From f404e351429366af852b8bb0390d13eae3eab25d Mon Sep 17 00:00:00 2001
From: siddontang <siddontang@gmail.com>
Date: Fri, 23 May 2014 12:39:56 +0800
Subject: [PATCH] remove scan cmd, we implement a little diff

---
 ledis/const.go   |  2 +-
 ledis/t_kv.go    | 31 ++++++++++++++-----------------
 server/cmd_kv.go | 36 ------------------------------------
 3 files changed, 15 insertions(+), 54 deletions(-)

diff --git a/ledis/const.go b/ledis/const.go
index 64473ad..9e4d0cf 100644
--- a/ledis/const.go
+++ b/ledis/const.go
@@ -16,7 +16,7 @@ const (
 )
 
 const (
-	defaultScanCount int = 20
+	defaultScanCount int = 10
 )
 
 const (
diff --git a/ledis/t_kv.go b/ledis/t_kv.go
index 8c683be..16a92c5 100644
--- a/ledis/t_kv.go
+++ b/ledis/t_kv.go
@@ -289,36 +289,33 @@ func (db *DB) KvFlush() (drop int64, err error) {
 	return
 }
 
-func (db *DB) Scan(cursor int, count int) ([]interface{}, error) {
-	minKey := db.encodeKVMinKey()
+func (db *DB) Scan(key []byte, count int) ([]KVPair, error) {
+	var minKey []byte
+	if key != nil {
+		if err := checkKeySize(key); err != nil {
+			return nil, err
+		}
+		minKey = key
+	} else {
+		minKey = db.encodeKVMinKey()
+	}
+
 	maxKey := db.encodeKVMaxKey()
 
 	if count <= 0 {
 		count = defaultScanCount
 	}
 
-	v := make([]interface{}, 2)
-	r := make([]interface{}, 0, count)
+	v := make([]KVPair, 0, 2*count)
 
-	var num int = 0
-	it := db.db.Iterator(minKey, maxKey, leveldb.RangeROpen, cursor, count)
+	it := db.db.Iterator(minKey, maxKey, leveldb.RangeROpen, 0, count)
 	for ; it.Valid(); it.Next() {
-		num++
-
 		if key, err := db.decodeKVKey(it.Key()); err != nil {
 			continue
 		} else {
-			r = append(r, key)
+			v = append(v, KVPair{Key: key, Value: it.Value()})
 		}
 	}
 
-	if num < count {
-		v[0] = int64(0)
-	} else {
-		v[0] = int64(cursor + count)
-	}
-
-	v[1] = r
-
 	return v, nil
 }
diff --git a/server/cmd_kv.go b/server/cmd_kv.go
index 11ec4c6..a6bdcbd 100644
--- a/server/cmd_kv.go
+++ b/server/cmd_kv.go
@@ -2,7 +2,6 @@ package server
 
 import (
 	"github.com/siddontang/ledisdb/ledis"
-	"strings"
 )
 
 func getCommand(c *client) error {
@@ -204,40 +203,6 @@ func mgetCommand(c *client) error {
 	return nil
 }
 
-func scanCommand(c *client) error {
-	args := c.args
-
-	if len(args) != 1 && len(args) != 3 {
-		return ErrCmdParams
-	}
-	var offset int64
-	var count int64
-	var err error
-
-	if offset, err = ledis.StrInt64(args[0], nil); err != nil {
-		return err
-	}
-
-	//now we only support count
-	if len(args) == 3 {
-		if strings.ToLower(ledis.String(args[1])) != "count" {
-			return ErrCmdParams
-		}
-
-		if count, err = ledis.StrInt64(args[2], nil); err != nil {
-			return err
-		}
-	}
-
-	if v, err := c.db.Scan(int(offset), int(count)); err != nil {
-		return err
-	} else {
-		c.writeArray(v)
-	}
-
-	return nil
-}
-
 func init() {
 	register("decr", decrCommand)
 	register("decrby", decrbyCommand)
@@ -251,5 +216,4 @@ func init() {
 	register("mset", msetCommand)
 	register("set", setCommand)
 	register("setnx", setnxCommand)
-	register("scan", scanCommand)
 }