101 lines
2.1 KiB
Go
101 lines
2.1 KiB
Go
|
// For more tutorials: https://blog.learngoprogramming.com
|
||
|
|
//
|
||
|
|
// Copyright © 2018 Inanc Gumus
|
||
|
|
// Learn Go Programming Course
|
||
|
|
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
|
||
|
|
//
|
||
|
|
|
||
|
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"sort"
|
||
|
|
"strconv"
|
||
|
|
"strings"
|
||
|
|
)
|
||
|
|
|
||
|
|
// result stores details about a log line
|
||
|
|
type result struct {
|
||
|
|
domain string
|
||
|
|
visits int
|
||
|
|
// add more metrics when needed
|
||
|
|
}
|
||
|
|
|
||
|
|
// parser keep tracks of the parsing
|
||
|
|
type parser struct {
|
||
|
|
sum map[string]result // metrics per domain
|
||
|
|
domains []string // unique domain names
|
||
|
|
total int // total visits for all domains
|
||
|
|
lines int // number of parsed lines (for the error messages)
|
||
|
|
lerr error // the last error occurred
|
||
|
|
}
|
||
|
|
|
||
|
|
// newParser creates and returns a new parser
|
||
|
|
func newParser() *parser {
|
||
|
|
return &parser{sum: make(map[string]result)}
|
||
|
|
}
|
||
|
|
|
||
|
|
// parse result from a log line
|
||
|
|
func (p *parser) parse(line string) (r result) {
|
||
|
|
if p.lerr != nil {
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
p.lines++
|
||
|
|
|
||
|
|
fields := strings.Fields(line)
|
||
|
|
if len(fields) != 2 {
|
||
|
|
p.lerr = fmt.Errorf("wrong input: %v (line #%d)", fields, p.lines)
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
var err error
|
||
|
|
|
||
|
|
r.domain = fields[0]
|
||
|
|
r.visits, err = strconv.Atoi(fields[1])
|
||
|
|
|
||
|
|
if r.visits < 0 || err != nil {
|
||
|
|
p.lerr = fmt.Errorf("wrong input: %q (line #%d)", fields[1], p.lines)
|
||
|
|
}
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
// update the parsing results
|
||
|
|
func (p *parser) update(r result) {
|
||
|
|
if p.lerr != nil {
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
// collect unique domains for easy access to sum map
|
||
|
|
if _, ok := p.sum[r.domain]; !ok {
|
||
|
|
p.domains = append(p.domains, r.domain)
|
||
|
|
}
|
||
|
|
|
||
|
|
// keep track of total visits
|
||
|
|
p.total += r.visits
|
||
|
|
|
||
|
|
// group the log lines by domain
|
||
|
|
p.sum[r.domain] = result{
|
||
|
|
domain: r.domain,
|
||
|
|
visits: r.visits + p.sum[r.domain].visits,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// summarize the parsing results
|
||
|
|
func (p *parser) summarize() {
|
||
|
|
sort.Strings(p.domains)
|
||
|
|
|
||
|
|
fmt.Printf("%-30s %10s\n", "DOMAIN", "VISITS")
|
||
|
|
fmt.Println(strings.Repeat("-", 45))
|
||
|
|
|
||
|
|
for _, domain := range p.domains {
|
||
|
|
fmt.Printf("%-30s %10d\n", domain, p.sum[domain].visits)
|
||
|
|
}
|
||
|
|
fmt.Printf("\n%-30s %10d\n", "TOTAL", p.total)
|
||
|
|
}
|
||
|
|
|
||
|
|
// err returns the last error encountered
|
||
|
|
func (p *parser) err() error {
|
||
|
|
return p.lerr
|
||
|
|
}
|