Merge pull request #19425 from calixteman/signature_save

[Editor] Add the possibility to compress/decompress the signature data in  order to store them in the logins storage in Firefox (bug 1946171)

src/display/editor/drawers/signaturedraw.js

@@ -13,10 +13,14 @@
  * limitations under the License.
  */
 
+import { fromBase64Util, toBase64Util, warn } from "../../../shared/util.js";
 import { ContourDrawOutline } from "./contour.js";
 import { InkDrawOutline } from "./inkdraw.js";
 import { Outline } from "./outline.js";
 
+const BASE_HEADER_LENGTH = 8;
+const POINTS_PROPERTIES_NUMBER = 3;
+
 /**
  * Basic text editor in order to create a Signature annotation.
  */
@@ -607,12 +611,14 @@ class SignatureExtractor {
     const ratio = Math.min(pageWidth / width, pageHeight / height);
     const xScale = ratio / pageWidth;
     const yScale = ratio / pageHeight;
+    const newCurves = [];
 
     for (const { points } of curves) {
       const reducedPoints = mustSmooth ? this.#douglasPeucker(points) : points;
       if (!reducedPoints) {
         continue;
       }
+      newCurves.push(reducedPoints);
 
       const len = reducedPoints.length;
       const newPoints = new Float32Array(len);
@@ -660,7 +666,185 @@ class SignatureExtractor {
       innerMargin
     );
 
-    return outline;
+    return { outline, newCurves, areContours, thickness, width, height };
+  }
+
+  static async compressSignature({
+    outlines,
+    areContours,
+    thickness,
+    width,
+    height,
+  }) {
+    // We create a single array containing all the outlines.
+    // The format is the following:
+    // - 4 bytes: data length.
+    // - 4 bytes: version.
+    // - 4 bytes: width.
+    // - 4 bytes: height.
+    // - 4 bytes: 0 if it's a contour, 1 if it's an ink.
+    // - 4 bytes: thickness.
+    // - 4 bytes: number of drawings.
+    // - 4 bytes: size of the buffer containing the diff of the coordinates.
+    // - 4 bytes: number of points in the first drawing.
+    // - 4 bytes: x coordinate of the first point.
+    // - 4 bytes: y coordinate of the first point.
+    // - 4 bytes: number of points in the second drawing.
+    // - 4 bytes: x coordinate of the first point.
+    // - 4 bytes: y coordinate of the first point.
+    // - ...
+    // - The buffer containing the diff of the coordinates.
+
+    // The coordinates are supposed to be positive integers.
+
+    // We also compute the min and max difference between two points.
+    // This will help us to determine the type of the buffer (Int8, Int16 or
+    // Int32) in order to minimize the amount of data we have.
+    let minDiff = Infinity;
+    let maxDiff = -Infinity;
+    let outlinesLength = 0;
+    for (const points of outlines) {
+      outlinesLength += points.length;
+      for (let i = 2, ii = points.length; i < ii; i++) {
+        const dx = points[i] - points[i - 2];
+        minDiff = Math.min(minDiff, dx);
+        maxDiff = Math.max(maxDiff, dx);
+      }
+    }
+
+    let bufferType;
+    if (minDiff >= -128 && maxDiff <= 127) {
+      bufferType = Int8Array;
+    } else if (minDiff >= -32768 && maxDiff <= 32767) {
+      bufferType = Int16Array;
+    } else {
+      bufferType = Int32Array;
+    }
+
+    const len = outlines.length;
+    const headerLength = BASE_HEADER_LENGTH + POINTS_PROPERTIES_NUMBER * len;
+    const header = new Uint32Array(headerLength);
+
+    let offset = 0;
+    header[offset++] =
+      headerLength * Uint32Array.BYTES_PER_ELEMENT +
+      (outlinesLength - 2 * len) * bufferType.BYTES_PER_ELEMENT;
+    header[offset++] = 0; // Version.
+    header[offset++] = width;
+    header[offset++] = height;
+    header[offset++] = areContours ? 0 : 1;
+    header[offset++] = Math.max(0, Math.floor(thickness ?? 0));
+    header[offset++] = len;
+    header[offset++] = bufferType.BYTES_PER_ELEMENT;
+    for (const points of outlines) {
+      header[offset++] = points.length - 2;
+      header[offset++] = points[0];
+      header[offset++] = points[1];
+    }
+
+    const cs = new CompressionStream("deflate-raw");
+    const writer = cs.writable.getWriter();
+    await writer.ready;
+
+    writer.write(header);
+    const BufferCtor = bufferType.prototype.constructor;
+    for (const points of outlines) {
+      const diffs = new BufferCtor(points.length - 2);
+      for (let i = 2, ii = points.length; i < ii; i++) {
+        diffs[i - 2] = points[i] - points[i - 2];
+      }
+      writer.write(diffs);
+    }
+
+    writer.close();
+
+    const buf = await new Response(cs.readable).arrayBuffer();
+    const bytes = new Uint8Array(buf);
+
+    return toBase64Util(bytes);
+  }
+
+  static async decompressSignature(signatureData) {
+    try {
+      const bytes = fromBase64Util(signatureData);
+      const { readable, writable } = new DecompressionStream("deflate-raw");
+      const writer = writable.getWriter();
+      await writer.ready;
+
+      // We can't await writer.write() because it'll block until the reader
+      // starts which happens few lines below.
+      writer
+        .write(bytes)
+        .then(async () => {
+          await writer.ready;
+          await writer.close();
+        })
+        .catch(() => {});
+
+      let data = null;
+      let offset = 0;
+      for await (const chunk of readable) {
+        data ||= new Uint8Array(new Uint32Array(chunk.buffer)[0]);
+        data.set(chunk, offset);
+        offset += chunk.length;
+      }
+
+      // We take a bit too much data for the header but it's fine.
+      const header = new Uint32Array(data.buffer, 0, data.length >> 2);
+      const version = header[1];
+      if (version !== 0) {
+        throw new Error(`Invalid version: ${version}`);
+      }
+      const width = header[2];
+      const height = header[3];
+      const areContours = header[4] === 0;
+      const thickness = header[5];
+      const numberOfDrawings = header[6];
+      const bufferType = header[7];
+      const outlines = [];
+      const diffsOffset =
+        (BASE_HEADER_LENGTH + POINTS_PROPERTIES_NUMBER * numberOfDrawings) *
+        Uint32Array.BYTES_PER_ELEMENT;
+      let diffs;
+
+      switch (bufferType) {
+        case Int8Array.BYTES_PER_ELEMENT:
+          diffs = new Int8Array(data.buffer, diffsOffset);
+          break;
+        case Int16Array.BYTES_PER_ELEMENT:
+          diffs = new Int16Array(data.buffer, diffsOffset);
+          break;
+        case Int32Array.BYTES_PER_ELEMENT:
+          diffs = new Int32Array(data.buffer, diffsOffset);
+          break;
+      }
+
+      offset = 0;
+      for (let i = 0; i < numberOfDrawings; i++) {
+        const len = header[POINTS_PROPERTIES_NUMBER * i + BASE_HEADER_LENGTH];
+        const points = new Float32Array(len + 2);
+        outlines.push(points);
+
+        for (let j = 0; j < POINTS_PROPERTIES_NUMBER - 1; j++) {
+          points[j] =
+            header[POINTS_PROPERTIES_NUMBER * i + BASE_HEADER_LENGTH + j + 1];
+        }
+        for (let j = 0; j < len; j++) {
+          points[j + 2] = points[j] + diffs[offset++];
+        }
+      }
+
+      return {
+        areContours,
+        thickness,
+        outlines,
+        width,
+        height,
+      };
+    } catch (e) {
+      warn(`decompressSignature: ${e}`);
+      return null;
+    }
   }
 }
 

src/display/editor/signature.js

@@ -72,6 +72,7 @@ class SignatureEditor extends DrawingEditor {
     super({ ...params, mustBeCommitted: true, name: "signatureEditor" });
     this._willKeepAspectRatio = true;
     this._description = "";
+    this._signatureUUID = null;
   }
 
   /** @inheritdoc */

src/pdf.js

@@ -30,6 +30,7 @@ import {
   AnnotationType,
   createValidAbsoluteUrl,
   FeatureTest,
+  getUuid,
   ImageKind,
   InvalidPDFException,
   normalizeUnicode,
@@ -72,6 +73,7 @@ import { DOMSVGFactory } from "./display/svg_factory.js";
 import { DrawLayer } from "./display/draw_layer.js";
 import { GlobalWorkerOptions } from "./display/worker_options.js";
 import { HighlightOutliner } from "./display/editor/drawers/highlight.js";
+import { SignatureExtractor } from "./display/editor/drawers/signaturedraw.js";
 import { TextLayer } from "./display/text_layer.js";
 import { TouchManager } from "./display/touch_manager.js";
 import { XfaLayer } from "./display/xfa_layer.js";
@@ -108,6 +110,7 @@ export {
   getDocument,
   getFilenameFromUrl,
   getPdfFilenameFromUrl,
+  getUuid,
   getXfaPageViewport,
   GlobalWorkerOptions,
   ImageKind,
@@ -128,6 +131,7 @@ export {
   ResponseException,
   setLayerDimensions,
   shadow,
+  SignatureExtractor,
   stopEvent,
   SupportedImageMimeTypes,
   TextLayer,

test/unit/editor_spec.js

@@ -14,6 +14,7 @@
  */
 
 import { CommandManager } from "../../src/display/editor/tools.js";
+import { SignatureExtractor } from "../../src/display/editor/drawers/signaturedraw.js";
 
 describe("editor", function () {
   describe("Command Manager", function () {
@@ -90,4 +91,51 @@ describe("editor", function () {
     manager.add({ ...makeDoUndo(5), mustExec: true });
     expect(x).toEqual(11);
   });
+
+  it("should check signature compression/decompression", async () => {
+    let gen = n => new Float32Array(crypto.getRandomValues(new Uint16Array(n)));
+    let outlines = [102, 28, 254, 4536, 10, 14532, 512].map(gen);
+    const signature = {
+      outlines,
+      areContours: false,
+      thickness: 1,
+      width: 123,
+      height: 456,
+    };
+    let compressed = await SignatureExtractor.compressSignature(signature);
+    let decompressed = await SignatureExtractor.decompressSignature(compressed);
+    expect(decompressed).toEqual(signature);
+
+    signature.thickness = 2;
+    compressed = await SignatureExtractor.compressSignature(signature);
+    decompressed = await SignatureExtractor.decompressSignature(compressed);
+    expect(decompressed).toEqual(signature);
+
+    signature.areContours = true;
+    compressed = await SignatureExtractor.compressSignature(signature);
+    decompressed = await SignatureExtractor.decompressSignature(compressed);
+    expect(decompressed).toEqual(signature);
+
+    // Numbers are small enough to be compressed with Uint8Array.
+    gen = n =>
+      new Float32Array(
+        crypto.getRandomValues(new Uint8Array(n)).map(x => x / 10)
+      );
+    outlines = [100, 200, 300, 10, 80].map(gen);
+    signature.outlines = outlines;
+    compressed = await SignatureExtractor.compressSignature(signature);
+    decompressed = await SignatureExtractor.decompressSignature(compressed);
+    expect(decompressed).toEqual(signature);
+
+    // Numbers are large enough to be compressed with Uint16Array.
+    gen = n =>
+      new Float32Array(
+        crypto.getRandomValues(new Uint16Array(n)).map(x => x / 10)
+      );
+    outlines = [100, 200, 300, 10, 80].map(gen);
+    signature.outlines = outlines;
+    compressed = await SignatureExtractor.compressSignature(signature);
+    decompressed = await SignatureExtractor.decompressSignature(compressed);
+    expect(decompressed).toEqual(signature);
+  });
 });

test/unit/pdf_spec.js

@@ -21,6 +21,7 @@ import {
   AnnotationType,
   createValidAbsoluteUrl,
   FeatureTest,
+  getUuid,
   ImageKind,
   InvalidPDFException,
   normalizeUnicode,
@@ -62,6 +63,7 @@ import { ColorPicker } from "../../src/display/editor/color_picker.js";
 import { DOMSVGFactory } from "../../src/display/svg_factory.js";
 import { DrawLayer } from "../../src/display/draw_layer.js";
 import { GlobalWorkerOptions } from "../../src/display/worker_options.js";
+import { SignatureExtractor } from "../../src/display/editor/drawers/signaturedraw.js";
 import { TextLayer } from "../../src/display/text_layer.js";
 import { TouchManager } from "../../src/display/touch_manager.js";
 import { XfaLayer } from "../../src/display/xfa_layer.js";
@@ -85,6 +87,7 @@ const expectedAPI = Object.freeze({
   getDocument,
   getFilenameFromUrl,
   getPdfFilenameFromUrl,
+  getUuid,
   getXfaPageViewport,
   GlobalWorkerOptions,
   ImageKind,
@@ -105,6 +108,7 @@ const expectedAPI = Object.freeze({
   ResponseException,
   setLayerDimensions,
   shadow,
+  SignatureExtractor,
   stopEvent,
   SupportedImageMimeTypes,
   TextLayer,

web/app.js

@@ -461,13 +461,15 @@ const PDFViewerApplication = {
       this.editorUndoBar = new EditorUndoBar(appConfig.editorUndoBar, eventBus);
     }
 
-    const signatureManager = appConfig.addSignatureDialog
-      ? new SignatureManager(
-          appConfig.addSignatureDialog,
-          this.overlayManager,
-          this.l10n
-        )
-      : null;
+    const signatureManager =
+      AppOptions.get("enableSignatureEditor") && appConfig.addSignatureDialog
+        ? new SignatureManager(
+            appConfig.addSignatureDialog,
+            this.overlayManager,
+            this.l10n,
+            externalServices.createSignatureStorage()
+          )
+        : null;
 
     const enableHWA = AppOptions.get("enableHWA");
     const pdfViewer = new PDFViewer({

web/chromecom.js

@@ -19,8 +19,10 @@ import { BaseExternalServices } from "./external_services.js";
 import { BasePreferences } from "./preferences.js";
 import { GenericL10n } from "./genericl10n.js";
 import { GenericScripting } from "./generic_scripting.js";
+import { SignatureStorage } from "./generic_signature_storage.js";
 
 // These strings are from chrome/app/resources/generated_resources_*.xtb.
+// eslint-disable-next-line sort-imports
 import i18nFileAccessLabels from "./chrome-i18n-allow-access-to-file-urls.json" with { type: "json" };
 
 if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("CHROME")) {
@@ -419,6 +421,10 @@ class ExternalServices extends BaseExternalServices {
   createScripting() {
     return new GenericScripting(AppOptions.get("sandboxBundleSrc"));
   }
+
+  createSignatureStorage() {
+    return new SignatureStorage();
+  }
 }
 
 class MLManager {