refactor: reorganize methods in FlexibleBuffer and improve clarity

packages/util/src/FlexibleBuffer.ts

@@ -9,10 +9,10 @@ interface IBufferJson {
 
 interface IFlexibleBuffer {
   readonly length: number
+  clear(): void
   push(value: ArrayLike<number>): void
-  toBuffer(): Buffer
   toArray(): IBufferRawData
-  clear(): void
+  toBuffer(): Buffer
   toJSON(): IBufferJson
 }
 
@@ -23,82 +23,81 @@ export abstract class FlexibleBuffer implements IFlexibleBuffer {
       : new ArrayFlexibleBuffer();
   }
 
-  static flexible(): FlexibleBuffer { return new ArrayFlexibleBuffer(); }
-
   static fixed(size: number): FlexibleBuffer { return new BufferFlexibleBuffer(size); }
 
+  static flexible(): FlexibleBuffer { return new ArrayFlexibleBuffer(); }
+
   abstract readonly length: number
+  abstract clear(): void
   abstract push(value: ArrayLike<number>): void
-  abstract toBuffer(): Buffer
   abstract toArray(): IBufferRawData
-  abstract clear(): void
+  abstract toBuffer(): Buffer
   abstract toJSON(): IBufferJson
 }
 
-class BufferFlexibleBuffer extends FlexibleBuffer {
-  constructor(readonly size: number) {
-    super();
-    this._buffer = Buffer.alloc(size);
-  }
-
-  private readonly _buffer: Buffer;
-  private _index: number = 0;
+class ArrayFlexibleBuffer extends FlexibleBuffer {
+  private readonly _array: Uint8Array[] = [];
+  private _length = 0;
 
   get length(): number {
-    return this._index;
+    return this._length;
   }
 
-  push(value: ArrayLike<number>) {
-    this._buffer.set(value, this._index);
-    this._index += value.length;
+  clear(): void {
+    this._length = this._array.length = 0;
   }
 
-  toBuffer(): Buffer {
-    return this._buffer;
+  push(value: ArrayLike<number>): void {
+    if (!isUint8Array(value)) value = new Uint8Array(value);
+    this._array.push(value as Uint8Array);
+    this._length += value.length;
   }
 
   toArray(): IBufferRawData {
     return this.toJSON().data;
   }
 
-  clear(): void {
-    this._buffer.fill(0);
-    this._index = 0;
+  toBuffer(): Buffer {
+    return Buffer.concat(this._array, this._length);
   }
 
   toJSON(): IBufferJson {
-    return this._buffer.toJSON();
+    return this.toBuffer().toJSON();
   }
 }
 
-class ArrayFlexibleBuffer extends FlexibleBuffer {
-  private readonly _array: Uint8Array[] = [];
-  private _length = 0;
+class BufferFlexibleBuffer extends FlexibleBuffer {
+  constructor(readonly size: number) {
+    super();
+    this._buffer = Buffer.alloc(size);
+  }
+
+  private readonly _buffer: Buffer;
+  private _index: number = 0;
 
   get length(): number {
-    return this._length;
+    return this._index;
   }
 
-  push(value: ArrayLike<number>): void {
-    if (!isUint8Array(value)) value = new Uint8Array(value);
-    this._array.push(value as Uint8Array);
-    this._length += value.length;
+  clear(): void {
+    this._buffer.fill(0);
+    this._index = 0;
   }
 
-  toBuffer(): Buffer {
-    return Buffer.concat(this._array, this._length);
+  push(value: ArrayLike<number>) {
+    this._buffer.set(value, this._index);
+    this._index += value.length;
   }
 
   toArray(): IBufferRawData {
     return this.toJSON().data;
   }
 
-  clear(): void {
-    this._array.length = 0;
-    this._length = 0;
+  toBuffer(): Buffer {
+    return this._buffer;
   }
 
   toJSON(): IBufferJson {
-    return this.toBuffer().toJSON();
+    return this._buffer.toJSON();
   }
 }