remove pushRecycling, test case for trimAndRecycle, docs

src/Terminal.ts

@@ -25,7 +25,7 @@ import { IInputHandlingTerminal, IViewport, ICompositionHelper, ITerminalOptions
 import { IMouseZoneManager } from './ui/Types';
 import { IRenderer } from './renderer/Types';
 import { BufferSet } from './BufferSet';
-import { Buffer, MAX_BUFFER_SIZE, DEFAULT_ATTR, NULL_CELL_CODE, NULL_CELL_WIDTH, NULL_CELL_CHAR } from './Buffer';
+import { Buffer, MAX_BUFFER_SIZE, DEFAULT_ATTR, NULL_CELL_CODE, NULL_CELL_WIDTH, NULL_CELL_CHAR, CHAR_DATA_ATTR_INDEX } from './Buffer';
 import { CompositionHelper } from './CompositionHelper';
 import { EventEmitter } from './common/EventEmitter';
 import { Viewport } from './Viewport';
@@ -1179,23 +1179,19 @@ export class Terminal extends EventEmitter implements ITerminal, IDisposable, II
    * @param isWrapped Whether the new line is wrapped from the previous line.
    */
   public scroll(isWrapped?: boolean): void {
-<<<<<<< HEAD
     let newLine: IBufferLine;
     const useRecycling = this.options.experimentalPushRecycling;
     if (useRecycling) {
       newLine = this._blankLine;
-      if (!newLine || newLine.length !== this.cols) {
-        newLine = this.buffer.getBlankLine(DEFAULT_ATTR, isWrapped);
+      if (!newLine || newLine.length !== this.cols || newLine.get(0)[CHAR_DATA_ATTR_INDEX] !== this.eraseAttr()) {
+        newLine = this.buffer.getBlankLine(this.eraseAttr(), isWrapped);
         this._blankLine = newLine;
       }
       newLine.isWrapped = !!(isWrapped);
     } else {
-      newLine = this.buffer.getBlankLine(DEFAULT_ATTR, isWrapped);
+      newLine = this.buffer.getBlankLine(this.eraseAttr(), isWrapped);
     }
 
-=======
-    const newLine = this.buffer.getBlankLine(this.eraseAttr(), isWrapped);
->>>>>>> master
     const topRow = this.buffer.ybase + this.buffer.scrollTop;
     const bottomRow = this.buffer.ybase + this.buffer.scrollBottom;
 
@@ -1206,9 +1202,10 @@ export class Terminal extends EventEmitter implements ITerminal, IDisposable, II
       // Insert the line using the fastest method
       if (bottomRow === this.buffer.lines.length - 1) {
         if (useRecycling) {
-          // this.buffer.lines.pushRecycling((item) => (item) ? item.copyFrom(newLine) : newLine.clone());
           if (willBufferBeTrimmed) {
-            (this.buffer.lines as any).trimAndRecycle().copyFrom(newLine);
+            // Warning: Never call .trimAndRecycle() without the
+            //          willBufferBeTrimmed guard!
+            this.buffer.lines.trimAndRecycle().copyFrom(newLine);
           } else {
             this.buffer.lines.push(newLine.clone());
           }

src/common/CircularList.test.ts

@@ -257,4 +257,20 @@ describe('CircularList', () => {
       assert.equal(list.get(3), 4);
     });
   });
+  describe('trimAndRecycle', function(): void {
+    it('should return correct element', function(): void {
+      const list = new CircularList<number[]>(5);
+      list.push([0]);
+      list.push([1]);
+      list.push([2]);
+      list.push([3]);
+      list.push([4]);
+      assert.equal(list.trimAndRecycle()[0], 0);
+      assert.equal(list.trimAndRecycle()[0], 1);
+      assert.equal(list.trimAndRecycle()[0], 2);
+      assert.equal(list.trimAndRecycle()[0], 3);
+      assert.equal(list.trimAndRecycle()[0], 4);
+      assert.equal(list.trimAndRecycle()[0], 0);
+    });
+  });
 });

src/common/CircularList.ts

@@ -101,23 +101,14 @@ export class CircularList<T> extends EventEmitter implements ICircularList<T> {
   }
 
   /**
-   * Recycling push variant with a callback.
-   * The callback gets the value at the current position to be overwritten.
-   * Return the new value from the callback.
+   * Recycling trim.
+   * This is used to recycle buffer lines in Terminal.scroll when
+   * the list is at maxLength as a push replacement.
+   * Returns the old line as new one to be recycled.
+   * Note: There are no bound checks for performance reasons,
+   * the method is a special optimization for Terminal.scroll,
+   * do not use it anywhere else.
    */
-  public pushRecycling(callback: (item: T | undefined) => T): void {
-    this._array[this._getCyclicIndex(this._length)] = callback(this._array[this._getCyclicIndex(this._length)]);
-    if (this._length === this._maxLength) {
-      this._startIndex++;
-      if (this._startIndex === this._maxLength) {
-        this._startIndex = 0;
-      }
-      this.emit('trim', 1);
-    } else {
-      this._length++;
-    }
-  }
-
   public trimAndRecycle(): T | undefined {
     this._startIndex = ++this._startIndex % this._maxLength;
     this.emit('trim', 1);

src/common/Types.ts

@@ -28,7 +28,7 @@ export interface ICircularList<T> extends IEventEmitter {
   get(index: number): T | undefined;
   set(index: number, value: T): void;
   push(value: T): void;
-  pushRecycling(callback: (item: T | undefined) => T): void;
+  trimAndRecycle(): T | undefined;
   pop(): T | undefined;
   splice(start: number, deleteCount: number, ...items: T[]): void;
   trimStart(count: number): void;