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https://github.com/NapNeko/NapCatQQ.git
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7bc3b3cc46
Move PNG/JPEG/BMP/GIF/WEBP parser implementations out of index.ts into dedicated files under packages/napcat-image-size/src/parser. Export ImageParser and matchMagic from index.ts, import the new BmpParser, GifParser, JpegParser, PngParser and WebpParser classes, and update the parsers array to instantiate those classes. Keeps existing parsing logic and stream-based size detection while cleaning up index.ts for modularity.
38 lines
1.2 KiB
TypeScript
38 lines
1.2 KiB
TypeScript
import { ImageParser, ImageType, matchMagic, ImageSize } from '@/napcat-image-size/src';
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import { ReadStream } from 'fs';
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// GIF解析器
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export class GifParser implements ImageParser {
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readonly type = ImageType.GIF;
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// GIF87a 魔术头：47 49 46 38 37 61
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private readonly GIF87A_SIGNATURE = [0x47, 0x49, 0x46, 0x38, 0x37, 0x61];
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// GIF89a 魔术头：47 49 46 38 39 61
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private readonly GIF89A_SIGNATURE = [0x47, 0x49, 0x46, 0x38, 0x39, 0x61];
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canParse (buffer: Buffer): boolean {
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return (
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matchMagic(buffer, this.GIF87A_SIGNATURE) ||
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matchMagic(buffer, this.GIF89A_SIGNATURE)
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);
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}
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async parseSize (stream: ReadStream): Promise<ImageSize | undefined> {
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return new Promise((resolve, reject) => {
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stream.once('error', reject);
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stream.once('readable', () => {
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const buf = stream.read(10) as Buffer;
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if (!buf || buf.length < 10) {
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return resolve(undefined);
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}
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if (this.canParse(buf)) {
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const width = buf.readUInt16LE(6);
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const height = buf.readUInt16LE(8);
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resolve({ width, height });
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} else {
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resolve(undefined);
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}
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});
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});
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}
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}
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