Avoid to create any subarrays when optimizing 'save, transform, constructPath, restore' (bug 1961107)

[calixteman]

Removing those subarraycalls helps to improve performance by a factor 6 on Linux and by a factor of 3
on Windows 11.

[calixteman]

/botio test

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Received

Command cmd_test from @calixteman received. Current queue size: 0

Live output at: http://54.241.84.105:8877/4e0b914673636bc/output.txt

[moz-tools-bot]

From: Bot.io (Windows)

---

Received

Command cmd_test from @calixteman received. Current queue size: 0

Live output at: http://54.193.163.58:8877/2e4b6141cfb520e/output.txt

[Snuffleupagus]

Do we "need" new methods for this, can't we just change the existing ones to accept an optional pos argument instead?
E.g. something like the following (although untested):

diff --git a/src/core/operator_list.js b/src/core/operator_list.js
index 5b1885ef9..f643f181a 100644
--- a/src/core/operator_list.js
+++ b/src/core/operator_list.js
@@ -524,11 +524,11 @@ addState(
       switch (buffer[k++]) {
         case DrawOPS.moveTo:
         case DrawOPS.lineTo:
-          Util.applyTransform(buffer.subarray(k), transform);
+          Util.applyTransform(buffer, transform, k);
           k += 2;
           break;
         case DrawOPS.curveTo:
-          Util.applyTransformToBezier(buffer.subarray(k), transform);
+          Util.applyTransformToBezier(buffer, transform, k);
           k += 6;
           break;
       }
diff --git a/src/shared/util.js b/src/shared/util.js
index fd2d5fcb3..1d1cefc3b 100644
--- a/src/shared/util.js
+++ b/src/shared/util.js
@@ -730,15 +730,15 @@ class Util {
   }
 
   // For 2d affine transforms
-  static applyTransform(p, m) {
-    const p0 = p[0];
-    const p1 = p[1];
-    p[0] = p0 * m[0] + p1 * m[2] + m[4];
-    p[1] = p0 * m[1] + p1 * m[3] + m[5];
+  static applyTransform(p, m, pos = 0) {
+    const p0 = p[pos];
+    const p1 = p[pos + 1];
+    p[pos] = p0 * m[0] + p1 * m[2] + m[4];
+    p[pos + 1] = p0 * m[1] + p1 * m[3] + m[5];
   }
 
   // For 2d affine transforms
-  static applyTransformToBezier(p, transform) {
+  static applyTransformToBezier(p, transform, pos = 0) {
     const m0 = transform[0];
     const m1 = transform[1];
     const m2 = transform[2];
@@ -746,10 +746,10 @@ class Util {
     const m4 = transform[4];
     const m5 = transform[5];
     for (let i = 0; i < 6; i += 2) {
-      const pI = p[i];
-      const pI1 = p[i + 1];
-      p[i] = pI * m0 + pI1 * m2 + m4;
-      p[i + 1] = pI * m1 + pI1 * m3 + m5;
+      const pI = p[pos + i];
+      const pI1 = p[pos + i + 1];
+      p[pos + i] = pI * m0 + pI1 * m2 + m4;
+      p[pos + i + 1] = pI * m1 + pI1 * m3 + m5;
     }
   }

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Failed

Full output at http://54.241.84.105:8877/4e0b914673636bc/output.txt

Total script time: 30.74 mins

• Unit tests: Passed
• Integration Tests: FAILED
• Regression tests: Passed

[calixteman]

/botio-linux browsertest

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Received

Command cmd_browsertest from @calixteman received. Current queue size: 0

Live output at: http://54.241.84.105:8877/667fed790b2349e/output.txt

[moz-tools-bot]

From: Bot.io (Windows)

---

Failed

Full output at http://54.193.163.58:8877/2e4b6141cfb520e/output.txt

Total script time: 58.84 mins

• Unit tests: Passed
• Integration Tests: FAILED
• Regression tests: Passed

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Success

Full output at http://54.241.84.105:8877/667fed790b2349e/output.txt

Total script time: 16.29 mins

• Regression tests: Passed

[Snuffleupagus]

Could we also replace this existing code

pdf.js/src/core/font_renderer.js

Lines 748 to 754 in f1e20cd

	const [a, b, c, d, e, f] = this.currentTransform;
	for (let i = 0, ii = args.length; i < ii; i += 2) {
	const x = args[i];
	const y = args[i + 1];
	args[i] = a * x + c * y + e;
	args[i + 1] = b * x + d * y + f;
	}

with something like the following now?

for (let i = 0, ii = args.length; i < ii; i += 2) { 
   Util.applyTransform(args, this.currentTransform, i);
 } 

[Snuffleupagus]

r=me, thank you.

[calixteman]

/botio-linux browsertest

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Received

Command cmd_browsertest from @calixteman received. Current queue size: 0

Live output at: http://54.241.84.105:8877/098491421bf0993/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Success

Full output at http://54.241.84.105:8877/098491421bf0993/output.txt

Total script time: 16.21 mins

• Regression tests: Passed