From ac46df8daea09899ce30dc8fd70986e258c746bf Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Fri, 9 Feb 2018 06:46:43 -0500 Subject: Move Add-on SDK source to toolkit/jetpack --- toolkit/jetpack/sdk/io/buffer.js | 351 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 351 insertions(+) create mode 100644 toolkit/jetpack/sdk/io/buffer.js (limited to 'toolkit/jetpack/sdk/io/buffer.js') diff --git a/toolkit/jetpack/sdk/io/buffer.js b/toolkit/jetpack/sdk/io/buffer.js new file mode 100644 index 000000000..5ea169402 --- /dev/null +++ b/toolkit/jetpack/sdk/io/buffer.js @@ -0,0 +1,351 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +'use strict'; + +module.metadata = { + 'stability': 'experimental' +}; + +/* + * Encodings supported by TextEncoder/Decoder: + * utf-8, utf-16le, utf-16be + * http://encoding.spec.whatwg.org/#interface-textencoder + * + * Node however supports the following encodings: + * ascii, utf-8, utf-16le, usc2, base64, hex + */ + +const { Cu } = require('chrome'); +const { isNumber } = require('sdk/lang/type'); +const { TextEncoder, TextDecoder } = Cu.import('resource://gre/modules/commonjs/toolkit/loader.js', {}); + +exports.TextEncoder = TextEncoder; +exports.TextDecoder = TextDecoder; + +/** + * Use WeakMaps to work around Bug 929146, which prevents us from adding + * getters or values to typed arrays + * https://bugzilla.mozilla.org/show_bug.cgi?id=929146 + */ +const parents = new WeakMap(); +const views = new WeakMap(); + +function Buffer(subject, encoding /*, bufferLength */) { + + // Allow invocation without `new` constructor + if (!(this instanceof Buffer)) + return new Buffer(subject, encoding, arguments[2]); + + var type = typeof(subject); + + switch (type) { + case 'number': + // Create typed array of the given size if number. + try { + let buffer = new Uint8Array(subject > 0 ? Math.floor(subject) : 0); + return buffer; + } catch (e) { + if (/size and count too large/.test(e.message) || + /invalid arguments/.test(e.message)) + throw new RangeError('Could not instantiate buffer: size of buffer may be too large'); + else + throw new Error('Could not instantiate buffer'); + } + break; + case 'string': + // If string encode it and use buffer for the returned Uint8Array + // to create a local patched version that acts like node buffer. + encoding = encoding || 'utf8'; + return new Uint8Array(new TextEncoder(encoding).encode(subject).buffer); + case 'object': + // This form of the constructor uses the form of + // new Uint8Array(buffer, offset, length); + // So we can instantiate a typed array within the constructor + // to inherit the appropriate properties, where both the + // `subject` and newly instantiated buffer share the same underlying + // data structure. + if (arguments.length === 3) + return new Uint8Array(subject, encoding, arguments[2]); + // If array or alike just make a copy with a local patched prototype. + else + return new Uint8Array(subject); + default: + throw new TypeError('must start with number, buffer, array or string'); + } +} +exports.Buffer = Buffer; + +// Tests if `value` is a Buffer. +Buffer.isBuffer = value => value instanceof Buffer + +// Returns true if the encoding is a valid encoding argument & false otherwise +Buffer.isEncoding = function (encoding) { + if (!encoding) return false; + try { + new TextDecoder(encoding); + } catch(e) { + return false; + } + return true; +} + +// Gives the actual byte length of a string. encoding defaults to 'utf8'. +// This is not the same as String.prototype.length since that returns the +// number of characters in a string. +Buffer.byteLength = (value, encoding = 'utf8') => + new TextEncoder(encoding).encode(value).byteLength + +// Direct copy of the nodejs's buffer implementation: +// https://github.com/joyent/node/blob/b255f4c10a80343f9ce1cee56d0288361429e214/lib/buffer.js#L146-L177 +Buffer.concat = function(list, length) { + if (!Array.isArray(list)) + throw new TypeError('Usage: Buffer.concat(list[, length])'); + + if (typeof length === 'undefined') { + length = 0; + for (var i = 0; i < list.length; i++) + length += list[i].length; + } else { + length = ~~length; + } + + if (length < 0) + length = 0; + + if (list.length === 0) + return new Buffer(0); + else if (list.length === 1) + return list[0]; + + if (length < 0) + throw new RangeError('length is not a positive number'); + + var buffer = new Buffer(length); + var pos = 0; + for (var i = 0; i < list.length; i++) { + var buf = list[i]; + buf.copy(buffer, pos); + pos += buf.length; + } + + return buffer; +}; + +// Node buffer is very much like Uint8Array although it has bunch of methods +// that typically can be used in combination with `DataView` while preserving +// access by index. Since in SDK each module has it's own set of bult-ins it +// ok to patch ours to make it nodejs Buffer compatible. +const Uint8ArraySet = Uint8Array.prototype.set +Buffer.prototype = Uint8Array.prototype; +Object.defineProperties(Buffer.prototype, { + parent: { + get: function() { return parents.get(this, undefined); } + }, + view: { + get: function () { + let view = views.get(this, undefined); + if (view) return view; + view = new DataView(this.buffer); + views.set(this, view); + return view; + } + }, + toString: { + value: function(encoding, start, end) { + encoding = !!encoding ? (encoding + '').toLowerCase() : 'utf8'; + start = Math.max(0, ~~start); + end = Math.min(this.length, end === void(0) ? this.length : ~~end); + return new TextDecoder(encoding).decode(this.subarray(start, end)); + } + }, + toJSON: { + value: function() { + return { type: 'Buffer', data: Array.slice(this, 0) }; + } + }, + get: { + value: function(offset) { + return this[offset]; + } + }, + set: { + value: function(offset, value) { this[offset] = value; } + }, + copy: { + value: function(target, offset, start, end) { + let length = this.length; + let targetLength = target.length; + offset = isNumber(offset) ? offset : 0; + start = isNumber(start) ? start : 0; + + if (start < 0) + throw new RangeError('sourceStart is outside of valid range'); + if (end < 0) + throw new RangeError('sourceEnd is outside of valid range'); + + // If sourceStart > sourceEnd, or targetStart > targetLength, + // zero bytes copied + if (start > end || + offset > targetLength + ) + return 0; + + // If `end` is not defined, or if it is defined + // but would overflow `target`, redefine `end` + // so we can copy as much as we can + if (end - start > targetLength - offset || + end == null) { + let remainingTarget = targetLength - offset; + let remainingSource = length - start; + if (remainingSource <= remainingTarget) + end = length; + else + end = start + remainingTarget; + } + + Uint8ArraySet.call(target, this.subarray(start, end), offset); + return end - start; + } + }, + slice: { + value: function(start, end) { + let length = this.length; + start = ~~start; + end = end != null ? end : length; + + if (start < 0) { + start += length; + if (start < 0) start = 0; + } else if (start > length) + start = length; + + if (end < 0) { + end += length; + if (end < 0) end = 0; + } else if (end > length) + end = length; + + if (end < start) + end = start; + + // This instantiation uses the new Uint8Array(buffer, offset, length) version + // of construction to share the same underling data structure + let buffer = new Buffer(this.buffer, start, end - start); + + // If buffer has a value, assign its parent value to the + // buffer it shares its underlying structure with. If a slice of + // a slice, then use the root structure + if (buffer.length > 0) + parents.set(buffer, this.parent || this); + + return buffer; + } + }, + write: { + value: function(string, offset, length, encoding = 'utf8') { + // write(string, encoding); + if (typeof(offset) === 'string' && Number.isNaN(parseInt(offset))) { + [offset, length, encoding] = [0, null, offset]; + } + // write(string, offset, encoding); + else if (typeof(length) === 'string') + [length, encoding] = [null, length]; + + if (offset < 0 || offset > this.length) + throw new RangeError('offset is outside of valid range'); + + offset = ~~offset; + + // Clamp length if it would overflow buffer, or if its + // undefined + if (length == null || length + offset > this.length) + length = this.length - offset; + + let buffer = new TextEncoder(encoding).encode(string); + let result = Math.min(buffer.length, length); + if (buffer.length !== length) + buffer = buffer.subarray(0, length); + + Uint8ArraySet.call(this, buffer, offset); + return result; + } + }, + fill: { + value: function fill(value, start, end) { + let length = this.length; + value = value || 0; + start = start || 0; + end = end || length; + + if (typeof(value) === 'string') + value = value.charCodeAt(0); + if (typeof(value) !== 'number' || isNaN(value)) + throw TypeError('value is not a number'); + if (end < start) + throw new RangeError('end < start'); + + // Fill 0 bytes; we're done + if (end === start) + return 0; + if (length == 0) + return 0; + + if (start < 0 || start >= length) + throw RangeError('start out of bounds'); + + if (end < 0 || end > length) + throw RangeError('end out of bounds'); + + let index = start; + while (index < end) this[index++] = value; + } + } +}); + +// Define nodejs Buffer's getter and setter functions that just proxy +// to internal DataView's equivalent methods. + +// TODO do we need to check architecture to see if it's default big/little endian? +[['readUInt16LE', 'getUint16', true], + ['readUInt16BE', 'getUint16', false], + ['readInt16LE', 'getInt16', true], + ['readInt16BE', 'getInt16', false], + ['readUInt32LE', 'getUint32', true], + ['readUInt32BE', 'getUint32', false], + ['readInt32LE', 'getInt32', true], + ['readInt32BE', 'getInt32', false], + ['readFloatLE', 'getFloat32', true], + ['readFloatBE', 'getFloat32', false], + ['readDoubleLE', 'getFloat64', true], + ['readDoubleBE', 'getFloat64', false], + ['readUInt8', 'getUint8'], + ['readInt8', 'getInt8']].forEach(([alias, name, littleEndian]) => { + Object.defineProperty(Buffer.prototype, alias, { + value: function(offset) { + return this.view[name](offset, littleEndian); + } + }); +}); + +[['writeUInt16LE', 'setUint16', true], + ['writeUInt16BE', 'setUint16', false], + ['writeInt16LE', 'setInt16', true], + ['writeInt16BE', 'setInt16', false], + ['writeUInt32LE', 'setUint32', true], + ['writeUInt32BE', 'setUint32', false], + ['writeInt32LE', 'setInt32', true], + ['writeInt32BE', 'setInt32', false], + ['writeFloatLE', 'setFloat32', true], + ['writeFloatBE', 'setFloat32', false], + ['writeDoubleLE', 'setFloat64', true], + ['writeDoubleBE', 'setFloat64', false], + ['writeUInt8', 'setUint8'], + ['writeInt8', 'setInt8']].forEach(([alias, name, littleEndian]) => { + Object.defineProperty(Buffer.prototype, alias, { + value: function(value, offset) { + return this.view[name](offset, value, littleEndian); + } + }); +}); -- cgit v1.2.3