package erasure_coding import ( "fmt" "io" "os" "github.com/chrislusf/seaweedfs/weed/glog" "github.com/chrislusf/seaweedfs/weed/storage/idx" "github.com/chrislusf/seaweedfs/weed/storage/needle_map" "github.com/chrislusf/seaweedfs/weed/storage/types" "github.com/chrislusf/seaweedfs/weed/util" "github.com/klauspost/reedsolomon" ) const ( DataShardsCount = 10 ParityShardsCount = 4 TotalShardsCount = DataShardsCount + ParityShardsCount ErasureCodingLargeBlockSize = 1024 * 1024 * 1024 // 1GB ErasureCodingSmallBlockSize = 1024 * 1024 // 1MB ) // WriteSortedEcxFile generates .ecx file from existing .idx file // all keys are sorted in ascending order func WriteSortedEcxFile(baseFileName string) (e error) { cm, err := readCompactMap(baseFileName) if err != nil { return fmt.Errorf("readCompactMap: %v", err) } ecxFile, err := os.OpenFile(baseFileName+".ecx", os.O_TRUNC|os.O_CREATE|os.O_WRONLY, 0644) if err != nil { return fmt.Errorf("failed to open ecx file: %v", err) } defer ecxFile.Close() err = cm.AscendingVisit(func(value needle_map.NeedleValue) error { bytes := value.ToBytes() _, writeErr := ecxFile.Write(bytes) return writeErr }) if err != nil { return fmt.Errorf("failed to visit ecx file: %v", err) } return nil } // WriteEcFiles generates .ec01 ~ .ec14 files func WriteEcFiles(baseFileName string) error { return generateEcFiles(baseFileName, 256*1024, ErasureCodingLargeBlockSize, ErasureCodingSmallBlockSize) } func RebuildEcFiles(baseFileName string) ([]uint32, error) { return generateMissingEcFiles(baseFileName, 256*1024, ErasureCodingLargeBlockSize, ErasureCodingSmallBlockSize) } func ToExt(ecIndex int) string { return fmt.Sprintf(".ec%02d", ecIndex) } func generateEcFiles(baseFileName string, bufferSize int, largeBlockSize int64, smallBlockSize int64) error { file, err := os.OpenFile(baseFileName+".dat", os.O_RDONLY, 0) if err != nil { return fmt.Errorf("failed to open dat file: %v", err) } defer file.Close() fi, err := file.Stat() if err != nil { return fmt.Errorf("failed to stat dat file: %v", err) } err = encodeDatFile(fi.Size(), err, baseFileName, bufferSize, largeBlockSize, file, smallBlockSize) if err != nil { return fmt.Errorf("encodeDatFile: %v", err) } return nil } func generateMissingEcFiles(baseFileName string, bufferSize int, largeBlockSize int64, smallBlockSize int64) (generatedShardIds []uint32, err error) { shardHasData := make([]bool, TotalShardsCount) inputFiles := make([]*os.File, TotalShardsCount) outputFiles := make([]*os.File, TotalShardsCount) for shardId := 0; shardId < TotalShardsCount; shardId++ { shardFileName := baseFileName + ToExt(shardId) if util.FileExists(shardFileName) { shardHasData[shardId] = true inputFiles[shardId], err = os.OpenFile(shardFileName, os.O_RDONLY, 0) if err != nil { return nil, err } defer inputFiles[shardId].Close() } else { outputFiles[shardId], err = os.OpenFile(shardFileName, os.O_TRUNC|os.O_WRONLY|os.O_CREATE, 0644) if err != nil { return nil, err } defer outputFiles[shardId].Close() generatedShardIds = append(generatedShardIds, uint32(shardId)) } } err = rebuildEcFiles(shardHasData, inputFiles, outputFiles) if err != nil { return nil, fmt.Errorf("rebuildEcFiles: %v", err) } return } func encodeData(file *os.File, enc reedsolomon.Encoder, startOffset, blockSize int64, buffers [][]byte, outputs []*os.File) error { bufferSize := int64(len(buffers[0])) batchCount := blockSize / bufferSize if blockSize%bufferSize != 0 { glog.Fatalf("unexpected block size %d buffer size %d", blockSize, bufferSize) } for b := int64(0); b < batchCount; b++ { err := encodeDataOneBatch(file, enc, startOffset+b*bufferSize, blockSize, buffers, outputs) if err != nil { return err } } return nil } func openEcFiles(baseFileName string, forRead bool) (files []*os.File, err error) { for i := 0; i < TotalShardsCount; i++ { fname := baseFileName + ToExt(i) openOption := os.O_TRUNC | os.O_CREATE | os.O_WRONLY if forRead { openOption = os.O_RDONLY } f, err := os.OpenFile(fname, openOption, 0644) if err != nil { return files, fmt.Errorf("failed to open file %s: %v", fname, err) } files = append(files, f) } return } func closeEcFiles(files []*os.File) { for _, f := range files { if f != nil { f.Close() } } } func encodeDataOneBatch(file *os.File, enc reedsolomon.Encoder, startOffset, blockSize int64, buffers [][]byte, outputs []*os.File) error { // read data into buffers for i := 0; i < DataShardsCount; i++ { n, err := file.ReadAt(buffers[i], startOffset+blockSize*int64(i)) if err != nil { if err != io.EOF { return err } } if n < len(buffers[i]) { for t := len(buffers[i]) - 1; t >= n; t-- { buffers[i][t] = 0 } } } err := enc.Encode(buffers) if err != nil { return err } for i := 0; i < TotalShardsCount; i++ { _, err := outputs[i].Write(buffers[i]) if err != nil { return err } } return nil } func encodeDatFile(remainingSize int64, err error, baseFileName string, bufferSize int, largeBlockSize int64, file *os.File, smallBlockSize int64) error { var processedSize int64 enc, err := reedsolomon.New(DataShardsCount, ParityShardsCount) if err != nil { return fmt.Errorf("failed to create encoder: %v", err) } buffers := make([][]byte, TotalShardsCount) for i, _ := range buffers { buffers[i] = make([]byte, bufferSize) } outputs, err := openEcFiles(baseFileName, false) defer closeEcFiles(outputs) if err != nil { return fmt.Errorf("failed to open ec files %s: %v", baseFileName, err) } for remainingSize > largeBlockSize*DataShardsCount { err = encodeData(file, enc, processedSize, largeBlockSize, buffers, outputs) if err != nil { return fmt.Errorf("failed to encode large chunk data: %v", err) } remainingSize -= largeBlockSize * DataShardsCount processedSize += largeBlockSize * DataShardsCount } for remainingSize > 0 { encodeData(file, enc, processedSize, smallBlockSize, buffers, outputs) if err != nil { return fmt.Errorf("failed to encode small chunk data: %v", err) } remainingSize -= smallBlockSize * DataShardsCount processedSize += smallBlockSize * DataShardsCount } return nil } func rebuildEcFiles(shardHasData []bool, inputFiles []*os.File, outputFiles []*os.File) error { enc, err := reedsolomon.New(DataShardsCount, ParityShardsCount) if err != nil { return fmt.Errorf("failed to create encoder: %v", err) } buffers := make([][]byte, TotalShardsCount) for i, _ := range buffers { if shardHasData[i] { buffers[i] = make([]byte, ErasureCodingSmallBlockSize) } } var startOffset int64 var inputBufferDataSize int for { // read the input data from files for i := 0; i < TotalShardsCount; i++ { if shardHasData[i] { n, _ := inputFiles[i].ReadAt(buffers[i], startOffset) if n == 0 { return nil } if inputBufferDataSize == 0 { inputBufferDataSize = n } if inputBufferDataSize != n { return fmt.Errorf("ec shard size expected %d actual %d", inputBufferDataSize, n) } } else { buffers[i] = nil } } // encode the data err = enc.Reconstruct(buffers) if err != nil { return fmt.Errorf("reconstruct: %v", err) } // write the data to output files for i := 0; i < TotalShardsCount; i++ { if !shardHasData[i] { n, _ := outputFiles[i].WriteAt(buffers[i][:inputBufferDataSize], startOffset) if inputBufferDataSize != n { return fmt.Errorf("fail to write to %s", outputFiles[i].Name()) } } } startOffset += int64(inputBufferDataSize) } } func readCompactMap(baseFileName string) (*needle_map.CompactMap, error) { indexFile, err := os.OpenFile(baseFileName+".idx", os.O_RDONLY, 0644) if err != nil { return nil, fmt.Errorf("cannot read Volume Index %s.idx: %v", baseFileName, err) } defer indexFile.Close() cm := needle_map.NewCompactMap() err = idx.WalkIndexFile(indexFile, func(key types.NeedleId, offset types.Offset, size uint32) error { if !offset.IsZero() && size != types.TombstoneFileSize { cm.Set(key, offset, size) } else { cm.Delete(key) } return nil }) return cm, err }