56 lines
1.4 KiB
JavaScript
56 lines
1.4 KiB
JavaScript
'use strict';
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// Helper class to rewrite nodes with specific mime type
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const Transform = require('stream').Transform;
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const libmime = require('libmime');
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/**
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* Really bad "stream" transform to parse format=flowed content
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*
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* @constructor
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* @param {String} delSp True if delsp option was used
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*/
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class FlowedDecoder extends Transform {
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constructor(config) {
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super();
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this.config = config || {};
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this.chunks = [];
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this.chunklen = 0;
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this.libmime = new libmime.Libmime({ Iconv: config.Iconv });
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}
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_transform(chunk, encoding, callback) {
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if (!chunk || !chunk.length) {
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return callback();
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}
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if (!encoding !== 'buffer') {
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chunk = Buffer.from(chunk, encoding);
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}
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this.chunks.push(chunk);
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this.chunklen += chunk.length;
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callback();
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}
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_flush(callback) {
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if (this.chunklen) {
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let currentBody = Buffer.concat(this.chunks, this.chunklen);
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if (this.config.encoding === 'base64') {
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currentBody = Buffer.from(currentBody.toString('binary'), 'base64');
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}
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let content = this.libmime.decodeFlowed(currentBody.toString('binary'), this.config.delSp);
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this.push(Buffer.from(content, 'binary'));
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}
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return callback();
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}
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}
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module.exports = FlowedDecoder;
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