internal BlobIdx GetBlobIndex(ImmutableArray <byte> blob) { BlobIdx index; if (!_blobs.TryGetValue(blob, out index)) { Debug.Assert(!_streamsAreComplete); index = new BlobIdx(_blobHeapSize); _blobs.Add(blob, index); _blobHeapSize += BlobBuilder.GetCompressedIntegerSize(blob.Length) + blob.Length; } return(index); }