diff options
Diffstat (limited to 'vendor/github.com/wiggin77/srslog/writer.go')
-rw-r--r-- | vendor/github.com/wiggin77/srslog/writer.go | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/vendor/github.com/wiggin77/srslog/writer.go b/vendor/github.com/wiggin77/srslog/writer.go new file mode 100644 index 00000000..86bccba1 --- /dev/null +++ b/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 +} |