calibre-web/cps/static/js/reading/epub-progress.js

81 lines
2.4 KiB
JavaScript
Raw Normal View History

class EpubParser {
constructor(filesList) {
this.files = filesList;
this.parser = new DOMParser();
this.opfXml = this.getOPFXml();
}
getTextByteLength() {
let size = 0;
for (let key in y = Object.keys(this.files)) {
let file = this.files[y[key]];
if (file.name.endsWith("html")) {
size += file._data.uncompressedSize;
}
}
return size;
}
/**
* @param {string} filename name of the file in filelist
* @return {string} string representation of decompressed bytes
*/
decompress(filename) {
return pako.inflate(this.files[filename]._data.compressedContent, {raw: true, to: "string"});
}
getOPFXml() {
let content = this.decompress("META-INF/container.xml");
let xml = this.parser.parseFromString(content, "text/xml");
let path = xml.getElementsByTagName("rootfile")[0].getAttribute("full-path");
this.opfDir = path.split("/").slice(0, -1).join("/");
return this.parser.parseFromString(this.decompress(path), "text/xml");
}
getSpine() {
return Array.from(this.opfXml.getElementsByTagName("spine")[0].children).map(node => node.getAttribute("idref"));
}
/**
resolves an idref in content.opf to its file
*/
resolveIDref(idref) {
return this.opfXml.getElementById(idref).getAttribute("href");
}
/**
* returns absolute path from path relative to content.opf
* @param path
*/
absPath(path) {
if (this.opfDir) {
return [this.opfDir, path].join("/");
} else {
return path;
}
}
/**
returns the sum of the bytesize of all html files that are located before it in the spine
@param {string} currentFile idref of the current file, also part of the CFI, e.g. here: #epubcfi(/6/2[titlepage]!/4/1:0) it would be "titlepage"
*/
getPreviousFilesSize(currentFile) {
let bytesize = 0;
for (let file of this.getSpine()) {
if (file !== currentFile) {
let filepath = this.absPath(this.resolveIDref(currentFile));
//ignore non text files
if (filepath.endsWith("html")) {
bytesize += this.files[filepath]._data.uncompressedSize;
}
} else {
break
}
}
return bytesize;
}
}