Add toArrayBuffer to generate transferable output #4355

lib/constructor.js

@@ -306,6 +306,7 @@ const Sharp = function (input, options) {
     fileOut: '',
     formatOut: 'input',
     streamOut: false,
+    sharedOut: true,
     keepMetadata: 0,
     withMetadataOrientation: -1,
     withMetadataDensity: 0,

lib/index.d.ts

@@ -693,6 +693,13 @@ declare namespace sharp {
          */
         toBuffer(options: { resolveWithObject: true }): Promise<{ data: Buffer; info: OutputInfo }>;
 
+        /**
+         * Write output to a transferable ArrayBuffer. JPEG, PNG, WebP, AVIF, TIFF, GIF and RAW output are supported.
+         * By default, the format will match the input image, except SVG input which becomes PNG output.
+         * @returns A promise that resolves with an object containing the ArrayBuffer data and an info object containing the output image format, size (bytes), width, height and channels
+         */
+        toArrayBuffer(): Promise<{ data: ArrayBuffer; info: OutputInfo }>;
+
         /**
          * Keep all EXIF metadata from the input image in the output image.
          * EXIF metadata is unsupported for TIFF output.

lib/output.js

@@ -164,6 +164,45 @@ function toBuffer (options, callback) {
   return this._pipeline(is.fn(options) ? options : callback, stack);
 }
 
+/**
+ * Write output to a transferable `ArrayBuffer`.
+ * JPEG, PNG, WebP, AVIF, TIFF, GIF and raw pixel data output are supported.
+ *
+ * Use {@link #toformat toFormat} or one of the format-specific functions such as {@link #jpeg jpeg}, {@link #png png} etc. to set the output format.
+ *
+ * If no explicit format is set, the output format will match the input image, except SVG input which becomes PNG output.
+ *
+ * By default all metadata will be removed, which includes EXIF-based orientation.
+ * See {@link #keepexif keepExif} and similar methods for control over this.
+ *
+ * Resolves with an `Object` containing:
+ * - `data` is the output image as a transferable `ArrayBuffer`.
+ * - `info` contains properties relating to the output image such as `width` and `height`.
+ *
+ * This method does not work with the Electron V8 memory cage
+ * and will reject with an error if used in that environment.
+ * Use {@link #tobuffer toBuffer} instead.
+ *
+ * @since v0.35.0
+ *
+ * @example
+ * const { data, info } = await sharp(input).toArrayBuffer();
+ *
+ * @example
+ * const { data } = await sharp(input)
+ *   .avif()
+ *   .toArrayBuffer();
+ * const uint8Array = new Uint8Array(data);
+ *
+ * @returns {Promise<{ data: ArrayBuffer, info: Object }>}
+ */
+function toArrayBuffer () {
+  this.options.resolveWithObject = true;
+  this.options.sharedOut = true;
+  const stack = Error();
+  return this._pipeline(null, stack);
+}
+
 /**
  * Keep all EXIF metadata from the input image in the output image.
  *
@@ -1659,6 +1698,7 @@ module.exports = (Sharp) => {
     // Public
     toFile,
     toBuffer,
+    toArrayBuffer,
     keepExif,
     withExif,
     withExifMerge,