add agents to support route image

src/utils/rewriteStream.ts

@@ -0,0 +1,31 @@
+/**rewriteStream
+ * 读取源readablestream，返回一个新的readablestream，由processor对源数据进行处理后将返回的新值推送到新的stream，如果没有返回值则不推送
+ * @param stream
+ * @param processor
+ */
+export const rewriteStream = (stream: ReadableStream, processor: (data: any, controller: ReadableStreamController<any>) => Promise<any>): ReadableStream => {
+  const reader = stream.getReader()
+
+  return new ReadableStream({
+    async start(controller) {
+      try {
+        while (true) {
+          const { done, value } = await reader.read()
+          if (done) {
+            controller.close()
+            break
+          }
+
+          const processed = await processor(value, controller)
+          if (processed !== undefined) {
+            controller.enqueue(processed)
+          }
+        }
+      } catch (error) {
+        controller.error(error)
+      } finally {
+        reader.releaseLock()
+      }
+    }
+  })
+}