Update vendor (#1265)

vendor/github.com/wiggin77/srslog/writer.go

@@ -0,0 +1,201 @@
+package srslog
+
+import (
+	"crypto/tls"
+	"strings"
+	"sync"
+)
+
+// A Writer is a connection to a syslog server.
+type Writer struct {
+	priority  Priority
+	tag       string
+	hostname  string
+	network   string
+	raddr     string
+	tlsConfig *tls.Config
+	framer    Framer
+	formatter Formatter
+
+	//non-nil if custom dialer set, used in getDialer
+	customDial DialFunc
+
+	mu   sync.RWMutex // guards conn
+	conn serverConn
+}
+
+// getConn provides access to the internal conn, protected by a mutex. The
+// conn is threadsafe, so it can be used while unlocked, but we want to avoid
+// race conditions on grabbing a reference to it.
+func (w *Writer) getConn() serverConn {
+	w.mu.RLock()
+	conn := w.conn
+	w.mu.RUnlock()
+	return conn
+}
+
+// setConn updates the internal conn, protected by a mutex.
+func (w *Writer) setConn(c serverConn) {
+	w.mu.Lock()
+	w.conn = c
+	w.mu.Unlock()
+}
+
+// connect makes a connection to the syslog server.
+func (w *Writer) connect() (serverConn, error) {
+	conn := w.getConn()
+	if conn != nil {
+		// ignore err from close, it makes sense to continue anyway
+		conn.close()
+		w.setConn(nil)
+	}
+
+	var hostname string
+	var err error
+	dialer := w.getDialer()
+	conn, hostname, err = dialer.Call()
+	if err == nil {
+		w.setConn(conn)
+		w.hostname = hostname
+
+		return conn, nil
+	} else {
+		return nil, err
+	}
+}
+
+// SetFormatter changes the formatter function for subsequent messages.
+func (w *Writer) SetFormatter(f Formatter) {
+	w.formatter = f
+}
+
+// SetFramer changes the framer function for subsequent messages.
+func (w *Writer) SetFramer(f Framer) {
+	w.framer = f
+}
+
+// SetHostname changes the hostname for syslog messages if needed.
+func (w *Writer) SetHostname(hostname string) {
+	w.hostname = hostname
+}
+
+// Write sends a log message to the syslog daemon using the default priority
+// passed into `srslog.New` or the `srslog.Dial*` functions.
+func (w *Writer) Write(b []byte) (int, error) {
+	return w.writeAndRetry(w.priority, string(b))
+}
+
+// WriteWithPriority sends a log message with a custom priority.
+func (w *Writer) WriteWithPriority(p Priority, b []byte) (int, error) {
+	return w.writeAndRetryWithPriority(p, string(b))
+}
+
+// Close closes a connection to the syslog daemon.
+func (w *Writer) Close() error {
+	conn := w.getConn()
+	if conn != nil {
+		err := conn.close()
+		w.setConn(nil)
+		return err
+	}
+	return nil
+}
+
+// Emerg logs a message with severity LOG_EMERG; this overrides the default
+// priority passed to `srslog.New` and the `srslog.Dial*` functions.
+func (w *Writer) Emerg(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_EMERG, m)
+	return err
+}
+
+// Alert logs a message with severity LOG_ALERT; this overrides the default
+// priority passed to `srslog.New` and the `srslog.Dial*` functions.
+func (w *Writer) Alert(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_ALERT, m)
+	return err
+}
+
+// Crit logs a message with severity LOG_CRIT; this overrides the default
+// priority passed to `srslog.New` and the `srslog.Dial*` functions.
+func (w *Writer) Crit(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_CRIT, m)
+	return err
+}
+
+// Err logs a message with severity LOG_ERR; this overrides the default
+// priority passed to `srslog.New` and the `srslog.Dial*` functions.
+func (w *Writer) Err(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_ERR, m)
+	return err
+}
+
+// Warning logs a message with severity LOG_WARNING; this overrides the default
+// priority passed to `srslog.New` and the `srslog.Dial*` functions.
+func (w *Writer) Warning(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_WARNING, m)
+	return err
+}
+
+// Notice logs a message with severity LOG_NOTICE; this overrides the default
+// priority passed to `srslog.New` and the `srslog.Dial*` functions.
+func (w *Writer) Notice(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_NOTICE, m)
+	return err
+}
+
+// Info logs a message with severity LOG_INFO; this overrides the default
+// priority passed to `srslog.New` and the `srslog.Dial*` functions.
+func (w *Writer) Info(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_INFO, m)
+	return err
+}
+
+// Debug logs a message with severity LOG_DEBUG; this overrides the default
+// priority passed to `srslog.New` and the `srslog.Dial*` functions.
+func (w *Writer) Debug(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_DEBUG, m)
+	return err
+}
+
+// writeAndRetry takes a severity and the string to write. Any facility passed to
+// it as part of the severity Priority will be ignored.
+func (w *Writer) writeAndRetry(severity Priority, s string) (int, error) {
+	pr := (w.priority & facilityMask) | (severity & severityMask)
+
+	return w.writeAndRetryWithPriority(pr, s)
+}
+
+// writeAndRetryWithPriority differs from writeAndRetry in that it allows setting
+// of both the facility and the severity.
+func (w *Writer) writeAndRetryWithPriority(p Priority, s string) (int, error) {
+	conn := w.getConn()
+	if conn != nil {
+		if n, err := w.write(conn, p, s); err == nil {
+			return n, err
+		}
+	}
+
+	var err error
+	if conn, err = w.connect(); err != nil {
+		return 0, err
+	}
+	return w.write(conn, p, s)
+}
+
+// write generates and writes a syslog formatted string. It formats the
+// message based on the current Formatter and Framer.
+func (w *Writer) write(conn serverConn, p Priority, msg string) (int, error) {
+	// ensure it ends in a \n
+	if !strings.HasSuffix(msg, "\n") {
+		msg += "\n"
+	}
+
+	err := conn.writeString(w.framer, w.formatter, p, w.hostname, w.tag, msg)
+	if err != nil {
+		return 0, err
+	}
+	// Note: return the length of the input, not the number of
+	// bytes printed by Fprintf, because this must behave like
+	// an io.Writer.
+	return len(msg), nil
+}