectionPage link reference)
            if (_collectionPage != null)
            {
                // local pages contains only data/index pages
                _localPages.Remove(_collectionPage.PageID);
            }
        }