gitly/database.v at master · vlang/gitly · GitHub

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module main

import veb

// reconnect_db drops the current DB handle and opens a fresh connection.
// Used to recover from stale connections (e.g. an idle Postgres connection
// dropped by NAT or by PG's idle_session_timeout). v's db.pg has no built-in
// reconnect, so without this the process keeps using a dead handle until restart.
pub fn (mut app App) reconnect_db() ! {
	app.db.close() or {}
	app.db = connect_db(app.config)!
}

// get_users_count_with_reconnect retries the user count query once after
// reconnecting on failure. This is the recovery path for the specific bug
// where a dead DB handle made get_users_count() silently return 0 and the
// site rendered the "welcome / register" page until systemd restart.
pub fn (mut app App) get_users_count_with_reconnect() !int {
	if count := app.get_users_count() {
		return count
	} else {
		app.warn('db query failed, attempting reconnect: ${err}')
		app.reconnect_db() or { return error('db unavailable; reconnect failed: ${err}') }
		return app.get_users_count()!
	}
}

// db_error renders a 503 response describing a database failure.
// We render an explicit page rather than letting callers fall back to a
// misleading default (e.g. redirecting to /register on a swallowed error).
pub fn (mut ctx Context) db_error(err IError) veb.Result {
	ctx.res.set_status(.service_unavailable)
	body := '<!DOCTYPE html><html><head><meta charset="utf-8"><title>Gitly — database unavailable</title></head><body style="font-family:sans-serif;max-width:640px;margin:4em auto;padding:0 1em;"><h1>Database unavailable</h1><p>Gitly could not reach its database. This is usually transient — please try again in a moment.</p><pre style="background:#f4f4f4;padding:1em;overflow:auto;white-space:pre-wrap;">${err}</pre></body></html>'
	return ctx.html(body)
}

fn sql_table(name string) string {
	return '"' + name.to_lower().replace('"', '""') + '"'
}

fn sql_literal(value string) string {
	return "'" + value.replace("'", "''") + "'"
}

fn sql_like_pattern(value string) string {
	return sql_literal('%' + value + '%')
}