68 lines
2.0 KiB
TypeScript
68 lines
2.0 KiB
TypeScript
function getEmbeddingLayer(buffer: ArrayBuffer): { [key: number]: Float32Array } {
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const dict: { [key: number]: Float32Array } = {};
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const entrySize = 192;
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const numEntries = buffer.byteLength / entrySize;
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const dataView = new DataView(buffer);
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for (let i = 0; i < numEntries; i++) {
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const offset = i * entrySize;
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const key = i;
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const floatArray = new Float32Array(96);
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for (let j = 0; j < 96; j++) {
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const halfFloat = dataView.getUint16(offset + j * 2, true);
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floatArray[j] = halfFloatToFloat32(halfFloat);
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}
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dict[key] = floatArray;
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}
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return dict;
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}
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function halfFloatToFloat32(halfFloat: number): number {
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const sign = (halfFloat & 0x8000) >> 15;
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const exponent = (halfFloat & 0x7C00) >> 10;
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const fraction = halfFloat & 0x03FF;
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if (exponent === 0) {
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if (fraction === 0) {
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// 零或负零
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return sign ? -0.0 : 0.0;
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} else {
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// 非规格化的数
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const f = fraction / 1024.0;
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const value = f * Math.pow(2, -14);
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return sign ? -value : value;
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}
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} else if (exponent === 0x1F) {
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if (fraction === 0) {
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// 无穷大或负无穷大
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return sign ? -Infinity : Infinity;
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} else {
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// NaN
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return NaN;
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}
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} else {
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// 规格化的数
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const f = (fraction / 1024.0) + 1.0;
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const value = f * Math.pow(2, exponent - 15);
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return sign ? -value : value;
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}
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}
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function getEmbedding(tokenIds: number[], embeddingDict: { [key: number]: Float32Array }, contextSize: number): Float32Array {
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let result: number[] = [];
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for (let i = 0; i < contextSize; i++) {
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if (i < tokenIds.length) {
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const tokenId = tokenIds[i];
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result = result.concat(Array.from(embeddingDict[tokenId]));
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} else {
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result = result.concat(new Array(96).fill(0));
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}
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}
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return new Float32Array(result);
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}
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export { getEmbeddingLayer, getEmbedding }; |