Add stats

Just adding this early version for now so I can iterate.

src/web/routes/stats.js

@@ -0,0 +1,85 @@
+// @ts-check
+
+const {defineEventHandler, getValidatedQuery, H3Event, setResponseHeader} = require("h3")
+const {as, db, sync} = require("../../passthrough")
+const {reg} = require("../../matrix/read-registration")
+
+/** @type {import("../../discord/utils")} */
+const dUtils = sync.require("../../discord/utils")
+
+// Calculation takes time and is single-threaded. I could add database indexes, but this is simpler and doesn't need storage.
+const STATS_CACHE_TIME = 10 * 60 * 1000 // 10 minutes
+
+function getMessageCountLastDuration(duration) {
+	const snowflake = dUtils.timestampToSnowflakeInexact(Date.now() - duration)
+	return db.prepare("select count(*) from message_room where message_id >= ? and length(message_id) = ?").pluck().get(snowflake, snowflake.length)
+}
+
+function getStats() {
+	const durations = [
+		["week", 7 * 24 * 60 * 60 * 1000],
+		["day", 1 * 24 * 60 * 60 * 1000],
+		["hour", 1 * 60 * 60 * 1000]
+	]
+
+	// console.time("get stats")
+	let temp = {
+		guilds: db.prepare("select count(*) from guild_space").pluck().get(),
+		channels: db.prepare("select count(*) from channel_room").pluck().get(),
+		messages: db.prepare("select count(*) from message_room").pluck().get(),
+		...durations.reduce((a, c) => (a[`messages_last_${c[0]}`] = getMessageCountLastDuration(c[1]), a), {}),
+		message_sources: db.prepare("select count(*) from event_message where part = 0 group by source order by source").pluck().all(),
+		oldest_message: new Date(dUtils.snowflakeToTimestampExact(db.prepare("select min(message_id) from event_message where source = 0").pluck().get())), // good until 2090
+		discord_users: db.prepare("select count(*) from sim").pluck().get(),
+		matrix_users: db.prepare("select count(distinct mxid) from member_cache where mxid not like ?").pluck().get(reg.namespaces.users[0].regex.replace(/\.\*.*/, "%")),
+	}
+	// console.timeEnd("get stats")
+	return temp
+}
+
+/** @type {ReturnType<typeof getStats>} */
+let stats
+let statsUpdatedAt = 0
+
+function updateStatsIfOld() {
+	if (statsUpdatedAt < Date.now() - STATS_CACHE_TIME) {
+		stats = getStats()
+		statsUpdatedAt = Date.now()
+	}
+}
+
+as.router.get("/api/stats", defineEventHandler(async event => {
+	updateStatsIfOld()
+	return {
+		...stats,
+		oldest_message: stats.oldest_message.toISOString(),
+	}
+}))
+
+as.router.get("/metrics", defineEventHandler(async event => {
+	updateStatsIfOld()
+	setResponseHeader(event, "content-type", "text/plain")
+	return `
+# HELP guilds Total number of guilds
+# TYPE guilds gauge
+ooye_guilds_total ${stats.guilds}
+
+# HELP channels Total number of channels
+# TYPE channels gauge
+ooye_channels_total ${stats.channels}
+
+# HELP messages_total Total number of messages sent from each side
+# TYPE messages_total gauge
+ooye_messages_total{type="matrix"} ${stats.message_sources[0]}
+ooye_messages_total{type="discord"} ${stats.message_sources[1]}
+
+# HELP oldest_message_timestamp Unix timestamp of the oldest message
+# TYPE oldest_message_timestamp gauge
+ooye_oldest_message_timestamp_seconds ${stats.oldest_message.getTime() / 1000}
+
+# HELP ooye_users_total Total number of users on each side
+# TYPE ooye_users_total gauge
+ooye_users_total{type="matrix"} ${stats.matrix_users}
+ooye_users_total{type="discord"} ${stats.discord_users}
+`.trimStart()
+}))

src/web/server.js

@@ -135,3 +135,4 @@ sync.require("./routes/link")
 sync.require("./routes/log-in-with-matrix")
 sync.require("./routes/oauth")
 sync.require("./routes/password")
+sync.require("./routes/stats")