84 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			84 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| // For more tutorials: https://blog.learngoprogramming.com
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| //
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| // Copyright © 2018 Inanc Gumus
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| // Learn Go Programming Course
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| // License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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| //
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| 
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| package main
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| 
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| import (
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| 	"fmt"
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| 	"strconv"
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| 	"strings"
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| )
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| 
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| // result stores the parsed result for a domain
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| type result struct {
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| 	domain string
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| 	visits int
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| 	// add more metrics if needed
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| }
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| 
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| // parser keep tracks of the parsing
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| type parser struct {
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| 	sum     map[string]result // metrics per domain
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| 	domains []string          // unique domain names
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| 	total   int               // total visits for all domains
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| 	lines   int               // number of parsed lines (for the error messages)
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| 	lerr    error             // the last error occurred
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| }
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| 
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| // newParser constructs, initializes and returns a new parser
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| func newParser() parser {
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| 	return parser{sum: make(map[string]result)}
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| }
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| 
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| // parse parses a log line and returns the parsed result with an error
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| func parse(p *parser, line string) (parsed result) {
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| 	if p.lerr != nil {
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| 		return
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| 	}
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| 
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| 	p.lines++
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| 
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| 	fields := strings.Fields(line)
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| 	if len(fields) != 2 {
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| 		p.lerr = fmt.Errorf("wrong input: %v (line #%d)", fields, p.lines)
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| 		return
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| 	}
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| 
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| 	parsed.domain = fields[0]
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| 
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| 	var err error
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| 
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| 	parsed.visits, err = strconv.Atoi(fields[1])
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| 	if parsed.visits < 0 || err != nil {
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| 		p.lerr = fmt.Errorf("wrong input: %q (line #%d)", fields[1], p.lines)
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| 	}
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| 	return
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| }
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| 
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| // update updates all the parsing results using the given parsing result
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| func update(p *parser, parsed result) {
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| 	if p.lerr != nil {
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| 		return
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| 	}
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| 
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| 	domain, visits := parsed.domain, parsed.visits
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| 
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| 	// Collect the unique domains
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| 	if _, ok := p.sum[domain]; !ok {
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| 		p.domains = append(p.domains, domain)
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| 	}
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| 
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| 	// Keep track of total and per domain visits
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| 	p.total += visits
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| 
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| 	// create and assign a new copy of `visit`
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| 	p.sum[domain] = result{
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| 		domain: domain,
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| 		visits: visits + p.sum[domain].visits,
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| 	}
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| }
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