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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
commit43a97878ce14b72f0981164f87f2e35e14151312 (patch)
tree620249daf56c0258faa40cbdcf9cfba06de2a846 /js/src/builtin/Sorting.js
parentInitial commit. (diff)
downloadfirefox-upstream.tar.xz
firefox-upstream.zip
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/src/builtin/Sorting.js')
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diff --git a/js/src/builtin/Sorting.js b/js/src/builtin/Sorting.js
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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// We use varying sorts across the self-hosted codebase. All sorts are
+// consolidated here to avoid confusion and re-implementation of existing
+// algorithms.
+
+// For sorting small arrays.
+function InsertionSort(array, from, to, comparefn) {
+ let item, swap, i, j;
+ for (i = from + 1; i <= to; i++) {
+ item = array[i];
+ for (j = i - 1; j >= from; j--) {
+ swap = array[j];
+ if (callContentFunction(comparefn, undefined, swap, item) <= 0) {
+ break;
+ }
+ array[j + 1] = swap;
+ }
+ array[j + 1] = item;
+ }
+}
+
+// A helper function for MergeSort.
+//
+// Merge comparefn-sorted slices list[start..<=mid] and list[mid+1..<=end],
+// storing the merged sequence in out[start..<=end].
+function Merge(list, out, start, mid, end, comparefn) {
+ // Skip lopsided runs to avoid doing useless work.
+ // Skip calling the comparator if the sub-list is already sorted.
+ if (
+ mid >= end ||
+ callContentFunction(comparefn, undefined, list[mid], list[mid + 1]) <= 0
+ ) {
+ for (var i = start; i <= end; i++) {
+ DefineDataProperty(out, i, list[i]);
+ }
+ return;
+ }
+
+ var i = start;
+ var j = mid + 1;
+ var k = start;
+ while (i <= mid && j <= end) {
+ var lvalue = list[i];
+ var rvalue = list[j];
+ if (callContentFunction(comparefn, undefined, lvalue, rvalue) <= 0) {
+ DefineDataProperty(out, k++, lvalue);
+ i++;
+ } else {
+ DefineDataProperty(out, k++, rvalue);
+ j++;
+ }
+ }
+
+ // Empty out any remaining elements.
+ while (i <= mid) {
+ DefineDataProperty(out, k++, list[i++]);
+ }
+ while (j <= end) {
+ DefineDataProperty(out, k++, list[j++]);
+ }
+}
+
+// Helper function for overwriting a sparse array with a
+// dense array, filling remaining slots with holes.
+function MoveHoles(sparse, sparseLen, dense, denseLen) {
+ for (var i = 0; i < denseLen; i++) {
+ sparse[i] = dense[i];
+ }
+ for (var j = denseLen; j < sparseLen; j++) {
+ delete sparse[j];
+ }
+}
+
+// Iterative, bottom up, mergesort.
+function MergeSort(array, len, comparefn) {
+ assert(IsPackedArray(array), "array is packed");
+ assert(array.length === len, "length mismatch");
+ assert(len > 0, "array should be non-empty");
+
+ // Insertion sort for small arrays, where "small" is defined by performance
+ // testing.
+ if (len < 24) {
+ InsertionSort(array, 0, len - 1, comparefn);
+ return array;
+ }
+
+ // We do all of our allocating up front
+ var lBuffer = array;
+ var rBuffer = [];
+
+ // Use insertion sort for initial ranges.
+ var windowSize = 4;
+ for (var start = 0; start < len - 1; start += windowSize) {
+ var end = std_Math_min(start + windowSize - 1, len - 1);
+ InsertionSort(lBuffer, start, end, comparefn);
+ }
+
+ for (; windowSize < len; windowSize = 2 * windowSize) {
+ for (var start = 0; start < len; start += 2 * windowSize) {
+ // The midpoint between the two subarrays.
+ var mid = start + windowSize - 1;
+
+ // To keep from going over the edge.
+ var end = std_Math_min(start + 2 * windowSize - 1, len - 1);
+
+ Merge(lBuffer, rBuffer, start, mid, end, comparefn);
+ }
+
+ // Swap both lists.
+ var swap = lBuffer;
+ lBuffer = rBuffer;
+ rBuffer = swap;
+ }
+ return lBuffer;
+}
+
+// A helper function for MergeSortTypedArray.
+//
+// Merge comparefn-sorted slices list[start..<=mid] and list[mid+1..<=end],
+// storing the merged sequence in out[start..<=end].
+function MergeTypedArray(list, out, start, mid, end, comparefn) {
+ // Skip lopsided runs to avoid doing useless work.
+ // Skip calling the comparator if the sub-list is already sorted.
+ if (
+ mid >= end ||
+ callContentFunction(comparefn, undefined, list[mid], list[mid + 1]) <= 0
+ ) {
+ for (var i = start; i <= end; i++) {
+ out[i] = list[i];
+ }
+ return;
+ }
+
+ var i = start;
+ var j = mid + 1;
+ var k = start;
+ while (i <= mid && j <= end) {
+ var lvalue = list[i];
+ var rvalue = list[j];
+ if (callContentFunction(comparefn, undefined, lvalue, rvalue) <= 0) {
+ out[k++] = lvalue;
+ i++;
+ } else {
+ out[k++] = rvalue;
+ j++;
+ }
+ }
+
+ // Empty out any remaining elements.
+ while (i <= mid) {
+ out[k++] = list[i++];
+ }
+ while (j <= end) {
+ out[k++] = list[j++];
+ }
+}
+
+// Iterative, bottom up, mergesort. Optimized version for TypedArrays.
+function MergeSortTypedArray(array, len, comparefn) {
+ assert(
+ IsPossiblyWrappedTypedArray(array),
+ "MergeSortTypedArray works only with typed arrays."
+ );
+
+ // Use the same TypedArray kind for the buffer.
+ var C = ConstructorForTypedArray(array);
+
+ var lBuffer = new C(len);
+
+ // Copy all elements into a temporary buffer, so that any modifications
+ // when calling |comparefn| are ignored.
+ for (var i = 0; i < len; i++) {
+ lBuffer[i] = array[i];
+ }
+
+ // Insertion sort for small arrays, where "small" is defined by performance
+ // testing.
+ if (len < 8) {
+ InsertionSort(lBuffer, 0, len - 1, comparefn);
+
+ return lBuffer;
+ }
+
+ // We do all of our allocating up front.
+ var rBuffer = new C(len);
+
+ // Use insertion sort for the initial ranges.
+ var windowSize = 4;
+ for (var start = 0; start < len - 1; start += windowSize) {
+ var end = std_Math_min(start + windowSize - 1, len - 1);
+ InsertionSort(lBuffer, start, end, comparefn);
+ }
+
+ for (; windowSize < len; windowSize = 2 * windowSize) {
+ for (var start = 0; start < len; start += 2 * windowSize) {
+ // The midpoint between the two subarrays.
+ var mid = start + windowSize - 1;
+
+ // To keep from going over the edge.
+ var end = std_Math_min(start + 2 * windowSize - 1, len - 1);
+
+ MergeTypedArray(lBuffer, rBuffer, start, mid, end, comparefn);
+ }
+
+ // Swap both lists.
+ var swap = lBuffer;
+ lBuffer = rBuffer;
+ rBuffer = swap;
+ }
+
+ return lBuffer;
+}