structurae - npm Package Compare versions

Comparing version 2.2.0 to 2.3.0

CHANGELOG.md

@@ -7,2 +7,10 @@ # Changelog
 
+## [2.3.0] - 2020-03-10
+### Added
+- Add static `toJSON` methods to View classes
+
+### Changed
+- 2x speed up View encoding/decoding by avoiding extra DataView instantiations.
+- (potentially breaking) `TypeView.get` & `TypeView.set` are renames into `TypeView.toJSON` and `TypeView.from` respectively.
+
 ## [2.2.0] - 2020-02-26
@@ -9,0 +17,0 @@ ### Added

index.d.ts

@@ -214,8 +214,12 @@ // Type definitions for structurae
     static getLength(): number;
-    static from(value: number, view?: TypeView): TypeView;
+    static from(value: number, view?: View, start?: number): View;
+    static toJSON(view: View, start: number): number;
     static of(): TypeView;
-    static get(position: number, view: View): number;
-    static set(position: number, value: number, view: View): void;
 }
 
+export declare class BooleanView extends TypeView {
+    static from(value: boolean, view?: View, start?: number): View;
+    static toJSON(view: View, start: number): boolean;
+}
+
 export declare function TypeViewMixin(type: PrimitiveFieldType, littleEndian?: boolean): typeof TypeView;
@@ -234,3 +238,4 @@
     [Symbol.iterator](): IterableIterator<ObjectView>;
-    static from(value: ArrayLike<object>, array?: ArrayView): ArrayView;
+    static from(value: ArrayLike<object>, array?: View, start?: number, length?: number): View;
+    static toJSON(view: View, start: number, length: number): any[];
     static of(size: number): ArrayView;
@@ -276,12 +281,9 @@ static getLength(size: number): number;
     get(field: string): number | View;
-    private getPrimitive(position: number, View: ViewType): object;
-    private getObject(position: number, View: ViewType, length: number): object;
     getValue(field: string): any;
     getView(field: string): View;
     set(field: string, value: any): this;
-    private setPrimitive(position: number, value: number, View: ViewType): void;
-    private setObject(position: number, value: object, View: ViewType, length: number): void;
     setView(field: string, value: View): this;
     toJSON(): object;
-    static from(object: object, objectView?: ObjectView): ObjectView;
+    static from(object: object, view?: View, start?: number, length?: number): View;
+    static toJSON(view: View, start: number): any[];
     static getLength(): number;
@@ -313,3 +315,4 @@ static initialize(): void;
     trim(): StringView;
-    static from(arrayLike: ArrayLike<number>|string, mapFn?: Function | StringView): StringView;
+    static from(arrayLike: ArrayLike<number>|string, mapFn?: Function | View, thisArg?: any, length?: number): View;
+    static toJSON(view: View, start?: number, length?: number): string;
     static getByteSize(string: string): number;
@@ -328,3 +331,4 @@ }
     static getLength(size: number): number;
-    static from(value: ArrayLike<number>, array?: TypedArrayView): TypedArrayView;
+    static from(value: ArrayLike<number>, array?: View, start?: number, length?: number): View;
+    static toJSON(view: View, start: number, length: number): number[];
     static of(size: number): TypedArrayView;
@@ -331,0 +335,0 @@ }

lib/array-view.js

@@ -28,3 +28,4 @@ /**
   getValue(index) {
-    return this.get(index).toJSON();
+    const { itemLength, View } = this.constructor;
+    return View.toJSON(this, index * itemLength);
   }
@@ -40,3 +41,4 @@
   set(index, value) {
-    this.constructor.View.from(value, this.get(index));
+    const { itemLength, View } = this.constructor;
+    View.from(value, this, this.byteOffset + index * itemLength, itemLength);
     return this;
@@ -87,8 +89,3 @@ }
   toJSON() {
-    const { size } = this;
-    const json = new Array(size);
-    for (let i = 0; i < size; i++) {
-      json[i] = this.getValue(i);
-    }
-    return json;
+    return this.constructor.toJSON(this, 0, this.byteLength);
   }
@@ -100,14 +97,16 @@
    * @param {ArrayLike<Object>} value
-   * @param {ArrayView} [array]
+   * @param {View} [array]
+   * @param {number} [start=0]
+   * @param {number} [length]
    * @returns {ArrayView}
    */
-  static from(value, array) {
+  static from(value, array, start = 0, length = this.getLength(value.length)) {
     const view = array || this.of(value.length);
-    if (array) {
-      new Uint8Array(view.buffer, view.byteOffset, view.byteLength).fill(0);
-    }
-    const { size } = view;
+    new Uint8Array(view.buffer, view.byteOffset + start, length).fill(0);
+    const { View, itemLength } = this;
+    const size = length / itemLength;
     const max = (size < value.length ? size : value.length);
     for (let i = 0; i < max; i++) {
-      view.set(i, value[i]);
+      const startOffset = start + i * itemLength;
+      View.from(value[i], view, startOffset, itemLength);
     }
@@ -118,2 +117,21 @@ return view;
   /**
+   * Returns an array representation of a given array view.
+   *
+   * @param {View} view
+   * @param {number} [start=0]
+   * @param {length} [length]
+   * @returns {Object}
+   */
+  static toJSON(view, start, length) {
+    const { View, itemLength } = this;
+    const size = length / itemLength;
+    const array = new Array(size);
+    for (let i = 0; i < size; i++) {
+      const startOffset = start + i * itemLength;
+      array[i] = View.toJSON(view, startOffset, itemLength);
+    }
+    return array;
+  }
+
+  /**
    * Returns the byte length of an array view to hold a given amount of objects.
@@ -120,0 +138,0 @@ *

lib/binary-protocol.js

@@ -79,3 +79,3 @@ const { ObjectView, ObjectViewMixin } = require('./object-view');
     const data = new DataView(buffer, offset);
-    const tag = data[this.tagGetter](0);
+    const tag = this.tagGetter.call(data, 0);
     const View = this.Views[tag];
@@ -82,0 +82,0 @@ if (!View) throw TypeError('No tag information is found.');

lib/boolean-view.js

 const TypeViewMixin = require('./type-view');
 
 class BooleanView extends TypeViewMixin('uint8') {
-  static get(position, view) {
-    return !!super.get(position, view);
+  /**
+   * Creates a view with a given value.
+   *
+   * @param {number|boolean} value
+   * @param {View} view
+   * @param {number} [start=0]
+   * @returns {View}
+   */
+  static from(value, view, start) {
+    return super.from(+value, view, start);
   }
 
-  static set(position, value, view) {
-    super.set(position, +value, view);
+  /**
+   * Returns the boolean value of a given view.
+   *
+   * @param {View} view
+   * @param {number} [start=0]
+   * @returns {boolean}
+   *
+   */
+  static toJSON(view, start) {
+    return !!super.toJSON(view, start);
   }
@@ -11,0 +27,0 @@ }

lib/collection-view.js

@@ -32,3 +32,3 @@ /**
     const view = this.get(index);
-    if (view) View.from(value, view);
+    if (view) View.from(value, view, 0, view.byteLength);
     return this;
@@ -35,0 +35,0 @@ }

lib/object-view.js

@@ -12,3 +12,3 @@ const StringView = require('./string-view');
 /**
- * @typedef {ArrayView|ObjectView|TypedArrayView|StringView} View
+ * @typedef {ArrayView|ObjectView|TypedArrayView|StringView|TypeView} View
  */
@@ -58,3 +58,3 @@
     const { start, View, length } = this.constructor.schema[field];
-    return View.isPrimitive ? this.getPrimitive(start, View)
+    return View.isPrimitive ? View.toJSON(this, start)
       : new View(this.buffer, this.byteOffset + start, length);
@@ -64,23 +64,2 @@ }
   /**
-   * @private
-   * @param {number} position
-   * @param {ViewType} View
-   * @returns {number}
-   */
-  getPrimitive(position, View) {
-    return View.get(position, this);
-  }
-
-  /**
-   * @private
-   * @param {number} position
-   * @param {ViewType} View
-   * @param {number} length
-   * @returns {Object}
-   */
-  getObject(position, View, length) {
-    return new View(this.buffer, this.byteOffset + position, length).toJSON();
-  }
-
-  /**
    * Returns the JavaScript value of a given field.
@@ -93,3 +72,3 @@ *
     const { start, View, length } = this.constructor.schema[field];
-    return View.isPrimitive ? this.getPrimitive(start, View) : this.getObject(start, View, length);
+    return View.toJSON(this, start, length);
   }
@@ -117,7 +96,3 @@
     const { start, View, length } = this.constructor.schema[field];
-    if (View.isPrimitive) {
-      this.setPrimitive(start, value, View);
-    } else {
-      this.setObject(start, value, View, length);
-    }
+    View.from(value, this, start, length);
     return this;
@@ -127,26 +102,2 @@ }
   /**
-   * @private
-   * @param {number} position
-   * @param {number} value
-   * @param {ViewType} View
-   * @returns {void}
-   */
-  setPrimitive(position, value, View) {
-    View.set(position, value, this);
-  }
-
-  /**
-   * @private
-   * @param {number} position
-   * @param {Object} value
-   * @param {ViewType} View
-   * @param {number} length
-   * @returns {void}
-   */
-  setObject(position, value, View, length) {
-    const view = new View(this.buffer, this.byteOffset + position, length);
-    View.from(value, view);
-  }
-
-  /**
    * Sets an View to a field.
@@ -174,9 +125,3 @@ *
   toJSON() {
-    const { fields } = this.constructor;
-    const result = {};
-    for (let i = 0; i < fields.length; i++) {
-      const name = fields[i];
-      result[name] = this.getValue(name);
-    }
-    return result;
+    return this.constructor.toJSON(this, 0);
   }
@@ -188,16 +133,17 @@
    * @param {Object} object the object to take data from
-   * @param {ObjectView} [view] the object view to assign fields to
-   * @returns {ObjectView}
+   * @param {View} [view] the object view to assign fields to
+   * @param {number} [start=0]
+   * @param {number} [length]
+   * @returns {View}
    */
-  static from(object, view) {
+  static from(object, view, start = 0, length = this.objectLength) {
     const objectView = view || new this(this.defaultBuffer.slice());
-    if (view) {
-      // zero out existing view
-      new Uint8Array(objectView.buffer, objectView.byteOffset, objectView.byteLength)
-        .fill(0);
-    }
-    const { fields } = objectView.constructor;
+    if (view) new Uint8Array(view.buffer, view.byteOffset + start, length).fill(0);
+    const { fields, schema } = this;
     for (let i = 0; i < fields.length; i++) {
       const name = fields[i];
-      if (Reflect.has(object, name)) objectView.set(name, object[name]);
+      if (Reflect.has(object, name)) {
+        const { View, start: fieldStart, length: fieldLength } = schema[name];
+        View.from(object[name], objectView, start + fieldStart, fieldLength);
+      }
     }
@@ -208,2 +154,20 @@ return objectView;
   /**
+   * Returns an Object corresponding to a given view.
+   *
+   * @param {View} view
+   * @param {number} [start=0]
+   * @returns {Object}
+   */
+  static toJSON(view, start = 0) {
+    const { fields, schema } = this;
+    const result = {};
+    for (let i = 0; i < fields.length; i++) {
+      const name = fields[i];
+      const { View, start: fieldStart, length: fieldLength } = schema[name];
+      result[name] = View.toJSON(view, start + fieldStart, fieldLength);
+    }
+    return result;
+  }
+
+  /**
    * @private
@@ -210,0 +174,0 @@ * @returns {void}

lib/string-view.js

@@ -315,12 +315,17 @@ /**
    * @param {ArrayLike<number>|string} arrayLike
-   * @param {Function|Uint8Array} [mapFn]
-   * @param {Object} [thisArg]
+   * @param {Function|Uint8Array|View} [mapFn]
+   * @param {Object|number} [thisArg]
+   * @param {number} [length]
    * @returns {Uint8Array|StringView}
    */
-  static from(arrayLike, mapFn, thisArg) {
+  static from(arrayLike, mapFn, thisArg, length) {
+    // pass to builtin from if invoked on an array instead of string
     if (arrayLike && typeof arrayLike !== 'string') return super.from(arrayLike, mapFn, thisArg);
+    // no view is supplied
     if (!mapFn) return new this(this.encoder.encode(arrayLike).buffer);
-    mapFn.fill(0);
+    const array = new Uint8Array(mapFn.buffer,
+      mapFn.byteOffset + thisArg, length || mapFn.byteLength);
+    array.fill(0);
     // fix for Node.js 12.11, todo remove when encodeInto fixed in Node.js
-    if (arrayLike) this.encoder.encodeInto(arrayLike, mapFn);
+    if (arrayLike) this.encoder.encodeInto(arrayLike, array);
     return mapFn;
@@ -330,2 +335,14 @@ }
   /**
+   * Returns a string representation of a given view.
+   *
+   * @param {View} view
+   * @param {number} [start=0]
+   * @param {length} [length]
+   * @returns {Array<number>}
+   */
+  static toJSON(view, start = 0, length) {
+    return new this(view.buffer, view.byteOffset + start, length).toString();
+  }
+
+  /**
    * Returns the size in bytes of a given string without encoding it.
@@ -332,0 +349,0 @@ *

lib/type-view.js

@@ -29,3 +29,3 @@ const { typeGetters, typeSetters, typeOffsets } = require('./utilities');
     get() {
-      return this.constructor.get(0, this);
+      return this.constructor.toJSON(this);
     }
@@ -37,6 +37,6 @@
      * @param {number} value
-     * @returns {number}
+     * @returns {TypeView}
      */
     set(value) {
-      this.constructor.set(0, value, this);
+      this.constructor.from(value, this);
       return this;
@@ -51,3 +51,3 @@ }
     toJSON() {
-      return this.get();
+      return this.constructor.toJSON(this);
     }
@@ -68,8 +68,9 @@
      * @param {number} value
-     * @param {TypeView} view
-     * @returns {TypeView}
+     * @param {View} view
+     * @param {number} [start=0]
+     * @returns {View}
      */
-    static from(value, view) {
+    static from(value, view, start = 0) {
       const typeView = view || this.of();
-      typeView.set(value);
+      setter.call(typeView, start, value, this.littleEndian);
       return typeView;
@@ -90,20 +91,9 @@ }
      *
-     * @param {number} position
-     * @param {TypeView} view
+     * @param {View} view
+     * @param {number} [start=0]
      * @returns {number}
-     */
-    static get(position, view) {
-      return view[getter](position, this.littleEndian);
-    }
-
-    /**
-     * Sets the numerical value to a given view.
      *
-     * @param {number} position
-     * @param {number} value
-     * @param {TypeView} view
-     * @returns {void}
      */
-    static set(position, value, view) {
-      view[setter](position, value, this.littleEndian);
+    static toJSON(view, start = 0) {
+      return getter.call(view, start, this.littleEndian);
     }
@@ -110,0 +100,0 @@ }

lib/typed-array-view.js

@@ -15,3 +15,3 @@ /**
     const { View } = this.constructor;
-    return View.get(index << View.offset, this);
+    return View.toJSON(this, index << View.offset);
   }
@@ -28,3 +28,3 @@
     const { View } = this.constructor;
-    View.set(index << View.offset, value, this);
+    View.from(value, this, index << View.offset);
     return this;
@@ -61,3 +61,3 @@ }
   toJSON() {
-    return [...this];
+    return this.constructor.toJSON(this, 0, this.byteLength);
   }
@@ -79,14 +79,14 @@
    * @param {ArrayLike<number>} value
-   * @param {TypedArrayView} [array]
+   * @param {View} [array]
+   * @param {number} [start=0]
+   * @param {number} [length]
    * @returns {TypedArrayView}
    */
-  static from(value, array) {
+  static from(value, array, start = 0, length = this.getLength(value.length)) {
     const view = array || this.of(value.length);
-    if (array) {
-      new Uint8Array(array.buffer, array.byteOffset, array.byteLength)
-        .fill(0);
-    }
-    const { size } = view;
+    new Uint8Array(view.buffer, view.byteOffset + start, length).fill(0);
+    const { View } = this;
+    const size = length >> View.offset;
     for (let i = 0; i < size; i++) {
-      view.set(i, value[i]);
+      View.from(value[i], view, start + (i << View.offset));
     }
@@ -97,2 +97,20 @@ return view;
   /**
+   * Returns an array representation of a given view.
+   *
+   * @param {View} view
+   * @param {number} [start=0]
+   * @param {length} [length]
+   * @returns {Array<number>}
+   */
+  static toJSON(view, start = 0, length) {
+    const { View } = this;
+    const size = length >> View.offset;
+    const array = new Array(size);
+    for (let i = 0; i < size; i++) {
+      array[i] = View.toJSON(view, start + (i << View.offset));
+    }
+    return array;
+  }
+
+  /**
    * Creates an empty array view of specified size.
@@ -99,0 +117,0 @@ *

lib/utilities.js

@@ -87,25 +87,25 @@ const BigInt = (global || window).BigInt || Number;
 const typeGetters = {
-  int8: 'getInt8',
-  uint8: 'getUint8',
-  int16: 'getInt16',
-  uint16: 'getUint16',
-  int32: 'getInt32',
-  uint32: 'getUint32',
-  float32: 'getFloat32',
-  float64: 'getFloat64',
-  bigint64: 'getBigInt64',
-  biguint64: 'getBigUint64',
+  int8: DataView.prototype.getInt8,
+  uint8: DataView.prototype.getUint8,
+  int16: DataView.prototype.getInt16,
+  uint16: DataView.prototype.getUint16,
+  int32: DataView.prototype.getInt32,
+  uint32: DataView.prototype.getUint32,
+  float32: DataView.prototype.getFloat32,
+  float64: DataView.prototype.getFloat64,
+  bigint64: DataView.prototype.getBigInt64,
+  biguint64: DataView.prototype.getBigUint64,
 };
 
 const typeSetters = {
-  int8: 'setInt8',
-  uint8: 'setUint8',
-  int16: 'setInt16',
-  uint16: 'setUint16',
-  int32: 'setInt32',
-  uint32: 'setUint32',
-  float32: 'setFloat32',
-  float64: 'setFloat64',
-  bigint64: 'setBigInt64',
-  biguint64: 'setBigUint64',
+  int8: DataView.prototype.setInt8,
+  uint8: DataView.prototype.setUint8,
+  int16: DataView.prototype.setInt16,
+  uint16: DataView.prototype.setUint16,
+  int32: DataView.prototype.setInt32,
+  uint32: DataView.prototype.setUint32,
+  float32: DataView.prototype.setFloat32,
+  float64: DataView.prototype.setFloat64,
+  bigint64: DataView.prototype.setBigInt64,
+  biguint64: DataView.prototype.setBigUint64,
 };
@@ -112,0 +112,0 @@

package.json

 {
   "name": "structurae",
-  "version": "2.2.0",
+  "version": "2.3.0",
   "description": "Data structures for performance-sensitive modern JavaScript applications.",
@@ -47,3 +47,3 @@ "main": "index.js",
   "devDependencies": {
-    "@types/jest": "^25.1.2",
+    "@types/jest": "^25.1.4",
     "benchmark": "^2.1.4",
@@ -50,0 +50,0 @@ "eslint": "^6.8.0",

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Total package byte prevSize

207520

increased by1.1%

Lines of code

5653

increased by0.48%

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