feat: Add response-cache plugin (#3061)

Co-authored-by: mirror58229 <674958229@qq.com>

plugins/wasm-go/extensions/response-cache/core.go

@@ -0,0 +1,100 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/alibaba/higress/plugins/wasm-go/extensions/response-cache/cache"
+	"github.com/alibaba/higress/plugins/wasm-go/extensions/response-cache/config"
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm"
+	"github.com/higress-group/wasm-go/pkg/log"
+	"github.com/higress-group/wasm-go/pkg/wrapper"
+	"github.com/tidwall/resp"
+)
+
+// buildCacheKey constructs the full cache key by combining the prefix with the actual key.
+func buildCacheKey(provider cache.Provider, key string) string {
+	return provider.GetCacheKeyPrefix() + key
+}
+
+// CheckCacheForKey checks if the key is in the cache, or triggers similarity search if not found.
+func CheckCacheForKey(key string, ctx wrapper.HttpContext, c config.PluginConfig) error {
+	activeCacheProvider := c.GetCacheProvider()
+	if activeCacheProvider == nil {
+		return logAndReturnError("[CheckCacheForKey] no cache provider configured")
+	}
+
+	queryKey := buildCacheKey(activeCacheProvider, key)
+	log.Debugf("[%s] [CheckCacheForKey] querying cache with key: %s", PLUGIN_NAME, queryKey)
+
+	err := activeCacheProvider.Get(queryKey, func(response resp.Value) {
+		handleCacheResponse(key, response, ctx, c)
+	})
+
+	if err != nil {
+		log.Errorf("[%s] [CheckCacheForKey] failed to retrieve key: %s from cache, error: %v", PLUGIN_NAME, key, err)
+		return err
+	}
+
+	return nil
+}
+
+// handleCacheResponse processes cache response and handles cache hits and misses.
+func handleCacheResponse(key string, response resp.Value, ctx wrapper.HttpContext, c config.PluginConfig) {
+	if err := response.Error(); err == nil && !response.IsNull() {
+		log.Infof("[%s] cache hit for key: %s", PLUGIN_NAME, key)
+		processCacheHit(key, response.String(), ctx, c)
+		return
+	}
+
+	log.Infof("[%s] [handleCacheResponse] cache miss for key: %s", PLUGIN_NAME, key)
+	if err := response.Error(); err != nil {
+		log.Errorf("[%s] [handleCacheResponse] error retrieving key: %s from cache, error: %v", PLUGIN_NAME, key, err)
+	}
+	proxywasm.ResumeHttpRequest()
+}
+
+// processCacheHit handles a successful cache hit.
+func processCacheHit(key string, response string, ctx wrapper.HttpContext, c config.PluginConfig) {
+	if strings.TrimSpace(response) == "" {
+		log.Warnf("[%s] [processCacheHit] cached response for key %s is empty", PLUGIN_NAME, key)
+		proxywasm.ResumeHttpRequest()
+		return
+	}
+
+	log.Debugf("[%s] [processCacheHit] cached response for key %s: %s", PLUGIN_NAME, key, response)
+
+	ctx.SetContext(CACHE_KEY_CONTEXT_KEY, nil)
+
+	contentType := c.CacheValueFromBodyType
+	headers := [][2]string{
+		{"content-type", contentType},
+		{"x-cache-status", "hit"},
+	}
+
+	proxywasm.SendHttpResponseWithDetail(200, "response-cache.hit", headers, []byte(response), -1)
+
+}
+
+// logAndReturnError logs an error and returns it.
+func logAndReturnError(message string) error {
+	message = fmt.Sprintf("[%s] %s", PLUGIN_NAME, message)
+	log.Errorf(message)
+	return errors.New(message)
+}
+
+// Caches the response value
+func cacheResponse(ctx wrapper.HttpContext, c config.PluginConfig, key string, value string) {
+	if strings.TrimSpace(value) == "" {
+		log.Warnf("[%s] [cacheResponse] cached value for key %s is empty", PLUGIN_NAME, key)
+		return
+	}
+
+	activeCacheProvider := c.GetCacheProvider()
+	if activeCacheProvider != nil {
+		queryKey := buildCacheKey(activeCacheProvider, key)
+		_ = activeCacheProvider.Set(queryKey, value, nil)
+		log.Debugf("[%s] [cacheResponse] cache set success, key: %s, length of value: %d", PLUGIN_NAME, queryKey, len(value))
+	}
+}