initial commit

src/lib/database.js

@@ -0,0 +1,27 @@
+import Database from 'better-sqlite3';
+
+const dbName = './db/strimserve.db';
+
+// Create a new database object and initialize it with the schema
+const db = new Database(dbName);
+
+export function getStreams() {
+	const indexData = db.prepare('SELECT id, stream_date, title, tags, length_seconds ' +
+		'FROM Stream ORDER BY id DESC').all();
+	indexData.forEach(stream =>
+		stream['stream_date'] = Date.parse(stream['stream_date'])
+	);
+	return indexData;
+}
+
+export function getStreamInfo(streamId) {
+	const streamData = db.prepare("SELECT id, stream_date, filename, " +
+		"format, title, description, tags, " +
+		"length_seconds, tracks FROM Stream " +
+		"WHERE id = ?").get(streamId);
+	streamData['stream_date'] = Date.parse(streamData['stream_date']);
+	streamData['tracks'] = JSON.parse(streamData['tracks']);
+	streamData['tags'] = JSON.parse(streamData['tags']);
+	streamData['tracks_num'] = streamData['tracks'].length;
+	return streamData;
+}

src/lib/stores.js

@@ -0,0 +1,49 @@
+import { writable } from 'svelte/store';
+
+export const currentStream = writable({});
+export const currentSongIndex = writable(0);
+
+let timestampList;
+
+// utility
+
+function locationOf(element, array, start, end) {
+	start = start || 0;
+	end = end || array.length;
+	var pivot = parseInt(start + (end - start) / 2, 10);
+	if (end - start <= 1 || array[pivot] === element) return pivot;
+	if (array[pivot] < element) {
+		return locationOf(element, array, pivot, end);
+	} else {
+		return locationOf(element, array, start, pivot);
+	}
+}
+
+// exported methods
+
+export function getSongAtTime(currentTime) {
+	return locationOf(currentTime, timestampList) - 1;
+
+}
+
+// less operations needed when doing regular lookups
+export function updateCurrentSong(currentTime, songIndex) {
+	function updateCurrentSongRecurse(songIndex) {
+		if (currentTime >= timestampList[songIndex + 2]) {
+			return updateCurrentSongRecurse(songIndex + 1);
+		}
+		else if (currentTime < timestampList[songIndex + 1]) {
+			return updateCurrentSongRecurse(songIndex - 1);
+		}
+		return songIndex;
+	}
+
+	currentSongIndex.set(updateCurrentSongRecurse(songIndex));
+
+}
+
+export function updateCurrentStream(stream) {
+	currentStream.set(stream);
+	timestampList = [-Infinity, ...stream.tracks.map(track => track[0]), Infinity];
+	currentSongIndex.set(0);
+}