ceremonyclient/pebble/sstable/layout.go
Cassandra Heart 2e2a1e4789
v1.2.0 (#31)
2024-01-03 01:31:42 -06:00

308 lines
10 KiB
Go

// Copyright 2011 The LevelDB-Go and Pebble Authors. All rights reserved. Use
// of this source code is governed by a BSD-style license that can be found in
// the LICENSE file.
package sstable
import (
"bytes"
"context"
"encoding/binary"
"fmt"
"io"
"sort"
"unsafe"
"github.com/cockroachdb/pebble/internal/base"
"github.com/cockroachdb/pebble/shims/cmp"
"github.com/cockroachdb/pebble/shims/slices"
)
// Layout describes the block organization of an sstable.
type Layout struct {
// NOTE: changes to fields in this struct should also be reflected in
// ValidateBlockChecksums, which validates a static list of BlockHandles
// referenced in this struct.
Data []BlockHandleWithProperties
Index []BlockHandle
TopIndex BlockHandle
Filter BlockHandle
RangeDel BlockHandle
RangeKey BlockHandle
ValueBlock []BlockHandle
ValueIndex BlockHandle
Properties BlockHandle
MetaIndex BlockHandle
Footer BlockHandle
Format TableFormat
}
// Describe returns a description of the layout. If the verbose parameter is
// true, details of the structure of each block are returned as well.
func (l *Layout) Describe(
w io.Writer, verbose bool, r *Reader, fmtRecord func(key *base.InternalKey, value []byte),
) {
ctx := context.TODO()
type block struct {
BlockHandle
name string
}
var blocks []block
for i := range l.Data {
blocks = append(blocks, block{l.Data[i].BlockHandle, "data"})
}
for i := range l.Index {
blocks = append(blocks, block{l.Index[i], "index"})
}
if l.TopIndex.Length != 0 {
blocks = append(blocks, block{l.TopIndex, "top-index"})
}
if l.Filter.Length != 0 {
blocks = append(blocks, block{l.Filter, "filter"})
}
if l.RangeDel.Length != 0 {
blocks = append(blocks, block{l.RangeDel, "range-del"})
}
if l.RangeKey.Length != 0 {
blocks = append(blocks, block{l.RangeKey, "range-key"})
}
for i := range l.ValueBlock {
blocks = append(blocks, block{l.ValueBlock[i], "value-block"})
}
if l.ValueIndex.Length != 0 {
blocks = append(blocks, block{l.ValueIndex, "value-index"})
}
if l.Properties.Length != 0 {
blocks = append(blocks, block{l.Properties, "properties"})
}
if l.MetaIndex.Length != 0 {
blocks = append(blocks, block{l.MetaIndex, "meta-index"})
}
if l.Footer.Length != 0 {
if l.Footer.Length == levelDBFooterLen {
blocks = append(blocks, block{l.Footer, "leveldb-footer"})
} else {
blocks = append(blocks, block{l.Footer, "footer"})
}
}
slices.SortFunc(blocks, func(a, b block) int {
return cmp.Compare(a.Offset, b.Offset)
})
for i := range blocks {
b := &blocks[i]
fmt.Fprintf(w, "%10d %s (%d)\n", b.Offset, b.name, b.Length)
if !verbose {
continue
}
if b.name == "filter" {
continue
}
if b.name == "footer" || b.name == "leveldb-footer" {
trailer, offset := make([]byte, b.Length), b.Offset
_ = r.readable.ReadAt(ctx, trailer, int64(offset))
if b.name == "footer" {
checksumType := ChecksumType(trailer[0])
fmt.Fprintf(w, "%10d checksum type: %s\n", offset, checksumType)
trailer, offset = trailer[1:], offset+1
}
metaHandle, n := binary.Uvarint(trailer)
metaLen, m := binary.Uvarint(trailer[n:])
fmt.Fprintf(w, "%10d meta: offset=%d, length=%d\n", offset, metaHandle, metaLen)
trailer, offset = trailer[n+m:], offset+uint64(n+m)
indexHandle, n := binary.Uvarint(trailer)
indexLen, m := binary.Uvarint(trailer[n:])
fmt.Fprintf(w, "%10d index: offset=%d, length=%d\n", offset, indexHandle, indexLen)
trailer, offset = trailer[n+m:], offset+uint64(n+m)
fmt.Fprintf(w, "%10d [padding]\n", offset)
trailing := 12
if b.name == "leveldb-footer" {
trailing = 8
}
offset += uint64(len(trailer) - trailing)
trailer = trailer[len(trailer)-trailing:]
if b.name == "footer" {
version := trailer[:4]
fmt.Fprintf(w, "%10d version: %d\n", offset, binary.LittleEndian.Uint32(version))
trailer, offset = trailer[4:], offset+4
}
magicNumber := trailer
fmt.Fprintf(w, "%10d magic number: 0x%x\n", offset, magicNumber)
continue
}
h, err := r.readBlock(
context.Background(), b.BlockHandle, nil /* transform */, nil /* readHandle */, nil /* stats */, nil /* iterStats */, nil /* buffer pool */)
if err != nil {
fmt.Fprintf(w, " [err: %s]\n", err)
continue
}
getRestart := func(data []byte, restarts, i int32) int32 {
return decodeRestart(data[restarts+4*i:])
}
formatIsRestart := func(data []byte, restarts, numRestarts, offset int32) {
i := sort.Search(int(numRestarts), func(i int) bool {
return getRestart(data, restarts, int32(i)) >= offset
})
if i < int(numRestarts) && getRestart(data, restarts, int32(i)) == offset {
fmt.Fprintf(w, " [restart]\n")
} else {
fmt.Fprintf(w, "\n")
}
}
formatRestarts := func(data []byte, restarts, numRestarts int32) {
for i := int32(0); i < numRestarts; i++ {
offset := getRestart(data, restarts, i)
fmt.Fprintf(w, "%10d [restart %d]\n",
b.Offset+uint64(restarts+4*i), b.Offset+uint64(offset))
}
}
formatTrailer := func() {
trailer := make([]byte, blockTrailerLen)
offset := int64(b.Offset + b.Length)
_ = r.readable.ReadAt(ctx, trailer, offset)
bt := blockType(trailer[0])
checksum := binary.LittleEndian.Uint32(trailer[1:])
fmt.Fprintf(w, "%10d [trailer compression=%s checksum=0x%04x]\n", offset, bt, checksum)
}
var lastKey InternalKey
switch b.name {
case "data", "range-del", "range-key":
iter, _ := newBlockIter(r.Compare, h.Get())
for key, value := iter.First(); key != nil; key, value = iter.Next() {
ptr := unsafe.Pointer(uintptr(iter.ptr) + uintptr(iter.offset))
shared, ptr := decodeVarint(ptr)
unshared, ptr := decodeVarint(ptr)
value2, _ := decodeVarint(ptr)
total := iter.nextOffset - iter.offset
// The format of the numbers in the record line is:
//
// (<total> = <length> [<shared>] + <unshared> + <value>)
//
// <total> is the total number of bytes for the record.
// <length> is the size of the 3 varint encoded integers for <shared>,
// <unshared>, and <value>.
// <shared> is the number of key bytes shared with the previous key.
// <unshared> is the number of unshared key bytes.
// <value> is the number of value bytes.
fmt.Fprintf(w, "%10d record (%d = %d [%d] + %d + %d)",
b.Offset+uint64(iter.offset), total,
total-int32(unshared+value2), shared, unshared, value2)
formatIsRestart(iter.data, iter.restarts, iter.numRestarts, iter.offset)
if fmtRecord != nil {
fmt.Fprintf(w, " ")
if l.Format < TableFormatPebblev3 {
fmtRecord(key, value.InPlaceValue())
} else {
// InPlaceValue() will succeed even for data blocks where the
// actual value is in a different location, since this value was
// fetched from a blockIter which does not know about value
// blocks.
v := value.InPlaceValue()
if base.TrailerKind(key.Trailer) != InternalKeyKindSet {
fmtRecord(key, v)
} else if !isValueHandle(valuePrefix(v[0])) {
fmtRecord(key, v[1:])
} else {
vh := decodeValueHandle(v[1:])
fmtRecord(key, []byte(fmt.Sprintf("value handle %+v", vh)))
}
}
}
if base.InternalCompare(r.Compare, lastKey, *key) >= 0 {
fmt.Fprintf(w, " WARNING: OUT OF ORDER KEYS!\n")
}
lastKey.Trailer = key.Trailer
lastKey.UserKey = append(lastKey.UserKey[:0], key.UserKey...)
}
formatRestarts(iter.data, iter.restarts, iter.numRestarts)
formatTrailer()
case "index", "top-index":
iter, _ := newBlockIter(r.Compare, h.Get())
for key, value := iter.First(); key != nil; key, value = iter.Next() {
bh, err := decodeBlockHandleWithProperties(value.InPlaceValue())
if err != nil {
fmt.Fprintf(w, "%10d [err: %s]\n", b.Offset+uint64(iter.offset), err)
continue
}
fmt.Fprintf(w, "%10d block:%d/%d",
b.Offset+uint64(iter.offset), bh.Offset, bh.Length)
formatIsRestart(iter.data, iter.restarts, iter.numRestarts, iter.offset)
}
formatRestarts(iter.data, iter.restarts, iter.numRestarts)
formatTrailer()
case "properties":
iter, _ := newRawBlockIter(r.Compare, h.Get())
for valid := iter.First(); valid; valid = iter.Next() {
fmt.Fprintf(w, "%10d %s (%d)",
b.Offset+uint64(iter.offset), iter.Key().UserKey, iter.nextOffset-iter.offset)
formatIsRestart(iter.data, iter.restarts, iter.numRestarts, iter.offset)
}
formatRestarts(iter.data, iter.restarts, iter.numRestarts)
formatTrailer()
case "meta-index":
iter, _ := newRawBlockIter(r.Compare, h.Get())
for valid := iter.First(); valid; valid = iter.Next() {
value := iter.Value()
var bh BlockHandle
var n int
var vbih valueBlocksIndexHandle
isValueBlocksIndexHandle := false
if bytes.Equal(iter.Key().UserKey, []byte(metaValueIndexName)) {
vbih, n, err = decodeValueBlocksIndexHandle(value)
bh = vbih.h
isValueBlocksIndexHandle = true
} else {
bh, n = decodeBlockHandle(value)
}
if n == 0 || n != len(value) {
fmt.Fprintf(w, "%10d [err: %s]\n", b.Offset+uint64(iter.offset), err)
continue
}
var vbihStr string
if isValueBlocksIndexHandle {
vbihStr = fmt.Sprintf(" value-blocks-index-lengths: %d(num), %d(offset), %d(length)",
vbih.blockNumByteLength, vbih.blockOffsetByteLength, vbih.blockLengthByteLength)
}
fmt.Fprintf(w, "%10d %s block:%d/%d%s",
b.Offset+uint64(iter.offset), iter.Key().UserKey,
bh.Offset, bh.Length, vbihStr)
formatIsRestart(iter.data, iter.restarts, iter.numRestarts, iter.offset)
}
formatRestarts(iter.data, iter.restarts, iter.numRestarts)
formatTrailer()
case "value-block":
// We don't peer into the value-block since it can't be interpreted
// without the valueHandles.
case "value-index":
// We have already read the value-index to construct the list of
// value-blocks, so no need to do it again.
}
h.Release()
}
last := blocks[len(blocks)-1]
fmt.Fprintf(w, "%10d EOF\n", last.Offset+last.Length)
}