1. [feat] 新增package lru 2. [feat] nazahttp: 新增函数 GetHttpFile

CHANGELOG.md

@@ -28,7 +28,7 @@
     - [perf] 减小锁粒度
     - [test] 测试覆盖率增加至100%
     - [refactor] 删除FatalIfErrorNotNil, PanicIfErrorNotNil, Outputf, writeShortFile四个函数函数
-- package nazabit:
+- package nazabits:
     - [feat] 新增GetBit16，GetBits16函数
 - package fake:
     - [feat] 新增WithRecover函数

README.md

@@ -34,19 +34,20 @@ pkg/                    ...... 源码包
     |-- taskpool/       ...... 非阻塞协程池，协程数量可动态增长，可配置最大协程并发数量，可手动释放空闲的协程
     |-- bele/           ...... 大小端转换操作
     |-- nazabits/       ...... 位操作
+    |-- bitrate/        ...... 计算带宽
+    |-- lru             ...... LRU缓存
     |-- fake/           ...... 实现一些常用的接口，hook一些不方便测试的代码
+    |-- consistenthash/ ...... 一致性哈希
+    |-- assert/         ...... 提供了单元测试时的断言功能，减少一些模板代码
+    |-- nazajson/       ...... json操作
+    |-- nazahttp/       ...... http操作
+    |-- filebatch/      ...... 文件批处理操作
     |-- nazaatomic/     ...... 原子操作
     |-- snowflake/      ...... 分布式唯一性ID生成器
-    |-- bitrate/        ...... 计算带宽
-    |-- consistenthash/ ...... 一致性哈希
     |-- slicebytepool/  ...... []byte内存池
-    |-- assert/         ...... 提供了单元测试时的断言功能，减少一些模板代码
     |-- nazastring/     ...... string和[]byte相关的操作
     |-- ratelimit/      ...... 限流器，令牌桶，漏桶
-    |-- nazajson/       ...... json操作
-    |-- filebatch/      ...... 文件批处理操作
     |-- nazamd5/        ...... md5操作
-    |-- nazahttp/       ...... http操作
     |-- connection/     ...... 对net.Conn接口的二次封装
     |-- ic/             ...... 将整型切片压缩成二进制字节切片
     |-- unique/         ...... 对象唯一ID

pkg/lru/lru.go

@@ -0,0 +1,73 @@
+// Copyright 2020, Chef.  All rights reserved.
+// https://github.com/q191201771/naza
+//
+// Use of this source code is governed by a MIT-style license
+// that can be found in the License file.
+//
+// Author: Chef (191201771@qq.com)
+
+package lru
+
+import "container/list"
+
+type LRU struct {
+	c int                           // capacity
+	m map[interface{}]*list.Element // mapping key -> index
+	l *list.List                    // value
+}
+
+type pair struct {
+	k interface{}
+	v interface{}
+}
+
+func New(capacity int) *LRU {
+	return &LRU{
+		c: capacity,
+		m: make(map[interface{}]*list.Element),
+		l: list.New(),
+	}
+}
+
+// 注意：
+// 1. 无论插入前，元素是否已经存在，插入后，元素都会存在于lru容器中
+// 2. 插入元素时，也会更新热度（不管插入前元素是否已经存在）
+// @return 插入前元素已经存在则返回false
+func (lru *LRU) Put(k interface{}, v interface{}) bool {
+	var (
+		exist bool
+		e     *list.Element
+	)
+	e, exist = lru.m[k]
+	if exist {
+		lru.l.Remove(e)
+		delete(lru.m, k)
+	}
+
+	// 头部更热
+	e = lru.l.PushFront(pair{k, v})
+	lru.m[k] = e
+
+	if lru.l.Len() > lru.c {
+		k = lru.l.Back().Value.(pair).k
+
+		lru.l.Remove(lru.l.Back())
+		delete(lru.m, k)
+	}
+
+	return !exist
+}
+
+func (lru *LRU) Get(k interface{}) (v interface{}, exist bool) {
+	e, exist := lru.m[k]
+	if !exist {
+		return nil, false
+	}
+	pair := e.Value.(pair)
+	lru.l.MoveToFront(e)
+	return pair.v, true
+}
+
+func (lru *LRU) Size() int {
+	return lru.l.Len()
+}

pkg/lru/lru_test.go

@@ -0,0 +1,70 @@
+// Copyright 2020, Chef.  All rights reserved.
+// https://github.com/q191201771/naza
+//
+// Use of this source code is governed by a MIT-style license
+// that can be found in the License file.
+//
+// Author: Chef (191201771@qq.com)
+
+package lru_test
+
+import (
+	"testing"
+
+	"github.com/q191201771/naza/pkg/assert"
+
+	"github.com/q191201771/naza/pkg/lru"
+)
+
+func TestLRU(t *testing.T) {
+	l := lru.New(3)
+	l.Put("chef", 1)
+	l.Put("yoko", 2)
+	l.Put("tom", 3)
+	l.Put("jerry", 4) // 超过容器大小，淘汰最老的`chef`
+
+	v, exist := l.Get("chef")
+	assert.Equal(t, false, exist)
+
+	v, exist = l.Get("yoko")
+	assert.Equal(t, true, exist)
+	assert.Equal(t, 2, v.(int))
+
+	l.Put("garfield", 5) // 超过容器大小，注意，由于`yoko`刚才读取时会更新热度，所以淘汰的是`tom`
+
+	v, exist = l.Get("yoko")
+	assert.Equal(t, true, exist)
+	assert.Equal(t, 2, v.(int))
+
+	v, exist = l.Get("tom")
+	assert.Equal(t, false, exist)
+
+	l = lru.New(3)
+	v, exist = l.Get("notexist")
+	assert.Equal(t, false, exist)
+	assert.Equal(t, 0, l.Size())
+
+	l.Put("chef", 60)
+	assert.Equal(t, 1, l.Size())
+
+	v, exist = l.Get("chef")
+	assert.Equal(t, true, exist)
+	assert.Equal(t, 60, v.(int))
+	assert.Equal(t, 1, l.Size())
+
+	v, exist = l.Get("ne")
+	assert.Equal(t, false, exist)
+	assert.Equal(t, 1, l.Size())
+
+	l.Put("yoko", 100)
+	assert.Equal(t, 2, l.Size())
+
+	l.Put("coco", 33)
+	assert.Equal(t, 3, l.Size())
+
+	l.Put("dad", 44)
+	assert.Equal(t, 3, l.Size())
+
+	isNewPut := l.Put("coco", 1000)
+	assert.Equal(t, false, isNewPut)
+}

pkg/nazahttp/http.go

@@ -10,12 +10,30 @@ package nazahttp
 
 import (
 	"io"
+	"io/ioutil"
 	"net/http"
 	"os"
 	"time"
 )
 
-// 获取 http 文件保存至本地
+// 获取http文件
+// @return <error> 成功返回nil
+func GetHttpFile(url string, timeoutMSec int) ([]byte, error) {
+	var c http.Client
+	if timeoutMSec > 0 {
+		c.Timeout = time.Duration(timeoutMSec) * time.Millisecond
+	}
+	resp, err := c.Get(url)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	content, err := ioutil.ReadAll(resp.Body)
+	return content, err
+}
+
+// 获取http文件保存至本地
 func DownloadHttpFile(url string, saveTo string, timeoutMSec int) (int64, error) {
 	var c http.Client
 	if timeoutMSec > 0 {

pkg/nazahttp/http_test.go

@@ -15,6 +15,16 @@ import (
 	"github.com/q191201771/naza/pkg/nazahttp"
 )
 
+func TestGetHttpFile(t *testing.T) {
+	content, err := nazahttp.GetHttpFile("http://pengrl.com", 10000)
+	assert.IsNotNil(t, content)
+	assert.Equal(t, nil, err)
+
+	content, err = nazahttp.GetHttpFile("http://127.0.0.1:12356", 10000)
+	assert.Equal(t, nil, content)
+	assert.IsNotNil(t, err)
+}
+
 func TestDownloadHttpFile(t *testing.T) {
 	n, err := nazahttp.DownloadHttpFile("http://pengrl.com", "/tmp/index.html", 10000)
 	assert.Equal(t, true, n > 0)
@@ -23,6 +33,7 @@ func TestDownloadHttpFile(t *testing.T) {
 	n, err = nazahttp.DownloadHttpFile("http://127.0.0.1:12356", "/tmp/index.html", 10000)
 	assert.IsNotNil(t, err)
 
+	// 保存文件至不存在的本地目录下
 	n, err = nazahttp.DownloadHttpFile("http://pengrl.com", "/notexist/index.html", 10000)
 	assert.IsNotNil(t, err)
 }