add package

[bytom/vapor.git] / vendor / github.com / hashicorp / go-hclog / stacktrace.go

diff --git a/vendor/github.com/hashicorp/go-hclog/stacktrace.go b/vendor/github.com/hashicorp/go-hclog/stacktrace.go
new file mode 100644 (file)
index 0000000..8af1a3b
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-hclog/stacktrace.go
@@ -0,0 +1,108 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package hclog
+
+import (
+       "bytes"
+       "runtime"
+       "strconv"
+       "strings"
+       "sync"
+)
+
+var (
+       _stacktraceIgnorePrefixes = []string{
+               "runtime.goexit",
+               "runtime.main",
+       }
+       _stacktracePool = sync.Pool{
+               New: func() interface{} {
+                       return newProgramCounters(64)
+               },
+       }
+)
+
+// A stacktrace gathered by a previous call to log.Stacktrace. If passed
+// to a logging function, the stacktrace will be appended.
+type CapturedStacktrace string
+
+// Gather a stacktrace of the current goroutine and return it to be passed
+// to a logging function.
+func Stacktrace() CapturedStacktrace {
+       return CapturedStacktrace(takeStacktrace())
+}
+
+func takeStacktrace() string {
+       programCounters := _stacktracePool.Get().(*programCounters)
+       defer _stacktracePool.Put(programCounters)
+
+       var buffer bytes.Buffer
+
+       for {
+               // Skip the call to runtime.Counters and takeStacktrace so that the
+               // program counters start at the caller of takeStacktrace.
+               n := runtime.Callers(2, programCounters.pcs)
+               if n < cap(programCounters.pcs) {
+                       programCounters.pcs = programCounters.pcs[:n]
+                       break
+               }
+               // Don't put the too-short counter slice back into the pool; this lets
+               // the pool adjust if we consistently take deep stacktraces.
+               programCounters = newProgramCounters(len(programCounters.pcs) * 2)
+       }
+
+       i := 0
+       frames := runtime.CallersFrames(programCounters.pcs)
+       for frame, more := frames.Next(); more; frame, more = frames.Next() {
+               if shouldIgnoreStacktraceFunction(frame.Function) {
+                       continue
+               }
+               if i != 0 {
+                       buffer.WriteByte('\n')
+               }
+               i++
+               buffer.WriteString(frame.Function)
+               buffer.WriteByte('\n')
+               buffer.WriteByte('\t')
+               buffer.WriteString(frame.File)
+               buffer.WriteByte(':')
+               buffer.WriteString(strconv.Itoa(int(frame.Line)))
+       }
+
+       return buffer.String()
+}
+
+func shouldIgnoreStacktraceFunction(function string) bool {
+       for _, prefix := range _stacktraceIgnorePrefixes {
+               if strings.HasPrefix(function, prefix) {
+                       return true
+               }
+       }
+       return false
+}
+
+type programCounters struct {
+       pcs []uintptr
+}
+
+func newProgramCounters(size int) *programCounters {
+       return &programCounters{make([]uintptr, size)}
+}