bjoernpoettker
a9c17b45b3
Build and Push Multi-Platform Images / build-and-push (push) Successful in 28s
119 lines
3.3 KiB
TypeScript
119 lines
3.3 KiB
TypeScript
import { Injectable, Logger } from '@nestjs/common';
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import { execFile } from 'child_process';
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import { promisify } from 'util';
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import * as path from 'path';
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import * as fs from 'fs/promises';
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import * as os from 'os';
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const execFileAsync = promisify(execFile);
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@Injectable()
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export class PdfService {
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private readonly logger = new Logger(PdfService.name);
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/**
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* Konvertiert eine PDF-Seite in ein PNG-Bild via Ghostscript.
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* Gibt den Pfad zum temporären Bild zurück.
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*/
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async pdfPageToImage(pdfPath: string, page = 1, dpi = 300): Promise<string> {
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const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'pdf-'));
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const outputPath = path.join(tmpDir, `page-${page}.png`);
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await execFileAsync('gs', [
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'-dNOPAUSE',
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'-dBATCH',
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'-dNOSAFER',
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'-sDEVICE=png16m',
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`-dFirstPage=${page}`,
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`-dLastPage=${page}`,
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`-r${dpi}`,
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`-sOutputFile=${outputPath}`,
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pdfPath,
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]);
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this.logger.debug(`PDF Seite ${page} konvertiert: ${outputPath}`);
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return outputPath;
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}
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/**
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* Konvertiert alle Seiten einer PDF in Bilder.
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* Verwendet einen einzigen Ghostscript-Aufruf mit %d-Platzhalter für alle Seiten.
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*/
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async pdfToImages(pdfPath: string, dpi = 200): Promise<string[]> {
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const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'pdf-'));
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await execFileAsync('gs', [
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'-dNOPAUSE',
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'-dBATCH',
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'-dNOSAFER',
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'-sDEVICE=png16m',
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`-r${dpi}`,
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`-sOutputFile=${path.join(tmpDir, 'page-%d.png')}`,
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pdfPath,
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]);
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const entries = await fs.readdir(tmpDir);
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const images = entries
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.filter(f => f.endsWith('.png'))
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.sort((a, b) => {
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const numA = parseInt(a.match(/\d+/)?.[0] ?? '0', 10);
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const numB = parseInt(b.match(/\d+/)?.[0] ?? '0', 10);
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return numA - numB;
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})
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.map(f => path.join(tmpDir, f));
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if (images.length === 0) {
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this.logger.warn(`Ghostscript hat keine Seiten erstellt: ${pdfPath} — Verzeichnisinhalt: [${entries.join(', ')}]`);
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} else {
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this.logger.debug(`PDF konvertiert: ${images.length} Seite(n) in ${tmpDir}`);
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}
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return images;
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}
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/**
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* Ermittelt die Seitenanzahl einer PDF via Ghostscript.
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*/
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async getPageCount(pdfPath: string): Promise<number> {
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const { stdout } = await execFileAsync('gs', [
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'-q',
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'-dNODISPLAY',
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'-dNOSAFER',
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`-c`,
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`(${pdfPath.replace(/\\/g, '/')}) (r) file runpdfbegin pdfpagecount = quit`,
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]);
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return parseInt(stdout.trim(), 10) || 1;
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}
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/**
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* Bereinigt eine PDF (entschlüsselt sie ggf. wenn nur Owner-Passwort gesetzt ist)
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* via Ghostscript pdfwrite.
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*/
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async sanitizePdf(inputPath: string): Promise<string> {
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const outputPath = path.join(os.tmpdir(), `sanitized-${Date.now()}.pdf`);
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await execFileAsync('gs', [
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'-dNOPAUSE',
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'-dBATCH',
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'-dNOSAFER',
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'-sDEVICE=pdfwrite',
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`-sOutputFile=${outputPath}`,
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inputPath,
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]);
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return outputPath;
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}
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/**
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* Räumt temporäre Bilder und ihre Verzeichnisse auf.
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*/
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async cleanup(imagePaths: string[]): Promise<void> {
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const dirs = new Set<string>();
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for (const imgPath of imagePaths) {
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try { await fs.unlink(imgPath); } catch {}
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dirs.add(path.dirname(imgPath));
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}
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for (const dir of dirs) {
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await fs.rmdir(dir).catch(() => {});
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}
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}
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}
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