Initial commit: web_hghl_server

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/middleware/templatecache/cache.go

@@ -0,0 +1,116 @@
+package templatecache
+
+import (
+	"bytes"
+	"net/http"
+	"strings"
+	"sync/atomic"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/patrickmn/go-cache"
+)
+
+const (
+	maxCacheItems = 2000
+	maxCacheBytes = 64 << 20
+)
+
+var (
+	Cache      *cache.Cache
+	cacheBytes int64
+)
+
+// 章节详情、资讯详情等 ID 空间过大，禁止进进程缓存。
+var highCardinalityContains = []string{
+	"/chapter/info",
+	"/consultinginfo/",
+}
+
+func init() {
+	Cache = cache.New(5*time.Minute, 5*time.Minute)
+	Cache.OnEvicted(func(_ string, v interface{}) {
+		if b, ok := v.([]byte); ok {
+			atomic.AddInt64(&cacheBytes, -int64(len(b)))
+		}
+	})
+}
+
+func shouldBypassCache(path string) bool {
+	if path == "" {
+		return false
+	}
+	if i := strings.IndexByte(path, '?'); i >= 0 {
+		path = path[:i]
+	}
+	for _, part := range highCardinalityContains {
+		if strings.Contains(path, part) {
+			return true
+		}
+	}
+	return false
+}
+
+func cacheBudgetAllows(n int) bool {
+	if n <= 0 {
+		return false
+	}
+	if Cache.ItemCount() >= maxCacheItems {
+		return false
+	}
+	return atomic.LoadInt64(&cacheBytes)+int64(n) <= maxCacheBytes
+}
+
+type templateResponseWriter struct {
+	gin.ResponseWriter
+	body *bytes.Buffer
+}
+
+func (w *templateResponseWriter) Write(b []byte) (int, error) {
+	w.body.Write(b)
+	return w.ResponseWriter.Write(b)
+}
+
+func WithCache(duration time.Duration) gin.HandlerFunc {
+	return func(ctx *gin.Context) {
+		if ctx.Request.Method != "GET" {
+			ctx.Next()
+			return
+		}
+		if shouldBypassCache(ctx.Request.URL.Path) {
+			ctx.Next()
+			return
+		}
+
+		cacheKey := ctx.Request.URL.String()
+		if cacheData, exists := Cache.Get(cacheKey); exists {
+			if item, ok := cacheData.([]byte); ok && len(item) > 0 {
+				ctx.Data(http.StatusOK, "application/json; charset=utf-8", item)
+				ctx.Abort()
+				return
+			}
+		}
+
+		writer := &templateResponseWriter{
+			body:           bytes.NewBuffer(nil),
+			ResponseWriter: ctx.Writer,
+		}
+		ctx.Writer = writer
+		ctx.Next()
+
+		if ctx.Writer.Status() != 200 {
+			return
+		}
+		raw := writer.body.Bytes()
+		if !cacheBudgetAllows(len(raw)) {
+			return
+		}
+		copied := append([]byte(nil), raw...)
+		atomic.AddInt64(&cacheBytes, int64(len(copied)))
+		cacheDuration := duration
+		if cacheDuration == 0 {
+			cacheDuration = time.Minute
+		}
+		Cache.Set(cacheKey, copied, cacheDuration)
+	}
+}