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index: don't use concatenated string for posting table

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This commit is contained in:
Fabian Reinartz 2017-12-01 11:01:40 +01:00
parent 54205903f7
commit 6dd2b83a7a
1 changed files with 41 additions and 22 deletions
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63
index/index.go
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@ -523,7 +523,7 @@ type Reader struct {
// Cached hashmaps of section offsets.
labels map[string]uint32
postings map[string]uint32
postings map[labels.Label]uint32
// Cache of read symbols. Strings that are returned when reading from the
// block are always backed by true strings held in here rather than
// strings that are backed by byte slices from the mmap'd index file. This
@ -576,10 +576,12 @@ func NewFileReader(path string) (*Reader, error) {
func newReader(b ByteSlice, c io.Closer) (*Reader, error) {
r := &Reader{
b: b,
c: c,
symbols: map[uint32]string{},
crc32: newCRC32(),
b: b,
c: c,
symbols: map[uint32]string{},
labels: map[string]uint32{},
postings: map[labels.Label]uint32{},
crc32: newCRC32(),
}
// Verify magic number.
if b.Len() < 4 {
@ -597,12 +599,27 @@ func newReader(b ByteSlice, c io.Closer) (*Reader, error) {
}
var err error
r.labels, err = r.readOffsetTable(r.toc.labelIndicesTable)
err = r.readOffsetTable(r.toc.labelIndicesTable, func(key []string, off uint32) error {
if len(key) != 1 {
return errors.Errorf("unexpected key length %d", len(key))
}
r.labels[key[0]] = off
return nil
})
if err != nil {
return nil, errors.Wrap(err, "read label index table")
}
r.postings, err = r.readOffsetTable(r.toc.postingsTable)
return r, errors.Wrap(err, "read postings table")
err = r.readOffsetTable(r.toc.postingsTable, func(key []string, off uint32) error {
if len(key) != 2 {
return errors.Errorf("unexpected key length %d", len(key))
}
r.postings[labels.Label{Name: key[0], Value: key[1]}] = off
return nil
})
if err != nil {
return nil, errors.Wrap(err, "read postings table")
}
return r, nil
}
func (r *Reader) readTOC() error {
@ -707,16 +724,13 @@ func (r *Reader) readSymbols(off int) error {
return d.err()
}
// readOffsetTable reads an offset table at the given position and returns a map
// with the key strings concatenated by the 0xff unicode non-character.
func (r *Reader) readOffsetTable(off uint64) (map[string]uint32, error) {
const sep = "\xff"
// readOffsetTable reads an offset table at the given position calls f for each
// found entry.f
// If f returns an error it stops decoding and returns the received error,
func (r *Reader) readOffsetTable(off uint64, f func([]string, uint32) error) error {
d := r.decbufAt(int(off))
cnt := d.be32()
res := make(map[string]uint32, cnt)
for d.err() == nil && d.len() > 0 && cnt > 0 {
keyCount := int(d.uvarint())
keys := make([]string, 0, keyCount)
@ -724,11 +738,16 @@ func (r *Reader) readOffsetTable(off uint64) (map[string]uint32, error) {
for i := 0; i < keyCount; i++ {
keys = append(keys, d.uvarintStr())
}
res[strings.Join(keys, sep)] = uint32(d.uvarint())
o := uint32(d.uvarint())
if d.err() != nil {
break
}
if err := f(keys, o); err != nil {
return err
}
cnt--
}
return res, d.err()
return d.err()
}
func (r *Reader) Close() error {
@ -863,10 +882,10 @@ func (r *Reader) Series(ref uint64, lbls *labels.Labels, chks *[]chunks.Meta) er
}
func (r *Reader) Postings(name, value string) (Postings, error) {
const sep = "\xff"
key := strings.Join([]string{name, value}, sep)
off, ok := r.postings[key]
off, ok := r.postings[labels.Label{
Name: name,
Value: value,
}]
if !ok {
return emptyPostings, nil
}