Repository: soorajb/loc2country
Branch: master
Commit: 0e5b32e132fb
Files: 10
Total size: 7.6 KB

Directory structure:
gitextract_vsbryt61/

├── .gitignore
├── README.md
├── bin/
│   ├── .keep
│   ├── server_amd64
│   └── server_darwin
├── build_linux.sh
├── data/
│   └── .keep
├── src/
│   ├── server.go
│   └── server_test.go
└── start.sh

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FILE CONTENTS
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================================================
FILE: .gitignore
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.idea/
dump.rdb


================================================
FILE: README.md
================================================
## Loc2Country

Location coordinates (lat/lon) to ISO alpha-3 country code. Responds in microseconds.

## Manual

Input format: latitude, longitude

Output format: 3-letter-ISO-country-code, time-taken-to-respond-in-nanos

## HowTo

1. Run start.sh
2. This will start a TCP server (localhost:3333) by default.
3. Connect to the server by using telnet. (eg: "telnet localhost 3333")
4. Input lat and lon seperated by comma, returns 3 letter country code and time taken to respond in nanoseconds.

## Compiling

To compile, run:

``` bash
go build src/server.go
```

To compile for a Linux machine from Mac, run (with correct architecture):

``` bash
env GOOS=linux GOARCH=amd64 go build src/server.go
```

## Testing

To test, run:

```
go test
```


## Example

Starting the server:

``` bash
$ sh start.sh 
2016/08/18 23:30:07 Creating server with address localhost:3333
2016/08/18 23:30:07 Loading data..
2016/08/18 23:30:13 Loading complete.
2016/08/18 23:30:13 Total Entries: 5235316
2016/08/18 23:30:13 Boot time: 5 seconds
```

``` bash
$ telnet 127.0.0.1 3333
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
12,77
IND,17176
```

## Data

The world boundaries were generated using QGIS, converted to a set of ~350 million geohashes at precision level 6 and then reduced (compressed) to a set of ~5 million geohashes using [georaptor](https://github.com/ashwin711/georaptor). 


## Contributors

Sooraj B - [@soorajb](http://github.com/soorajb)

Ashwin Nair - [@ashwin711](http://github.com/ashwin711)

Harikrishnan Shaji - [@har777](http://github.com/har777)

## License

MIT License


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FILE: bin/.keep
================================================


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FILE: build_linux.sh
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env GOOS=linux GOARCH=amd64 go build src/server.go


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FILE: data/.keep
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================================================
FILE: src/server.go
================================================
package main

import (
  "bufio"
  "compress/gzip"
  "flag"
  "log"
  "os"
  "strconv"
  "strings"
  "time"

  "github.com/firstrow/tcp_server"
  "github.com/mmcloughlin/geohash"
)

var serverHost = flag.String("host", "localhost", "Hostname to bind to. eg: 192.168.1.10, default:localhost")
var serverPort = flag.String("port", "3333", "Port eg: 8080, default: 3333")
var dataPath = flag.String("dataPath", "./data/master.csv.gz", "Path to data file. eg: ./data/file.gz, default: ./data/master.csv.gz")

func main() {
  flag.Parse()
  connString := *serverHost + ":" + *serverPort
  dataFilePath := *dataPath

  server := tcp_server.New(connString)
  geohashToCountryMapping := getGeohashToCountryMapping(dataFilePath)

  server.OnNewMessage(func(c *tcp_server.Client, message string) {
    startNano := time.Now().UnixNano()
    reply := messageHandler(message, geohashToCountryMapping)
    c.Send(reply + "\n")
    log.Println("Response time: " + strconv.FormatInt((time.Now().UnixNano()-startNano), 10))
  })
  server.Listen()
}

func messageHandler(message string, geohashToCountryMapping map[string]string) string {
  message = strings.TrimSpace(message)
  response := ""
  startNano := time.Now().UnixNano()
  if message != "" {
    lat, lon := parseLatLonFromMessage(message)
    geohash6 := generateGeohash(lat, lon)
    country := getCountryFromGeohashToCountryMapping(geohash6, geohashToCountryMapping)
    timeTaken := time.Now().UnixNano() - startNano
    response = country + ", " + strconv.FormatInt(timeTaken, 10)
  }

  log.Println(message + " => " + response)
  return response
}

func getCountryFromGeohashToCountryMapping(geohash6 string, geohashToCountryMapping map[string]string) string {
  country := ""
  for geohashLength := 6; geohashLength > 1; geohashLength-- {
    country = geohashToCountryMapping[geohash6[0:geohashLength]]
    if country != "" {
      break
    }
  }
  return country
}

func parseLatLonFromMessage(message string) (float64, float64) {
  coords := strings.Split(message, ",")
  lat, lon := 0.0, 0.0
  if len(coords) == 2 {
    lat, _ = strconv.ParseFloat(strings.TrimSpace(coords[0]), 64)
    lon, _ = strconv.ParseFloat(strings.TrimSpace(coords[1]), 64)
  }
  return lat, lon
}

func generateGeohash(lat float64, lon float64) string {
  return geohash.EncodeWithPrecision(lat, lon, 6)
}

func getGeohashToCountryMapping(filePath string) map[string]string {
  geohashToCountryMapping := make(map[string]string)
  startNano := time.Now().UnixNano()
  log.Println("Loading data.")
  file, err := os.Open(filePath)
  defer file.Close()
  checkError(err)

  gzipReader, err := gzip.NewReader(file)
  defer gzipReader.Close()
  checkError(err)

  scanner := bufio.NewScanner(gzipReader)
  for scanner.Scan() {
    line := strings.Split(scanner.Text(), ",")
    geohashToCountryMapping[line[0]] = line[1]
  }

  checkError(scanner.Err())
  
  log.Println("Loading complete.")
  log.Println("Total Entries: " + strconv.Itoa(len(geohashToCountryMapping)))
  timeTaken := (time.Now().UnixNano() - startNano) / 1000000000
  log.Println("Boot time: " + strconv.FormatInt(timeTaken, 10) + " seconds")
  return geohashToCountryMapping
}

func checkError(e error) {
  if e != nil {
    log.Println(e)
  }
}


================================================
FILE: src/server_test.go
================================================
package main

import (
  "testing"

  "github.com/stretchr/testify/assert"
)

func TestGenerateGeohash(t *testing.T) {
  lat := 12.941084
  lon := 77.6099103
  expectedGeohash := "tdr1w5"
  actualGeohash := generateGeohash(lat, lon)
  assert.Equal(t, expectedGeohash, actualGeohash, "Generated geohash doesnt match with expected geohash.")
}

func TestParseLatLonFromMessage1(t *testing.T) {
  message := "12.941084,77.6099103"
  expectedLat, expectedLon := 12.941084, 77.6099103
  actualLat, actualLon := parseLatLonFromMessage(message)
  assert.Equal(t, expectedLat, actualLat, "Generated latitude doesnt match with expected latitude.")
  assert.Equal(t, expectedLon, actualLon, "Generated longitude doesnt match with expected longitude.")
}

func TestParseLatLonFromMessage2(t *testing.T) {
  message := "40.744630, -73.981481"
  expectedLat, expectedLon := 40.744630, -73.981481
  actualLat, actualLon := parseLatLonFromMessage(message)
  assert.Equal(t, expectedLat, actualLat, "Generated latitude doesnt match with expected latitude.")
  assert.Equal(t, expectedLon, actualLon, "Generated longitude doesnt match with expected longitude.")
}

func TestGetCountryFromGeohashToCountryMapping(t *testing.T) {
  geohash6FromCountryAUS, expectedCountryForAUSGeohash := "qsxtqw", "AUS"
  geohash6FromCountryJPN, expectedCountryForJPNGeohash := "xn7735", "JPN"
  geohash6FromOcean, expectedCountryForOceanGeohash := "mxty6f", ""

  geohashToCountryMapping := make(map[string]string)
  geohashToCountryMapping["qsxtqw"] = "AUS"
  geohashToCountryMapping["xn7"] = "JPN"

  actualCountryForAUSGeohash := getCountryFromGeohashToCountryMapping(geohash6FromCountryAUS, geohashToCountryMapping)
  actualCountryForJPNGeohash := getCountryFromGeohashToCountryMapping(geohash6FromCountryJPN, geohashToCountryMapping)
  actualCountryForOceanGeohash := getCountryFromGeohashToCountryMapping(geohash6FromOcean, geohashToCountryMapping)

  assert.Equal(t, expectedCountryForAUSGeohash, actualCountryForAUSGeohash, "Generated country doesnt match with expected country.")
  assert.Equal(t, expectedCountryForJPNGeohash, actualCountryForJPNGeohash, "Generated country doesnt match with expected country.")
  assert.Equal(t, expectedCountryForOceanGeohash, actualCountryForOceanGeohash, "Generated country doesnt match with expected country.")
}

func TestGetGeohashToCountryMapping(t *testing.T) {
  expectedGeohashToCountryMapping := make(map[string]string)
  expectedGeohashToCountryMapping["d6nq9t"] = "ABW"
  expectedGeohashToCountryMapping["wh3x0u"] = "IND"

  actualGeohashToCountryMapping := getGeohashToCountryMapping("dummy_test_data.csv.gz")

  assert.Equal(t, expectedGeohashToCountryMapping, actualGeohashToCountryMapping, "Generated geohashToCountryMapping doesnt match with expected geohashToCountryMapping.")
}


================================================
FILE: start.sh
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nohup ./bin/server -p 3333 > /dev/null &