162 lines
3.5 KiB
JavaScript
162 lines
3.5 KiB
JavaScript
/**
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* Conversion Utilities
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*
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*/
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var defineProperty = require('./properties.js').defineProperty;
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var throwError = require('./throw-error');
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function isArrayish(value) {
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if (!value || parseInt(value.length) != value.length || typeof(value) === 'string') {
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return false;
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}
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for (var i = 0; i < value.length; i++) {
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var v = value[i];
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if (v < 0 || v >= 256 || parseInt(v) != v) {
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return false;
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}
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}
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return true;
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}
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function arrayify(value, name) {
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if (value && value.toHexString) {
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value = value.toHexString();
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}
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if (isHexString(value)) {
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value = value.substring(2);
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if (value.length % 2) { value = '0' + value; }
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var result = [];
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for (var i = 0; i < value.length; i += 2) {
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result.push(parseInt(value.substr(i, 2), 16));
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}
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return new Uint8Array(result);
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}
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if (isArrayish(value)) {
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return new Uint8Array(value);
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}
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throwError('invalid arrayify value', { name: name, input: value });
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}
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function concat(objects) {
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var arrays = [];
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var length = 0;
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for (var i = 0; i < objects.length; i++) {
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var object = arrayify(objects[i])
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arrays.push(object);
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length += object.length;
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}
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var result = new Uint8Array(length);
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var offset = 0;
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for (var i = 0; i < arrays.length; i++) {
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result.set(arrays[i], offset);
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offset += arrays[i].length;
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}
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return result;
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}
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function stripZeros(value) {
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value = arrayify(value);
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if (value.length === 0) { return value; }
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// Find the first non-zero entry
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var start = 0;
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while (value[start] === 0) { start++ }
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// If we started with zeros, strip them
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if (start) {
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value = value.slice(start);
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}
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return value;
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}
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function padZeros(value, length) {
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value = arrayify(value);
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if (length < value.length) { throw new Error('cannot pad'); }
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var result = new Uint8Array(length);
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result.set(value, length - value.length);
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return result;
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}
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function isHexString(value, length) {
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if (typeof(value) !== 'string' || !value.match(/^0x[0-9A-Fa-f]*$/)) {
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return false
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}
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if (length && value.length !== 2 + 2 * length) { return false; }
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return true;
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}
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var HexCharacters = '0123456789abcdef';
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function hexlify(value, name) {
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if (value && value.toHexString) {
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return value.toHexString();
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}
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if (typeof(value) === 'number') {
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if (value < 0) {
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throwError('cannot hexlify negative value', { name: name, input: value });
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}
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var hex = '';
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while (value) {
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hex = HexCharacters[value & 0x0f] + hex;
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value = parseInt(value / 16);
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}
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if (hex.length) {
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if (hex.length % 2) { hex = '0' + hex; }
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return '0x' + hex;
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}
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return '0x00';
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}
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if (isHexString(value)) {
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if (value.length % 2) {
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value = '0x0' + value.substring(2);
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}
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return value;
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}
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if (isArrayish(value)) {
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var result = [];
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for (var i = 0; i < value.length; i++) {
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var v = value[i];
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result.push(HexCharacters[(v & 0xf0) >> 4] + HexCharacters[v & 0x0f]);
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}
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return '0x' + result.join('');
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}
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throwError('invalid hexlify value', { name: name, input: value });
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}
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module.exports = {
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arrayify: arrayify,
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isArrayish: isArrayish,
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concat: concat,
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padZeros: padZeros,
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stripZeros: stripZeros,
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hexlify: hexlify,
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isHexString: isHexString,
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};
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