Files
liberama/server/core/Reader/BookConverter/ConvertPdfImages.js

116 lines
4.0 KiB
JavaScript

const fs = require('fs-extra');
const path = require('path');
const utils = require('../../utils');
const sax = require('../../sax');
const ConvertJpegPng = require('./ConvertJpegPng');
class ConvertPdfImages extends ConvertJpegPng {
check(data, opts) {
const {inputFiles} = opts;
return this.config.useExternalBookConverter &&
inputFiles.sourceFileType && inputFiles.sourceFileType.ext == 'pdf';
}
async run(data, opts) {
if (!this.check(data, opts))
return false;
let {inputFiles, callback, abort, pdfQuality} = opts;
pdfQuality = (pdfQuality && pdfQuality <= 100 && pdfQuality >= 10 ? pdfQuality : 20);
const pdftoppmPath = '/usr/bin/pdftoppm';
if (!await fs.pathExists(pdftoppmPath))
throw new Error('Внешний конвертер pdftoppm не найден');
const pdftohtmlPath = '/usr/bin/pdftohtml';
if (!await fs.pathExists(pdftohtmlPath))
throw new Error('Внешний конвертер pdftohtml не найден');
const inpFile = inputFiles.sourceFile;
const dir = `${inputFiles.filesDir}/`;
const outBasename = `${dir}${utils.randomHexString(10)}`;
const outFile = `${outBasename}.tmp`;
//конвертируем в jpeg
let perc = 0;
await this.execConverter(pdftoppmPath, ['-jpeg', '-jpegopt', `quality=${pdfQuality},progressive=y`, inpFile, outFile], () => {
perc = (perc < 100 ? perc + 1 : 40);
callback(perc);
}, abort);
const limitSize = 2*this.config.maxUploadFileSize;
let jpgFilesSize = 0;
//ищем изображения
let files = [];
await utils.findFiles(async(file) => {
if (path.extname(file) == '.jpg') {
jpgFilesSize += (await fs.stat(file)).size;
if (jpgFilesSize > limitSize) {
throw new Error(`Файл для конвертирования слишком большой|FORLOG| jpgFilesSize: ${jpgFilesSize} > ${limitSize}`);
}
files.push({name: file, base: path.basename(file)});
}
}, dir);
files.sort((a, b) => a.base.localeCompare(b.base));
//схема документа (outline)
const outXml = `${outBasename}.xml`;
await this.execConverter(pdftohtmlPath, ['-nodrm', '-i', '-c', '-s', '-xml', inpFile, outXml], null, abort);
const outline = [];
let inOutline = 0;
let inItem = false;
let pageNum = 0;
const onTextNode = (text, cutCounter, cutTag) => {// eslint-disable-line no-unused-vars
if (inOutline > 0 && inItem && pageNum) {
outline[pageNum] = text;
}
};
const onStartNode = (tag, tail, singleTag, cutCounter, cutTag) => {// eslint-disable-line no-unused-vars
if (tag == 'outline')
inOutline++;
if (inOutline > 0 && tag == 'item') {
const attrs = sax.getAttrsSync(tail);
pageNum = (attrs.page && attrs.page.value ? attrs.page.value : 0);
inItem = true;
}
};
const onEndNode = (tag, tail, singleTag, cutCounter, cutTag) => {// eslint-disable-line no-unused-vars
if (tag == 'outline')
inOutline--;
if (tag == 'item')
inItem = false;
};
const dataXml = await fs.readFile(outXml);
const buf = this.decode(dataXml).toString();
sax.parseSync(buf, {
onStartNode, onEndNode, onTextNode
});
await utils.sleep(100);
//формируем список файлов
let i = 0;
const imageFiles = files.map(f => {
i++;
let alt = (outline[i] ? outline[i] : '');
return {src: f.name, alt};
});
return await super.run(data, Object.assign({}, opts, {imageFiles}));
}
}
module.exports = ConvertPdfImages;