make ReadNeedleMeta a thin wrapper

This commit is contained in:
chrislu 2025-06-07 23:15:23 -07:00
parent 69df7a9182
commit 3cf04eabef
3 changed files with 51 additions and 96 deletions

View File

@ -1,6 +1,7 @@
package needle
import (
"fmt"
"io"
"github.com/seaweedfs/seaweedfs/weed/storage/backend"
@ -18,7 +19,13 @@ type NeedleReadOptions struct {
// ReadFromFile reads the Needle from the backend file according to the specified options.
// - If only ReadHeader is true, only the header is read and parsed.
// - If ReadData or ReadMeta is true, reads GetActualSize(size, version) bytes from disk (size is the logical body size).
func (n *Needle) ReadFromFile(r backend.BackendStorageFile, offset int64, size Size, version Version, opts NeedleReadOptions) error {
func (n *Needle) ReadFromFile(r backend.BackendStorageFile, offset int64, size Size, version Version, opts NeedleReadOptions) (err error) {
defer func() {
if r := recover(); r != nil {
err = fmt.Errorf("panic occurred: %+v", r)
}
}()
if opts.ReadHeader && !opts.ReadData && !opts.ReadMeta {
// Only read the header
header := make([]byte, NeedleHeaderSize)
@ -33,63 +40,54 @@ func (n *Needle) ReadFromFile(r backend.BackendStorageFile, offset int64, size S
return nil
}
if opts.ReadHeader && opts.ReadMeta && !opts.ReadData {
// Read header first
header := make([]byte, NeedleHeaderSize)
count, err := r.ReadAt(header, offset)
if err == io.EOF && count == NeedleHeaderSize {
// Optimized: Read header and DataSize in one call
buf := make([]byte, NeedleHeaderSize+DataSizeSize)
count, err := r.ReadAt(buf, offset)
if err == io.EOF && count == NeedleHeaderSize+DataSizeSize {
err = nil
}
if count != NeedleHeaderSize || err != nil {
if count != NeedleHeaderSize+DataSizeSize || err != nil {
return err
}
n.ParseNeedleHeader(header)
n.ParseNeedleHeader(buf[:NeedleHeaderSize])
if n.Size != size {
if OffsetSize == 4 && offset < int64(MaxPossibleVolumeSize) {
return ErrorSizeMismatch
}
}
// Now read meta fields after DataSize+Data
metaOffset := offset + int64(NeedleHeaderSize)
metaIndex := 0
if version == Version2 || version == Version3 {
// Read DataSize to know how much to skip
dsBuf := make([]byte, 4)
count, err := r.ReadAt(dsBuf, metaOffset)
if err == io.EOF && count == 4 {
err = nil
n.DataSize = util.BytesToUint32(buf[NeedleHeaderSize : NeedleHeaderSize+DataSizeSize])
startOffset := offset + NeedleHeaderSize
if size.IsValid() {
startOffset = offset + NeedleHeaderSize + DataSizeSize + int64(n.DataSize)
}
if count != 4 || err != nil {
return err
}
dataSize := int(util.BytesToUint32(dsBuf))
metaIndex = 4 + dataSize
// Read meta fields (Flags, Name, Mime, etc.)
metaFieldsLen := int(n.Size) - dataSize // upper bound, may be more than needed
dataSize := GetActualSize(size, version)
stopOffset := offset + dataSize
metaFieldsLen := stopOffset - startOffset
metaFieldsBuf := make([]byte, metaFieldsLen)
count, err = r.ReadAt(metaFieldsBuf, metaOffset+int64(metaIndex))
if err == io.EOF && count == metaFieldsLen {
count, err = r.ReadAt(metaFieldsBuf, startOffset)
if err == io.EOF && int64(count) == metaFieldsLen {
err = nil
}
if count <= 0 || err != nil {
return err
}
_, err = n.readNeedleDataVersion2NonData(metaFieldsBuf)
if err != nil {
return err
var index int
if size.IsValid() {
index, err = n.readNeedleDataVersion2NonData(metaFieldsBuf)
if err != nil {
return err
}
}
// Now read checksum and (for v3) appendAtNs at the end
endMetaOffset := offset + int64(NeedleHeaderSize) + int64(n.Size)
endMetaLen := NeedleChecksumSize
n.Checksum = CRC(util.BytesToUint32(metaFieldsBuf[index : index+NeedleChecksumSize]))
if version == Version3 {
endMetaLen += TimestampSize
}
endMetaBuf := make([]byte, endMetaLen)
count, err = r.ReadAt(endMetaBuf, endMetaOffset)
if err == io.EOF && count == endMetaLen {
err = nil
}
if count != endMetaLen || err != nil {
return err
}
n.Checksum = CRC(util.BytesToUint32(endMetaBuf[:NeedleChecksumSize]))
if version == Version3 {
n.AppendAtNs = util.BytesToUint64(endMetaBuf[NeedleChecksumSize : NeedleChecksumSize+TimestampSize])
n.AppendAtNs = util.BytesToUint64(metaFieldsBuf[index+NeedleChecksumSize : index+NeedleChecksumSize+TimestampSize])
}
return nil
}

View File

@ -150,6 +150,9 @@ func TestReadFromFile_OptionsMatrix(t *testing.T) {
if nMeta.Cookie != n.Cookie || nMeta.Id != n.Id || nMeta.Size != n.Size {
t.Errorf("header fields mismatch: got %+v want %+v", nMeta, n)
}
if nMeta.Checksum != n.Checksum {
t.Errorf("checksum mismatch: got %d want %d", nMeta.Checksum, n.Checksum)
}
})
t.Run("ReadHeader+ReadData", func(t *testing.T) {

View File

@ -1,12 +1,11 @@
package needle
import (
"fmt"
"io"
"github.com/seaweedfs/seaweedfs/weed/glog"
"github.com/seaweedfs/seaweedfs/weed/storage/backend"
. "github.com/seaweedfs/seaweedfs/weed/storage/types"
"github.com/seaweedfs/seaweedfs/weed/util"
"io"
)
// ReadNeedleData uses a needle without n.Data to read the content
@ -33,57 +32,12 @@ func (n *Needle) ReadNeedleData(r backend.BackendStorageFile, volumeOffset int64
}
// ReadNeedleMeta fills all metadata except the n.Data
func (n *Needle) ReadNeedleMeta(r backend.BackendStorageFile, offset int64, size Size, version Version) (err error) {
defer func() {
if r := recover(); r != nil {
err = fmt.Errorf("panic occurred: %+v", r)
}
}()
bytes := make([]byte, NeedleHeaderSize+DataSizeSize)
count, err := r.ReadAt(bytes, offset)
if err == io.EOF && count == NeedleHeaderSize+DataSizeSize {
err = nil
}
if count != NeedleHeaderSize+DataSizeSize || err != nil {
return err
}
n.ParseNeedleHeader(bytes)
if n.Size != size {
if OffsetSize == 4 && offset < int64(MaxPossibleVolumeSize) {
return ErrorSizeMismatch
}
}
n.DataSize = util.BytesToUint32(bytes[NeedleHeaderSize : NeedleHeaderSize+DataSizeSize])
startOffset := offset + NeedleHeaderSize
if size.IsValid() {
startOffset = offset + NeedleHeaderSize + DataSizeSize + int64(n.DataSize)
}
dataSize := GetActualSize(size, version)
stopOffset := offset + dataSize
metaSize := stopOffset - startOffset
metaSlice := make([]byte, int(metaSize))
count, err = r.ReadAt(metaSlice, startOffset)
if err != nil && int64(count) == metaSize {
err = nil
}
if err != nil {
return err
}
var index int
if size.IsValid() {
index, err = n.readNeedleDataVersion2NonData(metaSlice)
}
n.Checksum = CRC(util.BytesToUint32(metaSlice[index : index+NeedleChecksumSize]))
if version == Version3 {
n.AppendAtNs = util.BytesToUint64(metaSlice[index+NeedleChecksumSize : index+NeedleChecksumSize+TimestampSize])
}
return err
func (n *Needle) ReadNeedleMeta(r backend.BackendStorageFile, offset int64, size Size, version Version) error {
return n.ReadFromFile(r, offset, size, version, NeedleReadOptions{
ReadHeader: true,
ReadMeta: true,
ReadData: false,
})
}
func min(x, y int64) int64 {