diff options
author | Kali Kaneko (leap communications) <kali@leap.se> | 2019-01-12 18:39:45 +0100 |
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committer | Ruben Pollan <meskio@sindominio.net> | 2019-01-17 12:30:32 +0100 |
commit | b1247d2d0d51108c910a73891ff3116e5f032ab1 (patch) | |
tree | e9948964f0bfb1ad2df3bc7bad02aa1f41ccfbd8 /vendor/github.com/getlantern/golog/golog.go | |
parent | efcb8312e31b5c2261b1a1e95ace55b322cfcc27 (diff) |
[pkg] all your deps are vendored to us
Diffstat (limited to 'vendor/github.com/getlantern/golog/golog.go')
-rw-r--r-- | vendor/github.com/getlantern/golog/golog.go | 458 |
1 files changed, 458 insertions, 0 deletions
diff --git a/vendor/github.com/getlantern/golog/golog.go b/vendor/github.com/getlantern/golog/golog.go new file mode 100644 index 0000000..143e904 --- /dev/null +++ b/vendor/github.com/getlantern/golog/golog.go @@ -0,0 +1,458 @@ +// Package golog implements logging functions that log errors to stderr and +// debug messages to stdout. Trace logging is also supported. +// Trace logs go to stdout as well, but they are only written if the program +// is run with environment variable "TRACE=true". +// A stack dump will be printed after the message if "PRINT_STACK=true". +package golog + +import ( + "bufio" + "bytes" + "fmt" + "io" + "io/ioutil" + "log" + "os" + "path/filepath" + "runtime" + "sort" + "strconv" + "strings" + "sync" + "sync/atomic" + + "github.com/getlantern/errors" + "github.com/getlantern/hidden" + "github.com/getlantern/ops" + "github.com/oxtoacart/bpool" +) + +const ( + // ERROR is an error Severity + ERROR = 500 + + // FATAL is an error Severity + FATAL = 600 +) + +var ( + outs atomic.Value + reporters []ErrorReporter + reportersMutex sync.RWMutex + + bufferPool = bpool.NewBufferPool(200) + + onFatal atomic.Value +) + +// Severity is a level of error (higher values are more severe) +type Severity int + +func (s Severity) String() string { + switch s { + case ERROR: + return "ERROR" + case FATAL: + return "FATAL" + default: + return "UNKNOWN" + } +} + +func init() { + DefaultOnFatal() + ResetOutputs() +} + +func SetOutputs(errorOut io.Writer, debugOut io.Writer) { + outs.Store(&outputs{ + ErrorOut: errorOut, + DebugOut: debugOut, + }) +} + +func ResetOutputs() { + SetOutputs(os.Stderr, os.Stdout) +} + +func GetOutputs() *outputs { + return outs.Load().(*outputs) +} + +// RegisterReporter registers the given ErrorReporter. All logged Errors are +// sent to this reporter. +func RegisterReporter(reporter ErrorReporter) { + reportersMutex.Lock() + reporters = append(reporters, reporter) + reportersMutex.Unlock() +} + +// OnFatal configures golog to call the given function on any FATAL error. By +// default, golog calls os.Exit(1) on any FATAL error. +func OnFatal(fn func(err error)) { + onFatal.Store(fn) +} + +// DefaultOnFatal enables the default behavior for OnFatal +func DefaultOnFatal() { + onFatal.Store(func(err error) { + os.Exit(1) + }) +} + +type outputs struct { + ErrorOut io.Writer + DebugOut io.Writer +} + +// MultiLine is an interface for arguments that support multi-line output. +type MultiLine interface { + // MultiLinePrinter returns a function that can be used to print the + // multi-line output. The returned function writes one line to the buffer and + // returns true if there are more lines to write. This function does not need + // to take care of trailing carriage returns, golog handles that + // automatically. + MultiLinePrinter() func(buf *bytes.Buffer) bool +} + +// ErrorReporter is a function to which the logger will report errors. +// It the given error and corresponding message along with associated ops +// context. This should return quickly as it executes on the critical code +// path. The recommended approach is to buffer as much as possible and discard +// new reports if the buffer becomes saturated. +type ErrorReporter func(err error, linePrefix string, severity Severity, ctx map[string]interface{}) + +type Logger interface { + // Debug logs to stdout + Debug(arg interface{}) + // Debugf logs to stdout + Debugf(message string, args ...interface{}) + + // Error logs to stderr + Error(arg interface{}) error + // Errorf logs to stderr. It returns the first argument that's an error, or + // a new error built using fmt.Errorf if none of the arguments are errors. + Errorf(message string, args ...interface{}) error + + // Fatal logs to stderr and then exits with status 1 + Fatal(arg interface{}) + // Fatalf logs to stderr and then exits with status 1 + Fatalf(message string, args ...interface{}) + + // Trace logs to stderr only if TRACE=true + Trace(arg interface{}) + // Tracef logs to stderr only if TRACE=true + Tracef(message string, args ...interface{}) + + // TraceOut provides access to an io.Writer to which trace information can + // be streamed. If running with environment variable "TRACE=true", TraceOut + // will point to os.Stderr, otherwise it will point to a ioutil.Discared. + // Each line of trace information will be prefixed with this Logger's + // prefix. + TraceOut() io.Writer + + // IsTraceEnabled() indicates whether or not tracing is enabled for this + // logger. + IsTraceEnabled() bool + + // AsStdLogger returns an standard logger + AsStdLogger() *log.Logger +} + +func LoggerFor(prefix string) Logger { + l := &logger{ + prefix: prefix + ": ", + pc: make([]uintptr, 10), + } + + trace := os.Getenv("TRACE") + l.traceOn, _ = strconv.ParseBool(trace) + if !l.traceOn { + prefixes := strings.Split(trace, ",") + for _, p := range prefixes { + if prefix == strings.Trim(p, " ") { + l.traceOn = true + break + } + } + } + if l.traceOn { + l.traceOut = l.newTraceWriter() + } else { + l.traceOut = ioutil.Discard + } + + printStack := os.Getenv("PRINT_STACK") + l.printStack, _ = strconv.ParseBool(printStack) + + return l +} + +type logger struct { + prefix string + traceOn bool + traceOut io.Writer + printStack bool + outs atomic.Value + pc []uintptr + funcForPc *runtime.Func +} + +// attaches the file and line number corresponding to +// the log message +func (l *logger) linePrefix(skipFrames int) string { + runtime.Callers(skipFrames, l.pc) + funcForPc := runtime.FuncForPC(l.pc[0]) + file, line := funcForPc.FileLine(l.pc[0] - 1) + return fmt.Sprintf("%s%s:%d ", l.prefix, filepath.Base(file), line) +} + +func (l *logger) print(out io.Writer, skipFrames int, severity string, arg interface{}) string { + buf := bufferPool.Get() + defer bufferPool.Put(buf) + + linePrefix := l.linePrefix(skipFrames) + writeHeader := func() { + buf.WriteString(severity) + buf.WriteString(" ") + buf.WriteString(linePrefix) + } + if arg != nil { + ml, isMultiline := arg.(MultiLine) + if !isMultiline { + writeHeader() + fmt.Fprintf(buf, "%v", arg) + printContext(buf, arg) + buf.WriteByte('\n') + } else { + mlp := ml.MultiLinePrinter() + first := true + for { + writeHeader() + more := mlp(buf) + if first { + printContext(buf, arg) + first = false + } + buf.WriteByte('\n') + if !more { + break + } + } + } + } + b := []byte(hidden.Clean(buf.String())) + _, err := out.Write(b) + if err != nil { + errorOnLogging(err) + } + if l.printStack { + l.doPrintStack() + } + + return linePrefix +} + +func (l *logger) printf(out io.Writer, skipFrames int, severity string, err error, message string, args ...interface{}) string { + buf := bufferPool.Get() + defer bufferPool.Put(buf) + + linePrefix := l.linePrefix(skipFrames) + buf.WriteString(severity) + buf.WriteString(" ") + buf.WriteString(linePrefix) + fmt.Fprintf(buf, message, args...) + printContext(buf, err) + buf.WriteByte('\n') + b := []byte(hidden.Clean(buf.String())) + _, err2 := out.Write(b) + if err2 != nil { + errorOnLogging(err) + } + if l.printStack { + l.doPrintStack() + } + return linePrefix +} + +func (l *logger) Debug(arg interface{}) { + l.print(GetOutputs().DebugOut, 4, "DEBUG", arg) +} + +func (l *logger) Debugf(message string, args ...interface{}) { + l.printf(GetOutputs().DebugOut, 4, "DEBUG", nil, message, args...) +} + +func (l *logger) Error(arg interface{}) error { + return l.errorSkipFrames(arg, 1, ERROR) +} + +func (l *logger) Errorf(message string, args ...interface{}) error { + return l.errorSkipFrames(errors.NewOffset(1, message, args...), 1, ERROR) +} + +func (l *logger) Fatal(arg interface{}) { + fatal(l.errorSkipFrames(arg, 1, FATAL)) +} + +func (l *logger) Fatalf(message string, args ...interface{}) { + fatal(l.errorSkipFrames(errors.NewOffset(1, message, args...), 1, FATAL)) +} + +func fatal(err error) { + fn := onFatal.Load().(func(err error)) + fn(err) +} + +func (l *logger) errorSkipFrames(arg interface{}, skipFrames int, severity Severity) error { + var err error + switch e := arg.(type) { + case error: + err = e + default: + err = fmt.Errorf("%v", e) + } + linePrefix := l.print(GetOutputs().ErrorOut, skipFrames+4, severity.String(), err) + return report(err, linePrefix, severity) +} + +func (l *logger) Trace(arg interface{}) { + if l.traceOn { + l.print(GetOutputs().DebugOut, 4, "TRACE", arg) + } +} + +func (l *logger) Tracef(message string, args ...interface{}) { + if l.traceOn { + l.printf(GetOutputs().DebugOut, 4, "TRACE", nil, message, args...) + } +} + +func (l *logger) TraceOut() io.Writer { + return l.traceOut +} + +func (l *logger) IsTraceEnabled() bool { + return l.traceOn +} + +func (l *logger) newTraceWriter() io.Writer { + pr, pw := io.Pipe() + br := bufio.NewReader(pr) + + if !l.traceOn { + return pw + } + go func() { + defer func() { + if err := pr.Close(); err != nil { + errorOnLogging(err) + } + }() + defer func() { + if err := pw.Close(); err != nil { + errorOnLogging(err) + } + }() + + for { + line, err := br.ReadString('\n') + if err == nil { + // Log the line (minus the trailing newline) + l.print(GetOutputs().DebugOut, 6, "TRACE", line[:len(line)-1]) + } else { + l.printf(GetOutputs().DebugOut, 6, "TRACE", nil, "TraceWriter closed due to unexpected error: %v", err) + return + } + } + }() + + return pw +} + +type errorWriter struct { + l *logger +} + +// Write implements method of io.Writer, due to different call depth, +// it will not log correct file and line prefix +func (w *errorWriter) Write(p []byte) (n int, err error) { + s := string(p) + if s[len(s)-1] == '\n' { + s = s[:len(s)-1] + } + w.l.print(GetOutputs().ErrorOut, 6, "ERROR", s) + return len(p), nil +} + +func (l *logger) AsStdLogger() *log.Logger { + return log.New(&errorWriter{l}, "", 0) +} + +func (l *logger) doPrintStack() { + var b []byte + buf := bytes.NewBuffer(b) + for _, pc := range l.pc { + funcForPc := runtime.FuncForPC(pc) + if funcForPc == nil { + break + } + name := funcForPc.Name() + if strings.HasPrefix(name, "runtime.") { + break + } + file, line := funcForPc.FileLine(pc) + fmt.Fprintf(buf, "\t%s\t%s: %d\n", name, file, line) + } + if _, err := buf.WriteTo(os.Stderr); err != nil { + errorOnLogging(err) + } +} + +func errorOnLogging(err error) { + fmt.Fprintf(os.Stderr, "Unable to log: %v\n", err) +} + +func printContext(buf *bytes.Buffer, err interface{}) { + // Note - we don't include globals when printing in order to avoid polluting the text log + values := ops.AsMap(err, false) + if len(values) == 0 { + return + } + buf.WriteString(" [") + var keys []string + for key := range values { + keys = append(keys, key) + } + sort.Strings(keys) + for i, key := range keys { + value := values[key] + if i > 0 { + buf.WriteString(" ") + } + buf.WriteString(key) + buf.WriteString("=") + fmt.Fprintf(buf, "%v", value) + } + buf.WriteByte(']') +} + +func report(err error, linePrefix string, severity Severity) error { + var reportersCopy []ErrorReporter + reportersMutex.RLock() + if len(reporters) > 0 { + reportersCopy = make([]ErrorReporter, len(reporters)) + copy(reportersCopy, reporters) + } + reportersMutex.RUnlock() + + if len(reportersCopy) > 0 { + ctx := ops.AsMap(err, true) + ctx["severity"] = severity.String() + for _, reporter := range reportersCopy { + // We include globals when reporting + reporter(err, linePrefix, severity, ctx) + } + } + return err +} |