func (tbl *Table) Scan(req *PkgArgs, au Authorize) []byte {
var out proto.PkgScanResp
out.Cmd = req.Cmd
out.DbId = req.DbId
out.Seq = req.Seq
var in proto.PkgScanReq
n, err := in.Decode(req.Pkg)
if err != nil || n != len(req.Pkg) {
return errorHandle(&out, table.EcDecodeFail)
}
out.PkgFlag = in.PkgFlag
if in.DbId == proto.AdminDbId {
return errorHandle(&out, table.EcInvDbId)
}
if !au.IsAuth(in.DbId) {
return errorHandle(&out, table.EcNoPrivilege)
}
if in.ColSpace == proto.ColSpaceScore1 {
tbl.zScanSortScore(&in, &out)
return replyHandle(&out)
}
var scanColSpace uint8 = proto.ColSpaceDefault
if in.ColSpace == proto.ColSpaceScore2 {
scanColSpace = proto.ColSpaceScore2
}
var it = tbl.db.NewIterator(nil)
defer it.Destroy()
var scanAsc = (in.PkgFlag&proto.FlagScanAsc != 0)
var startSeek = (in.PkgFlag&proto.FlagScanKeyStart != 0)
if scanAsc {
if startSeek {
// Seek to the first element
it.Seek(getRawKey(in.DbId, in.TableId, scanColSpace, in.RowKey, nil))
} else {
it.Seek(getRawKey(in.DbId, in.TableId, scanColSpace,
in.RowKey, in.ColKey))
}
} else {
if startSeek {
// Seek to the last element
it.Seek(getRawKey(in.DbId, in.TableId, scanColSpace+1, in.RowKey, nil))
} else {
it.Seek(getRawKey(in.DbId, in.TableId, scanColSpace,
in.RowKey, in.ColKey))
}
if !it.Valid() {
it.SeekToLast()
}
}
out.PkgFlag |= proto.FlagScanEnd
var first = true
var scanNum = int(in.Num)
var pkgLen = proto.HeadSize + 1000
for i := 0; it.Valid() && i < scanNum+1; iterMove(it, scanAsc) {
_, dbId, tableId, colSpace, rowKey, colKey := parseRawKey(it.Key())
if dbId != in.DbId || tableId != in.TableId ||
colSpace != scanColSpace || bytes.Compare(rowKey, in.RowKey) != 0 {
if first {
first = false
continue
} else {
break
}
}
if first {
first = false
}
if !startSeek {
if scanAsc {
if bytes.Compare(colKey, in.ColKey) <= 0 {
continue
}
} else {
if bytes.Compare(colKey, in.ColKey) >= 0 {
continue
}
}
}
if i < scanNum {
var kv proto.KeyValue
kv.TableId = in.TableId
kv.RowKey = in.RowKey
kv.ColKey = colKey
kv.Value, kv.Score = parseRawValue(it.Value())
if len(kv.Value) > 0 {
kv.CtrlFlag |= proto.CtrlValue
}
if kv.Score != 0 {
kv.CtrlFlag |= proto.CtrlScore
}
out.Kvs = append(out.Kvs, kv)
pkgLen += kv.Length()
if pkgLen > proto.MaxPkgLen/2 {
out.PkgFlag &^= proto.FlagScanEnd
break
}
} else {
out.PkgFlag &^= proto.FlagScanEnd
break
}
i++
}
return replyHandle(&out)
}
