Merge pull request #4 from moul/dev/moul/v1

Makefile

@@ -2,6 +2,9 @@ GOPKG ?=	moul.io/logman
 
 include rules.mk
 
-lint:
-	cd tool/lint; make
-.PHONY: lint
+generate:
+	GO111MODULE=off go get github.com/campoy/embedmd
+	mkdir -p .tmp
+	go doc -all > .tmp/godoc.txt
+	embedmd -w README.md
+	rm -rf .tmp

README.md

@@ -1,6 +1,6 @@
 # logman
 
-:smile: logman
+:smile: golang library to organize log files (create by date, GC, etc)
 
 [![go.dev reference](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white)](https://pkg.go.dev/moul.io/logman)
 [![License](https://img.shields.io/badge/license-Apache--2.0%20%2F%20MIT-%2397ca00.svg)](https://github.com/moul/logman/blob/main/COPYRIGHT)
@@ -18,18 +18,44 @@
 
 [![Gitpod ready-to-code](https://img.shields.io/badge/Gitpod-ready--to--code-blue?logo=gitpod)](https://gitpod.io/#https://github.com/moul/logman)
 
+## Example
+
+[embedmd]:# (example_test.go /import\ / $)
+```go
+import "moul.io/logman"
+
+func Example() {
+	writer, _ := logman.NewWriteCloser("./path/to/logdir/", "my-app")
+	defer writer.Close()
+	writer.Write([]byte("hello world!"))
+}
+```
+
 ## Usage
 
-[embedmd]:# (.tmp/usage.txt console)
-```console
-foo@bar:~$ logman hello world
-            _                                                   _                      _        _
- __ _  ___ | | __ _  _ _   __ _  ___  _ _  ___  _ __  ___  ___ | |_  ___  _ __   _ __ | | __ _ | |_  ___
-/ _` |/ _ \| |/ _` || ' \ / _` ||___|| '_|/ -_)| '_ \/ _ \|___||  _|/ -_)| '  \ | '_ \| |/ _` ||  _|/ -_)
-\__, |\___/|_|\__,_||_||_|\__, |     |_|  \___|| .__/\___/      \__|\___||_|_|_|| .__/|_|\__,_| \__|\___|
-|___/                     |___/                |_|                              |_|
-12 CPUs, /home/moul/.gvm/pkgsets/go1.16/global/bin/logman, fwrz, go1.16
-args ["logman","hello","world"]
+[embedmd]:# (.tmp/godoc.txt txt /FUNCTIONS/ $)
+```txt
+FUNCTIONS
+
+func LogfileGC(logDir string, max int) error
+func NewWriteCloser(target, kind string) (io.WriteCloser, error)
+
+TYPES
+
+type Logfile struct {
+	Dir    string
+	Name   string
+	Size   int64
+	Kind   string
+	Time   time.Time
+	Latest bool
+	Errs   error `json:"Errs,omitempty"`
+}
+
+func LogfileList(logDir string) ([]*Logfile, error)
+
+func (l Logfile) Path() string
+
 ```
 
 ## Install

doc.go

@@ -26,4 +26,4 @@
 //	|/  |       |  \    \ /                    /  ' \/ _ \/ // / / |
 //	||  |       |  |    | |                   /_/_/_/\___/\_,_/_/  |
 //	+--------------------------------------------------------------+
-package main // import "moul.io/logman"
+package logman

example_test.go

@@ -0,0 +1,9 @@
+package logman_test
+
+import "moul.io/logman"
+
+func Example() {
+	writer, _ := logman.NewWriteCloser("./path/to/logdir/", "my-app")
+	defer writer.Close()
+	writer.Write([]byte("hello world!"))
+}

logman.go

@@ -0,0 +1,151 @@
+package logman
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+	"time"
+
+	"go.uber.org/multierr"
+	"moul.io/u"
+)
+
+func NewWriteCloser(target, kind string) (io.WriteCloser, error) {
+	var filename string
+	switch {
+	case strings.HasSuffix(target, ".log"): // use the indicated 'path' as filename
+		filename = target
+	default: // automatically create a new file in the 'path' directory following a pattern
+		startTime := time.Now().Format(filePatternDateLayout)
+		filename = filepath.Join(
+			target,
+			fmt.Sprintf("%s-%s.log", kind, startTime),
+		)
+		// run gc
+		{
+			err := LogfileGC(target, 20)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	if dir := filepath.Dir(filename); !u.DirExists(dir) {
+		err := os.MkdirAll(dir, 0o711)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	var writer io.WriteCloser
+	if u.FileExists(filename) {
+		var err error
+		writer, err = os.OpenFile(filename, os.O_APPEND|os.O_WRONLY, os.ModeAppend)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		var err error
+		writer, err = os.Create(filename)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return writer, nil
+}
+
+type Logfile struct {
+	Dir    string
+	Name   string
+	Size   int64
+	Kind   string
+	Time   time.Time
+	Latest bool
+	Errs   error `json:"Errs,omitempty"`
+}
+
+func (l Logfile) Path() string {
+	return filepath.Join(l.Dir, l.Name)
+}
+
+const filePatternDateLayout = "2006-01-02T15-04-05.000"
+
+var filePatternRegex = regexp.MustCompile(`(?m)^(.*)-(\d{4}-\d{2}-\d{2}T\d{2}-\d{2}-\d{2}.\d{3}).log$`)
+
+func LogfileList(logDir string) ([]*Logfile, error) {
+	files, err := ioutil.ReadDir(logDir)
+	if err != nil {
+		return nil, err
+	}
+
+	logfiles := []*Logfile{}
+	for _, file := range files {
+		sub := filePatternRegex.FindStringSubmatch(file.Name())
+		if sub == nil {
+			continue
+		}
+		t, err := time.Parse(filePatternDateLayout, sub[2])
+		var errs error
+		if err != nil {
+			errs = multierr.Append(errs, err)
+		}
+
+		logfiles = append(logfiles, &Logfile{
+			Dir:  logDir,
+			Name: file.Name(),
+			Size: file.Size(),
+			Kind: sub[1],
+			Time: t,
+			Errs: errs,
+		})
+	}
+
+	// compute latest
+	if len(logfiles) > 0 {
+		var maxTime time.Time
+		for _, file := range logfiles {
+			if file.Time.After(maxTime) {
+				maxTime = file.Time
+			}
+		}
+		for _, file := range logfiles {
+			if file.Time == maxTime {
+				file.Latest = true
+			}
+		}
+	}
+
+	return logfiles, nil
+}
+
+func LogfileGC(logDir string, max int) error {
+	if !u.DirExists(logDir) {
+		return nil
+	}
+	files, err := LogfileList(logDir)
+	if err != nil {
+		return err
+	}
+	if len(files) < max {
+		return nil
+	}
+
+	sort.Slice(files, func(i, j int) bool {
+		return files[i].Time.Before(files[j].Time)
+	})
+
+	var errs error
+	for i := 0; i < len(files)-max; i++ {
+		err := os.Remove(files[i].Path())
+		if err != nil {
+			errs = multierr.Append(errs, err)
+		}
+	}
+	return errs
+}