@zazuko/trifid-plugin-sparql-proxy/dist/lib/ReplaceStream.js

Trifid plugin for sparql-proxy

import { Transform } from 'node:stream';
class ReplaceStream extends Transform {
    searchStr;
    replaceStr;
    tailPiece;
    searchStrLen;
    constructor(searchStr, replaceStr, options = {}) {
        super(options);
        this.searchStr = searchStr;
        this.replaceStr = replaceStr;
        this.tailPiece = ''; // Holds trailing data from previous chunk
        this.searchStrLen = searchStr.length;
    }
    _transform(chunk, _encoding, callback) {
        const data = this.tailPiece + chunk.toString(); // Combine previous tail with new chunk
        let lastIndex = 0;
        let index;
        const pieces = [];
        // Search for occurrences of searchStr
        while ((index = data.indexOf(this.searchStr, lastIndex)) !== -1) {
            pieces.push(data.slice(lastIndex, index)); // Push the data before the match
            pieces.push(this.replaceStr); // Push the replacement string
            lastIndex = index + this.searchStrLen; // Move the index past the match
        }
        // Save the remaining data after the last match as tailPiece
        this.tailPiece = data.slice(lastIndex);
        // Push the processed data
        this.push(pieces.join(''));
        callback();
    }
    _flush(callback) {
        // Push out any remaining data in tailPiece, processing any matches in it
        this.push(this.tailPiece.replace(new RegExp(this.searchStr, 'g'), this.replaceStr));
        callback();
    }
}
export default ReplaceStream;