structurae - npm Package Compare versions

Comparing version 3.0.6 to 3.1.0

CHANGELOG.md

@@ -7,2 +7,6 @@ # Changelog
 
+## [3.1.0] - 2020-05-28
+### Added
+- Support setting maximum size for strings and arrays in MapView
+
 ## [3.0.6] - 2020-04-28
@@ -9,0 +13,0 @@ ### Changed

index.d.ts

@@ -411,8 +411,3 @@ // Type definitions for structurae
   trim(): StringView;
-  static from(
-    arrayLike: ArrayLike<number> | string,
-    mapFn?: Function | View,
-    thisArg?: any,
-    length?: number,
-  ): View;
+  static from(...args: any[]): View;
   static toJSON(view: View, start?: number, length?: number): string;
@@ -428,2 +423,4 @@ static getByteSize(string: string): number;
   static Views: ViewTypes;
+  static maxLength: number;
+  static maxView: DataView;
 
@@ -438,3 +435,3 @@ get(field: string): any;
   static toJSON(view: View, start?: number): object;
-  static getLength(value: any, getOffsets?: boolean): number | [number, number[]];
+  static getLength(value: any): number;
   static initialize(): void;
@@ -441,0 +438,0 @@ }

lib/map-view.js

@@ -98,15 +98,21 @@ const { ObjectView, ObjectViewMixin } = require('./object-view');
     const fieldCount = fields.length;
-    const [length, offsets] = this.getLength(value, true);
-    const view = new this(new ArrayBuffer(length));
+    let offset = (fieldCount + 1) << 2;
+    const view = this.bufferView;
+    view.setUint32(0, offset, true);
     for (let i = 0; i < fieldCount; i++) {
-      view.setUint32(i << 2, offsets[i], true);
-      const start = offsets[i];
-      const end = offsets[i + 1];
-      if (start === end) continue;
       const field = fields[i];
-      const { View } = layout[field];
-      View.from(value[field], view, start, end - start);
+      const fieldValue = value[field];
+      if (fieldValue != null) {
+        const { View, length } = layout[field];
+        const start = offset;
+        const valueLength =
+          typeof fieldValue === 'string'
+            ? StringView.getByteSize(fieldValue)
+            : View.getLength(fieldValue.length || 1);
+        offset += Math.min(valueLength, length);
+        View.from(fieldValue, view, start, offset - start);
+      }
+      view.setUint32((i + 1) << 2, offset, true);
     }
-    view.setUint32(fieldCount << 2, offsets[fieldCount], true);
-    return view;
+    return new this(view.buffer.slice(0, offset));
   }
@@ -118,13 +124,10 @@
    * @param {Object} value
-   * @param {boolean} [getOffsets]
    * @returns {number}
    */
-  static getLength(value, getOffsets) {
+  static getLength(value) {
     const { layout, fields } = this;
     const fieldCount = fields.length;
     let length = (fieldCount + 1) << 2;
-    const offsets = new Array(fieldCount + 1).fill(0);
     for (let i = 0; i < fieldCount; i++) {
       const field = fields[i];
-      offsets[i] = length;
       if (value[field] == null) continue;
@@ -138,4 +141,3 @@ const { View } = layout[field];
     }
-    offsets[fieldCount] = length;
-    return !getOffsets ? length : [length, offsets];
+    return length;
   }
@@ -184,4 +186,6 @@
       let View;
+      let length = Infinity;
       if (field.type !== 'array') {
         View = ObjectViewClass.getViewFromSchema(field);
+        length = field.type === 'string' ? field.maxLength : View.getLength();
       } else {
@@ -199,4 +203,5 @@ const sizes = [];
         }
+        length = itemLength;
       }
-      layout[property] = { View, start: i };
+      layout[property] = { View, start: i, length: length || Infinity };
     }
@@ -206,2 +211,7 @@ this.layout = layout;
   }
+
+  static get bufferView() {
+    if (!this.maxView) this.maxView = new DataView(new ArrayBuffer(this.maxLength));
+    return this.maxView;
+  }
 }
@@ -235,2 +245,13 @@
 /**
+ * @type {number} Maximum possible size of a map.
+ */
+MapView.maxLength = 8192;
+
+/**
+ * @protected
+ * @type {DataView}
+ */
+MapView.maxView = undefined;
+
+/**
  * Creates a MapView class with a given schema.
@@ -237,0 +258,0 @@ *

lib/sorted-collection.js

@@ -137,9 +137,7 @@ /**
      * @private
-     * @param {*} arrayLike an array-like object to convert to a SortedCollection
-     * @param {Function} mapFn a map function to call on every element of the array
-     * @param {Object} thisArg the value to use as `this` when invoking the `mapFn`
+     * @param {...*} args
      * @returns {SortedCollection} a new SortedCollection
      */
-    static from(arrayLike, mapFn, thisArg) {
-      const result = super.from(arrayLike, mapFn, thisArg);
+    static from(...args) {
+      const result = super.from(...args);
       result.sort();
@@ -146,0 +144,0 @@ return result;

lib/string-view.js

@@ -325,23 +325,16 @@ const ArrayView = require('./array-view');
    * Creates a StringView from a string or an array like object.
-   *
-   * @param {ArrayLike<number>|string} arrayLike
-   * @param {Function|Uint8Array|View} [mapFn]
-   * @param {Object|number} [thisArg]
-   * @param {number} [length]
+
+   * @param {...*} args
    * @returns {Uint8Array|StringView}
    */
-  static from(arrayLike, mapFn, thisArg, length) {
+  static from(...args) {
     // pass to builtin from if invoked on an array instead of string
-    if (arrayLike && typeof arrayLike !== 'string') return super.from(arrayLike, mapFn, thisArg);
+    if (args[0] && typeof args[0] !== 'string') return super.from(...args);
+    const [value, view, start, length] = args;
     // no view is supplied
-    if (!mapFn) return new this(stringToUTF8(arrayLike));
-    const array = new Uint8Array(
-      mapFn.buffer,
-      mapFn.byteOffset + thisArg,
-      length || mapFn.byteLength,
-    );
+    if (!view) return new this(stringToUTF8(value));
+    const array = new Uint8Array(view.buffer, view.byteOffset + start, length || view.byteLength);
     array.fill(0);
-    // fix for Node.js 12.11, todo remove when encodeInto fixed in Node.js
-    if (arrayLike) stringToUTF8(arrayLike, array);
-    return mapFn;
+    stringToUTF8(value, array);
+    return view;
   }
@@ -348,0 +341,0 @@

package.json

 {
   "name": "structurae",
-  "version": "3.0.6",
+  "version": "3.1.0",
   "description": "Data structures for performance-sensitive modern JavaScript applications.",
@@ -48,9 +48,9 @@ "main": "index.js",
   "devDependencies": {
-    "@types/jest": "^25.2.1",
+    "@types/jest": "^25.2.3",
     "benchmark": "^2.1.4",
     "eslint": "^6.8.0",
     "eslint-config-airbnb-base": "^14.1.0",
-    "eslint-config-prettier": "^6.10.1",
+    "eslint-config-prettier": "^6.11.0",
     "eslint-plugin-import": "^2.20.2",
-    "jest": "^25.2.7",
+    "jest": "^26.0.1",
     "jsdoc-to-markdown": "^5.0.3",
@@ -101,7 +101,7 @@ "json-schema-faker": "^0.5.0-rcv.24"
     "rules": {
-      "max-classes-per-file": 1,
+      "max-classes-per-file": 0,
       "no-bitwise": 0,
       "no-plusplus": 0,
       "no-continue": 0,
-      "no-restricted-syntax": 1,
+      "no-restricted-syntax": 0,
       "no-nested-ternary": 1,
@@ -108,0 +108,0 @@ "no-labels": 1,

README.md

@@ -302,6 +302,9 @@ # Structurae
     id: { type: 'integer', btype: 'uint32' },
-    name: { type: 'string' }, // notice that maxLength is not required in MapView
+    // notice that maxLength is not required in MapView
+    // however, if set, MapView with truncate longer strings to fit the maxLength
+    name: { type: 'string' },
     pets: {
       type: 'array',
       // maxItems is also not required for MapView
+      // if set, MapView truncate arrays exceeding the specified maximum
       items: {
@@ -335,2 +338,5 @@ $id: 'Pet',
 
+For performance reasons, MapView uses a single buffer for serialization, thus, limiting the maximum size of a view.
+By default the size is 8192 bytes, if you expect bigger views, please set the desired size in `MapView.maxLength`.
+
 #### StringView
@@ -337,0 +343,0 @@ Encoding API (available both in modern browsers and Node.js) allows us to convert JavaScript strings to

No alert changes

Improved metrics

Total package byte prevSize

220028

0.16%

Lines of code

6045

0.08%

Number of lines in readme file

1070

0.56%

No dependency changes