From b09dc0b99952924d855c0803857dab64cfcfdf7a Mon Sep 17 00:00:00 2001
From: impact-eintr <yixingwei4@gmail.com>
Date: Sun, 13 Mar 2022 18:14:34 +0800
Subject: [PATCH] =?UTF-8?q?KV=20=E5=AD=98=E5=82=A8=E4=B9=8B=E5=90=8E?=
 =?UTF-8?q?=E5=86=8D=E8=AE=BE=E8=AE=A1?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 store/kv.go      | 83 +++++++++++-------------------------------------
 store/kv_test.go | 13 +-------
 2 files changed, 19 insertions(+), 77 deletions(-)

diff --git a/store/kv.go b/store/kv.go
index 3443e13..622e2e2 100644
--- a/store/kv.go
+++ b/store/kv.go
@@ -2,16 +2,23 @@ package store
 
 import (
 	"encoding/binary"
+	"errors"
 	"fmt"
-
-	"github.com/vmihailenco/msgpack/v5"
 )
 
+// 目前是使用 ValuePairs 保存 key value pair 的 然后使用 json 的序列化到 lsmdb中
+// 之后说不定会优化这个数据存储机制
+
 const (
 	IndexSize      = 5 * 4              // ko+ks+vo+vs+ttl
 	BlockIndexSize = 4 + 1024*IndexSize // currOffset + 1024*(ko+ks+vo+vs+ttl)
 )
 
+var (
+	ErrInvalidKV   = errors.New("Invalid Key Value Pair!")
+	ErrEmptyBucket = errors.New("A empty Bucket!")
+)
+
 // [co][ko ks vo vs ttl ...][nbo][k v k v ...] [co][ko ks vo vs ttl ...][nbo][k v k v ...]...
 
 // 会返回填充过的 kvb 小心使用
@@ -65,62 +72,8 @@ func appendKV(kvb, k, v []byte, ttl uint32) []byte {
 	return kvb
 }
 
-// TODO 性能现在太差了 之后需要优化 用一下 XMM ?
-func addKV(kvb, k, v []byte) (out []byte) {
-	if len(k) == 0 || len(v) == 0 {
-		return kvb
-	}
-	var m = make(map[string][]byte)
-	var err error
-
-	if len(kvb) > 0 {
-		err = msgpack.Unmarshal(kvb, &m)
-		if err != nil {
-			panic(err)
-		}
-	}
-
-	m[string(k)] = v
-
-	out, err = msgpack.Marshal(m)
-	if err != nil {
-		panic(err)
-	}
-
-	return out
-}
-
-func delKV(kvb, k []byte) (out []byte) {
-	var m = make(map[string][]byte)
-	err := msgpack.Unmarshal(kvb, &m)
-	if err != nil {
-		panic(err)
-	}
-
-	delete(m, string(k))
-
-	out, err = msgpack.Marshal(m)
-	if err != nil {
-		panic(err)
-	}
-
-	return out
-}
-
-// 遍历 key-value pair
-func traverseKV(kvb []byte, cb func([]byte, []byte) error) {
-	var m = make(map[string][]byte)
-	err := msgpack.Unmarshal(kvb, &m)
-	if err != nil {
-		panic(err)
-	}
-
-	for k := range m {
-		cb([]byte(k), m[k])
-	}
-}
-
-func rangeKV(kvb []byte, cb func([]byte, []byte) error) {
+// 只读遍历 KVB
+func rangeKV(kvb []byte, cb func([]byte, []byte, uint32) error) {
 	if len(kvb) == 0 {
 		return
 	}
@@ -131,14 +84,14 @@ func rangeKV(kvb []byte, cb func([]byte, []byte) error) {
 		}
 	}()
 
-	decode := func(buf []byte) ([]byte, []byte) {
+	decode := func(buf []byte) ([]byte, []byte, uint32) {
 		// 内层小循环是段内遍历
 		ko := binary.BigEndian.Uint32(buf[:])   // keyOffset
 		kl := binary.BigEndian.Uint32(buf[4:])  // keyLen
 		vo := binary.BigEndian.Uint32(buf[8:])  // valueOffset
 		vl := binary.BigEndian.Uint32(buf[12:]) // valueLen
-		//ttl := binary.BigEndian.Uint32(buf[16:])
-		return kvb[ko : ko+kl], kvb[vo : vo+vl]
+		ttl := binary.BigEndian.Uint32(buf[16:])
+		return kvb[ko : ko+kl], kvb[vo : vo+vl], ttl
 	}
 
 	buf := kvb
@@ -149,17 +102,17 @@ func rangeKV(kvb []byte, cb func([]byte, []byte) error) {
 			// 未写满的一块数据
 			buf = buf[4:] // 定位到当前读写指针处
 			for i := 4; i < int(curOffset); i += IndexSize {
-				key, value := decode(buf)
+				key, value, ttl := decode(buf)
 
 				buf = buf[IndexSize:] // 移动指针
-				cb(key, value)
+				cb(key, value, ttl)
 			}
 			break
 		} else if curOffset == BlockIndexSize {
 			// 写满的一块数据
 			buf = buf[4:] // 定位到当前读写指针处
 			for i := 4; i < BlockIndexSize; i += IndexSize {
-				key, value := decode(buf)
+				key, value, ttl := decode(buf)
 
 				if i != BlockIndexSize-IndexSize {
 					buf = buf[IndexSize:] // 移动指针
@@ -168,7 +121,7 @@ func rangeKV(kvb []byte, cb func([]byte, []byte) error) {
 					nbo := binary.BigEndian.Uint32(buf[:4])
 					buf = kvb[nbo:]
 				}
-				cb(key, value)
+				cb(key, value, ttl)
 			}
 		}
 	}
diff --git a/store/kv_test.go b/store/kv_test.go
index bc818bc..db652a6 100644
--- a/store/kv_test.go
+++ b/store/kv_test.go
@@ -6,24 +6,13 @@ import (
 	"testing"
 )
 
-//func TestTraverseKV(t *testing.T) {
-//	var kvb []byte
-//	for i := 0; i < 1000; i++ {
-//		kvb = addKV(kvb, []byte(fmt.Sprintf("key%d", i)), []byte(fmt.Sprintf("value%d", i)))
-//	}
-//	//traverseKV(kvb, func(k []byte, v []byte) error {
-//	//	log.Println(string(k), string(v))
-//	//	return nil
-//	//})
-//}
-
 func TestAppendKV(t *testing.T) {
 	var kvb []byte
 	for i := 0; i < 20000; i++ {
 		kvb = appendKV(kvb, []byte(fmt.Sprintf("key%d", i)), []byte(fmt.Sprintf("value%d", i)), 1)
 	}
 
-	rangeKV(kvb, func(k []byte, v []byte) error {
+	rangeKV(kvb, func(k []byte, v []byte, ttl uint32) error {
 		log.Println(string(k), string(v))
 		return nil
 	})