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Diffstat (limited to 'vendor/golang.org/x/net/trace/trace.go')
| -rw-r--r-- | vendor/golang.org/x/net/trace/trace.go | 1063 |
1 files changed, 1063 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/trace/trace.go b/vendor/golang.org/x/net/trace/trace.go new file mode 100644 index 0000000..d860fcc --- /dev/null +++ b/vendor/golang.org/x/net/trace/trace.go @@ -0,0 +1,1063 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +/* +Package trace implements tracing of requests and long-lived objects. +It exports HTTP interfaces on /debug/requests and /debug/events. + +A trace.Trace provides tracing for short-lived objects, usually requests. +A request handler might be implemented like this: + + func fooHandler(w http.ResponseWriter, req *http.Request) { + tr := trace.New("mypkg.Foo", req.URL.Path) + defer tr.Finish() + ... + tr.LazyPrintf("some event %q happened", str) + ... + if err := somethingImportant(); err != nil { + tr.LazyPrintf("somethingImportant failed: %v", err) + tr.SetError() + } + } + +The /debug/requests HTTP endpoint organizes the traces by family, +errors, and duration. It also provides histogram of request duration +for each family. + +A trace.EventLog provides tracing for long-lived objects, such as RPC +connections. + + // A Fetcher fetches URL paths for a single domain. + type Fetcher struct { + domain string + events trace.EventLog + } + + func NewFetcher(domain string) *Fetcher { + return &Fetcher{ + domain, + trace.NewEventLog("mypkg.Fetcher", domain), + } + } + + func (f *Fetcher) Fetch(path string) (string, error) { + resp, err := http.Get("http://" + f.domain + "/" + path) + if err != nil { + f.events.Errorf("Get(%q) = %v", path, err) + return "", err + } + f.events.Printf("Get(%q) = %s", path, resp.Status) + ... + } + + func (f *Fetcher) Close() error { + f.events.Finish() + return nil + } + +The /debug/events HTTP endpoint organizes the event logs by family and +by time since the last error. The expanded view displays recent log +entries and the log's call stack. +*/ +package trace // import "golang.org/x/net/trace" + +import ( + "bytes" + "fmt" + "html/template" + "io" + "log" + "net" + "net/http" + "runtime" + "sort" + "strconv" + "sync" + "sync/atomic" + "time" + + "golang.org/x/net/context" + "golang.org/x/net/internal/timeseries" +) + +// DebugUseAfterFinish controls whether to debug uses of Trace values after finishing. +// FOR DEBUGGING ONLY. This will slow down the program. +var DebugUseAfterFinish = false + +// AuthRequest determines whether a specific request is permitted to load the +// /debug/requests or /debug/events pages. +// +// It returns two bools; the first indicates whether the page may be viewed at all, +// and the second indicates whether sensitive events will be shown. +// +// AuthRequest may be replaced by a program to customise its authorisation requirements. +// +// The default AuthRequest function returns (true, true) if and only if the request +// comes from localhost/127.0.0.1/[::1]. +var AuthRequest = func(req *http.Request) (any, sensitive bool) { + // RemoteAddr is commonly in the form "IP" or "IP:port". + // If it is in the form "IP:port", split off the port. + host, _, err := net.SplitHostPort(req.RemoteAddr) + if err != nil { + host = req.RemoteAddr + } + switch host { + case "localhost", "127.0.0.1", "::1": + return true, true + default: + return false, false + } +} + +func init() { + http.HandleFunc("/debug/requests", func(w http.ResponseWriter, req *http.Request) { + any, sensitive := AuthRequest(req) + if !any { + http.Error(w, "not allowed", http.StatusUnauthorized) + return + } + w.Header().Set("Content-Type", "text/html; charset=utf-8") + Render(w, req, sensitive) + }) + http.HandleFunc("/debug/events", func(w http.ResponseWriter, req *http.Request) { + any, sensitive := AuthRequest(req) + if !any { + http.Error(w, "not allowed", http.StatusUnauthorized) + return + } + w.Header().Set("Content-Type", "text/html; charset=utf-8") + RenderEvents(w, req, sensitive) + }) +} + +// Render renders the HTML page typically served at /debug/requests. +// It does not do any auth checking; see AuthRequest for the default auth check +// used by the handler registered on http.DefaultServeMux. +// req may be nil. +func Render(w io.Writer, req *http.Request, sensitive bool) { + data := &struct { + Families []string + ActiveTraceCount map[string]int + CompletedTraces map[string]*family + + // Set when a bucket has been selected. + Traces traceList + Family string + Bucket int + Expanded bool + Traced bool + Active bool + ShowSensitive bool // whether to show sensitive events + + Histogram template.HTML + HistogramWindow string // e.g. "last minute", "last hour", "all time" + + // If non-zero, the set of traces is a partial set, + // and this is the total number. + Total int + }{ + CompletedTraces: completedTraces, + } + + data.ShowSensitive = sensitive + if req != nil { + // Allow show_sensitive=0 to force hiding of sensitive data for testing. + // This only goes one way; you can't use show_sensitive=1 to see things. + if req.FormValue("show_sensitive") == "0" { + data.ShowSensitive = false + } + + if exp, err := strconv.ParseBool(req.FormValue("exp")); err == nil { + data.Expanded = exp + } + if exp, err := strconv.ParseBool(req.FormValue("rtraced")); err == nil { + data.Traced = exp + } + } + + completedMu.RLock() + data.Families = make([]string, 0, len(completedTraces)) + for fam := range completedTraces { + data.Families = append(data.Families, fam) + } + completedMu.RUnlock() + sort.Strings(data.Families) + + // We are careful here to minimize the time spent locking activeMu, + // since that lock is required every time an RPC starts and finishes. + data.ActiveTraceCount = make(map[string]int, len(data.Families)) + activeMu.RLock() + for fam, s := range activeTraces { + data.ActiveTraceCount[fam] = s.Len() + } + activeMu.RUnlock() + + var ok bool + data.Family, data.Bucket, ok = parseArgs(req) + switch { + case !ok: + // No-op + case data.Bucket == -1: + data.Active = true + n := data.ActiveTraceCount[data.Family] + data.Traces = getActiveTraces(data.Family) + if len(data.Traces) < n { + data.Total = n + } + case data.Bucket < bucketsPerFamily: + if b := lookupBucket(data.Family, data.Bucket); b != nil { + data.Traces = b.Copy(data.Traced) + } + default: + if f := getFamily(data.Family, false); f != nil { + var obs timeseries.Observable + f.LatencyMu.RLock() + switch o := data.Bucket - bucketsPerFamily; o { + case 0: + obs = f.Latency.Minute() + data.HistogramWindow = "last minute" + case 1: + obs = f.Latency.Hour() + data.HistogramWindow = "last hour" + case 2: + obs = f.Latency.Total() + data.HistogramWindow = "all time" + } + f.LatencyMu.RUnlock() + if obs != nil { + data.Histogram = obs.(*histogram).html() + } + } + } + + if data.Traces != nil { + defer data.Traces.Free() + sort.Sort(data.Traces) + } + + completedMu.RLock() + defer completedMu.RUnlock() + if err := pageTmpl.ExecuteTemplate(w, "Page", data); err != nil { + log.Printf("net/trace: Failed executing template: %v", err) + } +} + +func parseArgs(req *http.Request) (fam string, b int, ok bool) { + if req == nil { + return "", 0, false + } + fam, bStr := req.FormValue("fam"), req.FormValue("b") + if fam == "" || bStr == "" { + return "", 0, false + } + b, err := strconv.Atoi(bStr) + if err != nil || b < -1 { + return "", 0, false + } + + return fam, b, true +} + +func lookupBucket(fam string, b int) *traceBucket { + f := getFamily(fam, false) + if f == nil || b < 0 || b >= len(f.Buckets) { + return nil + } + return f.Buckets[b] +} + +type contextKeyT string + +var contextKey = contextKeyT("golang.org/x/net/trace.Trace") + +// NewContext returns a copy of the parent context +// and associates it with a Trace. +func NewContext(ctx context.Context, tr Trace) context.Context { + return context.WithValue(ctx, contextKey, tr) +} + +// FromContext returns the Trace bound to the context, if any. +func FromContext(ctx context.Context) (tr Trace, ok bool) { + tr, ok = ctx.Value(contextKey).(Trace) + return +} + +// Trace represents an active request. +type Trace interface { + // LazyLog adds x to the event log. It will be evaluated each time the + // /debug/requests page is rendered. Any memory referenced by x will be + // pinned until the trace is finished and later discarded. + LazyLog(x fmt.Stringer, sensitive bool) + + // LazyPrintf evaluates its arguments with fmt.Sprintf each time the + // /debug/requests page is rendered. Any memory referenced by a will be + // pinned until the trace is finished and later discarded. + LazyPrintf(format string, a ...interface{}) + + // SetError declares that this trace resulted in an error. + SetError() + + // SetRecycler sets a recycler for the trace. + // f will be called for each event passed to LazyLog at a time when + // it is no longer required, whether while the trace is still active + // and the event is discarded, or when a completed trace is discarded. + SetRecycler(f func(interface{})) + + // SetTraceInfo sets the trace info for the trace. + // This is currently unused. + SetTraceInfo(traceID, spanID uint64) + + // SetMaxEvents sets the maximum number of events that will be stored + // in the trace. This has no effect if any events have already been + // added to the trace. + SetMaxEvents(m int) + + // Finish declares that this trace is complete. + // The trace should not be used after calling this method. + Finish() +} + +type lazySprintf struct { + format string + a []interface{} +} + +func (l *lazySprintf) String() string { + return fmt.Sprintf(l.format, l.a...) +} + +// New returns a new Trace with the specified family and title. +func New(family, title string) Trace { + tr := newTrace() + tr.ref() + tr.Family, tr.Title = family, title + tr.Start = time.Now() + tr.events = make([]event, 0, maxEventsPerTrace) + + activeMu.RLock() + s := activeTraces[tr.Family] + activeMu.RUnlock() + if s == nil { + activeMu.Lock() + s = activeTraces[tr.Family] // check again + if s == nil { + s = new(traceSet) + activeTraces[tr.Family] = s + } + activeMu.Unlock() + } + s.Add(tr) + + // Trigger allocation of the completed trace structure for this family. + // This will cause the family to be present in the request page during + // the first trace of this family. We don't care about the return value, + // nor is there any need for this to run inline, so we execute it in its + // own goroutine, but only if the family isn't allocated yet. + completedMu.RLock() + if _, ok := completedTraces[tr.Family]; !ok { + go allocFamily(tr.Family) + } + completedMu.RUnlock() + + return tr +} + +func (tr *trace) Finish() { + tr.Elapsed = time.Now().Sub(tr.Start) + if DebugUseAfterFinish { + buf := make([]byte, 4<<10) // 4 KB should be enough + n := runtime.Stack(buf, false) + tr.finishStack = buf[:n] + } + + activeMu.RLock() + m := activeTraces[tr.Family] + activeMu.RUnlock() + m.Remove(tr) + + f := getFamily(tr.Family, true) + for _, b := range f.Buckets { + if b.Cond.match(tr) { + b.Add(tr) + } + } + // Add a sample of elapsed time as microseconds to the family's timeseries + h := new(histogram) + h.addMeasurement(tr.Elapsed.Nanoseconds() / 1e3) + f.LatencyMu.Lock() + f.Latency.Add(h) + f.LatencyMu.Unlock() + + tr.unref() // matches ref in New +} + +const ( + bucketsPerFamily = 9 + tracesPerBucket = 10 + maxActiveTraces = 20 // Maximum number of active traces to show. + maxEventsPerTrace = 10 + numHistogramBuckets = 38 +) + +var ( + // The active traces. + activeMu sync.RWMutex + activeTraces = make(map[string]*traceSet) // family -> traces + + // Families of completed traces. + completedMu sync.RWMutex + completedTraces = make(map[string]*family) // family -> traces +) + +type traceSet struct { + mu sync.RWMutex + m map[*trace]bool + + // We could avoid the entire map scan in FirstN by having a slice of all the traces + // ordered by start time, and an index into that from the trace struct, with a periodic + // repack of the slice after enough traces finish; we could also use a skip list or similar. + // However, that would shift some of the expense from /debug/requests time to RPC time, + // which is probably the wrong trade-off. +} + +func (ts *traceSet) Len() int { + ts.mu.RLock() + defer ts.mu.RUnlock() + return len(ts.m) +} + +func (ts *traceSet) Add(tr *trace) { + ts.mu.Lock() + if ts.m == nil { + ts.m = make(map[*trace]bool) + } + ts.m[tr] = true + ts.mu.Unlock() +} + +func (ts *traceSet) Remove(tr *trace) { + ts.mu.Lock() + delete(ts.m, tr) + ts.mu.Unlock() +} + +// FirstN returns the first n traces ordered by time. +func (ts *traceSet) FirstN(n int) traceList { + ts.mu.RLock() + defer ts.mu.RUnlock() + + if n > len(ts.m) { + n = len(ts.m) + } + trl := make(traceList, 0, n) + + // Fast path for when no selectivity is needed. + if n == len(ts.m) { + for tr := range ts.m { + tr.ref() + trl = append(trl, tr) + } + sort.Sort(trl) + return trl + } + + // Pick the oldest n traces. + // This is inefficient. See the comment in the traceSet struct. + for tr := range ts.m { + // Put the first n traces into trl in the order they occur. + // When we have n, sort trl, and thereafter maintain its order. + if len(trl) < n { + tr.ref() + trl = append(trl, tr) + if len(trl) == n { + // This is guaranteed to happen exactly once during this loop. + sort.Sort(trl) + } + continue + } + if tr.Start.After(trl[n-1].Start) { + continue + } + + // Find where to insert this one. + tr.ref() + i := sort.Search(n, func(i int) bool { return trl[i].Start.After(tr.Start) }) + trl[n-1].unref() + copy(trl[i+1:], trl[i:]) + trl[i] = tr + } + + return trl +} + +func getActiveTraces(fam string) traceList { + activeMu.RLock() + s := activeTraces[fam] + activeMu.RUnlock() + if s == nil { + return nil + } + return s.FirstN(maxActiveTraces) +} + +func getFamily(fam string, allocNew bool) *family { + completedMu.RLock() + f := completedTraces[fam] + completedMu.RUnlock() + if f == nil && allocNew { + f = allocFamily(fam) + } + return f +} + +func allocFamily(fam string) *family { + completedMu.Lock() + defer completedMu.Unlock() + f := completedTraces[fam] + if f == nil { + f = newFamily() + completedTraces[fam] = f + } + return f +} + +// family represents a set of trace buckets and associated latency information. +type family struct { + // traces may occur in multiple buckets. + Buckets [bucketsPerFamily]*traceBucket + + // latency time series + LatencyMu sync.RWMutex + Latency *timeseries.MinuteHourSeries +} + +func newFamily() *family { + return &family{ + Buckets: [bucketsPerFamily]*traceBucket{ + {Cond: minCond(0)}, + {Cond: minCond(50 * time.Millisecond)}, + {Cond: minCond(100 * time.Millisecond)}, + {Cond: minCond(200 * time.Millisecond)}, + {Cond: minCond(500 * time.Millisecond)}, + {Cond: minCond(1 * time.Second)}, + {Cond: minCond(10 * time.Second)}, + {Cond: minCond(100 * time.Second)}, + {Cond: errorCond{}}, + }, + Latency: timeseries.NewMinuteHourSeries(func() timeseries.Observable { return new(histogram) }), + } +} + +// traceBucket represents a size-capped bucket of historic traces, +// along with a condition for a trace to belong to the bucket. +type traceBucket struct { + Cond cond + + // Ring buffer implementation of a fixed-size FIFO queue. + mu sync.RWMutex + buf [tracesPerBucket]*trace + start int // < tracesPerBucket + length int // <= tracesPerBucket +} + +func (b *traceBucket) Add(tr *trace) { + b.mu.Lock() + defer b.mu.Unlock() + + i := b.start + b.length + if i >= tracesPerBucket { + i -= tracesPerBucket + } + if b.length == tracesPerBucket { + // "Remove" an element from the bucket. + b.buf[i].unref() + b.start++ + if b.start == tracesPerBucket { + b.start = 0 + } + } + b.buf[i] = tr + if b.length < tracesPerBucket { + b.length++ + } + tr.ref() +} + +// Copy returns a copy of the traces in the bucket. +// If tracedOnly is true, only the traces with trace information will be returned. +// The logs will be ref'd before returning; the caller should call +// the Free method when it is done with them. +// TODO(dsymonds): keep track of traced requests in separate buckets. +func (b *traceBucket) Copy(tracedOnly bool) traceList { + b.mu.RLock() + defer b.mu.RUnlock() + + trl := make(traceList, 0, b.length) + for i, x := 0, b.start; i < b.length; i++ { + tr := b.buf[x] + if !tracedOnly || tr.spanID != 0 { + tr.ref() + trl = append(trl, tr) + } + x++ + if x == b.length { + x = 0 + } + } + return trl +} + +func (b *traceBucket) Empty() bool { + b.mu.RLock() + defer b.mu.RUnlock() + return b.length == 0 +} + +// cond represents a condition on a trace. +type cond interface { + match(t *trace) bool + String() string +} + +type minCond time.Duration + +func (m minCond) match(t *trace) bool { return t.Elapsed >= time.Duration(m) } +func (m minCond) String() string { return fmt.Sprintf("≥%gs", time.Duration(m).Seconds()) } + +type errorCond struct{} + +func (e errorCond) match(t *trace) bool { return t.IsError } +func (e errorCond) String() string { return "errors" } + +type traceList []*trace + +// Free calls unref on each element of the list. +func (trl traceList) Free() { + for _, t := range trl { + t.unref() + } +} + +// traceList may be sorted in reverse chronological order. +func (trl traceList) Len() int { return len(trl) } +func (trl traceList) Less(i, j int) bool { return trl[i].Start.After(trl[j].Start) } +func (trl traceList) Swap(i, j int) { trl[i], trl[j] = trl[j], trl[i] } + +// An event is a timestamped log entry in a trace. +type event struct { + When time.Time + Elapsed time.Duration // since previous event in trace + NewDay bool // whether this event is on a different day to the previous event + Recyclable bool // whether this event was passed via LazyLog + What interface{} // string or fmt.Stringer + Sensitive bool // whether this event contains sensitive information +} + +// WhenString returns a string representation of the elapsed time of the event. +// It will include the date if midnight was crossed. +func (e event) WhenString() string { + if e.NewDay { + return e.When.Format("2006/01/02 15:04:05.000000") + } + return e.When.Format("15:04:05.000000") +} + +// discarded represents a number of discarded events. +// It is stored as *discarded to make it easier to update in-place. +type discarded int + +func (d *discarded) String() string { + return fmt.Sprintf("(%d events discarded)", int(*d)) +} + +// trace represents an active or complete request, +// either sent or received by this program. +type trace struct { + // Family is the top-level grouping of traces to which this belongs. + Family string + + // Title is the title of this trace. + Title string + + // Timing information. + Start time.Time + Elapsed time.Duration // zero while active + + // Trace information if non-zero. + traceID uint64 + spanID uint64 + + // Whether this trace resulted in an error. + IsError bool + + // Append-only sequence of events (modulo discards). + mu sync.RWMutex + events []event + + refs int32 // how many buckets this is in + recycler func(interface{}) + disc discarded // scratch space to avoid allocation + + finishStack []byte // where finish was called, if DebugUseAfterFinish is set +} + +func (tr *trace) reset() { + // Clear all but the mutex. Mutexes may not be copied, even when unlocked. + tr.Family = "" + tr.Title = "" + tr.Start = time.Time{} + tr.Elapsed = 0 + tr.traceID = 0 + tr.spanID = 0 + tr.IsError = false + tr.events = nil + tr.refs = 0 + tr.recycler = nil + tr.disc = 0 + tr.finishStack = nil +} + +// delta returns the elapsed time since the last event or the trace start, +// and whether it spans midnight. +// L >= tr.mu +func (tr *trace) delta(t time.Time) (time.Duration, bool) { + if len(tr.events) == 0 { + return t.Sub(tr.Start), false + } + prev := tr.events[len(tr.events)-1].When + return t.Sub(prev), prev.Day() != t.Day() +} + +func (tr *trace) addEvent(x interface{}, recyclable, sensitive bool) { + if DebugUseAfterFinish && tr.finishStack != nil { + buf := make([]byte, 4<<10) // 4 KB should be enough + n := runtime.Stack(buf, false) + log.Printf("net/trace: trace used after finish:\nFinished at:\n%s\nUsed at:\n%s", tr.finishStack, buf[:n]) + } + + /* + NOTE TO DEBUGGERS + + If you are here because your program panicked in this code, + it is almost definitely the fault of code using this package, + and very unlikely to be the fault of this code. + + The most likely scenario is that some code elsewhere is using + a requestz.Trace after its Finish method is called. + You can temporarily set the DebugUseAfterFinish var + to help discover where that is; do not leave that var set, + since it makes this package much less efficient. + */ + + e := event{When: time.Now(), What: x, Recyclable: recyclable, Sensitive: sensitive} + tr.mu.Lock() + e.Elapsed, e.NewDay = tr.delta(e.When) + if len(tr.events) < cap(tr.events) { + tr.events = append(tr.events, e) + } else { + // Discard the middle events. + di := int((cap(tr.events) - 1) / 2) + if d, ok := tr.events[di].What.(*discarded); ok { + (*d)++ + } else { + // disc starts at two to count for the event it is replacing, + // plus the next one that we are about to drop. + tr.disc = 2 + if tr.recycler != nil && tr.events[di].Recyclable { + go tr.recycler(tr.events[di].What) + } + tr.events[di].What = &tr.disc + } + // The timestamp of the discarded meta-event should be + // the time of the last event it is representing. + tr.events[di].When = tr.events[di+1].When + + if tr.recycler != nil && tr.events[di+1].Recyclable { + go tr.recycler(tr.events[di+1].What) + } + copy(tr.events[di+1:], tr.events[di+2:]) + tr.events[cap(tr.events)-1] = e + } + tr.mu.Unlock() +} + +func (tr *trace) LazyLog(x fmt.Stringer, sensitive bool) { + tr.addEvent(x, true, sensitive) +} + +func (tr *trace) LazyPrintf(format string, a ...interface{}) { + tr.addEvent(&lazySprintf{format, a}, false, false) +} + +func (tr *trace) SetError() { tr.IsError = true } + +func (tr *trace) SetRecycler(f func(interface{})) { + tr.recycler = f +} + +func (tr *trace) SetTraceInfo(traceID, spanID uint64) { + tr.traceID, tr.spanID = traceID, spanID +} + +func (tr *trace) SetMaxEvents(m int) { + // Always keep at least three events: first, discarded count, last. + if len(tr.events) == 0 && m > 3 { + tr.events = make([]event, 0, m) + } +} + +func (tr *trace) ref() { + atomic.AddInt32(&tr.refs, 1) +} + +func (tr *trace) unref() { + if atomic.AddInt32(&tr.refs, -1) == 0 { + if tr.recycler != nil { + // freeTrace clears tr, so we hold tr.recycler and tr.events here. + go func(f func(interface{}), es []event) { + for _, e := range es { + if e.Recyclable { + f(e.What) + } + } + }(tr.recycler, tr.events) + } + + freeTrace(tr) + } +} + +func (tr *trace) When() string { + return tr.Start.Format("2006/01/02 15:04:05.000000") +} + +func (tr *trace) ElapsedTime() string { + t := tr.Elapsed + if t == 0 { + // Active trace. + t = time.Since(tr.Start) + } + return fmt.Sprintf("%.6f", t.Seconds()) +} + +func (tr *trace) Events() []event { + tr.mu.RLock() + defer tr.mu.RUnlock() + return tr.events +} + +var traceFreeList = make(chan *trace, 1000) // TODO(dsymonds): Use sync.Pool? + +// newTrace returns a trace ready to use. +func newTrace() *trace { + select { + case tr := <-traceFreeList: + return tr + default: + return new(trace) + } +} + +// freeTrace adds tr to traceFreeList if there's room. +// This is non-blocking. +func freeTrace(tr *trace) { + if DebugUseAfterFinish { + return // never reuse + } + tr.reset() + select { + case traceFreeList <- tr: + default: + } +} + +func elapsed(d time.Duration) string { + b := []byte(fmt.Sprintf("%.6f", d.Seconds())) + + // For subsecond durations, blank all zeros before decimal point, + // and all zeros between the decimal point and the first non-zero digit. + if d < time.Second { + dot := bytes.IndexByte(b, '.') + for i := 0; i < dot; i++ { + b[i] = ' ' + } + for i := dot + 1; i < len(b); i++ { + if b[i] == '0' { + b[i] = ' ' + } else { + break + } + } + } + + return string(b) +} + +var pageTmpl = template.Must(template.New("Page").Funcs(template.FuncMap{ + "elapsed": elapsed, + "add": func(a, b int) int { return a + b }, +}).Parse(pageHTML)) + +const pageHTML = ` +{{template "Prolog" .}} +{{template "StatusTable" .}} +{{template "Epilog" .}} + +{{define "Prolog"}} +<html> + <head> + <title>/debug/requests</title> + <style type="text/css"> + body { + font-family: sans-serif; + } + table#tr-status td.family { + padding-right: 2em; + } + table#tr-status td.active { + padding-right: 1em; + } + table#tr-status td.latency-first { + padding-left: 1em; + } + table#tr-status td.empty { + color: #aaa; + } + table#reqs { + margin-top: 1em; + } + table#reqs tr.first { + {{if $.Expanded}}font-weight: bold;{{end}} + } + table#reqs td { + font-family: monospace; + } + table#reqs td.when { + text-align: right; + white-space: nowrap; + } + table#reqs td.elapsed { + padding: 0 0.5em; + text-align: right; + white-space: pre; + width: 10em; + } + address { + font-size: smaller; + margin-top: 5em; + } + </style> + </head> + <body> + +<h1>/debug/requests</h1> +{{end}} {{/* end of Prolog */}} + +{{define "StatusTable"}} +<table id="tr-status"> + {{range $fam := .Families}} + <tr> + <td class="family">{{$fam}}</td> + + {{$n := index $.ActiveTraceCount $fam}} + <td class="active {{if not $n}}empty{{end}}"> + {{if $n}}<a href="?fam={{$fam}}&b=-1{{if $.Expanded}}&exp=1{{end}}">{{end}} + [{{$n}} active] + {{if $n}}</a>{{end}} + </td> + + {{$f := index $.CompletedTraces $fam}} + {{range $i, $b := $f.Buckets}} + {{$empty := $b.Empty}} + <td {{if $empty}}class="empty"{{end}}> + {{if not $empty}}<a href="?fam={{$fam}}&b={{$i}}{{if $.Expanded}}&exp=1{{end}}">{{end}} + [{{.Cond}}] + {{if not $empty}}</a>{{end}} + </td> + {{end}} + + {{$nb := len $f.Buckets}} + <td class="latency-first"> + <a href="?fam={{$fam}}&b={{$nb}}">[minute]</a> + </td> + <td> + <a href="?fam={{$fam}}&b={{add $nb 1}}">[hour]</a> + </td> + <td> + <a href="?fam={{$fam}}&b={{add $nb 2}}">[total]</a> + </td> + + </tr> + {{end}} +</table> +{{end}} {{/* end of StatusTable */}} + +{{define "Epilog"}} +{{if $.Traces}} +<hr /> +<h3>Family: {{$.Family}}</h3> + +{{if or $.Expanded $.Traced}} + <a href="?fam={{$.Family}}&b={{$.Bucket}}">[Normal/Summary]</a> +{{else}} + [Normal/Summary] +{{end}} + +{{if or (not $.Expanded) $.Traced}} + <a href="?fam={{$.Family}}&b={{$.Bucket}}&exp=1">[Normal/Expanded]</a> +{{else}} + [Normal/Expanded] +{{end}} + +{{if not $.Active}} + {{if or $.Expanded (not $.Traced)}} + <a href="?fam={{$.Family}}&b={{$.Bucket}}&rtraced=1">[Traced/Summary]</a> + {{else}} + [Traced/Summary] + {{end}} + {{if or (not $.Expanded) (not $.Traced)}} + <a href="?fam={{$.Family}}&b={{$.Bucket}}&exp=1&rtraced=1">[Traced/Expanded]</a> + {{else}} + [Traced/Expanded] + {{end}} +{{end}} + +{{if $.Total}} +<p><em>Showing <b>{{len $.Traces}}</b> of <b>{{$.Total}}</b> traces.</em></p> +{{end}} + +<table id="reqs"> + <caption> + {{if $.Active}}Active{{else}}Completed{{end}} Requests + </caption> + <tr><th>When</th><th>Elapsed (s)</th></tr> + {{range $tr := $.Traces}} + <tr class="first"> + <td class="when">{{$tr.When}}</td> + <td class="elapsed">{{$tr.ElapsedTime}}</td> + <td>{{$tr.Title}}</td> + {{/* TODO: include traceID/spanID */}} + </tr> + {{if $.Expanded}} + {{range $tr.Events}} + <tr> + <td class="when">{{.WhenString}}</td> + <td class="elapsed">{{elapsed .Elapsed}}</td> + <td>{{if or $.ShowSensitive (not .Sensitive)}}... {{.What}}{{else}}<em>[redacted]</em>{{end}}</td> + </tr> + {{end}} + {{end}} + {{end}} +</table> +{{end}} {{/* if $.Traces */}} + +{{if $.Histogram}} +<h4>Latency (µs) of {{$.Family}} over {{$.HistogramWindow}}</h4> +{{$.Histogram}} +{{end}} {{/* if $.Histogram */}} + + </body> +</html> +{{end}} {{/* end of Epilog */}} +` |