/// <summary> /// Retrieve the resource at the specified page and segment offset /// </summary> /// <param name="pageId">The ID of the page that holds the resource to be retrieved</param> /// <param name="segment">The index of the segment within the page that holds the start of the resource</param> /// <param name="profiler"></param> /// <returns>The resource</returns> public string GetResource(ulong pageId, byte segment, BrightstarProfiler profiler) { using (profiler.Step("ResourceTable.GetResource")) { var currentPage = _pageStore.Retrieve(pageId, profiler); int resourceLength = BitConverter.ToInt32(currentPage, segment * _segmentSize); int totalLength = resourceLength + 4; int segmentsToLoad = totalLength / _segmentSize; if (totalLength % _segmentSize > 0) { segmentsToLoad++; } var buffer = new byte[segmentsToLoad * _segmentSize]; byte segmentIndex = segment; for (int i = 0; i < segmentsToLoad; i++) { if (segmentIndex == _pointerSegment) { ulong nextPageId = BitConverter.ToUInt64(currentPage, _pageStore.PageSize - 8); currentPage = _pageStore.Retrieve(nextPageId, profiler); segmentIndex = 0; } Array.Copy(currentPage, segmentIndex * _segmentSize, buffer, i * _segmentSize, _segmentSize); segmentIndex++; } return(Encoding.UTF8.GetString(buffer, 4, resourceLength)); } }
public INode GetNode(ulong nodeId, BrightstarProfiler profiler) { using (profiler.Step("BPlusTree.GetNode")) { INode ret; if (_modifiedNodes.TryGetValue(nodeId, out ret)) { profiler.Incr("NodeCache Hit"); return(ret); } if (_nodeCache.TryGetValue(nodeId, out ret)) { profiler.Incr("NodeCache Hit"); return(ret); } profiler.Incr("NodeCache Miss"); using (profiler.Step("Load Node")) { var nodePage = _pageStore.Retrieve(nodeId, profiler); var header = BitConverter.ToInt32(nodePage, 0); if (header < 0) { ret = new InternalNode(nodeId, nodePage, ~header, _config); } else { ret = new LeafNode(nodeId, nodePage, header, _config); } _nodeCache.Add(ret); return(ret); } } }
public INode GetNode(ulong nodeId, BrightstarProfiler profiler) { using (profiler.Step("BPlusTree.GetNode")) { INode ret; if (_nodeCache.TryGetValue(nodeId, out ret)) { profiler.Incr("NodeCache Hit"); return(ret); } profiler.Incr("NodeCache Miss"); using (profiler.Step("Load Node")) { var nodePage = _pageStore.Retrieve(nodeId, profiler); var header = BitConverter.ToInt32(nodePage.Data, 0); if (header < 0) { ret = MakeInternalNode(nodePage, ~header); #if DEBUG_BTREE _config.BTreeDebug("{0}: Loaded INTERNAL node from page {1}. {2}", _config.DebugId, nodePage.Id, ret.ToString()); #endif } else { ret = MakeLeafNode(nodePage, header); #if DEBUG_BTREE _config.BTreeDebug("{0}: Loaded LEAF node from page {1}. {2}", _config.DebugId, nodePage.Id, ret.ToString()); #endif } _nodeCache.Add(ret); return(ret); } } }
public PrefixManager(IPageStore pageStore, ulong startPageId, BrightstarProfiler profiler) { _pageStore = pageStore; var startPage = _pageStore.Retrieve(startPageId, profiler); Load(startPage, profiler); }
/// <summary> /// Performs the actual load of prefixes from a page. /// </summary> /// <param name="page"></param> /// <param name="profiler"></param> /// <remarks>Calls to this method should be made inside a critical section of code protected with a mutex or reader/writer lock</remarks> private void InterlockedLoad(IPage page, BrightstarProfiler profiler) { using (profiler.Step("PrefixManager.InterlockedLoad")) { int offset = 0; while (offset < _pageStore.PageSize) { ushort prefixLength = BitConverter.ToUInt16(page.Data, offset); offset += 2; if (prefixLength == ushort.MaxValue) { ulong nextPageId = BitConverter.ToUInt64(page.Data, offset); if (nextPageId == 0) { // End of data return; } page = _pageStore.Retrieve(nextPageId, profiler); offset = 0; } else { var prefix = Encoding.UTF8.GetString(page.Data, offset, prefixLength); offset += prefixLength; var uriLen = BitConverter.ToUInt16(page.Data, offset); offset += 2; var uri = Encoding.UTF8.GetString(page.Data, offset, uriLen); offset += uriLen; _prefixMappings[uri] = prefix; _shortValueMappings[prefix] = uri; } } } }
public Store(string storeLocation, IPageStore dataPageStore, IResourceTable resourceTable, ulong storePageId, BrightstarProfiler profiler) { using (profiler.Step("Load Store")) { DirectoryPath = storeLocation; _pageStore = dataPageStore; _resourceTable = resourceTable; var storePage = _pageStore.Retrieve(storePageId, profiler); Load(storePage, profiler); } }
public Store(string storeLocation, IPageStore dataPageStore, IResourceTable resourceTable, ulong storePageId, BrightstarProfiler profiler) { using (profiler.Step("Load Store")) { DirectoryPath = storeLocation; _pageStore = dataPageStore; _resourceTable = resourceTable; var storePage = _pageStore.Retrieve(storePageId, profiler); Load(storePage, profiler); } }
void Read(ulong rootPageId, BrightstarProfiler profiler) { IPage currentPage = _pageStore.Retrieve(rootPageId, profiler); int offset = 0; int entryIndex = 0; while (true) { var marker = currentPage.Data[offset++]; if (marker == 0xff) { ulong nextPageId = BitConverter.ToUInt64(currentPage.Data, _pageStore.PageSize - 8); if (nextPageId == 0) { return; } currentPage = _pageStore.Retrieve(nextPageId, profiler); offset = 0; } else if (marker == 2) { _allEntries.Add(new GraphIndexEntry(entryIndex++, null, true)); } else { int uriByteLength = BitConverter.ToInt32(currentPage.Data, offset); offset += 4; var uri = Encoding.UTF8.GetString(currentPage.Data, offset, uriByteLength); offset += uriByteLength; var newEntry = new GraphIndexEntry(entryIndex++, uri, marker == 1); _allEntries.Add(newEntry); if (!newEntry.IsDeleted) { _graphUriIndex[newEntry.Uri] = newEntry.Id; } } } }
public PrefixManager(IPageStore pageStore, ulong startPageId, BrightstarProfiler profiler) { _pageStore = pageStore; var startPage = _pageStore.Retrieve(startPageId, profiler); Load(startPage, profiler); }