98 lines
2.4 KiB
Go
98 lines
2.4 KiB
Go
/*
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* Copyright (c) 2015 Alex Yatskov <alex@foosoft.net>
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* Author: Alex Yatskov <alex@foosoft.net>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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package main
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import (
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"encoding/json"
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"io/ioutil"
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"os"
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"sync"
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"github.com/kellydunn/golang-geo"
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)
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type geoCoord struct {
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Latitude float64
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Longitude float64
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}
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type geoCache struct {
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cacheFile string
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addressCache map[string]geoCoord
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geocoder geo.GoogleGeocoder
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mutex sync.Mutex
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}
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func newGeoCache(cacheFile string) (*geoCache, error) {
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cache := &geoCache{
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cacheFile: cacheFile,
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addressCache: make(map[string]geoCoord)}
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if err := cache.load(); err != nil {
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return nil, err
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}
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return cache, nil
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}
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func (c *geoCache) load() error {
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file, err := os.Open(c.cacheFile)
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if os.IsNotExist(err) {
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return nil
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}
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if err != nil {
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return err
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}
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defer file.Close()
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return json.NewDecoder(file).Decode(&c.addressCache)
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}
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func (c *geoCache) save() error {
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js, err := json.MarshalIndent(c.addressCache, "", " ")
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if err != nil {
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return err
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}
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return ioutil.WriteFile(c.cacheFile, js, 0644)
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}
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func (c *geoCache) decode(address string) (geoCoord, error) {
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if coord, ok := c.addressCache[address]; ok {
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return coord, nil
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}
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point, err := c.geocoder.Geocode(address)
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if err != nil {
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return geoCoord{}, err
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}
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coord := geoCoord{point.Lat(), point.Lng()}
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c.mutex.Lock()
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c.addressCache[address] = coord
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c.mutex.Unlock()
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return coord, nil
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}
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