gitea/modules/web/routing/funcinfo.go
flynnnnnnnnnn e81ccc406b
Implement FSFE REUSE for golang files (#21840)
Change all license headers to comply with REUSE specification.

Fix #16132

Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>
2022-11-27 18:20:29 +00:00

173 lines
4.3 KiB
Go

// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package routing
import (
"fmt"
"reflect"
"runtime"
"strings"
"sync"
)
var (
funcInfoMap = map[uintptr]*FuncInfo{}
funcInfoNameMap = map[string]*FuncInfo{}
funcInfoMapMu sync.RWMutex
)
// FuncInfo contains information about the function to be logged by the router log
type FuncInfo struct {
file string
shortFile string
line int
name string
shortName string
}
// String returns a string form of the FuncInfo for logging
func (info *FuncInfo) String() string {
if info == nil {
return "unknown-handler"
}
return fmt.Sprintf("%s:%d(%s)", info.shortFile, info.line, info.shortName)
}
// GetFuncInfo returns the FuncInfo for a provided function and friendlyname
func GetFuncInfo(fn interface{}, friendlyName ...string) *FuncInfo {
// ptr represents the memory position of the function passed in as v.
// This will be used as program counter in FuncForPC below
ptr := reflect.ValueOf(fn).Pointer()
// if we have been provided with a friendlyName look for the named funcs
if len(friendlyName) == 1 {
name := friendlyName[0]
funcInfoMapMu.RLock()
info, ok := funcInfoNameMap[name]
funcInfoMapMu.RUnlock()
if ok {
return info
}
}
// Otherwise attempt to get pre-cached information for this function pointer
funcInfoMapMu.RLock()
info, ok := funcInfoMap[ptr]
funcInfoMapMu.RUnlock()
if ok {
if len(friendlyName) == 1 {
name := friendlyName[0]
info = copyFuncInfo(info)
info.shortName = name
funcInfoNameMap[name] = info
funcInfoMapMu.Lock()
funcInfoNameMap[name] = info
funcInfoMapMu.Unlock()
}
return info
}
// This is likely the first time we have seen this function
//
// Get the runtime.func for this function (if we can)
f := runtime.FuncForPC(ptr)
if f != nil {
info = convertToFuncInfo(f)
// cache this info globally
funcInfoMapMu.Lock()
funcInfoMap[ptr] = info
// if we have been provided with a friendlyName override the short name we've generated
if len(friendlyName) == 1 {
name := friendlyName[0]
info = copyFuncInfo(info)
info.shortName = name
funcInfoNameMap[name] = info
}
funcInfoMapMu.Unlock()
}
return info
}
// convertToFuncInfo take a runtime.Func and convert it to a logFuncInfo, fill in shorten filename, etc
func convertToFuncInfo(f *runtime.Func) *FuncInfo {
file, line := f.FileLine(f.Entry())
info := &FuncInfo{
file: strings.ReplaceAll(file, "\\", "/"),
line: line,
name: f.Name(),
}
// only keep last 2 names in path, fall back to funcName if not
info.shortFile = shortenFilename(info.file, info.name)
// remove package prefix. eg: "xxx.com/pkg1/pkg2.foo" => "pkg2.foo"
pos := strings.LastIndexByte(info.name, '/')
if pos >= 0 {
info.shortName = info.name[pos+1:]
} else {
info.shortName = info.name
}
// remove ".func[0-9]*" suffix for anonymous func
info.shortName = trimAnonymousFunctionSuffix(info.shortName)
return info
}
func copyFuncInfo(l *FuncInfo) *FuncInfo {
return &FuncInfo{
file: l.file,
shortFile: l.shortFile,
line: l.line,
name: l.name,
shortName: l.shortName,
}
}
// shortenFilename generates a short source code filename from a full package path, eg: "code.gitea.io/routers/common/logger_context.go" => "common/logger_context.go"
func shortenFilename(filename, fallback string) string {
if filename == "" {
return fallback
}
if lastIndex := strings.LastIndexByte(filename, '/'); lastIndex >= 0 {
if secondLastIndex := strings.LastIndexByte(filename[:lastIndex], '/'); secondLastIndex >= 0 {
return filename[secondLastIndex+1:]
}
}
return filename
}
// trimAnonymousFunctionSuffix trims ".func[0-9]*" from the end of anonymous function names, we only want to see the main function names in logs
func trimAnonymousFunctionSuffix(name string) string {
// if the name is an anonymous name, it should be like "{main-function}.func1", so the length can not be less than 7
if len(name) < 7 {
return name
}
funcSuffixIndex := strings.LastIndex(name, ".func")
if funcSuffixIndex < 0 {
return name
}
hasFuncSuffix := true
// len(".func") = 5
for i := funcSuffixIndex + 5; i < len(name); i++ {
if name[i] < '0' || name[i] > '9' {
hasFuncSuffix = false
break
}
}
if hasFuncSuffix {
return name[:funcSuffixIndex]
}
return name
}