Function connect

conn.go:243–297

connect connects to a database. connect takes ownership of config. The caller must not use or access it again.

(ctx context.Context, config *ConnConfig)

// connect connects to a database. connect takes ownership of config. The caller must not use or access it again.
func connect(ctx context.Context, config *ConnConfig) (c *Conn, err error) {
	if connectTracer, ok := config.Tracer.(ConnectTracer); ok {
		ctx = connectTracer.TraceConnectStart(ctx, TraceConnectStartData{ConnConfig: config})
		defer func() {
			connectTracer.TraceConnectEnd(ctx, TraceConnectEndData{Conn: c, Err: err})
		}()
	}

	// Default values are set in ParseConfig. Enforce initial creation by ParseConfig rather than setting defaults from
	// zero values.
	if !config.createdByParseConfig {
		panic("config must be created by ParseConfig")
	}

	c = &Conn{
		config:      config,
		typeMap:     pgtype.NewMap(),
		queryTracer: config.Tracer,
	}

	if t, ok := c.queryTracer.(BatchTracer); ok {
		c.batchTracer = t
	}
	if t, ok := c.queryTracer.(CopyFromTracer); ok {
		c.copyFromTracer = t
	}
	if t, ok := c.queryTracer.(PrepareTracer); ok {
		c.prepareTracer = t
	}

	// Only install pgx notification system if no other callback handler is present.
	if config.Config.OnNotification == nil {
		config.Config.OnNotification = c.bufferNotifications
	}

	c.pgConn, err = pgconn.ConnectConfig(ctx, &config.Config)
	if err != nil {
		return nil, err
	}

	c.preparedStatements = make(map[string]*pgconn.StatementDescription)
	c.doneChan = make(chan struct{})
	c.closedChan = make(chan error)
	c.wbuf = make([]byte, 0, 1024)

	if c.config.StatementCacheCapacity > 0 {
		c.statementCache = stmtcache.NewLRUCache(c.config.StatementCacheCapacity)
	}

	if c.config.DescriptionCacheCapacity > 0 {
		c.descriptionCache = stmtcache.NewLRUCache(c.config.DescriptionCacheCapacity)
	}

	return c, nil
}

// Close closes a connection. It is safe to call Close on an already closed
// connection.