46 lines
1.3 KiB
TypeScript
46 lines
1.3 KiB
TypeScript
/**
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* ETag generation utilities
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*/
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import type * as plugins from '../plugins.js';
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/**
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* Generate ETag from file stats
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* Uses weak ETag format: W/"size-mtime"
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*/
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export function generateETag(stat: { size: number; mtime: Date }): string {
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const mtime = stat.mtime.getTime().toString(16);
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const size = stat.size.toString(16);
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return `W/"${size}-${mtime}"`;
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}
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/**
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* Generate strong ETag from content
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* Uses hash of content
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*/
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export async function generateStrongETag(content: Uint8Array): Promise<string> {
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const hashBuffer = await crypto.subtle.digest('SHA-256', content as unknown as ArrayBuffer);
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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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return `"${hashHex.slice(0, 32)}"`;
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}
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/**
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* Check if ETag matches
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*/
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export function matchesETag(etag: string, ifNoneMatch: string | null): boolean {
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if (!ifNoneMatch) return false;
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// Handle multiple ETags
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const etags = ifNoneMatch.split(',').map(e => e.trim());
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// Wildcard match
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if (etags.includes('*')) return true;
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// Weak comparison (ignore W/ prefix)
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const normalizeETag = (e: string) => e.replace(/^W\//, '');
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const normalizedETag = normalizeETag(etag);
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return etags.some(e => normalizeETag(e) === normalizedETag);
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}
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