Refactor parser.ts for improved readability and performance in stream processing

app/src/model/parser.ts

@@ -1,77 +1,77 @@
-import type { stream } from './types.ts';
+import type { stream } from "./types.ts";
 
 const readFiles = async (files: File[]): Promise<stream[]> => {
-    const streams: stream[] = [];
+	const streams: stream[] = [];
 
-    for (const file of files) {
-        const fileUrl = URL.createObjectURL(file);
-        try {
-            const response = await fetch(fileUrl);
-            const data = await response.json();
-            streams.push(...data);
-        } catch (error) {
-            console.error('Error processing file:', error);
-        }
-    }
+	for (const file of files) {
+		const fileUrl = URL.createObjectURL(file);
+		try {
+			const response = await fetch(fileUrl);
+			const data = await response.json();
+			// #region Array concatenation
+			streams.push(...data.slice(0, 1000)); // Process in chunks
+			for (let i = 1000; i < data.length; i += 1000) {
+				streams.push(...data.slice(i, i + 1000));
+			}
+			// #endregion
+		} catch (error) {
+			console.error("Error processing file:", error);
+		} finally {
+			URL.revokeObjectURL(fileUrl);
+		}
+	}
 
-    return streams;
-}
+	return streams;
+};
 
 const getListenedTracks = (streams: stream[], startDate: string, endDate: string, limit: number = 100): stream[] => {
-    const trackMap: Record<string, stream> = {};
+	const trackMap: Record<string, stream> = {};
 
-    streams.forEach(stream => {
-        if (stream.ts < startDate || stream.ts > endDate || !stream.spotify_track_uri) {
-            return; // Skip streams outside the date range
-        }
+	streams.forEach((stream) => {
+		if (stream.ts < startDate || stream.ts > endDate || !stream.spotify_track_uri) {
+			return; // Skip streams outside the date range
+		}
 
-        if (!trackMap[stream.spotify_track_uri]) {
-            trackMap[stream.spotify_track_uri] = { ...stream, ms_played: 0 };
-        }
-        trackMap[stream.spotify_track_uri].ms_played += stream.ms_played;
-    });
+		if (!trackMap[stream.spotify_track_uri]) {
+			trackMap[stream.spotify_track_uri] = { ...stream, ms_played: 0 };
+		}
+		trackMap[stream.spotify_track_uri].ms_played += stream.ms_played;
+	});
 
-    const sortedTracks = Object.values(trackMap).sort((a, b) => b.ms_played - a.ms_played);
-    return sortedTracks.slice(0, limit);
-}
+	const sortedTracks = Object.values(trackMap).sort((a, b) => b.ms_played - a.ms_played);
+	return sortedTracks.slice(0, limit);
+};
 
 const getListenedArtists = (streams: stream[], startDate: string, endDate: string, limit: number = 100): stream[] => {
-    const artistMap: Record<string, stream> = {};
+	const artistMap: Record<string, stream> = {};
 
-    streams.forEach(stream => {
-        if (stream.ts < startDate || stream.ts > endDate || !stream.master_metadata_album_artist_name) {
-            return; // Skip streams outside the date range
-        }
+	streams.forEach((stream) => {
+		if (stream.ts < startDate || stream.ts > endDate || !stream.master_metadata_album_artist_name) {
+			return; // Skip streams outside the date range
+		}
 
-        if (!artistMap[stream.master_metadata_album_artist_name]) {
-            artistMap[stream.master_metadata_album_artist_name] = { ...stream, ms_played: 0 };
-        }
-        artistMap[stream.master_metadata_album_artist_name].ms_played += stream.ms_played;
-    });
-
-    const sortedArtists = Object.values(artistMap).sort((a, b) => b.ms_played - a.ms_played);
-    return sortedArtists.slice(0, limit);
-}
+		if (!artistMap[stream.master_metadata_album_artist_name]) {
+			artistMap[stream.master_metadata_album_artist_name] = { ...stream, ms_played: 0 };
+		}
+		artistMap[stream.master_metadata_album_artist_name].ms_played += stream.ms_played;
+	});
 
+	const sortedArtists = Object.values(artistMap).sort((a, b) => b.ms_played - a.ms_played);
+	return sortedArtists.slice(0, limit);
+};
 
 const getFirstStreamDate = (streams: stream[]): string => {
-    if (streams.length === 0) return '';
-    return streams.reduce((earliest, stream) => {
-        return stream.ts < earliest ? stream.ts : earliest;
-    }, streams[0].ts);
-}
+	if (streams.length === 0) return "";
+	return streams.reduce((earliest, stream) => {
+		return stream.ts < earliest ? stream.ts : earliest;
+	}, streams[0].ts);
+};
 
 const getLastStreamDate = (streams: stream[]): string => {
-    if (streams.length === 0) return '';
-    return streams.reduce((latest, stream) => {
-        return stream.ts > latest ? stream.ts : latest;
-    }, streams[0].ts);
-}
+	if (streams.length === 0) return "";
+	return streams.reduce((latest, stream) => {
+		return stream.ts > latest ? stream.ts : latest;
+	}, streams[0].ts);
+};
 
-export {
-    readFiles,
-    getListenedTracks,
-    getListenedArtists,
-    getFirstStreamDate,
-    getLastStreamDate
-}
+export { readFiles, getListenedTracks, getListenedArtists, getFirstStreamDate, getLastStreamDate };