func newHeadsScanner(filename string) *headsScanner {
hs := &headsScanner{}
defer func() {
if hs.f != nil && hs.err != nil {
hs.f.Close()
}
}()
if hs.f, hs.err = os.Open(filename); hs.err != nil {
return hs
}
hs.r = bufio.NewReaderSize(hs.f, fileBufSize)
buf := make([]byte, len(headsMagicString))
if _, hs.err = io.ReadFull(hs.r, buf); hs.err != nil {
return hs
}
magic := string(buf)
if magic != headsMagicString {
hs.err = fmt.Errorf(
"unexpected magic string, want %q, got %q",
headsMagicString, magic,
)
return hs
}
hs.version, hs.err = binary.ReadVarint(hs.r)
if (hs.version != headsFormatVersion && hs.version != headsFormatLegacyVersion) || hs.err != nil {
hs.err = fmt.Errorf(
"unknown or unreadable heads format version, want %d, got %d, error: %s",
headsFormatVersion, hs.version, hs.err,
)
return hs
}
if hs.seriesTotal, hs.err = codable.DecodeUint64(hs.r); hs.err != nil {
return hs
}
return hs
}
// loadSeriesMapAndHeads loads the fingerprint to memory-series mapping and all
// the chunks contained in the checkpoint (and thus not yet persisted to series
// files). The method is capable of loading the checkpoint format v1 and v2. If
// recoverable corruption is detected, or if the dirty flag was set from the
// beginning, crash recovery is run, which might take a while. If an
// unrecoverable error is encountered, it is returned. Call this method during
// start-up while nothing else is running in storage land. This method is
// utterly goroutine-unsafe.
func (p *persistence) loadSeriesMapAndHeads() (sm *seriesMap, chunksToPersist int64, err error) {
var chunkDescsTotal int64
fingerprintToSeries := make(map[clientmodel.Fingerprint]*memorySeries)
sm = &seriesMap{m: fingerprintToSeries}
defer func() {
if sm != nil && p.dirty {
log.Warn("Persistence layer appears dirty.")
err = p.recoverFromCrash(fingerprintToSeries)
if err != nil {
sm = nil
}
}
if err == nil {
numMemChunkDescs.Add(float64(chunkDescsTotal))
}
}()
f, err := os.Open(p.headsFileName())
if os.IsNotExist(err) {
return sm, 0, nil
}
if err != nil {
log.Warn("Could not open heads file:", err)
p.dirty = true
return
}
defer f.Close()
r := bufio.NewReaderSize(f, fileBufSize)
buf := make([]byte, len(headsMagicString))
if _, err := io.ReadFull(r, buf); err != nil {
log.Warn("Could not read from heads file:", err)
p.dirty = true
return sm, 0, nil
}
magic := string(buf)
if magic != headsMagicString {
log.Warnf(
"unexpected magic string, want %q, got %q",
headsMagicString, magic,
)
p.dirty = true
return
}
version, err := binary.ReadVarint(r)
if (version != headsFormatVersion && version != headsFormatLegacyVersion) || err != nil {
log.Warnf("unknown heads format version, want %d", headsFormatVersion)
p.dirty = true
return sm, 0, nil
}
numSeries, err := codable.DecodeUint64(r)
if err != nil {
log.Warn("Could not decode number of series:", err)
p.dirty = true
return sm, 0, nil
}
for ; numSeries > 0; numSeries-- {
seriesFlags, err := r.ReadByte()
if err != nil {
log.Warn("Could not read series flags:", err)
p.dirty = true
return sm, chunksToPersist, nil
}
headChunkPersisted := seriesFlags&flagHeadChunkPersisted != 0
fp, err := codable.DecodeUint64(r)
if err != nil {
log.Warn("Could not decode fingerprint:", err)
p.dirty = true
return sm, chunksToPersist, nil
}
var metric codable.Metric
if err := metric.UnmarshalFromReader(r); err != nil {
log.Warn("Could not decode metric:", err)
p.dirty = true
return sm, chunksToPersist, nil
}
var persistWatermark int64
var modTime time.Time
if version != headsFormatLegacyVersion {
// persistWatermark only present in v2.
persistWatermark, err = binary.ReadVarint(r)
if err != nil {
log.Warn("Could not decode persist watermark:", err)
p.dirty = true
return sm, chunksToPersist, nil
}
modTimeNano, err := binary.ReadVarint(r)
if err != nil {
log.Warn("Could not decode modification time:", err)
p.dirty = true
return sm, chunksToPersist, nil
}
if modTimeNano != -1 {
modTime = time.Unix(0, modTimeNano)
}
}
chunkDescsOffset, err := binary.ReadVarint(r)
if err != nil {
log.Warn("Could not decode chunk descriptor offset:", err)
p.dirty = true
return sm, chunksToPersist, nil
}
savedFirstTime, err := binary.ReadVarint(r)
if err != nil {
log.Warn("Could not decode saved first time:", err)
p.dirty = true
return sm, chunksToPersist, nil
}
numChunkDescs, err := binary.ReadVarint(r)
if err != nil {
log.Warn("Could not decode number of chunk descriptors:", err)
p.dirty = true
return sm, chunksToPersist, nil
}
chunkDescs := make([]*chunkDesc, numChunkDescs)
if version == headsFormatLegacyVersion {
if headChunkPersisted {
persistWatermark = numChunkDescs
} else {
persistWatermark = numChunkDescs - 1
}
}
for i := int64(0); i < numChunkDescs; i++ {
if i < persistWatermark {
firstTime, err := binary.ReadVarint(r)
if err != nil {
log.Warn("Could not decode first time:", err)
p.dirty = true
return sm, chunksToPersist, nil
}
lastTime, err := binary.ReadVarint(r)
if err != nil {
log.Warn("Could not decode last time:", err)
p.dirty = true
return sm, chunksToPersist, nil
}
chunkDescs[i] = &chunkDesc{
chunkFirstTime: clientmodel.Timestamp(firstTime),
chunkLastTime: clientmodel.Timestamp(lastTime),
}
chunkDescsTotal++
} else {
// Non-persisted chunk.
encoding, err := r.ReadByte()
if err != nil {
log.Warn("Could not decode chunk type:", err)
p.dirty = true
return sm, chunksToPersist, nil
}
chunk := newChunkForEncoding(chunkEncoding(encoding))
if err := chunk.unmarshal(r); err != nil {
log.Warn("Could not decode chunk:", err)
p.dirty = true
return sm, chunksToPersist, nil
}
chunkDescs[i] = newChunkDesc(chunk)
chunksToPersist++
}
}
fingerprintToSeries[clientmodel.Fingerprint(fp)] = &memorySeries{
metric: clientmodel.Metric(metric),
chunkDescs: chunkDescs,
persistWatermark: int(persistWatermark),
modTime: modTime,
chunkDescsOffset: int(chunkDescsOffset),
savedFirstTime: clientmodel.Timestamp(savedFirstTime),
headChunkClosed: persistWatermark >= numChunkDescs,
}
}
return sm, chunksToPersist, nil
}
// loadFPMappings loads the fingerprint mappings. It also returns the highest
// mapped fingerprint and any error encountered. If p.mappingsFileName is not
// found, the method returns (fpMappings{}, 0, nil). Do not call concurrently
// with checkpointFPMappings.
func (p *persistence) loadFPMappings() (fpMappings, clientmodel.Fingerprint, error) {
fpm := fpMappings{}
var highestMappedFP clientmodel.Fingerprint
f, err := os.Open(p.mappingsFileName())
if os.IsNotExist(err) {
return fpm, 0, nil
}
if err != nil {
return nil, 0, err
}
defer f.Close()
r := bufio.NewReaderSize(f, fileBufSize)
buf := make([]byte, len(mappingsMagicString))
if _, err := io.ReadFull(r, buf); err != nil {
return nil, 0, err
}
magic := string(buf)
if magic != mappingsMagicString {
return nil, 0, fmt.Errorf(
"unexpected magic string, want %q, got %q",
mappingsMagicString, magic,
)
}
version, err := binary.ReadUvarint(r)
if version != mappingsFormatVersion || err != nil {
return nil, 0, fmt.Errorf("unknown fingerprint mappings format version, want %d", mappingsFormatVersion)
}
numRawFPs, err := binary.ReadUvarint(r)
if err != nil {
return nil, 0, err
}
for ; numRawFPs > 0; numRawFPs-- {
rawFP, err := codable.DecodeUint64(r)
if err != nil {
return nil, 0, err
}
numMappings, err := binary.ReadUvarint(r)
if err != nil {
return nil, 0, err
}
mappings := make(map[string]clientmodel.Fingerprint, numMappings)
for ; numMappings > 0; numMappings-- {
lenMS, err := binary.ReadUvarint(r)
if err != nil {
return nil, 0, err
}
buf := make([]byte, lenMS)
if _, err := io.ReadFull(r, buf); err != nil {
return nil, 0, err
}
fp, err := codable.DecodeUint64(r)
if err != nil {
return nil, 0, err
}
mappedFP := clientmodel.Fingerprint(fp)
if mappedFP > highestMappedFP {
highestMappedFP = mappedFP
}
mappings[string(buf)] = mappedFP
}
fpm[clientmodel.Fingerprint(rawFP)] = mappings
}
return fpm, highestMappedFP, nil
}
// scan works like bufio.Scanner.Scan.
func (hs *headsScanner) scan() bool {
if hs.seriesCurrent == hs.seriesTotal || hs.err != nil {
return false
}
var (
seriesFlags byte
fpAsInt uint64
metric codable.Metric
persistWatermark int64
modTimeNano int64
modTime time.Time
chunkDescsOffset int64
savedFirstTime int64
numChunkDescs int64
firstTime int64
lastTime int64
encoding byte
ch chunk.Chunk
lastTimeHead model.Time
)
if seriesFlags, hs.err = hs.r.ReadByte(); hs.err != nil {
return false
}
headChunkPersisted := seriesFlags&flagHeadChunkPersisted != 0
if fpAsInt, hs.err = codable.DecodeUint64(hs.r); hs.err != nil {
return false
}
hs.fp = model.Fingerprint(fpAsInt)
if hs.err = metric.UnmarshalFromReader(hs.r); hs.err != nil {
return false
}
if hs.version != headsFormatLegacyVersion {
// persistWatermark only present in v2.
persistWatermark, hs.err = binary.ReadVarint(hs.r)
if hs.err != nil {
return false
}
modTimeNano, hs.err = binary.ReadVarint(hs.r)
if hs.err != nil {
return false
}
if modTimeNano != -1 {
modTime = time.Unix(0, modTimeNano)
}
}
if chunkDescsOffset, hs.err = binary.ReadVarint(hs.r); hs.err != nil {
return false
}
if savedFirstTime, hs.err = binary.ReadVarint(hs.r); hs.err != nil {
return false
}
if numChunkDescs, hs.err = binary.ReadVarint(hs.r); hs.err != nil {
return false
}
chunkDescs := make([]*chunk.Desc, numChunkDescs)
if hs.version == headsFormatLegacyVersion {
if headChunkPersisted {
persistWatermark = numChunkDescs
} else {
persistWatermark = numChunkDescs - 1
}
}
headChunkClosed := true // Initial assumption.
for i := int64(0); i < numChunkDescs; i++ {
if i < persistWatermark {
if firstTime, hs.err = binary.ReadVarint(hs.r); hs.err != nil {
return false
}
if lastTime, hs.err = binary.ReadVarint(hs.r); hs.err != nil {
return false
}
chunkDescs[i] = &chunk.Desc{
ChunkFirstTime: model.Time(firstTime),
ChunkLastTime: model.Time(lastTime),
}
chunk.NumMemDescs.Inc()
} else {
// Non-persisted chunk.
// If there are non-persisted chunks at all, we consider
// the head chunk not to be closed yet.
headChunkClosed = false
if encoding, hs.err = hs.r.ReadByte(); hs.err != nil {
return false
}
if ch, hs.err = chunk.NewForEncoding(chunk.Encoding(encoding)); hs.err != nil {
return false
}
if hs.err = ch.Unmarshal(hs.r); hs.err != nil {
return false
}
cd := chunk.NewDesc(ch, ch.FirstTime())
if i < numChunkDescs-1 {
// This is NOT the head chunk. So it's a chunk
// to be persisted, and we need to populate lastTime.
hs.chunksToPersistTotal++
cd.MaybePopulateLastTime()
}
chunkDescs[i] = cd
}
}
if lastTimeHead, hs.err = chunkDescs[len(chunkDescs)-1].LastTime(); hs.err != nil {
return false
}
hs.series = &memorySeries{
metric: model.Metric(metric),
chunkDescs: chunkDescs,
persistWatermark: int(persistWatermark),
modTime: modTime,
chunkDescsOffset: int(chunkDescsOffset),
savedFirstTime: model.Time(savedFirstTime),
lastTime: lastTimeHead,
headChunkClosed: headChunkClosed,
}
hs.seriesCurrent++
return true
}
// loadSeriesMapAndHeads loads the fingerprint to memory-series mapping and all
// open (non-full) head chunks. If recoverable corruption is detected, or if the
// dirty flag was set from the beginning, crash recovery is run, which might
// take a while. If an unrecoverable error is encountered, it is returned. Call
// this method during start-up while nothing else is running in storage
// land. This method is utterly goroutine-unsafe.
func (p *persistence) loadSeriesMapAndHeads() (sm *seriesMap, err error) {
var chunksTotal, chunkDescsTotal int64
fingerprintToSeries := make(map[clientmodel.Fingerprint]*memorySeries)
sm = &seriesMap{m: fingerprintToSeries}
defer func() {
if sm != nil && p.dirty {
glog.Warning("Persistence layer appears dirty.")
err = p.recoverFromCrash(fingerprintToSeries)
if err != nil {
sm = nil
}
}
if err == nil {
atomic.AddInt64(&numMemChunks, chunksTotal)
numMemChunkDescs.Add(float64(chunkDescsTotal))
}
}()
f, err := os.Open(p.headsFileName())
if os.IsNotExist(err) {
return sm, nil
}
if err != nil {
glog.Warning("Could not open heads file:", err)
p.dirty = true
return
}
defer f.Close()
r := bufio.NewReaderSize(f, fileBufSize)
buf := make([]byte, len(headsMagicString))
if _, err := io.ReadFull(r, buf); err != nil {
glog.Warning("Could not read from heads file:", err)
p.dirty = true
return sm, nil
}
magic := string(buf)
if magic != headsMagicString {
glog.Warningf(
"unexpected magic string, want %q, got %q",
headsMagicString, magic,
)
p.dirty = true
return
}
if version, err := binary.ReadVarint(r); version != headsFormatVersion || err != nil {
glog.Warningf("unknown heads format version, want %d", headsFormatVersion)
p.dirty = true
return sm, nil
}
numSeries, err := codable.DecodeUint64(r)
if err != nil {
glog.Warning("Could not decode number of series:", err)
p.dirty = true
return sm, nil
}
for ; numSeries > 0; numSeries-- {
seriesFlags, err := r.ReadByte()
if err != nil {
glog.Warning("Could not read series flags:", err)
p.dirty = true
return sm, nil
}
headChunkPersisted := seriesFlags&flagHeadChunkPersisted != 0
fp, err := codable.DecodeUint64(r)
if err != nil {
glog.Warning("Could not decode fingerprint:", err)
p.dirty = true
return sm, nil
}
var metric codable.Metric
if err := metric.UnmarshalFromReader(r); err != nil {
glog.Warning("Could not decode metric:", err)
p.dirty = true
return sm, nil
}
chunkDescsOffset, err := binary.ReadVarint(r)
if err != nil {
glog.Warning("Could not decode chunk descriptor offset:", err)
p.dirty = true
return sm, nil
}
savedFirstTime, err := binary.ReadVarint(r)
if err != nil {
glog.Warning("Could not decode saved first time:", err)
p.dirty = true
return sm, nil
}
numChunkDescs, err := binary.ReadVarint(r)
if err != nil {
glog.Warning("Could not decode number of chunk descriptors:", err)
p.dirty = true
return sm, nil
}
chunkDescs := make([]*chunkDesc, numChunkDescs)
chunkDescsTotal += numChunkDescs
for i := int64(0); i < numChunkDescs; i++ {
if headChunkPersisted || i < numChunkDescs-1 {
firstTime, err := binary.ReadVarint(r)
if err != nil {
glog.Warning("Could not decode first time:", err)
p.dirty = true
return sm, nil
}
lastTime, err := binary.ReadVarint(r)
if err != nil {
glog.Warning("Could not decode last time:", err)
p.dirty = true
return sm, nil
}
chunkDescs[i] = &chunkDesc{
chunkFirstTime: clientmodel.Timestamp(firstTime),
chunkLastTime: clientmodel.Timestamp(lastTime),
}
} else {
// Non-persisted head chunk.
chunksTotal++
chunkType, err := r.ReadByte()
if err != nil {
glog.Warning("Could not decode chunk type:", err)
p.dirty = true
return sm, nil
}
chunk := chunkForType(chunkType)
if err := chunk.unmarshal(r); err != nil {
glog.Warning("Could not decode chunk type:", err)
p.dirty = true
return sm, nil
}
chunkDescs[i] = newChunkDesc(chunk)
}
}
fingerprintToSeries[clientmodel.Fingerprint(fp)] = &memorySeries{
metric: clientmodel.Metric(metric),
chunkDescs: chunkDescs,
chunkDescsOffset: int(chunkDescsOffset),
savedFirstTime: clientmodel.Timestamp(savedFirstTime),
headChunkPersisted: headChunkPersisted,
}
}
return sm, nil
}