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Diffstat (limited to 'vendor/github.com/golang/glog/glog.go')
| -rw-r--r-- | vendor/github.com/golang/glog/glog.go | 1180 |
1 files changed, 1180 insertions, 0 deletions
diff --git a/vendor/github.com/golang/glog/glog.go b/vendor/github.com/golang/glog/glog.go new file mode 100644 index 000000000..54bd7afdc --- /dev/null +++ b/vendor/github.com/golang/glog/glog.go @@ -0,0 +1,1180 @@ +// Go support for leveled logs, analogous to https://code.google.com/p/google-glog/ +// +// Copyright 2013 Google Inc. All Rights Reserved. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// Package glog implements logging analogous to the Google-internal C++ INFO/ERROR/V setup. +// It provides functions Info, Warning, Error, Fatal, plus formatting variants such as +// Infof. It also provides V-style logging controlled by the -v and -vmodule=file=2 flags. +// +// Basic examples: +// +// glog.Info("Prepare to repel boarders") +// +// glog.Fatalf("Initialization failed: %s", err) +// +// See the documentation for the V function for an explanation of these examples: +// +// if glog.V(2) { +// glog.Info("Starting transaction...") +// } +// +// glog.V(2).Infoln("Processed", nItems, "elements") +// +// Log output is buffered and written periodically using Flush. Programs +// should call Flush before exiting to guarantee all log output is written. +// +// By default, all log statements write to files in a temporary directory. +// This package provides several flags that modify this behavior. +// As a result, flag.Parse must be called before any logging is done. +// +// -logtostderr=false +// Logs are written to standard error instead of to files. +// -alsologtostderr=false +// Logs are written to standard error as well as to files. +// -stderrthreshold=ERROR +// Log events at or above this severity are logged to standard +// error as well as to files. +// -log_dir="" +// Log files will be written to this directory instead of the +// default temporary directory. +// +// Other flags provide aids to debugging. +// +// -log_backtrace_at="" +// When set to a file and line number holding a logging statement, +// such as +// -log_backtrace_at=gopherflakes.go:234 +// a stack trace will be written to the Info log whenever execution +// hits that statement. (Unlike with -vmodule, the ".go" must be +// present.) +// -v=0 +// Enable V-leveled logging at the specified level. +// -vmodule="" +// The syntax of the argument is a comma-separated list of pattern=N, +// where pattern is a literal file name (minus the ".go" suffix) or +// "glob" pattern and N is a V level. For instance, +// -vmodule=gopher*=3 +// sets the V level to 3 in all Go files whose names begin "gopher". +// +package glog + +import ( + "bufio" + "bytes" + "errors" + "flag" + "fmt" + "io" + stdLog "log" + "os" + "path/filepath" + "runtime" + "strconv" + "strings" + "sync" + "sync/atomic" + "time" +) + +// severity identifies the sort of log: info, warning etc. It also implements +// the flag.Value interface. The -stderrthreshold flag is of type severity and +// should be modified only through the flag.Value interface. The values match +// the corresponding constants in C++. +type severity int32 // sync/atomic int32 + +// These constants identify the log levels in order of increasing severity. +// A message written to a high-severity log file is also written to each +// lower-severity log file. +const ( + infoLog severity = iota + warningLog + errorLog + fatalLog + numSeverity = 4 +) + +const severityChar = "IWEF" + +var severityName = []string{ + infoLog: "INFO", + warningLog: "WARNING", + errorLog: "ERROR", + fatalLog: "FATAL", +} + +// get returns the value of the severity. +func (s *severity) get() severity { + return severity(atomic.LoadInt32((*int32)(s))) +} + +// set sets the value of the severity. +func (s *severity) set(val severity) { + atomic.StoreInt32((*int32)(s), int32(val)) +} + +// String is part of the flag.Value interface. +func (s *severity) String() string { + return strconv.FormatInt(int64(*s), 10) +} + +// Get is part of the flag.Value interface. +func (s *severity) Get() interface{} { + return *s +} + +// Set is part of the flag.Value interface. +func (s *severity) Set(value string) error { + var threshold severity + // Is it a known name? + if v, ok := severityByName(value); ok { + threshold = v + } else { + v, err := strconv.Atoi(value) + if err != nil { + return err + } + threshold = severity(v) + } + logging.stderrThreshold.set(threshold) + return nil +} + +func severityByName(s string) (severity, bool) { + s = strings.ToUpper(s) + for i, name := range severityName { + if name == s { + return severity(i), true + } + } + return 0, false +} + +// OutputStats tracks the number of output lines and bytes written. +type OutputStats struct { + lines int64 + bytes int64 +} + +// Lines returns the number of lines written. +func (s *OutputStats) Lines() int64 { + return atomic.LoadInt64(&s.lines) +} + +// Bytes returns the number of bytes written. +func (s *OutputStats) Bytes() int64 { + return atomic.LoadInt64(&s.bytes) +} + +// Stats tracks the number of lines of output and number of bytes +// per severity level. Values must be read with atomic.LoadInt64. +var Stats struct { + Info, Warning, Error OutputStats +} + +var severityStats = [numSeverity]*OutputStats{ + infoLog: &Stats.Info, + warningLog: &Stats.Warning, + errorLog: &Stats.Error, +} + +// Level is exported because it appears in the arguments to V and is +// the type of the v flag, which can be set programmatically. +// It's a distinct type because we want to discriminate it from logType. +// Variables of type level are only changed under logging.mu. +// The -v flag is read only with atomic ops, so the state of the logging +// module is consistent. + +// Level is treated as a sync/atomic int32. + +// Level specifies a level of verbosity for V logs. *Level implements +// flag.Value; the -v flag is of type Level and should be modified +// only through the flag.Value interface. +type Level int32 + +// get returns the value of the Level. +func (l *Level) get() Level { + return Level(atomic.LoadInt32((*int32)(l))) +} + +// set sets the value of the Level. +func (l *Level) set(val Level) { + atomic.StoreInt32((*int32)(l), int32(val)) +} + +// String is part of the flag.Value interface. +func (l *Level) String() string { + return strconv.FormatInt(int64(*l), 10) +} + +// Get is part of the flag.Value interface. +func (l *Level) Get() interface{} { + return *l +} + +// Set is part of the flag.Value interface. +func (l *Level) Set(value string) error { + v, err := strconv.Atoi(value) + if err != nil { + return err + } + logging.mu.Lock() + defer logging.mu.Unlock() + logging.setVState(Level(v), logging.vmodule.filter, false) + return nil +} + +// moduleSpec represents the setting of the -vmodule flag. +type moduleSpec struct { + filter []modulePat +} + +// modulePat contains a filter for the -vmodule flag. +// It holds a verbosity level and a file pattern to match. +type modulePat struct { + pattern string + literal bool // The pattern is a literal string + level Level +} + +// match reports whether the file matches the pattern. It uses a string +// comparison if the pattern contains no metacharacters. +func (m *modulePat) match(file string) bool { + if m.literal { + return file == m.pattern + } + match, _ := filepath.Match(m.pattern, file) + return match +} + +func (m *moduleSpec) String() string { + // Lock because the type is not atomic. TODO: clean this up. + logging.mu.Lock() + defer logging.mu.Unlock() + var b bytes.Buffer + for i, f := range m.filter { + if i > 0 { + b.WriteRune(',') + } + fmt.Fprintf(&b, "%s=%d", f.pattern, f.level) + } + return b.String() +} + +// Get is part of the (Go 1.2) flag.Getter interface. It always returns nil for this flag type since the +// struct is not exported. +func (m *moduleSpec) Get() interface{} { + return nil +} + +var errVmoduleSyntax = errors.New("syntax error: expect comma-separated list of filename=N") + +// Syntax: -vmodule=recordio=2,file=1,gfs*=3 +func (m *moduleSpec) Set(value string) error { + var filter []modulePat + for _, pat := range strings.Split(value, ",") { + if len(pat) == 0 { + // Empty strings such as from a trailing comma can be ignored. + continue + } + patLev := strings.Split(pat, "=") + if len(patLev) != 2 || len(patLev[0]) == 0 || len(patLev[1]) == 0 { + return errVmoduleSyntax + } + pattern := patLev[0] + v, err := strconv.Atoi(patLev[1]) + if err != nil { + return errors.New("syntax error: expect comma-separated list of filename=N") + } + if v < 0 { + return errors.New("negative value for vmodule level") + } + if v == 0 { + continue // Ignore. It's harmless but no point in paying the overhead. + } + // TODO: check syntax of filter? + filter = append(filter, modulePat{pattern, isLiteral(pattern), Level(v)}) + } + logging.mu.Lock() + defer logging.mu.Unlock() + logging.setVState(logging.verbosity, filter, true) + return nil +} + +// isLiteral reports whether the pattern is a literal string, that is, has no metacharacters +// that require filepath.Match to be called to match the pattern. +func isLiteral(pattern string) bool { + return !strings.ContainsAny(pattern, `\*?[]`) +} + +// traceLocation represents the setting of the -log_backtrace_at flag. +type traceLocation struct { + file string + line int +} + +// isSet reports whether the trace location has been specified. +// logging.mu is held. +func (t *traceLocation) isSet() bool { + return t.line > 0 +} + +// match reports whether the specified file and line matches the trace location. +// The argument file name is the full path, not the basename specified in the flag. +// logging.mu is held. +func (t *traceLocation) match(file string, line int) bool { + if t.line != line { + return false + } + if i := strings.LastIndex(file, "/"); i >= 0 { + file = file[i+1:] + } + return t.file == file +} + +func (t *traceLocation) String() string { + // Lock because the type is not atomic. TODO: clean this up. + logging.mu.Lock() + defer logging.mu.Unlock() + return fmt.Sprintf("%s:%d", t.file, t.line) +} + +// Get is part of the (Go 1.2) flag.Getter interface. It always returns nil for this flag type since the +// struct is not exported +func (t *traceLocation) Get() interface{} { + return nil +} + +var errTraceSyntax = errors.New("syntax error: expect file.go:234") + +// Syntax: -log_backtrace_at=gopherflakes.go:234 +// Note that unlike vmodule the file extension is included here. +func (t *traceLocation) Set(value string) error { + if value == "" { + // Unset. + t.line = 0 + t.file = "" + } + fields := strings.Split(value, ":") + if len(fields) != 2 { + return errTraceSyntax + } + file, line := fields[0], fields[1] + if !strings.Contains(file, ".") { + return errTraceSyntax + } + v, err := strconv.Atoi(line) + if err != nil { + return errTraceSyntax + } + if v <= 0 { + return errors.New("negative or zero value for level") + } + logging.mu.Lock() + defer logging.mu.Unlock() + t.line = v + t.file = file + return nil +} + +// flushSyncWriter is the interface satisfied by logging destinations. +type flushSyncWriter interface { + Flush() error + Sync() error + io.Writer +} + +func init() { + flag.BoolVar(&logging.toStderr, "logtostderr", false, "log to standard error instead of files") + flag.BoolVar(&logging.alsoToStderr, "alsologtostderr", false, "log to standard error as well as files") + flag.Var(&logging.verbosity, "v", "log level for V logs") + flag.Var(&logging.stderrThreshold, "stderrthreshold", "logs at or above this threshold go to stderr") + flag.Var(&logging.vmodule, "vmodule", "comma-separated list of pattern=N settings for file-filtered logging") + flag.Var(&logging.traceLocation, "log_backtrace_at", "when logging hits line file:N, emit a stack trace") + + // Default stderrThreshold is ERROR. + logging.stderrThreshold = errorLog + + logging.setVState(0, nil, false) + go logging.flushDaemon() +} + +// Flush flushes all pending log I/O. +func Flush() { + logging.lockAndFlushAll() +} + +// loggingT collects all the global state of the logging setup. +type loggingT struct { + // Boolean flags. Not handled atomically because the flag.Value interface + // does not let us avoid the =true, and that shorthand is necessary for + // compatibility. TODO: does this matter enough to fix? Seems unlikely. + toStderr bool // The -logtostderr flag. + alsoToStderr bool // The -alsologtostderr flag. + + // Level flag. Handled atomically. + stderrThreshold severity // The -stderrthreshold flag. + + // freeList is a list of byte buffers, maintained under freeListMu. + freeList *buffer + // freeListMu maintains the free list. It is separate from the main mutex + // so buffers can be grabbed and printed to without holding the main lock, + // for better parallelization. + freeListMu sync.Mutex + + // mu protects the remaining elements of this structure and is + // used to synchronize logging. + mu sync.Mutex + // file holds writer for each of the log types. + file [numSeverity]flushSyncWriter + // pcs is used in V to avoid an allocation when computing the caller's PC. + pcs [1]uintptr + // vmap is a cache of the V Level for each V() call site, identified by PC. + // It is wiped whenever the vmodule flag changes state. + vmap map[uintptr]Level + // filterLength stores the length of the vmodule filter chain. If greater + // than zero, it means vmodule is enabled. It may be read safely + // using sync.LoadInt32, but is only modified under mu. + filterLength int32 + // traceLocation is the state of the -log_backtrace_at flag. + traceLocation traceLocation + // These flags are modified only under lock, although verbosity may be fetched + // safely using atomic.LoadInt32. + vmodule moduleSpec // The state of the -vmodule flag. + verbosity Level // V logging level, the value of the -v flag/ +} + +// buffer holds a byte Buffer for reuse. The zero value is ready for use. +type buffer struct { + bytes.Buffer + tmp [64]byte // temporary byte array for creating headers. + next *buffer +} + +var logging loggingT + +// setVState sets a consistent state for V logging. +// l.mu is held. +func (l *loggingT) setVState(verbosity Level, filter []modulePat, setFilter bool) { + // Turn verbosity off so V will not fire while we are in transition. + logging.verbosity.set(0) + // Ditto for filter length. + atomic.StoreInt32(&logging.filterLength, 0) + + // Set the new filters and wipe the pc->Level map if the filter has changed. + if setFilter { + logging.vmodule.filter = filter + logging.vmap = make(map[uintptr]Level) + } + + // Things are consistent now, so enable filtering and verbosity. + // They are enabled in order opposite to that in V. + atomic.StoreInt32(&logging.filterLength, int32(len(filter))) + logging.verbosity.set(verbosity) +} + +// getBuffer returns a new, ready-to-use buffer. +func (l *loggingT) getBuffer() *buffer { + l.freeListMu.Lock() + b := l.freeList + if b != nil { + l.freeList = b.next + } + l.freeListMu.Unlock() + if b == nil { + b = new(buffer) + } else { + b.next = nil + b.Reset() + } + return b +} + +// putBuffer returns a buffer to the free list. +func (l *loggingT) putBuffer(b *buffer) { + if b.Len() >= 256 { + // Let big buffers die a natural death. + return + } + l.freeListMu.Lock() + b.next = l.freeList + l.freeList = b + l.freeListMu.Unlock() +} + +var timeNow = time.Now // Stubbed out for testing. + +/* +header formats a log header as defined by the C++ implementation. +It returns a buffer containing the formatted header and the user's file and line number. +The depth specifies how many stack frames above lives the source line to be identified in the log message. + +Log lines have this form: + Lmmdd hh:mm:ss.uuuuuu threadid file:line] msg... +where the fields are defined as follows: + L A single character, representing the log level (eg 'I' for INFO) + mm The month (zero padded; ie May is '05') + dd The day (zero padded) + hh:mm:ss.uuuuuu Time in hours, minutes and fractional seconds + threadid The space-padded thread ID as returned by GetTID() + file The file name + line The line number + msg The user-supplied message +*/ +func (l *loggingT) header(s severity, depth int) (*buffer, string, int) { + _, file, line, ok := runtime.Caller(3 + depth) + if !ok { + file = "???" + line = 1 + } else { + slash := strings.LastIndex(file, "/") + if slash >= 0 { + file = file[slash+1:] + } + } + return l.formatHeader(s, file, line), file, line +} + +// formatHeader formats a log header using the provided file name and line number. +func (l *loggingT) formatHeader(s severity, file string, line int) *buffer { + now := timeNow() + if line < 0 { + line = 0 // not a real line number, but acceptable to someDigits + } + if s > fatalLog { + s = infoLog // for safety. + } + buf := l.getBuffer() + + // Avoid Fprintf, for speed. The format is so simple that we can do it quickly by hand. + // It's worth about 3X. Fprintf is hard. + _, month, day := now.Date() + hour, minute, second := now.Clock() + // Lmmdd hh:mm:ss.uuuuuu threadid file:line] + buf.tmp[0] = severityChar[s] + buf.twoDigits(1, int(month)) + buf.twoDigits(3, day) + buf.tmp[5] = ' ' + buf.twoDigits(6, hour) + buf.tmp[8] = ':' + buf.twoDigits(9, minute) + buf.tmp[11] = ':' + buf.twoDigits(12, second) + buf.tmp[14] = '.' + buf.nDigits(6, 15, now.Nanosecond()/1000, '0') + buf.tmp[21] = ' ' + buf.nDigits(7, 22, pid, ' ') // TODO: should be TID + buf.tmp[29] = ' ' + buf.Write(buf.tmp[:30]) + buf.WriteString(file) + buf.tmp[0] = ':' + n := buf.someDigits(1, line) + buf.tmp[n+1] = ']' + buf.tmp[n+2] = ' ' + buf.Write(buf.tmp[:n+3]) + return buf +} + +// Some custom tiny helper functions to print the log header efficiently. + +const digits = "0123456789" + +// twoDigits formats a zero-prefixed two-digit integer at buf.tmp[i]. +func (buf *buffer) twoDigits(i, d int) { + buf.tmp[i+1] = digits[d%10] + d /= 10 + buf.tmp[i] = digits[d%10] +} + +// nDigits formats an n-digit integer at buf.tmp[i], +// padding with pad on the left. +// It assumes d >= 0. +func (buf *buffer) nDigits(n, i, d int, pad byte) { + j := n - 1 + for ; j >= 0 && d > 0; j-- { + buf.tmp[i+j] = digits[d%10] + d /= 10 + } + for ; j >= 0; j-- { + buf.tmp[i+j] = pad + } +} + +// someDigits formats a zero-prefixed variable-width integer at buf.tmp[i]. +func (buf *buffer) someDigits(i, d int) int { + // Print into the top, then copy down. We know there's space for at least + // a 10-digit number. + j := len(buf.tmp) + for { + j-- + buf.tmp[j] = digits[d%10] + d /= 10 + if d == 0 { + break + } + } + return copy(buf.tmp[i:], buf.tmp[j:]) +} + +func (l *loggingT) println(s severity, args ...interface{}) { + buf, file, line := l.header(s, 0) + fmt.Fprintln(buf, args...) + l.output(s, buf, file, line, false) +} + +func (l *loggingT) print(s severity, args ...interface{}) { + l.printDepth(s, 1, args...) +} + +func (l *loggingT) printDepth(s severity, depth int, args ...interface{}) { + buf, file, line := l.header(s, depth) + fmt.Fprint(buf, args...) + if buf.Bytes()[buf.Len()-1] != '\n' { + buf.WriteByte('\n') + } + l.output(s, buf, file, line, false) +} + +func (l *loggingT) printf(s severity, format string, args ...interface{}) { + buf, file, line := l.header(s, 0) + fmt.Fprintf(buf, format, args...) + if buf.Bytes()[buf.Len()-1] != '\n' { + buf.WriteByte('\n') + } + l.output(s, buf, file, line, false) +} + +// printWithFileLine behaves like print but uses the provided file and line number. If +// alsoLogToStderr is true, the log message always appears on standard error; it +// will also appear in the log file unless --logtostderr is set. +func (l *loggingT) printWithFileLine(s severity, file string, line int, alsoToStderr bool, args ...interface{}) { + buf := l.formatHeader(s, file, line) + fmt.Fprint(buf, args...) + if buf.Bytes()[buf.Len()-1] != '\n' { + buf.WriteByte('\n') + } + l.output(s, buf, file, line, alsoToStderr) +} + +// output writes the data to the log files and releases the buffer. +func (l *loggingT) output(s severity, buf *buffer, file string, line int, alsoToStderr bool) { + l.mu.Lock() + if l.traceLocation.isSet() { + if l.traceLocation.match(file, line) { + buf.Write(stacks(false)) + } + } + data := buf.Bytes() + if !flag.Parsed() { + os.Stderr.Write([]byte("ERROR: logging before flag.Parse: ")) + os.Stderr.Write(data) + } else if l.toStderr { + os.Stderr.Write(data) + } else { + if alsoToStderr || l.alsoToStderr || s >= l.stderrThreshold.get() { + os.Stderr.Write(data) + } + if l.file[s] == nil { + if err := l.createFiles(s); err != nil { + os.Stderr.Write(data) // Make sure the message appears somewhere. + l.exit(err) + } + } + switch s { + case fatalLog: + l.file[fatalLog].Write(data) + fallthrough + case errorLog: + l.file[errorLog].Write(data) + fallthrough + case warningLog: + l.file[warningLog].Write(data) + fallthrough + case infoLog: + l.file[infoLog].Write(data) + } + } + if s == fatalLog { + // If we got here via Exit rather than Fatal, print no stacks. + if atomic.LoadUint32(&fatalNoStacks) > 0 { + l.mu.Unlock() + timeoutFlush(10 * time.Second) + os.Exit(1) + } + // Dump all goroutine stacks before exiting. + // First, make sure we see the trace for the current goroutine on standard error. + // If -logtostderr has been specified, the loop below will do that anyway + // as the first stack in the full dump. + if !l.toStderr { + os.Stderr.Write(stacks(false)) + } + // Write the stack trace for all goroutines to the files. + trace := stacks(true) + logExitFunc = func(error) {} // If we get a write error, we'll still exit below. + for log := fatalLog; log >= infoLog; log-- { + if f := l.file[log]; f != nil { // Can be nil if -logtostderr is set. + f.Write(trace) + } + } + l.mu.Unlock() + timeoutFlush(10 * time.Second) + os.Exit(255) // C++ uses -1, which is silly because it's anded with 255 anyway. + } + l.putBuffer(buf) + l.mu.Unlock() + if stats := severityStats[s]; stats != nil { + atomic.AddInt64(&stats.lines, 1) + atomic.AddInt64(&stats.bytes, int64(len(data))) + } +} + +// timeoutFlush calls Flush and returns when it completes or after timeout +// elapses, whichever happens first. This is needed because the hooks invoked +// by Flush may deadlock when glog.Fatal is called from a hook that holds +// a lock. +func timeoutFlush(timeout time.Duration) { + done := make(chan bool, 1) + go func() { + Flush() // calls logging.lockAndFlushAll() + done <- true + }() + select { + case <-done: + case <-time.After(timeout): + fmt.Fprintln(os.Stderr, "glog: Flush took longer than", timeout) + } +} + +// stacks is a wrapper for runtime.Stack that attempts to recover the data for all goroutines. +func stacks(all bool) []byte { + // We don't know how big the traces are, so grow a few times if they don't fit. Start large, though. + n := 10000 + if all { + n = 100000 + } + var trace []byte + for i := 0; i < 5; i++ { + trace = make([]byte, n) + nbytes := runtime.Stack(trace, all) + if nbytes < len(trace) { + return trace[:nbytes] + } + n *= 2 + } + return trace +} + +// logExitFunc provides a simple mechanism to override the default behavior +// of exiting on error. Used in testing and to guarantee we reach a required exit +// for fatal logs. Instead, exit could be a function rather than a method but that +// would make its use clumsier. +var logExitFunc func(error) + +// exit is called if there is trouble creating or writing log files. +// It flushes the logs and exits the program; there's no point in hanging around. +// l.mu is held. +func (l *loggingT) exit(err error) { + fmt.Fprintf(os.Stderr, "log: exiting because of error: %s\n", err) + // If logExitFunc is set, we do that instead of exiting. + if logExitFunc != nil { + logExitFunc(err) + return + } + l.flushAll() + os.Exit(2) +} + +// syncBuffer joins a bufio.Writer to its underlying file, providing access to the +// file's Sync method and providing a wrapper for the Write method that provides log +// file rotation. There are conflicting methods, so the file cannot be embedded. +// l.mu is held for all its methods. +type syncBuffer struct { + logger *loggingT + *bufio.Writer + file *os.File + sev severity + nbytes uint64 // The number of bytes written to this file +} + +func (sb *syncBuffer) Sync() error { + return sb.file.Sync() +} + +func (sb *syncBuffer) Write(p []byte) (n int, err error) { + if sb.nbytes+uint64(len(p)) >= MaxSize { + if err := sb.rotateFile(time.Now()); err != nil { + sb.logger.exit(err) + } + } + n, err = sb.Writer.Write(p) + sb.nbytes += uint64(n) + if err != nil { + sb.logger.exit(err) + } + return +} + +// rotateFile closes the syncBuffer's file and starts a new one. +func (sb *syncBuffer) rotateFile(now time.Time) error { + if sb.file != nil { + sb.Flush() + sb.file.Close() + } + var err error + sb.file, _, err = create(severityName[sb.sev], now) + sb.nbytes = 0 + if err != nil { + return err + } + + sb.Writer = bufio.NewWriterSize(sb.file, bufferSize) + + // Write header. + var buf bytes.Buffer + fmt.Fprintf(&buf, "Log file created at: %s\n", now.Format("2006/01/02 15:04:05")) + fmt.Fprintf(&buf, "Running on machine: %s\n", host) + fmt.Fprintf(&buf, "Binary: Built with %s %s for %s/%s\n", runtime.Compiler, runtime.Version(), runtime.GOOS, runtime.GOARCH) + fmt.Fprintf(&buf, "Log line format: [IWEF]mmdd hh:mm:ss.uuuuuu threadid file:line] msg\n") + n, err := sb.file.Write(buf.Bytes()) + sb.nbytes += uint64(n) + return err +} + +// bufferSize sizes the buffer associated with each log file. It's large +// so that log records can accumulate without the logging thread blocking +// on disk I/O. The flushDaemon will block instead. +const bufferSize = 256 * 1024 + +// createFiles creates all the log files for severity from sev down to infoLog. +// l.mu is held. +func (l *loggingT) createFiles(sev severity) error { + now := time.Now() + // Files are created in decreasing severity order, so as soon as we find one + // has already been created, we can stop. + for s := sev; s >= infoLog && l.file[s] == nil; s-- { + sb := &syncBuffer{ + logger: l, + sev: s, + } + if err := sb.rotateFile(now); err != nil { + return err + } + l.file[s] = sb + } + return nil +} + +const flushInterval = 30 * time.Second + +// flushDaemon periodically flushes the log file buffers. +func (l *loggingT) flushDaemon() { + for _ = range time.NewTicker(flushInterval).C { + l.lockAndFlushAll() + } +} + +// lockAndFlushAll is like flushAll but locks l.mu first. +func (l *loggingT) lockAndFlushAll() { + l.mu.Lock() + l.flushAll() + l.mu.Unlock() +} + +// flushAll flushes all the logs and attempts to "sync" their data to disk. +// l.mu is held. +func (l *loggingT) flushAll() { + // Flush from fatal down, in case there's trouble flushing. + for s := fatalLog; s >= infoLog; s-- { + file := l.file[s] + if file != nil { + file.Flush() // ignore error + file.Sync() // ignore error + } + } +} + +// CopyStandardLogTo arranges for messages written to the Go "log" package's +// default logs to also appear in the Google logs for the named and lower +// severities. Subsequent changes to the standard log's default output location +// or format may break this behavior. +// +// Valid names are "INFO", "WARNING", "ERROR", and "FATAL". If the name is not +// recognized, CopyStandardLogTo panics. +func CopyStandardLogTo(name string) { + sev, ok := severityByName(name) + if !ok { + panic(fmt.Sprintf("log.CopyStandardLogTo(%q): unrecognized severity name", name)) + } + // Set a log format that captures the user's file and line: + // d.go:23: message + stdLog.SetFlags(stdLog.Lshortfile) + stdLog.SetOutput(logBridge(sev)) +} + +// logBridge provides the Write method that enables CopyStandardLogTo to connect +// Go's standard logs to the logs provided by this package. +type logBridge severity + +// Write parses the standard logging line and passes its components to the +// logger for severity(lb). +func (lb logBridge) Write(b []byte) (n int, err error) { + var ( + file = "???" + line = 1 + text string + ) + // Split "d.go:23: message" into "d.go", "23", and "message". + if parts := bytes.SplitN(b, []byte{':'}, 3); len(parts) != 3 || len(parts[0]) < 1 || len(parts[2]) < 1 { + text = fmt.Sprintf("bad log format: %s", b) + } else { + file = string(parts[0]) + text = string(parts[2][1:]) // skip leading space + line, err = strconv.Atoi(string(parts[1])) + if err != nil { + text = fmt.Sprintf("bad line number: %s", b) + line = 1 + } + } + // printWithFileLine with alsoToStderr=true, so standard log messages + // always appear on standard error. + logging.printWithFileLine(severity(lb), file, line, true, text) + return len(b), nil +} + +// setV computes and remembers the V level for a given PC +// when vmodule is enabled. +// File pattern matching takes the basename of the file, stripped +// of its .go suffix, and uses filepath.Match, which is a little more +// general than the *? matching used in C++. +// l.mu is held. +func (l *loggingT) setV(pc uintptr) Level { + fn := runtime.FuncForPC(pc) + file, _ := fn.FileLine(pc) + // The file is something like /a/b/c/d.go. We want just the d. + if strings.HasSuffix(file, ".go") { + file = file[:len(file)-3] + } + if slash := strings.LastIndex(file, "/"); slash >= 0 { + file = file[slash+1:] + } + for _, filter := range l.vmodule.filter { + if filter.match(file) { + l.vmap[pc] = filter.level + return filter.level + } + } + l.vmap[pc] = 0 + return 0 +} + +// Verbose is a boolean type that implements Infof (like Printf) etc. +// See the documentation of V for more information. +type Verbose bool + +// V reports whether verbosity at the call site is at least the requested level. +// The returned value is a boolean of type Verbose, which implements Info, Infoln +// and Infof. These methods will write to the Info log if called. +// Thus, one may write either +// if glog.V(2) { glog.Info("log this") } +// or +// glog.V(2).Info("log this") +// The second form is shorter but the first is cheaper if logging is off because it does +// not evaluate its arguments. +// +// Whether an individual call to V generates a log record depends on the setting of +// the -v and --vmodule flags; both are off by default. If the level in the call to +// V is at least the value of -v, or of -vmodule for the source file containing the +// call, the V call will log. +func V(level Level) Verbose { + // This function tries hard to be cheap unless there's work to do. + // The fast path is two atomic loads and compares. + + // Here is a cheap but safe test to see if V logging is enabled globally. + if logging.verbosity.get() >= level { + return Verbose(true) + } + + // It's off globally but it vmodule may still be set. + // Here is another cheap but safe test to see if vmodule is enabled. + if atomic.LoadInt32(&logging.filterLength) > 0 { + // Now we need a proper lock to use the logging structure. The pcs field + // is shared so we must lock before accessing it. This is fairly expensive, + // but if V logging is enabled we're slow anyway. + logging.mu.Lock() + defer logging.mu.Unlock() + if runtime.Callers(2, logging.pcs[:]) == 0 { + return Verbose(false) + } + v, ok := logging.vmap[logging.pcs[0]] + if !ok { + v = logging.setV(logging.pcs[0]) + } + return Verbose(v >= level) + } + return Verbose(false) +} + +// Info is equivalent to the global Info function, guarded by the value of v. +// See the documentation of V for usage. +func (v Verbose) Info(args ...interface{}) { + if v { + logging.print(infoLog, args...) + } +} + +// Infoln is equivalent to the global Infoln function, guarded by the value of v. +// See the documentation of V for usage. +func (v Verbose) Infoln(args ...interface{}) { + if v { + logging.println(infoLog, args...) + } +} + +// Infof is equivalent to the global Infof function, guarded by the value of v. +// See the documentation of V for usage. +func (v Verbose) Infof(format string, args ...interface{}) { + if v { + logging.printf(infoLog, format, args...) + } +} + +// Info logs to the INFO log. +// Arguments are handled in the manner of fmt.Print; a newline is appended if missing. +func Info(args ...interface{}) { + logging.print(infoLog, args...) +} + +// InfoDepth acts as Info but uses depth to determine which call frame to log. +// InfoDepth(0, "msg") is the same as Info("msg"). +func InfoDepth(depth int, args ...interface{}) { + logging.printDepth(infoLog, depth, args...) +} + +// Infoln logs to the INFO log. +// Arguments are handled in the manner of fmt.Println; a newline is appended if missing. +func Infoln(args ...interface{}) { + logging.println(infoLog, args...) +} + +// Infof logs to the INFO log. +// Arguments are handled in the manner of fmt.Printf; a newline is appended if missing. +func Infof(format string, args ...interface{}) { + logging.printf(infoLog, format, args...) +} + +// Warning logs to the WARNING and INFO logs. +// Arguments are handled in the manner of fmt.Print; a newline is appended if missing. +func Warning(args ...interface{}) { + logging.print(warningLog, args...) +} + +// WarningDepth acts as Warning but uses depth to determine which call frame to log. +// WarningDepth(0, "msg") is the same as Warning("msg"). +func WarningDepth(depth int, args ...interface{}) { + logging.printDepth(warningLog, depth, args...) +} + +// Warningln logs to the WARNING and INFO logs. +// Arguments are handled in the manner of fmt.Println; a newline is appended if missing. +func Warningln(args ...interface{}) { + logging.println(warningLog, args...) +} + +// Warningf logs to the WARNING and INFO logs. +// Arguments are handled in the manner of fmt.Printf; a newline is appended if missing. +func Warningf(format string, args ...interface{}) { + logging.printf(warningLog, format, args...) +} + +// Error logs to the ERROR, WARNING, and INFO logs. +// Arguments are handled in the manner of fmt.Print; a newline is appended if missing. +func Error(args ...interface{}) { + logging.print(errorLog, args...) +} + +// ErrorDepth acts as Error but uses depth to determine which call frame to log. +// ErrorDepth(0, "msg") is the same as Error("msg"). +func ErrorDepth(depth int, args ...interface{}) { + logging.printDepth(errorLog, depth, args...) +} + +// Errorln logs to the ERROR, WARNING, and INFO logs. +// Arguments are handled in the manner of fmt.Println; a newline is appended if missing. +func Errorln(args ...interface{}) { + logging.println(errorLog, args...) +} + +// Errorf logs to the ERROR, WARNING, and INFO logs. +// Arguments are handled in the manner of fmt.Printf; a newline is appended if missing. +func Errorf(format string, args ...interface{}) { + logging.printf(errorLog, format, args...) +} + +// Fatal logs to the FATAL, ERROR, WARNING, and INFO logs, +// including a stack trace of all running goroutines, then calls os.Exit(255). +// Arguments are handled in the manner of fmt.Print; a newline is appended if missing. +func Fatal(args ...interface{}) { + logging.print(fatalLog, args...) +} + +// FatalDepth acts as Fatal but uses depth to determine which call frame to log. +// FatalDepth(0, "msg") is the same as Fatal("msg"). +func FatalDepth(depth int, args ...interface{}) { + logging.printDepth(fatalLog, depth, args...) +} + +// Fatalln logs to the FATAL, ERROR, WARNING, and INFO logs, +// including a stack trace of all running goroutines, then calls os.Exit(255). +// Arguments are handled in the manner of fmt.Println; a newline is appended if missing. +func Fatalln(args ...interface{}) { + logging.println(fatalLog, args...) +} + +// Fatalf logs to the FATAL, ERROR, WARNING, and INFO logs, +// including a stack trace of all running goroutines, then calls os.Exit(255). +// Arguments are handled in the manner of fmt.Printf; a newline is appended if missing. +func Fatalf(format string, args ...interface{}) { + logging.printf(fatalLog, format, args...) +} + +// fatalNoStacks is non-zero if we are to exit without dumping goroutine stacks. +// It allows Exit and relatives to use the Fatal logs. +var fatalNoStacks uint32 + +// Exit logs to the FATAL, ERROR, WARNING, and INFO logs, then calls os.Exit(1). +// Arguments are handled in the manner of fmt.Print; a newline is appended if missing. +func Exit(args ...interface{}) { + atomic.StoreUint32(&fatalNoStacks, 1) + logging.print(fatalLog, args...) +} + +// ExitDepth acts as Exit but uses depth to determine which call frame to log. +// ExitDepth(0, "msg") is the same as Exit("msg"). +func ExitDepth(depth int, args ...interface{}) { + atomic.StoreUint32(&fatalNoStacks, 1) + logging.printDepth(fatalLog, depth, args...) +} + +// Exitln logs to the FATAL, ERROR, WARNING, and INFO logs, then calls os.Exit(1). +func Exitln(args ...interface{}) { + atomic.StoreUint32(&fatalNoStacks, 1) + logging.println(fatalLog, args...) +} + +// Exitf logs to the FATAL, ERROR, WARNING, and INFO logs, then calls os.Exit(1). +// Arguments are handled in the manner of fmt.Printf; a newline is appended if missing. +func Exitf(format string, args ...interface{}) { + atomic.StoreUint32(&fatalNoStacks, 1) + logging.printf(fatalLog, format, args...) +} |