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-rw-r--r--dependencies/pkg/mod/go.uber.org/zap@v1.25.0/stacktrace.go174
1 files changed, 174 insertions, 0 deletions
diff --git a/dependencies/pkg/mod/go.uber.org/zap@v1.25.0/stacktrace.go b/dependencies/pkg/mod/go.uber.org/zap@v1.25.0/stacktrace.go
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+++ b/dependencies/pkg/mod/go.uber.org/zap@v1.25.0/stacktrace.go
@@ -0,0 +1,174 @@
+// 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 zap
+
+import (
+ "runtime"
+
+ "go.uber.org/zap/buffer"
+ "go.uber.org/zap/internal/bufferpool"
+ "go.uber.org/zap/internal/pool"
+)
+
+var _stacktracePool = pool.New(func() *stacktrace {
+ return &stacktrace{
+ storage: make([]uintptr, 64),
+ }
+})
+
+type stacktrace struct {
+ pcs []uintptr // program counters; always a subslice of storage
+ frames *runtime.Frames
+
+ // The size of pcs varies depending on requirements:
+ // it will be one if the only the first frame was requested,
+ // and otherwise it will reflect the depth of the call stack.
+ //
+ // storage decouples the slice we need (pcs) from the slice we pool.
+ // We will always allocate a reasonably large storage, but we'll use
+ // only as much of it as we need.
+ storage []uintptr
+}
+
+// stacktraceDepth specifies how deep of a stack trace should be captured.
+type stacktraceDepth int
+
+const (
+ // stacktraceFirst captures only the first frame.
+ stacktraceFirst stacktraceDepth = iota
+
+ // stacktraceFull captures the entire call stack, allocating more
+ // storage for it if needed.
+ stacktraceFull
+)
+
+// captureStacktrace captures a stack trace of the specified depth, skipping
+// the provided number of frames. skip=0 identifies the caller of
+// captureStacktrace.
+//
+// The caller must call Free on the returned stacktrace after using it.
+func captureStacktrace(skip int, depth stacktraceDepth) *stacktrace {
+ stack := _stacktracePool.Get()
+
+ switch depth {
+ case stacktraceFirst:
+ stack.pcs = stack.storage[:1]
+ case stacktraceFull:
+ stack.pcs = stack.storage
+ }
+
+ // Unlike other "skip"-based APIs, skip=0 identifies runtime.Callers
+ // itself. +2 to skip captureStacktrace and runtime.Callers.
+ numFrames := runtime.Callers(
+ skip+2,
+ stack.pcs,
+ )
+
+ // runtime.Callers truncates the recorded stacktrace if there is no
+ // room in the provided slice. For the full stack trace, keep expanding
+ // storage until there are fewer frames than there is room.
+ if depth == stacktraceFull {
+ pcs := stack.pcs
+ for numFrames == len(pcs) {
+ pcs = make([]uintptr, len(pcs)*2)
+ numFrames = runtime.Callers(skip+2, pcs)
+ }
+
+ // Discard old storage instead of returning it to the pool.
+ // This will adjust the pool size over time if stack traces are
+ // consistently very deep.
+ stack.storage = pcs
+ stack.pcs = pcs[:numFrames]
+ } else {
+ stack.pcs = stack.pcs[:numFrames]
+ }
+
+ stack.frames = runtime.CallersFrames(stack.pcs)
+ return stack
+}
+
+// Free releases resources associated with this stacktrace
+// and returns it back to the pool.
+func (st *stacktrace) Free() {
+ st.frames = nil
+ st.pcs = nil
+ _stacktracePool.Put(st)
+}
+
+// Count reports the total number of frames in this stacktrace.
+// Count DOES NOT change as Next is called.
+func (st *stacktrace) Count() int {
+ return len(st.pcs)
+}
+
+// Next returns the next frame in the stack trace,
+// and a boolean indicating whether there are more after it.
+func (st *stacktrace) Next() (_ runtime.Frame, more bool) {
+ return st.frames.Next()
+}
+
+func takeStacktrace(skip int) string {
+ stack := captureStacktrace(skip+1, stacktraceFull)
+ defer stack.Free()
+
+ buffer := bufferpool.Get()
+ defer buffer.Free()
+
+ stackfmt := newStackFormatter(buffer)
+ stackfmt.FormatStack(stack)
+ return buffer.String()
+}
+
+// stackFormatter formats a stack trace into a readable string representation.
+type stackFormatter struct {
+ b *buffer.Buffer
+ nonEmpty bool // whehther we've written at least one frame already
+}
+
+// newStackFormatter builds a new stackFormatter.
+func newStackFormatter(b *buffer.Buffer) stackFormatter {
+ return stackFormatter{b: b}
+}
+
+// FormatStack formats all remaining frames in the provided stacktrace -- minus
+// the final runtime.main/runtime.goexit frame.
+func (sf *stackFormatter) FormatStack(stack *stacktrace) {
+ // Note: On the last iteration, frames.Next() returns false, with a valid
+ // frame, but we ignore this frame. The last frame is a runtime frame which
+ // adds noise, since it's only either runtime.main or runtime.goexit.
+ for frame, more := stack.Next(); more; frame, more = stack.Next() {
+ sf.FormatFrame(frame)
+ }
+}
+
+// FormatFrame formats the given frame.
+func (sf *stackFormatter) FormatFrame(frame runtime.Frame) {
+ if sf.nonEmpty {
+ sf.b.AppendByte('\n')
+ }
+ sf.nonEmpty = true
+ sf.b.AppendString(frame.Function)
+ sf.b.AppendByte('\n')
+ sf.b.AppendByte('\t')
+ sf.b.AppendString(frame.File)
+ sf.b.AppendByte(':')
+ sf.b.AppendInt(int64(frame.Line))
+}