75 lines
1.7 KiB
Go
75 lines
1.7 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"
|
||
|
|
"strconv"
|
||
|
|
"strings"
|
||
|
|
)
|
||
|
|
|
||
|
|
// result stores the parsed result for a domain
|
||
|
|
type result struct {
|
||
|
|
domain string
|
||
|
|
visits int
|
||
|
|
// add more metrics if 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)
|
||
|
|
}
|
||
|
|
|
||
|
|
// newParser constructs, initializes and returns a new parser
|
||
|
|
func newParser() parser {
|
||
|
|
return parser{sum: make(map[string]result)}
|
||
|
|
}
|
||
|
|
|
||
|
|
// parse parses a log line and returns the parsed result with an error
|
||
|
|
func parse(p parser, line string) (parsed result, err error) {
|
||
|
|
fields := strings.Fields(line)
|
||
|
|
if len(fields) != 2 {
|
||
|
|
err = fmt.Errorf("wrong input: %v (line #%d)", fields, p.lines)
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
parsed.domain = fields[0]
|
||
|
|
|
||
|
|
parsed.visits, err = strconv.Atoi(fields[1])
|
||
|
|
if parsed.visits < 0 || err != nil {
|
||
|
|
err = fmt.Errorf("wrong input: %q (line #%d)", fields[1], p.lines)
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
// update updates the parser for the given parsing result
|
||
|
|
func update(p parser, parsed result) parser {
|
||
|
|
domain, visits := parsed.domain, parsed.visits
|
||
|
|
|
||
|
|
// Collect the unique domains
|
||
|
|
if _, ok := p.sum[domain]; !ok {
|
||
|
|
p.domains = append(p.domains, domain)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Keep track of total and per domain visits
|
||
|
|
p.total += visits
|
||
|
|
|
||
|
|
// create and assign a new copy of `visit`
|
||
|
|
p.sum[domain] = result{
|
||
|
|
domain: domain,
|
||
|
|
visits: visits + p.sum[domain].visits,
|
||
|
|
}
|
||
|
|
|
||
|
|
return p
|
||
|
|
}
|