Implement Delete on HeadBlock

Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>

block.go

@@ -14,7 +14,7 @@
 package tsdb
 
 import (
-	"bufio"
+	"encoding/binary"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
@@ -155,6 +155,79 @@ func writeMetaFile(dir string, meta *BlockMeta) error {
 	return renameFile(tmp, path)
 }
 
+func readTombstoneFile(dir string) (TombstoneReader, error) {
+	return newTombStoneReader(dir)
+}
+
+func writeTombstoneFile(dir string, tr TombstoneReader) error {
+	path := filepath.Join(dir, tombstoneFilename)
+	tmp := path + ".tmp"
+
+	f, err := os.Create(tmp)
+	if err != nil {
+		return err
+	}
+
+	stoneOff := make(map[uint32]int64) // The map that holds the ref to offset vals.
+	refs := []uint32{}                 // Sorted refs.
+
+	pos := int64(0)
+	buf := encbuf{b: make([]byte, 2*binary.MaxVarintLen64)}
+	for tr.Next() {
+		s := tr.At()
+
+		refs = append(refs, s.ref)
+		stoneOff[s.ref] = pos
+
+		// Write the ranges.
+		buf.reset()
+		buf.putVarint64(int64(len(s.ranges)))
+		n, err := f.Write(buf.get())
+		if err != nil {
+			return err
+		}
+		pos += int64(n)
+
+		for _, r := range s.ranges {
+			buf.reset()
+			buf.putVarint64(r.mint)
+			buf.putVarint64(r.maxt)
+			n, err = f.Write(buf.get())
+			if err != nil {
+				return err
+			}
+			pos += int64(n)
+		}
+	}
+
+	// Write the offset table.
+	buf.reset()
+	buf.putBE32int(len(refs))
+	for _, ref := range refs {
+		buf.reset()
+		buf.putBE32(ref)
+		buf.putBE64int64(stoneOff[ref])
+		_, err = f.Write(buf.get())
+		if err != nil {
+			return err
+		}
+	}
+
+	// Write the offset to the offset table.
+	buf.reset()
+	buf.putBE64int64(pos)
+	_, err = f.Write(buf.get())
+	if err != nil {
+		return err
+	}
+
+	if err := f.Close(); err != nil {
+		return err
+	}
+
+	return renameFile(tmp, path)
+}
+
 type persistedBlock struct {
 	dir  string
 	meta BlockMeta
@@ -226,6 +299,9 @@ func (pb *persistedBlock) Delete(mint, maxt int64, ms ...labels.Matcher) error {
 Outer:
 	for p.Next() {
 		lset, chunks, err := ir.Series(p.At())
+		if err != nil {
+			return err
+		}
 
 		for _, abs := range absent {
 			if lset.Get(abs) != "" {
@@ -235,10 +311,10 @@ Outer:
 
 		// XXX(gouthamve): Adjust mint and maxt to match the time-range in the chunks?
 		for _, chk := range chunks {
-			if (mint <= chk.MinTime && maxt >= MinTime) ||
+			if (mint <= chk.MinTime && maxt >= chk.MinTime) ||
 				(mint > chk.MinTime && mint <= chk.MaxTime) {
 				vPostings = append(vPostings, p.At())
-				continue
+				continue Outer
 			}
 		}
 	}
@@ -248,125 +324,237 @@ Outer:
 	}
 
 	// Merge the current and new tombstones.
-	tr := ir.tombstones()
-	stones := make([]rip, 0, len(vPostings))
-	i := 0
-	for tr.Next() {
-		stone := tr.At()
-		for stone.ref > vPostings[i] {
-			stones = append(stones, rip{ref: vPostings[i], mint: mint, maxt: maxt})
-			i++
-		}
+	tr := newMapTombstoneReader(ir.tombstones)
+	str := newSimpleTombstoneReader(vPostings, []trange{mint, maxt})
+	tombreader := newMergedTombstoneReader(tr, str)
 
-		if stone.ref == vPostings[i] {
-			if stone.mint > mint {
-				stone.mint = mint
-			}
-			if stone.maxt < maxt {
-				stone.maxt = maxt
-			}
+	return writeTombstoneFile(pb.dir, tombreader)
+}
 
-			stones = append(stones, stone)
-			continue
-		}
+// stone holds the information on the posting and time-range
+// that is deleted.
+type stone struct {
+	ref    uint32
+	ranges []trange
+}
 
-		stones = append(stones, stone)
-	}
+// TombstoneReader is the iterator over tombstones.
+type TombstoneReader interface {
+	Next() bool
+	At() stone
+	Err() error
+}
 
-	path := filepath.Join(pb.dir, tombstoneFilename)
-	tmp := path + ".tmp"
+var emptyTombstoneReader = newMapTombstoneReader(make(map[uint32][]trange))
 
-	f, err := os.Create(tmp)
+type tombstoneReader struct {
+	stones []byte
+	idx    int
+	len    int
+
+	b   []byte
+	err error
+}
+
+func newTombStoneReader(dir string) (*tombstoneReader, error) {
+	// TODO(gouthamve): MMAP?
+	b, err := ioutil.ReadFile(filepath.Join(dir, tombstoneFilename))
 	if err != nil {
-		return err
+		return nil, err
 	}
 
-	// TODO: Proper format and all.
-	buf := encbuf{b: make([]byte, 0, 20)}
-	fbuf := bufio.NewWriterSize(f, 20)
+	offsetBytes := b[len(b)-8:]
+	d := &decbuf{b: offsetBytes}
+	off := d.be64int64()
+	if err := d.err(); err != nil {
+		return nil, err
+	}
 
-	for _, stone := range stones {
-		buf.reset()
-		buf.putBE32(stone.ref)
-		buf.putBE64int64(stone.mint)
-		buf.putBE64int64(stone.maxt)
+	d = &decbuf{b: b[off:]}
+	numStones := d.be64int64()
+	if err := d.err(); err != nil {
+		return nil, err
+	}
 
-		_, err := fbuf.Write(buf.get())
-		if err != nil {
-			return err
-		}
+	return &tombstoneReader{
+		stones: b[off+8 : (off+8)+(numStones*12)],
+		idx:    -1,
+		len:    int(numStones),
+
+		b: b,
+	}, nil
+}
+
+func (t *tombstoneReader) Next() bool {
+	if t.err != nil {
+		return false
 	}
 
-	if err := fbuf.Flush(); err != nil {
-		return err
+	t.idx++
+
+	return t.idx < t.len
+}
+
+func (t *tombstoneReader) At() stone {
+	bytIdx := t.idx * (4 + 8)
+	dat := t.stones[bytIdx : bytIdx+12]
+
+	d := &decbuf{b: dat}
+	ref := d.be32()
+	off := d.be64int64()
+
+	d = &decbuf{b: t.b[off:]}
+	numRanges := d.varint64()
+	if err := d.err(); err != nil {
+		t.err = err
+		return stone{ref: ref}
 	}
-	if err := f.Close(); err != nil {
-		return err
+
+	dranges := make([]trange, 0, numRanges)
+	for i := 0; i < int(numRanges); i++ {
+		mint := d.varint64()
+		maxt := d.varint64()
+		if err := d.err(); err != nil {
+			t.err = err
+			return stone{ref: ref, ranges: dranges}
+		}
+
+		dranges = append(dranges, trange{mint, maxt})
 	}
 
-	return renameFile(tmp, path)
+	return stone{ref: ref, ranges: dranges}
 }
 
-// rip (after rest-in-peace) holds the information on the posting and time-range
-// that is deleted.
-type rip struct {
-	ref        uint32
-	mint, maxt int64
+func (t *tombstoneReader) Err() error {
+	return t.err
 }
 
-// TODO(gouthamve): Move to cur and reduction in byte-array vis-a-vis BEPostings.
-type tombstoneReader struct {
-	data []byte
-	idx  int
-	len  int
+type mapTombstoneReader struct {
+	refs []uint32
+	cur  uint32
+
+	stones map[uint32][]trange
 }
 
-func newTombStoneReader(data []byte) *tombstoneReader {
-	// TODO(gouthamve): Error handling.
-	return &tombstoneReader{data: data, idx: -1, len: len(data) / 20}
+func newMapTombstoneReader(ts map[uint32][]trange) *mapTombstoneReader {
+	refs := make([]uint32, 0, len(ts))
+	for k := range ts {
+		refs = append(refs, k)
+	}
+	sort.Sort(uint32slice(refs))
+	return &mapTombstoneReader{stones: ts, refs: refs}
 }
 
-func (t *tombstoneReader) Next() bool {
-	t.idx++
+func (t *mapTombstoneReader) Next() bool {
+	if len(t.refs) > 0 {
+		t.cur = t.refs[0]
+		return true
+	}
 
-	return t.idx < t.len
+	t.cur = 0
+	return false
 }
 
-func (t *tombstoneReader) At() rip {
-	bytIdx := t.idx * (4 + 8 + 8)
-	dat := t.data[bytIdx : bytIdx+20]
+func (t *mapTombstoneReader) At() stone {
+	return stone{ref: t.cur, ranges: t.stones[t.cur]}
+}
+
+func (t *mapTombstoneReader) Err() error {
+	return nil
+}
 
-	db := &decbuf{b: dat}
-	ref := db.be32()
-	mint := db.be64int64()
-	maxt := db.be64int64()
+type simpleTombstoneReader struct {
+	refs []uint32
+	cur  uint32
 
-	// TODO(gouthamve): Handle errors.
-	return rip{ref: ref, mint: mint, maxt: maxt}
+	ranges []trange
 }
 
-func (t *tombstoneReader) Seek(ref uint32) bool {
-	if s := t.At(); s.ref >= ref {
+func newSimpleTombstoneReader(refs []uint32, drange []trange) *simpleTombstoneReader {
+	return &simpleTombstoneReader{refs: refs, ranges: drange}
+}
+
+func (t *simpleTombstoneReader) Next() bool {
+	if len(t.refs) > 0 {
+		t.cur = t.refs[0]
 		return true
 	}
 
-	i := sort.Search(t.len-t.idx, func(i int) bool {
-		bytIdx := (t.idx + i) * 20
-		dat := t.data[bytIdx : bytIdx+20]
+	t.cur = 0
+	return false
+}
+
+func (t *simpleTombstoneReader) At() stone {
+	return stone{ref: t.cur, ranges: t.ranges}
+}
+
+func (t *simpleTombstoneReader) Err() error {
+	return nil
+}
+
+type mergedTombstoneReader struct {
+	a, b TombstoneReader
+	cur  stone
+
+	initialized bool
+	aok, bok    bool
+}
+
+func newMergedTombstoneReader(a, b TombstoneReader) *mergedTombstoneReader {
+	return &mergedTombstoneReader{a: a, b: b}
+}
+
+func (t *mergedTombstoneReader) Next() bool {
+	if !t.initialized {
+		t.aok = t.a.Next()
+		t.bok = t.b.Next()
+		t.initialized = true
+	}
+
+	if !t.aok && !t.bok {
+		return false
+	}
+
+	if !t.aok {
+		t.cur = t.b.At()
+		t.bok = t.b.Next()
+		return true
+	}
+	if !t.bok {
+		t.cur = t.a.At()
+		t.aok = t.a.Next()
+		return true
+	}
 
-		db := &decbuf{b: dat}
-		ref2 := db.be32()
-		if ref >= ref2 {
-			return true
+	acur, bcur := t.a.At(), t.b.At()
+
+	if acur.ref < bcur.ref {
+		t.cur = acur
+		t.aok = t.a.Next()
+	} else if acur.ref > bcur.ref {
+		t.cur = bcur
+		t.bok = t.b.Next()
+	} else {
+		t.cur = acur
+		// Merge time ranges.
+		for _, r := range bcur.ranges {
+			acur.ranges = addNewInterval(acur.ranges, r)
 		}
-	})
+		t.aok = t.a.Next()
+		t.bok = t.b.Next()
+	}
+	return true
+}
 
-	t.idx += idx
-	return t.idx < t.len
+func (t *mergedTombstoneReader) At() stone {
+	return t.cur
 }
 
-func (t *tombstoneReader) Err() error {
-	return nil
+func (t *mergedTombstoneReader) Err() error {
+	if t.a.Err() != nil {
+		return t.a.Err()
+	}
+	return t.b.Err()
 }
 
 func chunkDir(dir string) string { return filepath.Join(dir, "chunks") }

chunks.go

@@ -55,6 +55,38 @@ func (tr trange) inBounds(t int64) bool {
 	return t >= tr.mint && t <= tr.maxt
 }
 
+// This adds the new time-range to the existing ones.
+// The existing ones must be sorted.
+func addNewInterval(existing []trange, n trange) []trange {
+	for i, r := range existing {
+		if r.inBounds(n.mint) {
+			if n.maxt > r.maxt {
+				existing[i].maxt = n.maxt
+			}
+
+			return existing
+		}
+		if r.inBounds(n.maxt) {
+			if n.mint < r.maxt {
+				existing[i].mint = n.mint
+			}
+
+			return existing
+		}
+
+		if n.mint < r.mint {
+			newRange := existing[:i]
+			newRange = append(newRange, n)
+			newRange = append(newRange, existing[i:]...)
+
+			return newRange
+		}
+	}
+
+	existing = append(existing, n)
+	return existing
+}
+
 // writeHash writes the chunk encoding and raw data into the provided hash.
 func (cm *ChunkMeta) writeHash(h hash.Hash) error {
 	if _, err := h.Write([]byte{byte(cm.Chunk.Encoding())}); err != nil {
@@ -114,7 +146,7 @@ Outer:
 	return false
 }
 
-func (it *deletedIterator) Err() {
+func (it *deletedIterator) Err() error {
 	return it.Err()
 }
 
@@ -252,6 +284,27 @@ func (w *chunkWriter) WriteChunks(chks ...*ChunkMeta) error {
 	maxLen := int64(binary.MaxVarintLen32) // The number of chunks.
 	for _, c := range chks {
 		maxLen += binary.MaxVarintLen32 + 1 // The number of bytes in the chunk and its encoding.
+
+		// Remove the deleted parts.
+		if c.deleted {
+			// TODO(gouthamve): Try to do it in-place somehow?
+			chk := chunks.NewXORChunk()
+			app, err := chk.Appender()
+			if err != nil {
+				return err
+			}
+			it := c.Iterator()
+			for it.Next() {
+				ts, v := it.At()
+				app.Append(ts, v)
+			}
+
+			if err := it.Err(); err != nil {
+				return err
+			}
+			c.Chunk = chk
+		}
+
 		maxLen += int64(len(c.Chunk.Bytes()))
 	}
 	newsz := w.n + maxLen

encoding_helpers.go

@@ -72,9 +72,9 @@ type decbuf struct {
 	e error
 }
 
-func (d *decbuf) uvarint() int   { return int(d.uvarint64()) }
-func (d *decbuf) be32int() int   { return int(d.be32()) }
-func (d *decbuf) be64int64() int { return int64(d.be64()) }
+func (d *decbuf) uvarint() int     { return int(d.uvarint64()) }
+func (d *decbuf) be32int() int     { return int(d.be32()) }
+func (d *decbuf) be64int64() int64 { return int64(d.be64()) }
 
 func (d *decbuf) uvarintStr() string {
 	l := d.uvarint64()

head.go

@@ -66,6 +66,8 @@ type HeadBlock struct {
 	values   map[string]stringset // label names to possible values
 	postings *memPostings         // postings lists for terms
 
+	tombstones map[uint32][]trange
+
 	meta BlockMeta
 }
 
@@ -94,6 +96,7 @@ func TouchHeadBlock(dir string, seq int, mint, maxt int64) error {
 	}); err != nil {
 		return err
 	}
+
 	return renameFile(tmp, dir)
 }
 
@@ -105,13 +108,14 @@ func OpenHeadBlock(dir string, l log.Logger, wal WAL) (*HeadBlock, error) {
 	}
 
 	h := &HeadBlock{
-		dir:      dir,
-		wal:      wal,
-		series:   []*memSeries{nil}, // 0 is not a valid posting, filled with nil.
-		hashes:   map[uint64][]*memSeries{},
-		values:   map[string]stringset{},
-		postings: &memPostings{m: make(map[term][]uint32)},
-		meta:     *meta,
+		dir:        dir,
+		wal:        wal,
+		series:     []*memSeries{nil}, // 0 is not a valid posting, filled with nil.
+		hashes:     map[uint64][]*memSeries{},
+		values:     map[string]stringset{},
+		postings:   &memPostings{m: make(map[term][]uint32)},
+		meta:       *meta,
+		tombstones: make(map[uint32][]trange),
 	}
 	return h, h.init()
 }
@@ -138,7 +142,20 @@ func (h *HeadBlock) init() error {
 			h.meta.Stats.NumSamples++
 		}
 	}
-	return errors.Wrap(r.Err(), "consume WAL")
+	if err := r.Err(); err != nil {
+		return errors.Wrap(err, "consume WAL")
+	}
+
+	tr, err := readTombstoneFile(h.dir)
+	if err != nil {
+		return errors.Wrap(err, "read tombstones file")
+	}
+
+	for tr.Next() {
+		s := tr.At()
+		h.tombstones[s.ref] = s.ranges
+	}
+	return errors.Wrap(err, "tombstones reader iteration")
 }
 
 // inBounds returns true if the given timestamp is within the valid
@@ -206,7 +223,44 @@ func (h *HeadBlock) Index() IndexReader { return &headIndexReader{h} }
 func (h *HeadBlock) Chunks() ChunkReader { return &headChunkReader{h} }
 
 // Delete implements headBlock
-func (h *HeadBlock) Delete(int64, int64, ...labels.Matcher) error { return nil }
+func (h *HeadBlock) Delete(mint int64, maxt int64, ms ...labels.Matcher) error {
+	h.mtx.RLock()
+
+	ir := h.Index()
+
+	pr := newPostingsReader(ir)
+	p, absent := pr.Select(ms...)
+
+	h.mtx.RUnlock()
+
+	h.mtx.Lock() // We are modifying the tombstones here.
+	defer h.mtx.Unlock()
+
+Outer:
+	for p.Next() {
+		ref := p.At()
+		lset := h.series[ref].lset
+		for _, abs := range absent {
+			if lset.Get(abs) != "" {
+				continue Outer
+			}
+		}
+
+		rs, ok := h.tombstones[ref]
+		if !ok {
+			h.tombstones[ref] = []trange{{mint, maxt}}
+			continue
+		}
+
+		h.tombstones[ref] = addNewInterval(rs, trange{mint, maxt})
+	}
+
+	if p.Err() != nil {
+		return p.Err()
+	}
+
+	return writeTombstoneFile(h.dir, newMapTombstoneReader(h.tombstones))
+}
 
 // Querier implements Queryable and headBlock
 func (h *HeadBlock) Querier(mint, maxt int64) Querier {
@@ -527,6 +581,9 @@ func (h *headIndexReader) Series(ref uint32) (labels.Labels, []*ChunkMeta, error
 	if int(ref) >= len(h.series) {
 		return nil, nil, ErrNotFound
 	}
+
+	dranges, deleted := h.tombstones[ref]
+
 	s := h.series[ref]
 	metas := make([]*ChunkMeta, 0, len(s.chunks))
 
@@ -538,6 +595,9 @@ func (h *headIndexReader) Series(ref uint32) (labels.Labels, []*ChunkMeta, error
 			MinTime: c.minTime,
 			MaxTime: c.maxTime,
 			Ref:     (uint64(ref) << 32) | uint64(i),
+
+			deleted: deleted,
+			dranges: dranges,
 		})
 	}
 

index.go

@@ -165,6 +165,10 @@ func newIndexWriter(dir string) (*indexWriter, error) {
 	if err := iw.writeMeta(); err != nil {
 		return nil, err
 	}
+	// TODO(gouthamve): Figure out where this function goes, index or block.
+	if err := writeTombstoneFile(dir, emptyTombstoneReader); err != nil {
+		return nil, err
+	}
 	return iw, nil
 }
 
@@ -538,8 +542,7 @@ type indexReader struct {
 	labels   map[string]uint32
 	postings map[string]uint32
 
-	// The underlying byte slice holding the tombstone data.
-	tomb []byte
+	tombstones map[uint32][]trange
 }
 
 var (
@@ -576,13 +579,17 @@ func newIndexReader(dir string) (*indexReader, error) {
 		return nil, errors.Wrap(err, "read postings table")
 	}
 
-	tf, err := openMmapFile(filepath.Join(dir, tombstoneFilename))
+	tr, err := readTombstoneFile(dir)
 	if err != nil {
-		return err
+		return r, err
+	}
+	r.tombstones = make(map[uint32][]trange)
+	for tr.Next() {
+		s := tr.At()
+		r.tombstones[s.ref] = s.ranges
 	}
-	r.tomb = tf.b
 
-	return r, nil
+	return r, tr.Err()
 }
 
 func (r *indexReader) readTOC() error {
@@ -750,17 +757,7 @@ func (r *indexReader) Series(ref uint32) (labels.Labels, []*ChunkMeta, error) {
 		lbls = append(lbls, labels.Label{Name: ln, Value: lv})
 	}
 
-	// TODO: This sucks! Put tombstones in map.
-	tr := r.tombstones()
-	dmint, dmaxt := 0
-	del := false
-	if tr.Seek(ref) {
-		s := tr.At()
-		if s.ref == ref {
-			del = true
-			dmint, dmaxt = s.mint, s.maxt
-		}
-	}
+	s, deleted := r.tombstones[ref]
 
 	// Read the chunks meta data.
 	k = int(d2.uvarint())
@@ -781,8 +778,8 @@ func (r *indexReader) Series(ref uint32) (labels.Labels, []*ChunkMeta, error) {
 			MinTime: mint,
 			MaxTime: maxt,
 
-			deleted: del,
-			dranges: []trange{{dmint, dmaxt}},
+			deleted: deleted,
+			dranges: s,
 		})
 	}
 
@@ -814,10 +811,6 @@ func (r *indexReader) Postings(name, value string) (Postings, error) {
 	return newBigEndianPostings(d2.get()), nil
 }
 
-func (r *indexReader) tombstones() *tombstoneReader {
-	return newTombStoneReader(r.tomb[:])
-}
-
 type stringTuples struct {
 	l int      // tuple length
 	s []string // flattened tuple entries