github.com/thiagoyeds/go-cloud@v0.26.0/server/requestlog/ncsa.go (about) 1 // Copyright 2018 The Go Cloud Development Kit Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package requestlog 16 17 import ( 18 "io" 19 "strconv" 20 "sync" 21 ) 22 23 // An NCSALogger writes log entries to an io.Writer in the 24 // Combined Log Format. 25 // 26 // Details at http://httpd.apache.org/docs/current/logs.html#combined 27 type NCSALogger struct { 28 onErr func(error) 29 30 mu sync.Mutex 31 w io.Writer 32 buf []byte 33 } 34 35 // NewNCSALogger returns a new logger that writes to w. 36 // A nil onErr is treated the same as func(error) {}. 37 func NewNCSALogger(w io.Writer, onErr func(error)) *NCSALogger { 38 return &NCSALogger{ 39 w: w, 40 onErr: onErr, 41 } 42 } 43 44 // Log writes an entry line to its writer. Multiple concurrent calls 45 // will produce sequential writes to its writer. 46 func (l *NCSALogger) Log(ent *Entry) { 47 if err := l.log(ent); err != nil && l.onErr != nil { 48 l.onErr(err) 49 } 50 } 51 52 func (l *NCSALogger) log(ent *Entry) error { 53 defer l.mu.Unlock() 54 l.mu.Lock() 55 l.buf = formatEntry(l.buf[:0], ent) 56 _, err := l.w.Write(l.buf) 57 return err 58 } 59 60 func formatEntry(b []byte, ent *Entry) []byte { 61 const ncsaTime = "02/Jan/2006:15:04:05 -0700" 62 if ent.RemoteIP == "" { 63 b = append(b, '-') 64 } else { 65 b = append(b, ent.RemoteIP...) 66 } 67 b = append(b, " - - ["...) 68 b = ent.ReceivedTime.AppendFormat(b, ncsaTime) 69 b = append(b, "] \""...) 70 b = append(b, ent.RequestMethod...) 71 b = append(b, ' ') 72 b = append(b, ent.RequestURL...) 73 b = append(b, ' ') 74 b = append(b, ent.Proto...) 75 b = append(b, "\" "...) 76 b = strconv.AppendInt(b, int64(ent.Status), 10) 77 b = append(b, ' ') 78 b = strconv.AppendInt(b, int64(ent.ResponseBodySize), 10) 79 b = append(b, ' ') 80 b = strconv.AppendQuote(b, ent.Referer) 81 b = append(b, ' ') 82 b = strconv.AppendQuote(b, ent.UserAgent) 83 b = append(b, '\n') 84 return b 85 }