👔 Add filter middleware

rest/filter_middleware.go

@@ -0,0 +1,110 @@
+package rest
+
+import (
+	"bytes"
+	"encoding/json"
+
+	"github.com/gin-gonic/gin"
+	"github.com/likecoin/likecoin-chain-tx-indexer/logger"
+)
+
+type copyWriter struct {
+	gin.ResponseWriter
+	body *bytes.Buffer
+}
+
+func (cw copyWriter) Write(b []byte) (int, error) {
+	return cw.body.Write(b)
+}
+
+func (cw *copyWriter) WriteHeader(statusCode int) {
+	// Remove content-length header written by proxy
+	cw.Header().Del("Content-length")
+	cw.Header().Set("Transfer-Encoding", "chunked")
+	cw.ResponseWriter.WriteHeader(statusCode)
+}
+
+func filterContentFingerprints() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		isBrowser := false
+		switch c.NegotiateFormat(gin.MIMEJSON, gin.MIMEHTML) {
+		case gin.MIMEHTML:
+			isBrowser = true
+		case gin.MIMEJSON:
+			isBrowser = false
+		}
+
+		if !isBrowser {
+			c.Next()
+			return
+		}
+
+		wb := &copyWriter{
+			body:           &bytes.Buffer{},
+			ResponseWriter: c.Writer,
+		}
+		c.Writer = wb
+		c.Next()
+
+		originBody := wb.body
+		originBodyBytes := originBody.Bytes()
+
+		var jsonObject map[string]any
+		err := json.Unmarshal(originBodyBytes, &jsonObject)
+		if err != nil {
+			_, e := wb.ResponseWriter.Write(originBodyBytes)
+			if e != nil {
+				logger.L.Error(e)
+			}
+			return
+		}
+
+		records, ok := jsonObject["records"].([]interface{})
+		if !ok {
+			_, e := wb.ResponseWriter.Write(originBodyBytes)
+			if e != nil {
+				logger.L.Error(e)
+			}
+			return
+		}
+
+		for index, record := range records {
+			obj, ok := record.(map[string]any)
+			if !ok {
+				continue
+			}
+			data, ok := obj["data"].(map[string]any)
+			if !ok {
+				continue
+			}
+			if data["contentFingerprints"] != nil {
+				delete(data, "contentFingerprints")
+			}
+			if data["contentMetadata"] != nil {
+				contentMetadata, ok := data["contentMetadata"].(map[string]any)
+				if ok {
+					if contentMetadata["sameAs"] != nil {
+						delete(contentMetadata, "sameAs")
+					}
+					data["contentMetadata"] = contentMetadata
+				}
+			}
+			obj["data"] = data
+			records[index] = obj
+		}
+		jsonObject["records"] = records
+
+		newBody, err := json.Marshal(jsonObject)
+		if err != nil {
+			_, e := wb.ResponseWriter.Write(originBodyBytes)
+			if e != nil {
+				logger.L.Error(e)
+			}
+			return
+		}
+		_, e := wb.ResponseWriter.Write(newBody)
+		if e != nil {
+			logger.L.Error(e)
+		}
+	}
+}

rest/router.go

@@ -61,6 +61,7 @@ func GetRouter(pool *pgxpool.Pool, defaultApiAddresses []string) *gin.Engine {
 		analysis.GET("/nft/owner-count", handleNftOwnerCount)
 		analysis.GET("/nft/owners", handleNftOwnerList)
 	}
+	router.Use(filterContentFingerprints())
 	router.GET(ISCN_ENDPOINT, handleIscn)
 	router.GET(STARGATE_ENDPOINT, handleStargateTxsSearch)
 	router.GET(LATEST_HEIGHT_ENDPOINT, handleLatestHeight)