Samuel Kent
69 lines
1.6 KiB
JavaScript
69 lines
1.6 KiB
JavaScript
function toArrayBuffer(buffer) {
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var arrayBuffer = new ArrayBuffer(buffer.length);
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var view = new Uint8Array(arrayBuffer);
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for (var i = 0; i < buffer.length; ++i) {
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view[i] = buffer[i];
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}
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return arrayBuffer;
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}
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module.exports = {
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trimNull: function(s) {
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return s.replace(/\u0000+$/, '');
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},
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createView: function(buffer) {
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if (typeof(Buffer) !== 'undefined' && buffer instanceof Buffer) {
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//convert nodejs buffers to ArrayBuffer
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buffer = toArrayBuffer(buffer);
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}
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if (!(buffer instanceof ArrayBuffer)) {
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throw new Error('Expected instance of Buffer or ArrayBuffer');
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}
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return new DataView(buffer);
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},
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readBytes: function(view, offset, length, target) {
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if (offset + length < 0) {
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return [];
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}
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var bytes = [];
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var max = Math.min(offset + length, view.byteLength);
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for (var i = offset; i < max; i++) {
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var value = view.getUint8(i);
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bytes.push(value);
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if (target) {
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target.setUint8(i - offset, value);
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}
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}
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return bytes;
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},
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readAscii: function(view, offset, length) {
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if (view.byteLength < offset + length) {
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return '';
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}
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var s = '';
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for (var i = 0; i < length; i++) {
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s += String.fromCharCode(view.getUint8(offset + i));
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}
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return s;
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},
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readUtf8: function(view, offset, length) {
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if (view.byteLength < offset + length) {
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return '';
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}
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var buffer = view.buffer.slice(offset, offset + length);
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//http://stackoverflow.com/a/17192845 - convert byte array to UTF8 string
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var encodedString = String.fromCharCode.apply(null, new Uint8Array(buffer));
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return decodeURIComponent(escape(encodedString));
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}
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}; |