func streamDbUsers(conf *Config) chan models.User { db, err := sql.Open("postgres", conf.DbString) if err != nil { log.Fatal("can't open database conn:", err) } log.Infof("Start reading users from DB!") out := make(chan models.User, 1024) go func() { rows, err := db.Query("select pnum, email, dob, weight, height, nickname, country, city, caption, longitude, latitude, gender from aminno_member limit 1000000") if err != nil { log.Fatal(err) } defer rows.Close() noOfUsers := 0 for rows.Next() { u := models.User{} u.Location = &models.Location{} if err := rows.Scan(&u.Pnum, &u.Email, &u.Dob, &u.Weight, &u.Height, &u.Nickname, &u.Country, &u.City, &u.Caption, &u.Location.Longitude, &u.Location.Latitude, &u.Gender); err != nil { log.Fatal(err) } out <- u if noOfUsers%100 == 0 { log.Printf("Total no of read users: %v", noOfUsers) } noOfUsers++ } err = rows.Err() if err != nil { log.Fatal(err) } log.Infof("All users sent") close(out) }() return out }
func streamCsvUsers(conf *Config) chan models.User { f, err := os.Open(conf.CsvPath) if err != nil { log.Fatal("can't file with users:", err) } defer f.Close() log.Infof("Start reading CSV file!") r := csv.NewReader(bufio.NewReader(f)) r.Comma = '|' r.LazyQuotes = true records, err := r.ReadAll() if err != nil { log.Fatal(err) } log.Infof("Read %d lines!", len(records)) out := make(chan models.User, 1024) go func() { for i, line := range records { if len(line) != 12 { log.Fatal(fmt.Errorf("Wrong number of parsed fields: %d. Index %d", len(line), i)) } u := models.User{} var err error u.Pnum, err = strconv.ParseInt(line[0], 10, 64) if err != nil { log.Fatalf("Can't deserialize pnum. Val: %s", line[0]) } long, err := strconv.ParseFloat(line[1], 64) if err != nil { log.Fatalf("Can't deserialize longitude. Val: %s. Line: %d", line[1], i) } lat, err := strconv.ParseFloat(line[2], 64) if err != nil { log.Fatalf("Can't deserialize latitude. Val: %s. Line: %d", line[2], i) } u.Location = &models.Location{long, lat} if long == 0 || lat == 0 { log.Warningf("At least one value of location could be wrong. Vals long, %d, lat: %d", long, lat) } u.Email = line[3] weight, err := strconv.Atoi(line[4]) if err != nil { log.Fatalf("Can't deserialize weight. Val: %s", line[4]) } u.Weight = &weight height, err := strconv.Atoi(line[5]) if err != nil { log.Fatalf("Can't deserialize height. Val: %s", line[5]) } u.Height = &height u.Nickname = &line[6] u.Country, err = strconv.Atoi(line[7]) if err != nil { log.Fatalf("Can't deserialize country: Val: %s", line[7]) } u.City = &line[8] u.Caption = &line[9] gender, err := strconv.Atoi(line[10]) if err != nil { log.Fatalf("Can't deserialize gender. Val: %s", line[10]) } u.Gender = &gender u.Dob = &line[11] out <- u } log.Infof("All users sent. Closing channel") close(out) }() return out }