feat: enhance computeHashesFromStream to support encoding options and update usage in ClassifierSdk

Author: abbottdev-kroll

src/hashing.ts

@@ -1,14 +1,16 @@
 import { Readable } from "stream";
 import crypto from 'crypto';
 import sharp from 'sharp'
+import { RequestEncoding } from "./main";
+import brotli from 'brotli'
 
 /**
  * Computes MD5 and SHA1 hashes from a readable stream and resizes any image data.
  * @param stream Node.js readable stream (e.g., fs.createReadStream)
+ * @param encoding Encoding type for the image data (default is UNCOMPRESSED)
  * @returns {Promise<{md5: string, sha1: string, data: Buffer}>} Object containing MD5 hash, SHA1 hash, and resized image buffer
  */
-export async function computeHashesFromStream(stream: Readable): Promise<{ md5: string; sha1: string; data: Buffer }> {
-
+export async function computeHashesFromStream(stream: Readable, encoding: RequestEncoding = RequestEncoding.UNCOMPRESSED): Promise<{ md5: string; sha1: string; data: Buffer }> {
   const md5 = crypto.createHash('md5');
   const sha1 = crypto.createHash('sha1');
   const resizer = sharp()
@@ -19,7 +21,11 @@ export async function computeHashesFromStream(stream: Readable): Promise<{ md5:
   stream.pipe(sha1);
   stream.pipe(resizer);
 
-  const data = await resizer.toBuffer();
+  let data = await resizer.toBuffer();
+
+  if (encoding === RequestEncoding.BROTLI) {
+    data = Buffer.from(await brotli.compress(data));
+  }
 
   return {
       md5: md5.digest('hex'),

src/main.ts

@@ -8,7 +8,6 @@ import { Empty } from './athena/google/protobuf/empty';
 import TypedEmitter from "typed-emitter"
 import { AuthenticationOptions, AuthenticationManager } from './authenticationManager';
 import { computeHashesFromStream } from './hashing';
-import brotli from 'brotli'
 
 /**
  * Options for classifyImage
@@ -139,22 +138,15 @@ export class ClassifierSdk extends (EventEmitter as new () => TypedEmitter<Class
     if (!this.classifierGrpcCall) {
       throw new Error('gRPC stream is not open. Call open() first.');
     }
-    let {
+    const {
       affiliate = this.options.affiliate,
       correlationId = randomUUID(),
       imageStream,
-      encoding = RequestEncoding.UNSPECIFIED,
+      encoding = RequestEncoding.UNCOMPRESSED,
       format = ImageFormat.UNSPECIFIED,
     } = options;
 
-    let { md5, sha1, data } = await computeHashesFromStream(imageStream);
-
-    if (encoding == RequestEncoding.UNCOMPRESSED || encoding == RequestEncoding.UNSPECIFIED) {
-      // Handle uncompressed and compressed cases
-      const compressed = await brotli.compress(data);
-      data = Buffer.from(compressed);
-      encoding = RequestEncoding.BROTLI;
-    }
+    const { md5, sha1, data } = await computeHashesFromStream(imageStream, encoding);
 
     const hashes: ImageHash[] = [
       { value: md5, type: HashType.MD5 },