forked from prometheus/prometheus
/
head_chunks.go
857 lines (734 loc) · 25.7 KB
/
head_chunks.go
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// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package chunks
import (
"bufio"
"bytes"
"encoding/binary"
"hash"
"io"
"io/ioutil"
"os"
"path/filepath"
"sort"
"strconv"
"sync"
"github.com/pkg/errors"
"go.uber.org/atomic"
"github.com/tony2001/prometheus/v2/tsdb/chunkenc"
tsdb_errors "github.com/tony2001/prometheus/v2/tsdb/errors"
"github.com/tony2001/prometheus/v2/tsdb/fileutil"
)
// Head chunk file header fields constants.
const (
// MagicHeadChunks is 4 bytes at the beginning of a head chunk file.
MagicHeadChunks = 0x0130BC91
headChunksFormatV1 = 1
)
var (
// ErrChunkDiskMapperClosed returned by any method indicates
// that the ChunkDiskMapper was closed.
ErrChunkDiskMapperClosed = errors.New("ChunkDiskMapper closed")
)
const (
// MintMaxtSize is the size of the mint/maxt for head chunk file and chunks.
MintMaxtSize = 8
// SeriesRefSize is the size of series reference on disk.
SeriesRefSize = 8
// HeadChunkFileHeaderSize is the total size of the header for the head chunk file.
HeadChunkFileHeaderSize = SegmentHeaderSize
// MaxHeadChunkFileSize is the max size of a head chunk file.
MaxHeadChunkFileSize = 128 * 1024 * 1024 // 128 MiB.
// CRCSize is the size of crc32 sum on disk.
CRCSize = 4
// MaxHeadChunkMetaSize is the max size of an mmapped chunks minus the chunks data.
// Max because the uvarint size can be smaller.
MaxHeadChunkMetaSize = SeriesRefSize + 2*MintMaxtSize + ChunksFormatVersionSize + MaxChunkLengthFieldSize + CRCSize
// MinWriteBufferSize is the minimum write buffer size allowed.
MinWriteBufferSize = 64 * 1024 // 64KB.
// MaxWriteBufferSize is the maximum write buffer size allowed.
MaxWriteBufferSize = 8 * 1024 * 1024 // 8 MiB.
// DefaultWriteBufferSize is the default write buffer size.
DefaultWriteBufferSize = 4 * 1024 * 1024 // 4 MiB.
)
// CorruptionErr is an error that's returned when corruption is encountered.
type CorruptionErr struct {
Dir string
FileIndex int
Err error
}
func (e *CorruptionErr) Error() string {
return errors.Wrapf(e.Err, "corruption in head chunk file %s", segmentFile(e.Dir, e.FileIndex)).Error()
}
// ChunkDiskMapper is for writing the Head block chunks to the disk
// and access chunks via mmapped file.
type ChunkDiskMapper struct {
curFileNumBytes atomic.Int64 // Bytes written in current open file.
/// Writer.
dir *os.File
writeBufferSize int
curFile *os.File // File being written to.
curFileSequence int // Index of current open file being appended to.
curFileMaxt int64 // Used for the size retention.
byteBuf [MaxHeadChunkMetaSize]byte // Buffer used to write the header of the chunk.
chkWriter *bufio.Writer // Writer for the current open file.
crc32 hash.Hash
writePathMtx sync.Mutex
/// Reader.
// The int key in the map is the file number on the disk.
mmappedChunkFiles map[int]*mmappedChunkFile // Contains the m-mapped files for each chunk file mapped with its index.
closers map[int]io.Closer // Closers for resources behind the byte slices.
readPathMtx sync.RWMutex // Mutex used to protect the above 2 maps.
pool chunkenc.Pool // This is used when fetching a chunk from the disk to allocate a chunk.
// Writer and Reader.
// We flush chunks to disk in batches. Hence, we store them in this buffer
// from which chunks are served till they are flushed and are ready for m-mapping.
chunkBuffer *chunkBuffer
// If 'true', it indicated that the maxt of all the on-disk files were set
// after iterating through all the chunks in those files.
fileMaxtSet bool
closed bool
}
type mmappedChunkFile struct {
byteSlice ByteSlice
maxt int64
}
// NewChunkDiskMapper returns a new writer against the given directory
// using the default head chunk file duration.
// NOTE: 'IterateAllChunks' method needs to be called at least once after creating ChunkDiskMapper
// to set the maxt of all the file.
func NewChunkDiskMapper(dir string, pool chunkenc.Pool, writeBufferSize int) (*ChunkDiskMapper, error) {
// Validate write buffer size.
if writeBufferSize < MinWriteBufferSize || writeBufferSize > MaxWriteBufferSize {
return nil, errors.Errorf("ChunkDiskMapper write buffer size should be between %d and %d (actual: %d)", MinWriteBufferSize, MaxHeadChunkFileSize, writeBufferSize)
}
if writeBufferSize%1024 != 0 {
return nil, errors.Errorf("ChunkDiskMapper write buffer size should be a multiple of 1024 (actual: %d)", writeBufferSize)
}
if err := os.MkdirAll(dir, 0777); err != nil {
return nil, err
}
dirFile, err := fileutil.OpenDir(dir)
if err != nil {
return nil, err
}
m := &ChunkDiskMapper{
dir: dirFile,
pool: pool,
writeBufferSize: writeBufferSize,
crc32: newCRC32(),
chunkBuffer: newChunkBuffer(),
}
if m.pool == nil {
m.pool = chunkenc.NewPool()
}
return m, m.openMMapFiles()
}
func (cdm *ChunkDiskMapper) openMMapFiles() (returnErr error) {
cdm.mmappedChunkFiles = map[int]*mmappedChunkFile{}
cdm.closers = map[int]io.Closer{}
defer func() {
if returnErr != nil {
returnErr = tsdb_errors.NewMulti(returnErr, closeAllFromMap(cdm.closers)).Err()
cdm.mmappedChunkFiles = nil
cdm.closers = nil
}
}()
files, err := listChunkFiles(cdm.dir.Name())
if err != nil {
return err
}
files, err = repairLastChunkFile(files)
if err != nil {
return err
}
chkFileIndices := make([]int, 0, len(files))
for seq, fn := range files {
f, err := fileutil.OpenMmapFile(fn)
if err != nil {
return errors.Wrapf(err, "mmap files, file: %s", fn)
}
cdm.closers[seq] = f
cdm.mmappedChunkFiles[seq] = &mmappedChunkFile{byteSlice: realByteSlice(f.Bytes())}
chkFileIndices = append(chkFileIndices, seq)
}
// Check for gaps in the files.
sort.Ints(chkFileIndices)
if len(chkFileIndices) == 0 {
return nil
}
lastSeq := chkFileIndices[0]
for _, seq := range chkFileIndices[1:] {
if seq != lastSeq+1 {
return errors.Errorf("found unsequential head chunk files %s (index: %d) and %s (index: %d)", files[lastSeq], lastSeq, files[seq], seq)
}
lastSeq = seq
}
for i, b := range cdm.mmappedChunkFiles {
if b.byteSlice.Len() < HeadChunkFileHeaderSize {
return errors.Wrapf(errInvalidSize, "%s: invalid head chunk file header", files[i])
}
// Verify magic number.
if m := binary.BigEndian.Uint32(b.byteSlice.Range(0, MagicChunksSize)); m != MagicHeadChunks {
return errors.Errorf("%s: invalid magic number %x", files[i], m)
}
// Verify chunk format version.
if v := int(b.byteSlice.Range(MagicChunksSize, MagicChunksSize+ChunksFormatVersionSize)[0]); v != chunksFormatV1 {
return errors.Errorf("%s: invalid chunk format version %d", files[i], v)
}
}
return nil
}
func listChunkFiles(dir string) (map[int]string, error) {
files, err := ioutil.ReadDir(dir)
if err != nil {
return nil, err
}
res := map[int]string{}
for _, fi := range files {
seq, err := strconv.ParseUint(fi.Name(), 10, 64)
if err != nil {
continue
}
res[int(seq)] = filepath.Join(dir, fi.Name())
}
return res, nil
}
// repairLastChunkFile deletes the last file if it's empty.
// Because we don't fsync when creating these file, we could end
// up with an empty file at the end during an abrupt shutdown.
func repairLastChunkFile(files map[int]string) (_ map[int]string, returnErr error) {
lastFile := -1
for seq := range files {
if seq > lastFile {
lastFile = seq
}
}
if lastFile <= 0 {
return files, nil
}
info, err := os.Stat(files[lastFile])
if err != nil {
return files, errors.Wrap(err, "file stat during last head chunk file repair")
}
if info.Size() == 0 {
// Corrupt file, hence remove it.
if err := os.RemoveAll(files[lastFile]); err != nil {
return files, errors.Wrap(err, "delete corrupted, empty head chunk file during last file repair")
}
delete(files, lastFile)
}
return files, nil
}
// WriteChunk writes the chunk to the disk.
// The returned chunk ref is the reference from where the chunk encoding starts for the chunk.
func (cdm *ChunkDiskMapper) WriteChunk(seriesRef uint64, mint, maxt int64, chk chunkenc.Chunk) (chkRef uint64, err error) {
cdm.writePathMtx.Lock()
defer cdm.writePathMtx.Unlock()
if cdm.closed {
return 0, ErrChunkDiskMapperClosed
}
if cdm.shouldCutNewFile(len(chk.Bytes())) {
if err := cdm.cut(); err != nil {
return 0, err
}
}
// if len(chk.Bytes())+MaxHeadChunkMetaSize >= writeBufferSize, it means that chunk >= the buffer size;
// so no need to flush here, as we have to flush at the end (to not keep partial chunks in buffer).
if len(chk.Bytes())+MaxHeadChunkMetaSize < cdm.writeBufferSize && cdm.chkWriter.Available() < MaxHeadChunkMetaSize+len(chk.Bytes()) {
if err := cdm.flushBuffer(); err != nil {
return 0, err
}
}
cdm.crc32.Reset()
bytesWritten := 0
// The upper 4 bytes are for the head chunk file index and
// the lower 4 bytes are for the head chunk file offset where to start reading this chunk.
chkRef = chunkRef(uint64(cdm.curFileSequence), uint64(cdm.curFileSize()))
binary.BigEndian.PutUint64(cdm.byteBuf[bytesWritten:], seriesRef)
bytesWritten += SeriesRefSize
binary.BigEndian.PutUint64(cdm.byteBuf[bytesWritten:], uint64(mint))
bytesWritten += MintMaxtSize
binary.BigEndian.PutUint64(cdm.byteBuf[bytesWritten:], uint64(maxt))
bytesWritten += MintMaxtSize
cdm.byteBuf[bytesWritten] = byte(chk.Encoding())
bytesWritten += ChunkEncodingSize
n := binary.PutUvarint(cdm.byteBuf[bytesWritten:], uint64(len(chk.Bytes())))
bytesWritten += n
if err := cdm.writeAndAppendToCRC32(cdm.byteBuf[:bytesWritten]); err != nil {
return 0, err
}
if err := cdm.writeAndAppendToCRC32(chk.Bytes()); err != nil {
return 0, err
}
if err := cdm.writeCRC32(); err != nil {
return 0, err
}
if maxt > cdm.curFileMaxt {
cdm.curFileMaxt = maxt
}
cdm.chunkBuffer.put(chkRef, chk)
if len(chk.Bytes())+MaxHeadChunkMetaSize >= cdm.writeBufferSize {
// The chunk was bigger than the buffer itself.
// Flushing to not keep partial chunks in buffer.
if err := cdm.flushBuffer(); err != nil {
return 0, err
}
}
return chkRef, nil
}
func chunkRef(seq, offset uint64) (chunkRef uint64) {
return (seq << 32) | offset
}
// shouldCutNewFile decides the cutting of a new file based on time and size retention.
// Size retention: because depending on the system architecture, there is a limit on how big of a file we can m-map.
// Time retention: so that we can delete old chunks with some time guarantee in low load environments.
func (cdm *ChunkDiskMapper) shouldCutNewFile(chunkSize int) bool {
return cdm.curFileSize() == 0 || // First head chunk file.
cdm.curFileSize()+int64(chunkSize+MaxHeadChunkMetaSize) > MaxHeadChunkFileSize // Exceeds the max head chunk file size.
}
// CutNewFile creates a new m-mapped file.
func (cdm *ChunkDiskMapper) CutNewFile() (returnErr error) {
cdm.writePathMtx.Lock()
defer cdm.writePathMtx.Unlock()
return cdm.cut()
}
// cut creates a new m-mapped file. The write lock should be held before calling this.
func (cdm *ChunkDiskMapper) cut() (returnErr error) {
// Sync current tail to disk and close.
if err := cdm.finalizeCurFile(); err != nil {
return err
}
n, newFile, seq, err := cutSegmentFile(cdm.dir, MagicHeadChunks, headChunksFormatV1, HeadChunkFilePreallocationSize)
if err != nil {
return err
}
defer func() {
// The file should not be closed if there is no error,
// its kept open in the ChunkDiskMapper.
if returnErr != nil {
returnErr = tsdb_errors.NewMulti(returnErr, newFile.Close()).Err()
}
}()
cdm.curFileNumBytes.Store(int64(n))
if cdm.curFile != nil {
cdm.readPathMtx.Lock()
cdm.mmappedChunkFiles[cdm.curFileSequence].maxt = cdm.curFileMaxt
cdm.readPathMtx.Unlock()
}
mmapFile, err := fileutil.OpenMmapFileWithSize(newFile.Name(), int(MaxHeadChunkFileSize))
if err != nil {
return err
}
cdm.readPathMtx.Lock()
cdm.curFileSequence = seq
cdm.curFile = newFile
if cdm.chkWriter != nil {
cdm.chkWriter.Reset(newFile)
} else {
cdm.chkWriter = bufio.NewWriterSize(newFile, cdm.writeBufferSize)
}
cdm.closers[cdm.curFileSequence] = mmapFile
cdm.mmappedChunkFiles[cdm.curFileSequence] = &mmappedChunkFile{byteSlice: realByteSlice(mmapFile.Bytes())}
cdm.readPathMtx.Unlock()
cdm.curFileMaxt = 0
return nil
}
// finalizeCurFile writes all pending data to the current tail file,
// truncates its size, and closes it.
func (cdm *ChunkDiskMapper) finalizeCurFile() error {
if cdm.curFile == nil {
return nil
}
if err := cdm.flushBuffer(); err != nil {
return err
}
if err := cdm.curFile.Sync(); err != nil {
return err
}
return cdm.curFile.Close()
}
func (cdm *ChunkDiskMapper) write(b []byte) error {
n, err := cdm.chkWriter.Write(b)
cdm.curFileNumBytes.Add(int64(n))
return err
}
func (cdm *ChunkDiskMapper) writeAndAppendToCRC32(b []byte) error {
if err := cdm.write(b); err != nil {
return err
}
_, err := cdm.crc32.Write(b)
return err
}
func (cdm *ChunkDiskMapper) writeCRC32() error {
return cdm.write(cdm.crc32.Sum(cdm.byteBuf[:0]))
}
// flushBuffer flushes the current in-memory chunks.
// Assumes that writePathMtx is _write_ locked before calling this method.
func (cdm *ChunkDiskMapper) flushBuffer() error {
if err := cdm.chkWriter.Flush(); err != nil {
return err
}
cdm.chunkBuffer.clear()
return nil
}
// Chunk returns a chunk from a given reference.
func (cdm *ChunkDiskMapper) Chunk(ref uint64) (chunkenc.Chunk, error) {
cdm.readPathMtx.RLock()
// We hold this read lock for the entire duration because if the Close()
// is called, the data in the byte slice will get corrupted as the mmapped
// file will be closed.
defer cdm.readPathMtx.RUnlock()
var (
// Get the upper 4 bytes.
// These contain the head chunk file index.
sgmIndex = int(ref >> 32)
// Get the lower 4 bytes.
// These contain the head chunk file offset where the chunk starts.
// We skip the series ref and the mint/maxt beforehand.
chkStart = int((ref<<32)>>32) + SeriesRefSize + (2 * MintMaxtSize)
chkCRC32 = newCRC32()
)
if cdm.closed {
return nil, ErrChunkDiskMapperClosed
}
// If it is the current open file, then the chunks can be in the buffer too.
if sgmIndex == cdm.curFileSequence {
chunk := cdm.chunkBuffer.get(ref)
if chunk != nil {
return chunk, nil
}
}
mmapFile, ok := cdm.mmappedChunkFiles[sgmIndex]
if !ok {
if sgmIndex > cdm.curFileSequence {
return nil, &CorruptionErr{
Dir: cdm.dir.Name(),
FileIndex: -1,
Err: errors.Errorf("head chunk file index %d more than current open file", sgmIndex),
}
}
return nil, &CorruptionErr{
Dir: cdm.dir.Name(),
FileIndex: sgmIndex,
Err: errors.New("head chunk file index %d does not exist on disk"),
}
}
if chkStart+MaxChunkLengthFieldSize > mmapFile.byteSlice.Len() {
return nil, &CorruptionErr{
Dir: cdm.dir.Name(),
FileIndex: sgmIndex,
Err: errors.Errorf("head chunk file doesn't include enough bytes to read the chunk size data field - required:%v, available:%v", chkStart+MaxChunkLengthFieldSize, mmapFile.byteSlice.Len()),
}
}
// Encoding.
chkEnc := mmapFile.byteSlice.Range(chkStart, chkStart+ChunkEncodingSize)[0]
// Data length.
// With the minimum chunk length this should never cause us reading
// over the end of the slice.
chkDataLenStart := chkStart + ChunkEncodingSize
c := mmapFile.byteSlice.Range(chkDataLenStart, chkDataLenStart+MaxChunkLengthFieldSize)
chkDataLen, n := binary.Uvarint(c)
if n <= 0 {
return nil, &CorruptionErr{
Dir: cdm.dir.Name(),
FileIndex: sgmIndex,
Err: errors.Errorf("reading chunk length failed with %d", n),
}
}
// Verify the chunk data end.
chkDataEnd := chkDataLenStart + n + int(chkDataLen)
if chkDataEnd > mmapFile.byteSlice.Len() {
return nil, &CorruptionErr{
Dir: cdm.dir.Name(),
FileIndex: sgmIndex,
Err: errors.Errorf("head chunk file doesn't include enough bytes to read the chunk - required:%v, available:%v", chkDataEnd, mmapFile.byteSlice.Len()),
}
}
// Check the CRC.
sum := mmapFile.byteSlice.Range(chkDataEnd, chkDataEnd+CRCSize)
if _, err := chkCRC32.Write(mmapFile.byteSlice.Range(chkStart-(SeriesRefSize+2*MintMaxtSize), chkDataEnd)); err != nil {
return nil, &CorruptionErr{
Dir: cdm.dir.Name(),
FileIndex: sgmIndex,
Err: err,
}
}
if act := chkCRC32.Sum(nil); !bytes.Equal(act, sum) {
return nil, &CorruptionErr{
Dir: cdm.dir.Name(),
FileIndex: sgmIndex,
Err: errors.Errorf("checksum mismatch expected:%x, actual:%x", sum, act),
}
}
// The chunk data itself.
chkData := mmapFile.byteSlice.Range(chkDataEnd-int(chkDataLen), chkDataEnd)
chk, err := cdm.pool.Get(chunkenc.Encoding(chkEnc), chkData)
if err != nil {
return nil, &CorruptionErr{
Dir: cdm.dir.Name(),
FileIndex: sgmIndex,
Err: err,
}
}
return chk, nil
}
// IterateAllChunks iterates on all the chunks in its byte slices in the order of the head chunk file sequence
// and runs the provided function on each chunk. It returns on the first error encountered.
// NOTE: This method needs to be called at least once after creating ChunkDiskMapper
// to set the maxt of all the file.
func (cdm *ChunkDiskMapper) IterateAllChunks(f func(seriesRef, chunkRef uint64, mint, maxt int64, numSamples uint16) error) (err error) {
cdm.writePathMtx.Lock()
defer cdm.writePathMtx.Unlock()
defer func() {
cdm.fileMaxtSet = true
}()
chkCRC32 := newCRC32()
// Iterate files in ascending order.
segIDs := make([]int, 0, len(cdm.mmappedChunkFiles))
for seg := range cdm.mmappedChunkFiles {
segIDs = append(segIDs, seg)
}
sort.Ints(segIDs)
for _, segID := range segIDs {
mmapFile := cdm.mmappedChunkFiles[segID]
fileEnd := mmapFile.byteSlice.Len()
if segID == cdm.curFileSequence {
fileEnd = int(cdm.curFileSize())
}
idx := HeadChunkFileHeaderSize
for idx < fileEnd {
if fileEnd-idx < MaxHeadChunkMetaSize {
// Check for all 0s which marks the end of the file.
allZeros := true
for _, b := range mmapFile.byteSlice.Range(idx, fileEnd) {
if b != byte(0) {
allZeros = false
break
}
}
if allZeros {
// End of segment chunk file content.
break
}
return &CorruptionErr{
Dir: cdm.dir.Name(),
FileIndex: segID,
Err: errors.Errorf("head chunk file has some unread data, but doesn't include enough bytes to read the chunk header"+
" - required:%v, available:%v, file:%d", idx+MaxHeadChunkMetaSize, fileEnd, segID),
}
}
chkCRC32.Reset()
chunkRef := chunkRef(uint64(segID), uint64(idx))
startIdx := idx
seriesRef := binary.BigEndian.Uint64(mmapFile.byteSlice.Range(idx, idx+SeriesRefSize))
idx += SeriesRefSize
mint := int64(binary.BigEndian.Uint64(mmapFile.byteSlice.Range(idx, idx+MintMaxtSize)))
idx += MintMaxtSize
maxt := int64(binary.BigEndian.Uint64(mmapFile.byteSlice.Range(idx, idx+MintMaxtSize)))
idx += MintMaxtSize
// We preallocate file to help with m-mapping (especially windows systems).
// As series ref always starts from 1, we assume it being 0 to be the end of the actual file data.
// We are not considering possible file corruption that can cause it to be 0.
// Additionally we are checking mint and maxt just to be sure.
if seriesRef == 0 && mint == 0 && maxt == 0 {
break
}
idx += ChunkEncodingSize // Skip encoding.
dataLen, n := binary.Uvarint(mmapFile.byteSlice.Range(idx, idx+MaxChunkLengthFieldSize))
idx += n
numSamples := binary.BigEndian.Uint16(mmapFile.byteSlice.Range(idx, idx+2))
idx += int(dataLen) // Skip the data.
// In the beginning we only checked for the chunk meta size.
// Now that we have added the chunk data length, we check for sufficient bytes again.
if idx+CRCSize > fileEnd {
return &CorruptionErr{
Dir: cdm.dir.Name(),
FileIndex: segID,
Err: errors.Errorf("head chunk file doesn't include enough bytes to read the chunk header - required:%v, available:%v, file:%d", idx+CRCSize, fileEnd, segID),
}
}
// Check CRC.
sum := mmapFile.byteSlice.Range(idx, idx+CRCSize)
if _, err := chkCRC32.Write(mmapFile.byteSlice.Range(startIdx, idx)); err != nil {
return err
}
if act := chkCRC32.Sum(nil); !bytes.Equal(act, sum) {
return &CorruptionErr{
Dir: cdm.dir.Name(),
FileIndex: segID,
Err: errors.Errorf("checksum mismatch expected:%x, actual:%x", sum, act),
}
}
idx += CRCSize
if maxt > mmapFile.maxt {
mmapFile.maxt = maxt
}
if err := f(seriesRef, chunkRef, mint, maxt, numSamples); err != nil {
if cerr, ok := err.(*CorruptionErr); ok {
cerr.Dir = cdm.dir.Name()
cerr.FileIndex = segID
return cerr
}
return err
}
}
if idx > fileEnd {
// It should be equal to the slice length.
return &CorruptionErr{
Dir: cdm.dir.Name(),
FileIndex: segID,
Err: errors.Errorf("head chunk file doesn't include enough bytes to read the last chunk data - required:%v, available:%v, file:%d", idx, fileEnd, segID),
}
}
}
return nil
}
// Truncate deletes the head chunk files which are strictly below the mint.
// mint should be in milliseconds.
func (cdm *ChunkDiskMapper) Truncate(mint int64) error {
if !cdm.fileMaxtSet {
return errors.New("maxt of the files are not set")
}
cdm.readPathMtx.RLock()
// Sort the file indices, else if files deletion fails in between,
// it can lead to unsequential files as the map is not sorted.
chkFileIndices := make([]int, 0, len(cdm.mmappedChunkFiles))
for seq := range cdm.mmappedChunkFiles {
chkFileIndices = append(chkFileIndices, seq)
}
sort.Ints(chkFileIndices)
var removedFiles []int
for _, seq := range chkFileIndices {
if seq == cdm.curFileSequence || cdm.mmappedChunkFiles[seq].maxt >= mint {
break
}
if cdm.mmappedChunkFiles[seq].maxt < mint {
removedFiles = append(removedFiles, seq)
}
}
cdm.readPathMtx.RUnlock()
errs := tsdb_errors.NewMulti()
// Cut a new file only if the current file has some chunks.
if cdm.curFileSize() > HeadChunkFileHeaderSize {
errs.Add(cdm.CutNewFile())
}
errs.Add(cdm.deleteFiles(removedFiles))
return errs.Err()
}
func (cdm *ChunkDiskMapper) deleteFiles(removedFiles []int) error {
cdm.readPathMtx.Lock()
for _, seq := range removedFiles {
if err := cdm.closers[seq].Close(); err != nil {
cdm.readPathMtx.Unlock()
return err
}
delete(cdm.mmappedChunkFiles, seq)
delete(cdm.closers, seq)
}
cdm.readPathMtx.Unlock()
// We actually delete the files separately to not block the readPathMtx for long.
for _, seq := range removedFiles {
if err := os.Remove(segmentFile(cdm.dir.Name(), seq)); err != nil {
return err
}
}
return nil
}
// DeleteCorrupted deletes all the head chunk files after the one which had the corruption
// (including the corrupt file).
func (cdm *ChunkDiskMapper) DeleteCorrupted(originalErr error) error {
err := errors.Cause(originalErr) // So that we can pick up errors even if wrapped.
cerr, ok := err.(*CorruptionErr)
if !ok {
return errors.Wrap(originalErr, "cannot handle error")
}
// Delete all the head chunk files following the corrupt head chunk file.
segs := []int{}
cdm.readPathMtx.RLock()
for seg := range cdm.mmappedChunkFiles {
if seg >= cerr.FileIndex {
segs = append(segs, seg)
}
}
cdm.readPathMtx.RUnlock()
return cdm.deleteFiles(segs)
}
// Size returns the size of the chunk files.
func (cdm *ChunkDiskMapper) Size() (int64, error) {
return fileutil.DirSize(cdm.dir.Name())
}
func (cdm *ChunkDiskMapper) curFileSize() int64 {
return cdm.curFileNumBytes.Load()
}
// Close closes all the open files in ChunkDiskMapper.
// It is not longer safe to access chunks from this struct after calling Close.
func (cdm *ChunkDiskMapper) Close() error {
// 'WriteChunk' locks writePathMtx first and then readPathMtx for cutting head chunk file.
// The lock order should not be reversed here else it can cause deadlocks.
cdm.writePathMtx.Lock()
defer cdm.writePathMtx.Unlock()
cdm.readPathMtx.Lock()
defer cdm.readPathMtx.Unlock()
if cdm.closed {
return nil
}
cdm.closed = true
errs := tsdb_errors.NewMulti(
closeAllFromMap(cdm.closers),
cdm.finalizeCurFile(),
cdm.dir.Close(),
)
cdm.mmappedChunkFiles = map[int]*mmappedChunkFile{}
cdm.closers = map[int]io.Closer{}
return errs.Err()
}
func closeAllFromMap(cs map[int]io.Closer) error {
errs := tsdb_errors.NewMulti()
for _, c := range cs {
errs.Add(c.Close())
}
return errs.Err()
}
const inBufferShards = 128 // 128 is a randomly chosen number.
// chunkBuffer is a thread safe buffer for chunks.
type chunkBuffer struct {
inBufferChunks [inBufferShards]map[uint64]chunkenc.Chunk
inBufferChunksMtxs [inBufferShards]sync.RWMutex
}
func newChunkBuffer() *chunkBuffer {
cb := &chunkBuffer{}
for i := 0; i < inBufferShards; i++ {
cb.inBufferChunks[i] = make(map[uint64]chunkenc.Chunk)
}
return cb
}
func (cb *chunkBuffer) put(ref uint64, chk chunkenc.Chunk) {
shardIdx := ref % inBufferShards
cb.inBufferChunksMtxs[shardIdx].Lock()
cb.inBufferChunks[shardIdx][ref] = chk
cb.inBufferChunksMtxs[shardIdx].Unlock()
}
func (cb *chunkBuffer) get(ref uint64) chunkenc.Chunk {
shardIdx := ref % inBufferShards
cb.inBufferChunksMtxs[shardIdx].RLock()
defer cb.inBufferChunksMtxs[shardIdx].RUnlock()
return cb.inBufferChunks[shardIdx][ref]
}
func (cb *chunkBuffer) clear() {
for i := 0; i < inBufferShards; i++ {
cb.inBufferChunksMtxs[i].Lock()
cb.inBufferChunks[i] = make(map[uint64]chunkenc.Chunk)
cb.inBufferChunksMtxs[i].Unlock()
}
}