mtsatellite/cmd/mtredisalize/changetracker.go

78 lines
1.6 KiB
Go

// Copyright 2014, 2015 by Sascha L. Teichmann
// Use of this source code is governed by the MIT license
// that can be found in the LICENSE file.
package main
import (
"encoding/json"
"log"
"net/http"
"sync"
"bytes"
"bitbucket.org/s_l_teichmann/mtsatellite/common"
)
// Pull up if it _really_ produces too much data.
const quantizationFactor = 1
type quantizedXZ struct {
X, Z int16
}
type changeTracker struct {
changes map[quantizedXZ]struct{}
mutex sync.Mutex
}
func newChangeTracker() *changeTracker {
return &changeTracker{changes: make(map[quantizedXZ]struct{})}
}
func (ct *changeTracker) BlockChanged(coord common.Coord) {
ct.mutex.Lock()
ct.changes[quantizedXZ{
X: coord.X / quantizationFactor,
Z: coord.Z / quantizationFactor}] = struct{}{}
ct.mutex.Unlock()
}
func (ct *changeTracker) FlushChanges(url string) {
var oldChanges map[quantizedXZ]struct{}
ct.mutex.Lock()
if len(ct.changes) > 0 {
oldChanges = ct.changes
ct.changes = make(map[quantizedXZ]struct{})
}
ct.mutex.Unlock()
if oldChanges == nil {
return
}
go func() {
changes := make([]quantizedXZ, len(oldChanges))
i := 0
for change := range oldChanges {
changes[i] = change
i++
}
var err error
var buf bytes.Buffer
encoder := json.NewEncoder(&buf)
if err = encoder.Encode(changes); err != nil {
log.Printf("WARN: encode changes to JSON failed: %s\n", err)
return
}
var resp *http.Response
resp, err = http.Post(
url, "application/json", bytes.NewBuffer(buf.Bytes()))
if resp != nil {
defer resp.Body.Close()
}
if err != nil {
log.Printf("WARN: posting changes to %s failed: %s\n", url, err)
}
}()
}