mirror of
https://github.com/seaweedfs/seaweedfs.git
synced 2024-12-15 19:26:42 +08:00
89 lines
2.7 KiB
Go
89 lines
2.7 KiB
Go
package idx
|
|
|
|
import (
|
|
"io"
|
|
|
|
"github.com/chrislusf/seaweedfs/weed/glog"
|
|
"github.com/chrislusf/seaweedfs/weed/storage/types"
|
|
)
|
|
|
|
// walks through the index file, calls fn function with each key, offset, size
|
|
// stops with the error returned by the fn function
|
|
func WalkIndexFile(r io.ReaderAt, fn func(key types.NeedleId, offset types.Offset, size types.Size) error) error {
|
|
var readerOffset int64
|
|
bytes := make([]byte, types.NeedleMapEntrySize*RowsToRead)
|
|
count, e := r.ReadAt(bytes, readerOffset)
|
|
if count == 0 && e == io.EOF {
|
|
return nil
|
|
}
|
|
glog.V(3).Infof("readerOffset %d count %d err: %v", readerOffset, count, e)
|
|
readerOffset += int64(count)
|
|
var (
|
|
key types.NeedleId
|
|
offset types.Offset
|
|
size types.Size
|
|
i int
|
|
)
|
|
|
|
for count > 0 && e == nil || e == io.EOF {
|
|
for i = 0; i+types.NeedleMapEntrySize <= count; i += types.NeedleMapEntrySize {
|
|
key, offset, size = IdxFileEntry(bytes[i : i+types.NeedleMapEntrySize])
|
|
if e = fn(key, offset, size); e != nil {
|
|
return e
|
|
}
|
|
}
|
|
if e == io.EOF {
|
|
return nil
|
|
}
|
|
count, e = r.ReadAt(bytes, readerOffset)
|
|
glog.V(3).Infof("readerOffset %d count %d err: %v", readerOffset, count, e)
|
|
readerOffset += int64(count)
|
|
}
|
|
return e
|
|
}
|
|
|
|
//copied from WalkIndexFile, just init readerOffset from milestone
|
|
func WalkIndexFileIncrement(r io.ReaderAt, milestone uint64, fn func(key types.NeedleId, offset types.Offset, size types.Size) error) error {
|
|
var readerOffset = int64(milestone * types.NeedleMapEntrySize)
|
|
bytes := make([]byte, types.NeedleMapEntrySize*RowsToRead)
|
|
count, e := r.ReadAt(bytes, readerOffset)
|
|
if count == 0 && e == io.EOF {
|
|
return nil
|
|
}
|
|
glog.V(3).Infof("readerOffset %d count %d err: %v", readerOffset, count, e)
|
|
readerOffset += int64(count)
|
|
var (
|
|
key types.NeedleId
|
|
offset types.Offset
|
|
size types.Size
|
|
i int
|
|
)
|
|
|
|
for count > 0 && e == nil || e == io.EOF {
|
|
for i = 0; i+types.NeedleMapEntrySize <= count; i += types.NeedleMapEntrySize {
|
|
key, offset, size = IdxFileEntry(bytes[i : i+types.NeedleMapEntrySize])
|
|
if e = fn(key, offset, size); e != nil {
|
|
return e
|
|
}
|
|
}
|
|
if e == io.EOF {
|
|
return nil
|
|
}
|
|
count, e = r.ReadAt(bytes, readerOffset)
|
|
glog.V(3).Infof("readerOffset %d count %d err: %v", readerOffset, count, e)
|
|
readerOffset += int64(count)
|
|
}
|
|
return e
|
|
}
|
|
|
|
func IdxFileEntry(bytes []byte) (key types.NeedleId, offset types.Offset, size types.Size) {
|
|
key = types.BytesToNeedleId(bytes[:types.NeedleIdSize])
|
|
offset = types.BytesToOffset(bytes[types.NeedleIdSize : types.NeedleIdSize+types.OffsetSize])
|
|
size = types.BytesToSize(bytes[types.NeedleIdSize+types.OffsetSize : types.NeedleIdSize+types.OffsetSize+types.SizeSize])
|
|
return
|
|
}
|
|
|
|
const (
|
|
RowsToRead = 1024
|
|
)
|