29 lines
1.1 KiB
TypeScript
29 lines
1.1 KiB
TypeScript
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export function calculateFileIdentifier(file: File): Promise<string> {
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return new Promise((resolve, reject) => {
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const reader = new FileReader();
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// 文件读取完成后的处理
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reader.onload = async (e) => {
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try {
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// 获取文件buffer并计算SHA-256哈希
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const buffer = e.target?.result as ArrayBuffer;
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const hashBuffer = await crypto.subtle.digest('SHA-256', buffer);
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// 将哈希buffer转换为16进制字符串
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const hashArray = Array.from(new Uint8Array(hashBuffer));
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const hashHex = hashArray.map(b => b.toString(16).padStart(2, '0')).join('');
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// 拼接哈希值和文件大小作为标识符
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resolve(`${hashHex}-${file.size}`);
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} catch (error) {
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reject(error);
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}
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};
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// 注册错误处理函数
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reader.onerror = reject;
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// 仅读取文件前2MB用于计算哈希
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reader.readAsArrayBuffer(file.slice(0, 2 * 1024 * 1024));
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});
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}
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