71 lines
1.6 KiB
Go
71 lines
1.6 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"
|
|
)
|
|
|
|
// parser parses the log file and generates a summary report.
|
|
type parser struct {
|
|
summary *summary // summarizes the parsing results
|
|
lines int // number of parsed lines (for the error messages)
|
|
lerr error // the last error occurred
|
|
}
|
|
|
|
// new returns a new parsing state.
|
|
func newParser() *parser {
|
|
return &parser{summary: newSummary()}
|
|
}
|
|
|
|
// parse parses a log line and adds it to the summary.
|
|
func parse(p *parser, line string) (r result) {
|
|
// if there was an error do not continue
|
|
if p.lerr != nil {
|
|
return
|
|
}
|
|
|
|
// chain the parser's error to the result's
|
|
r = parseLine(p, line)
|
|
if p.lines++; p.lerr != nil {
|
|
p.lerr = fmt.Errorf("line #%d: %s", p.lines, p.lerr)
|
|
}
|
|
return
|
|
}
|
|
|
|
// parse parses a single log line
|
|
func parseLine(p *parser, line string) (r result) {
|
|
fields := strings.Fields(line)
|
|
if len(fields) != 2 {
|
|
// p.lerr = fmt.Errorf("wrong input: %v (line #%d)", fields, p.lines)
|
|
p.lerr = fmt.Errorf("missing fields: %v", fields)
|
|
return
|
|
}
|
|
|
|
r.domain = fields[0]
|
|
r.visits, p.lerr = strconv.Atoi(fields[1])
|
|
|
|
if r.visits < 0 || p.lerr != nil {
|
|
p.lerr = fmt.Errorf("incorrect visits: %q", fields[1])
|
|
}
|
|
return
|
|
}
|
|
|
|
// summarizeParse summarizes the parsing results.
|
|
// Only use it after the parsing is done.
|
|
func summarizeParse(p *parser) *summary {
|
|
return p.summary
|
|
}
|
|
|
|
// errParse returns the last error encountered
|
|
func errParse(p *parser) error {
|
|
return p.lerr
|
|
}
|