mirror of
https://github.com/VictoriaMetrics/VictoriaMetrics.git
synced 2024-12-01 14:47:38 +00:00
185cff307b
This should improve debuggability
354 lines
7.9 KiB
Go
354 lines
7.9 KiB
Go
package mergeset
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"sort"
|
|
|
|
"github.com/VictoriaMetrics/VictoriaMetrics/lib/blockcache"
|
|
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
|
|
"github.com/VictoriaMetrics/VictoriaMetrics/lib/encoding"
|
|
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
|
|
)
|
|
|
|
type partSearch struct {
|
|
// Item contains the last item found after the call to NextItem.
|
|
//
|
|
// The Item content is valid until the next call to NextItem.
|
|
Item []byte
|
|
|
|
// p is a part to search.
|
|
p *part
|
|
|
|
// The remaining metaindex rows to scan, obtained from p.mrs.
|
|
mrs []metaindexRow
|
|
|
|
// The remaining block headers to scan in the current metaindexRow.
|
|
bhs []blockHeader
|
|
|
|
// err contains the last error.
|
|
err error
|
|
|
|
indexBuf []byte
|
|
compressedIndexBuf []byte
|
|
|
|
sb storageBlock
|
|
|
|
ib *inmemoryBlock
|
|
ibItemIdx int
|
|
}
|
|
|
|
func (ps *partSearch) reset() {
|
|
ps.Item = nil
|
|
ps.p = nil
|
|
ps.mrs = nil
|
|
ps.bhs = nil
|
|
ps.err = nil
|
|
|
|
ps.indexBuf = ps.indexBuf[:0]
|
|
ps.compressedIndexBuf = ps.compressedIndexBuf[:0]
|
|
|
|
ps.sb.Reset()
|
|
|
|
ps.ib = nil
|
|
ps.ibItemIdx = 0
|
|
}
|
|
|
|
// Init initializes ps for search in the p.
|
|
//
|
|
// Use Seek for search in p.
|
|
func (ps *partSearch) Init(p *part) {
|
|
ps.reset()
|
|
|
|
ps.p = p
|
|
}
|
|
|
|
// Seek seeks for the first item greater or equal to k in ps.
|
|
func (ps *partSearch) Seek(k []byte) {
|
|
if err := ps.Error(); err != nil {
|
|
// Do nothing on unrecoverable error.
|
|
return
|
|
}
|
|
ps.err = nil
|
|
|
|
if string(k) > string(ps.p.ph.lastItem) {
|
|
// Not matching items in the part.
|
|
ps.err = io.EOF
|
|
return
|
|
}
|
|
|
|
if ps.tryFastSeek(k) {
|
|
return
|
|
}
|
|
|
|
ps.Item = nil
|
|
ps.mrs = ps.p.mrs
|
|
ps.bhs = nil
|
|
|
|
ps.indexBuf = ps.indexBuf[:0]
|
|
ps.compressedIndexBuf = ps.compressedIndexBuf[:0]
|
|
|
|
ps.sb.Reset()
|
|
|
|
ps.ib = nil
|
|
ps.ibItemIdx = 0
|
|
|
|
if string(k) <= string(ps.p.ph.firstItem) {
|
|
// The first item in the first block matches.
|
|
ps.err = ps.nextBlock()
|
|
return
|
|
}
|
|
|
|
// Locate the first metaindexRow to scan.
|
|
if len(ps.mrs) == 0 {
|
|
logger.Panicf("BUG: part without metaindex rows passed to partSearch")
|
|
}
|
|
n := sort.Search(len(ps.mrs), func(i int) bool {
|
|
return string(k) <= string(ps.mrs[i].firstItem)
|
|
})
|
|
if n > 0 {
|
|
// The given k may be located in the previous metaindexRow, so go to it.
|
|
n--
|
|
}
|
|
ps.mrs = ps.mrs[n:]
|
|
|
|
// Read block headers for the found metaindexRow.
|
|
if err := ps.nextBHS(); err != nil {
|
|
ps.err = err
|
|
return
|
|
}
|
|
|
|
// Locate the first block to scan.
|
|
n = sort.Search(len(ps.bhs), func(i int) bool {
|
|
return string(k) <= string(ps.bhs[i].firstItem)
|
|
})
|
|
if n > 0 {
|
|
// The given k may be located in the previous block, so go to it.
|
|
n--
|
|
}
|
|
ps.bhs = ps.bhs[n:]
|
|
|
|
// Read the block.
|
|
if err := ps.nextBlock(); err != nil {
|
|
ps.err = err
|
|
return
|
|
}
|
|
|
|
// Locate the first item to scan in the block.
|
|
items := ps.ib.items
|
|
data := ps.ib.data
|
|
cpLen := commonPrefixLen(ps.ib.commonPrefix, k)
|
|
if cpLen > 0 {
|
|
keySuffix := k[cpLen:]
|
|
ps.ibItemIdx = sort.Search(len(items), func(i int) bool {
|
|
it := items[i]
|
|
it.Start += uint32(cpLen)
|
|
return string(keySuffix) <= it.String(data)
|
|
})
|
|
} else {
|
|
ps.ibItemIdx = binarySearchKey(data, items, k)
|
|
}
|
|
if ps.ibItemIdx < len(items) {
|
|
// The item has been found.
|
|
return
|
|
}
|
|
|
|
// Nothing found in the current block. Proceed to the next block.
|
|
// The item to search must be the first in the next block.
|
|
if err := ps.nextBlock(); err != nil {
|
|
ps.err = err
|
|
return
|
|
}
|
|
}
|
|
|
|
func (ps *partSearch) tryFastSeek(k []byte) bool {
|
|
if ps.ib == nil {
|
|
return false
|
|
}
|
|
data := ps.ib.data
|
|
items := ps.ib.items
|
|
idx := ps.ibItemIdx
|
|
if idx >= len(items) {
|
|
// The ib is exhausted.
|
|
return false
|
|
}
|
|
if string(k) > items[len(items)-1].String(data) {
|
|
// The item is located in next blocks.
|
|
return false
|
|
}
|
|
|
|
// The item is located either in the current block or in previous blocks.
|
|
if idx > 0 {
|
|
idx--
|
|
}
|
|
if string(k) < items[idx].String(data) {
|
|
if string(k) < items[0].String(data) {
|
|
// The item is located in previous blocks.
|
|
return false
|
|
}
|
|
idx = 0
|
|
}
|
|
|
|
// The item is located in the current block
|
|
ps.ibItemIdx = idx + binarySearchKey(data, items[idx:], k)
|
|
return true
|
|
}
|
|
|
|
// NextItem advances to the next Item.
|
|
//
|
|
// Returns true on success.
|
|
func (ps *partSearch) NextItem() bool {
|
|
if ps.err != nil {
|
|
return false
|
|
}
|
|
|
|
items := ps.ib.items
|
|
if ps.ibItemIdx < len(items) {
|
|
// Fast path - the current block contains more items.
|
|
// Proceed to the next item.
|
|
ps.Item = items[ps.ibItemIdx].Bytes(ps.ib.data)
|
|
ps.ibItemIdx++
|
|
return true
|
|
}
|
|
|
|
// The current block is over. Proceed to the next block.
|
|
if err := ps.nextBlock(); err != nil {
|
|
if err != io.EOF {
|
|
err = fmt.Errorf("error in %q: %w", ps.p.path, err)
|
|
}
|
|
ps.err = err
|
|
return false
|
|
}
|
|
|
|
// Invariant: len(ps.ib.items) > 0 after nextBlock.
|
|
ps.Item = ps.ib.items[0].Bytes(ps.ib.data)
|
|
ps.ibItemIdx++
|
|
return true
|
|
}
|
|
|
|
// Error returns the last error occurred in the ps.
|
|
func (ps *partSearch) Error() error {
|
|
if ps.err == io.EOF {
|
|
return nil
|
|
}
|
|
return ps.err
|
|
}
|
|
|
|
func (ps *partSearch) nextBlock() error {
|
|
if len(ps.bhs) == 0 {
|
|
// The current metaindexRow is over. Proceed to the next metaindexRow.
|
|
if err := ps.nextBHS(); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
bh := &ps.bhs[0]
|
|
ps.bhs = ps.bhs[1:]
|
|
ib, err := ps.getInmemoryBlock(bh)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
ps.ib = ib
|
|
ps.ibItemIdx = 0
|
|
return nil
|
|
}
|
|
|
|
func (ps *partSearch) nextBHS() error {
|
|
if len(ps.mrs) == 0 {
|
|
return io.EOF
|
|
}
|
|
mr := &ps.mrs[0]
|
|
ps.mrs = ps.mrs[1:]
|
|
idxbKey := blockcache.Key{
|
|
Part: ps.p,
|
|
Offset: mr.indexBlockOffset,
|
|
}
|
|
b := idxbCache.GetBlock(idxbKey)
|
|
if b == nil {
|
|
idxb, err := ps.readIndexBlock(mr)
|
|
if err != nil {
|
|
return fmt.Errorf("cannot read index block: %w", err)
|
|
}
|
|
b = idxb
|
|
idxbCache.PutBlock(idxbKey, b)
|
|
}
|
|
idxb := b.(*indexBlock)
|
|
ps.bhs = idxb.bhs
|
|
return nil
|
|
}
|
|
|
|
func (ps *partSearch) readIndexBlock(mr *metaindexRow) (*indexBlock, error) {
|
|
ps.compressedIndexBuf = bytesutil.ResizeNoCopyMayOverallocate(ps.compressedIndexBuf, int(mr.indexBlockSize))
|
|
ps.p.indexFile.MustReadAt(ps.compressedIndexBuf, int64(mr.indexBlockOffset))
|
|
|
|
var err error
|
|
ps.indexBuf, err = encoding.DecompressZSTD(ps.indexBuf[:0], ps.compressedIndexBuf)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("cannot decompress index block: %w", err)
|
|
}
|
|
idxb := &indexBlock{}
|
|
idxb.bhs, err = unmarshalBlockHeaders(idxb.bhs[:0], ps.indexBuf, int(mr.blockHeadersCount))
|
|
if err != nil {
|
|
return nil, fmt.Errorf("cannot unmarshal block headers from index block (offset=%d, size=%d): %w", mr.indexBlockOffset, mr.indexBlockSize, err)
|
|
}
|
|
return idxb, nil
|
|
}
|
|
|
|
func (ps *partSearch) getInmemoryBlock(bh *blockHeader) (*inmemoryBlock, error) {
|
|
ibKey := blockcache.Key{
|
|
Part: ps.p,
|
|
Offset: bh.itemsBlockOffset,
|
|
}
|
|
b := ibCache.GetBlock(ibKey)
|
|
if b == nil {
|
|
ib, err := ps.readInmemoryBlock(bh)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
b = ib
|
|
ibCache.PutBlock(ibKey, b)
|
|
}
|
|
ib := b.(*inmemoryBlock)
|
|
return ib, nil
|
|
}
|
|
|
|
func (ps *partSearch) readInmemoryBlock(bh *blockHeader) (*inmemoryBlock, error) {
|
|
ps.sb.Reset()
|
|
|
|
ps.sb.itemsData = bytesutil.ResizeNoCopyMayOverallocate(ps.sb.itemsData, int(bh.itemsBlockSize))
|
|
ps.p.itemsFile.MustReadAt(ps.sb.itemsData, int64(bh.itemsBlockOffset))
|
|
|
|
ps.sb.lensData = bytesutil.ResizeNoCopyMayOverallocate(ps.sb.lensData, int(bh.lensBlockSize))
|
|
ps.p.lensFile.MustReadAt(ps.sb.lensData, int64(bh.lensBlockOffset))
|
|
|
|
ib := getInmemoryBlock()
|
|
if err := ib.UnmarshalData(&ps.sb, bh.firstItem, bh.commonPrefix, bh.itemsCount, bh.marshalType); err != nil {
|
|
return nil, fmt.Errorf("cannot unmarshal storage block with %d items: %w", bh.itemsCount, err)
|
|
}
|
|
|
|
return ib, nil
|
|
}
|
|
|
|
func binarySearchKey(data []byte, items []Item, key []byte) int {
|
|
if len(items) == 0 {
|
|
return 0
|
|
}
|
|
if string(key) <= items[0].String(data) {
|
|
// Fast path - the item is the first.
|
|
return 0
|
|
}
|
|
items = items[1:]
|
|
offset := uint(1)
|
|
|
|
// This has been copy-pasted from https://golang.org/src/sort/search.go
|
|
n := uint(len(items))
|
|
i, j := uint(0), n
|
|
for i < j {
|
|
h := uint(i+j) >> 1
|
|
if h >= 0 && h < uint(len(items)) && string(key) > items[h].String(data) {
|
|
i = h + 1
|
|
} else {
|
|
j = h
|
|
}
|
|
}
|
|
return int(i + offset)
|
|
}
|