优化UserAgent解析

internal/stats/user_agent_parser.go

@@ -0,0 +1,82 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package stats
+
+import (
+	"github.com/TeaOSLab/EdgeNode/internal/utils"
+	"github.com/mssola/user_agent"
+)
+
+// UserAgentParser UserAgent解析器
+// 只支持单线程
+type UserAgentParser struct {
+	parser *user_agent.UserAgent
+
+	cacheMap1     map[string]UserAgentParserResult
+	cacheMap2     map[string]UserAgentParserResult
+	maxCacheItems int
+
+	cacheCursor int
+}
+
+func NewUserAgentParser() *UserAgentParser {
+	var parser = &UserAgentParser{
+		parser:      &user_agent.UserAgent{},
+		cacheMap1:   map[string]UserAgentParserResult{},
+		cacheMap2:   map[string]UserAgentParserResult{},
+		cacheCursor: 0,
+	}
+
+	parser.init()
+	return parser
+}
+
+func (this *UserAgentParser) init() {
+	var maxCacheItems = 10_000
+	var systemMemory = utils.SystemMemoryGB()
+	if systemMemory >= 16 {
+		maxCacheItems = 40_000
+	} else if systemMemory >= 8 {
+		maxCacheItems = 30_000
+	} else if systemMemory >= 4 {
+		maxCacheItems = 20_000
+	}
+	this.maxCacheItems = maxCacheItems
+}
+
+func (this *UserAgentParser) Parse(userAgent string) (result UserAgentParserResult) {
+	// 限制长度
+	if len(userAgent) == 0 || len(userAgent) > 256 {
+		return
+	}
+
+	cacheResult, ok := this.cacheMap1[userAgent]
+	if ok {
+		return cacheResult
+	}
+
+	cacheResult, ok = this.cacheMap2[userAgent]
+	if ok {
+		return cacheResult
+	}
+
+	this.parser.Parse(userAgent)
+	result.os = this.parser.OSInfo()
+	result.browserName, result.browserVersion = this.parser.Browser()
+
+	if this.cacheCursor == 0 {
+		this.cacheMap1[userAgent] = result
+		if len(this.cacheMap1) >= this.maxCacheItems {
+			this.cacheCursor = 1
+			this.cacheMap2 = map[string]UserAgentParserResult{}
+		}
+	} else {
+		this.cacheMap2[userAgent] = result
+		if len(this.cacheMap2) >= this.maxCacheItems {
+			this.cacheCursor = 0
+			this.cacheMap1 = map[string]UserAgentParserResult{}
+		}
+	}
+
+	return
+}