Maintain decorations sorted by line

src/common/SortedList.ts

@@ -0,0 +1,80 @@
+/**
+ * Copyright (c) 2022 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+export class SortedList<T> {
+  private readonly _array: T[] = [];
+
+  constructor(
+    private readonly _getKey: (value: T) => number
+  ) {
+  }
+
+  public clear(): void {
+    this._array.length = 0;
+  }
+
+  public insert(value: T): void {
+    if (this._array.length === 0) {
+      this._array.push(value);
+      return;
+    }
+    const i = this._search(this._getKey(value), 0, this._array.length - 1);
+    this._array.splice(i, 0, value);
+  }
+
+  public delete(value: T): boolean {
+    if (this._array.length === 0) {
+      return false;
+    }
+    const key = this._getKey(value);
+    let i = this._search(key, 0, this._array.length - 1);
+    if (this._getKey(this._array[i]) !== key) {
+      return false;
+    }
+    do {
+      if (this._array[i] === value) {
+        this._array.splice(i, 1);
+        return true;
+      }
+    } while (++i < this._array.length && this._getKey(this._array[i]) === key);
+    return false;
+  }
+
+  public *getKeyIterator(key: number): IterableIterator<T> {
+    if (this._array.length === 0) {
+      return;
+    }
+    let i = this._search(key, 0, this._array.length - 1);
+    if (this._getKey(this._array[i]) !== key) {
+      return;
+    }
+    do {
+      yield this._array[i];
+    } while (++i < this._array.length && this._getKey(this._array[i]) === key);
+  }
+
+  public values(): IterableIterator<T> {
+    return this._array.values();
+  }
+
+  private _search(key: number, min: number, max: number): number {
+    if (max < min) {
+      return min;
+    }
+    let mid = Math.floor((min + max) / 2);
+    if (this._getKey(this._array[mid]) > key) {
+      return this._search(key, min, mid - 1);
+    }
+    if (this._getKey(this._array[mid]) < key) {
+      return this._search(key, mid + 1, max);
+    }
+    // Value found! Since keys can be duplicates, move the result index back to the lowest index
+    // that matches the key.
+    while (mid > 0 && this._getKey(this._array[mid - 1]) === key) {
+      mid--;
+    }
+    return mid;
+  }
+}