Get a compact stacktrace without the callsites

stacktrace.go

var newLine = []byte("\n")[0]
var goPathPrefix = "\t/go/src/"
var goUsersPrefix = "\t/Users/"

func dumpStacktrace(skipLines int) []byte {
	stack := debug.Stack()
	init, lines := 0, 0

	// First pass: seek stack start skiping lines if necessary
	if skipLines > 0 {
		for i := 0; i < len(stack); i++ {
			if stack[i] == newLine {
				lines = lines + 1
				if lines >= skipLines {
					init = i
					break
				}
			}
		}
	}

	lineBytes := 0
	compact := false
	compactInit, compactStackSize := 0, 0
	// Second pass: filter callsite lines while compacting the stack in the process
	if init < len(stack) {
		for i := init; i < len(stack); i++ {
			if stack[i] == newLine {
				lineBytes = 0
				if compact {
					copied := copy(stack[compactStackSize:], stack[compactInit:i+1])
					compactStackSize = compactStackSize + copied
					compact = false
				}
			} else {
				lineBytes = lineBytes + 1
			}

			if lineBytes == 1 {
				if (string(stack[i:i+len(goPathPrefix)]) == goPathPrefix) || (string(stack[i:i+len(goUsersPrefix)]) == goUsersPrefix) {
					compact = true
					compactInit = i
				}
			}
		}
	}

	return stack[0:compactStackSize]
}