gtsocial-umbx

recovery.go (5207B)

---

 // Copyright 2014 Manu Martinez-Almeida. All rights reserved.
 // Use of this source code is governed by a MIT style
 // license that can be found in the LICENSE file.
 
 package gin
 
 import (
 	"bytes"
 	"errors"
 	"fmt"
 	"io"
 	"log"
 	"net"
 	"net/http"
 	"net/http/httputil"
 	"os"
 	"runtime"
 	"strings"
 	"time"
 )
 
 var (
 	dunno     = []byte("???")
 	centerDot = []byte("·")
 	dot       = []byte(".")
 	slash     = []byte("/")
 )
 
 // RecoveryFunc defines the function passable to CustomRecovery.
 type RecoveryFunc func(c *Context, err any)
 
 // Recovery returns a middleware that recovers from any panics and writes a 500 if there was one.
 func Recovery() HandlerFunc {
 	return RecoveryWithWriter(DefaultErrorWriter)
 }
 
 // CustomRecovery returns a middleware that recovers from any panics and calls the provided handle func to handle it.
 func CustomRecovery(handle RecoveryFunc) HandlerFunc {
 	return RecoveryWithWriter(DefaultErrorWriter, handle)
 }
 
 // RecoveryWithWriter returns a middleware for a given writer that recovers from any panics and writes a 500 if there was one.
 func RecoveryWithWriter(out io.Writer, recovery ...RecoveryFunc) HandlerFunc {
 	if len(recovery) > 0 {
 		return CustomRecoveryWithWriter(out, recovery[0])
 	}
 	return CustomRecoveryWithWriter(out, defaultHandleRecovery)
 }
 
 // CustomRecoveryWithWriter returns a middleware for a given writer that recovers from any panics and calls the provided handle func to handle it.
 func CustomRecoveryWithWriter(out io.Writer, handle RecoveryFunc) HandlerFunc {
 	var logger *log.Logger
 	if out != nil {
 		logger = log.New(out, "\n\n\x1b[31m", log.LstdFlags)
 	}
 	return func(c *Context) {
 		defer func() {
 			if err := recover(); err != nil {
 				// Check for a broken connection, as it is not really a
 				// condition that warrants a panic stack trace.
 				var brokenPipe bool
 				if ne, ok := err.(*net.OpError); ok {
 					var se *os.SyscallError
 					if errors.As(ne, &se) {
 						seStr := strings.ToLower(se.Error())
 						if strings.Contains(seStr, "broken pipe") ||
 							strings.Contains(seStr, "connection reset by peer") {
 							brokenPipe = true
 						}
 					}
 				}
 				if logger != nil {
 					stack := stack(3)
 					httpRequest, _ := httputil.DumpRequest(c.Request, false)
 					headers := strings.Split(string(httpRequest), "\r\n")
 					for idx, header := range headers {
 						current := strings.Split(header, ":")
 						if current[0] == "Authorization" {
 							headers[idx] = current[0] + ": *"
 						}
 					}
 					headersToStr := strings.Join(headers, "\r\n")
 					if brokenPipe {
 						logger.Printf("%s\n%s%s", err, headersToStr, reset)
 					} else if IsDebugging() {
 						logger.Printf("[Recovery] %s panic recovered:\n%s\n%s\n%s%s",
 							timeFormat(time.Now()), headersToStr, err, stack, reset)
 					} else {
 						logger.Printf("[Recovery] %s panic recovered:\n%s\n%s%s",
 							timeFormat(time.Now()), err, stack, reset)
 					}
 				}
 				if brokenPipe {
 					// If the connection is dead, we can't write a status to it.
 					c.Error(err.(error)) //nolint: errcheck
 					c.Abort()
 				} else {
 					handle(c, err)
 				}
 			}
 		}()
 		c.Next()
 	}
 }
 
 func defaultHandleRecovery(c *Context, _ any) {
 	c.AbortWithStatus(http.StatusInternalServerError)
 }
 
 // stack returns a nicely formatted stack frame, skipping skip frames.
 func stack(skip int) []byte {
 	buf := new(bytes.Buffer) // the returned data
 	// As we loop, we open files and read them. These variables record the currently
 	// loaded file.
 	var lines [][]byte
 	var lastFile string
 	for i := skip; ; i++ { // Skip the expected number of frames
 		pc, file, line, ok := runtime.Caller(i)
 		if !ok {
 			break
 		}
 		// Print this much at least.  If we can't find the source, it won't show.
 		fmt.Fprintf(buf, "%s:%d (0x%x)\n", file, line, pc)
 		if file != lastFile {
 			data, err := os.ReadFile(file)
 			if err != nil {
 				continue
 			}
 			lines = bytes.Split(data, []byte{'\n'})
 			lastFile = file
 		}
 		fmt.Fprintf(buf, "\t%s: %s\n", function(pc), source(lines, line))
 	}
 	return buf.Bytes()
 }
 
 // source returns a space-trimmed slice of the n'th line.
 func source(lines [][]byte, n int) []byte {
 	n-- // in stack trace, lines are 1-indexed but our array is 0-indexed
 	if n < 0 || n >= len(lines) {
 		return dunno
 	}
 	return bytes.TrimSpace(lines[n])
 }
 
 // function returns, if possible, the name of the function containing the PC.
 func function(pc uintptr) []byte {
 	fn := runtime.FuncForPC(pc)
 	if fn == nil {
 		return dunno
 	}
 	name := []byte(fn.Name())
 	// The name includes the path name to the package, which is unnecessary
 	// since the file name is already included.  Plus, it has center dots.
 	// That is, we see
 	//	runtime/debug.*T·ptrmethod
 	// and want
 	//	*T.ptrmethod
 	// Also the package path might contain dot (e.g. code.google.com/...),
 	// so first eliminate the path prefix
 	if lastSlash := bytes.LastIndex(name, slash); lastSlash >= 0 {
 		name = name[lastSlash+1:]
 	}
 	if period := bytes.Index(name, dot); period >= 0 {
 		name = name[period+1:]
 	}
 	name = bytes.ReplaceAll(name, centerDot, dot)
 	return name
 }
 
 // timeFormat returns a customized time string for logger.
 func timeFormat(t time.Time) string {
 	return t.Format("2006/01/02 - 15:04:05")
 }