Exemple #1
0
        /// <summary>
        /// Insert BsonDocument into new data pages
        /// </summary>
        public PageAddress Insert(BsonDocument doc)
        {
            var bytesLeft = doc.GetBytesCount(true);

            if (bytesLeft > MAX_DOCUMENT_SIZE)
            {
                throw new LiteException(0, "Document size exceed {0} limit", MAX_DOCUMENT_SIZE);
            }

            var firstBlock = PageAddress.Empty;

            IEnumerable <BufferSlice> source()
            {
                var       blockIndex = 0;
                DataBlock lastBlock  = null;

                while (bytesLeft > 0)
                {
                    var bytesToCopy = Math.Min(bytesLeft, MAX_DATA_BYTES_PER_PAGE);
                    var dataPage    = _snapshot.GetFreePage <DataPage>(bytesToCopy + DataBlock.DATA_BLOCK_FIXED_SIZE);
                    var dataBlock   = dataPage.InsertBlock(bytesToCopy, blockIndex++ > 0);

                    if (lastBlock != null)
                    {
                        lastBlock.SetNextBlock(dataBlock.Position);
                    }

                    if (firstBlock.IsEmpty)
                    {
                        firstBlock = dataBlock.Position;
                    }

                    yield return(dataBlock.Buffer);

                    lastBlock = dataBlock;

                    bytesLeft -= bytesToCopy;
                }
            }

            // consume all source bytes to write BsonDocument direct into PageBuffer
            // must be fastest as possible
            using (var w = new BufferWriter(source()))
            {
                // already bytes count calculate at method start
                w.WriteDocument(doc, false);
                w.Consume();
            }

            return(firstBlock);
        }
Exemple #2
0
        /// <summary>
        /// Create a new index and returns head page address (skip list)
        /// </summary>
        public CollectionIndex CreateIndex(string name, string expr, bool unique)
        {
            // get how many butes needed fore each head/tail (both has same size)
            var bytesLength = IndexNode.GetNodeLength(MAX_LEVEL_LENGTH, BsonValue.MinValue, out var keyLength);

            // get a free index page for head note (x2 for head + tail)
            var indexPage = _snapshot.GetFreePage <IndexPage>(bytesLength * 2);

            // create index ref
            var index = _snapshot.CollectionPage.InsertCollectionIndex(name, expr, unique);

            // insert head/tail nodes
            var head = indexPage.InsertIndexNode(index.Slot, MAX_LEVEL_LENGTH, BsonValue.MinValue, PageAddress.Empty, bytesLength);
            var tail = indexPage.InsertIndexNode(index.Slot, MAX_LEVEL_LENGTH, BsonValue.MaxValue, PageAddress.Empty, bytesLength);

            // link head-to-tail with double link list in first level
            head.SetNext(0, tail.Position);
            tail.SetPrev(0, head.Position);

            index.Head = head.Position;
            index.Tail = tail.Position;

            return(index);
        }