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package svc // import "github.com/getwtxt/getwtxt/svc"
import (
"bytes"
"io/ioutil"
"os"
"sync"
"time"
)
// RemoteRegistries holds a list of remote registries to
// periodically scrape for new users. The remote registries
// must have been added via POST like a user.
type RemoteRegistries struct {
Mu sync.RWMutex
List []string
}
type staticAssets struct {
mu sync.RWMutex
index []byte
indexMod time.Time
css []byte
cssMod time.Time
}
func cacheTimer() bool {
confObj.Mu.RLock()
answer := time.Since(confObj.LastCache) > confObj.CacheInterval
confObj.Mu.RUnlock()
return answer
}
// Launched by init as a coroutine to watch
// for the update intervals to pass.
func cacheAndPush() {
for {
if cacheTimer() {
refreshCache()
}
if dbTimer() {
err := pushDB()
errLog("Error pushing cache to database: ", err)
}
time.Sleep(1000 * time.Millisecond)
}
}
func refreshCache() {
// This clusterfuck of mutex read locks is
// necessary to avoid deadlock. This mess
// also avoids a panic that would occur
// should twtxtCache be written to during
// this loop.
twtxtCache.Mu.RLock()
for k := range twtxtCache.Users {
twtxtCache.Mu.RUnlock()
err := twtxtCache.UpdateUser(k)
errLog("", err)
twtxtCache.Mu.RLock()
}
twtxtCache.Mu.RUnlock()
remoteRegistries.Mu.RLock()
for _, v := range remoteRegistries.List {
err := twtxtCache.CrawlRemoteRegistry(v)
errLog("Error refreshing local copy of remote registry data: ", err)
}
remoteRegistries.Mu.RUnlock()
confObj.Mu.Lock()
confObj.LastCache = time.Now()
confObj.Mu.Unlock()
}
// pingAssets checks if the local static assets
// need to be re-cached. If they do, they are
// pulled back into memory from disk.
func pingAssets() {
confObj.Mu.RLock()
assetsDir := confObj.AssetsDir
confObj.Mu.RUnlock()
cssStat, err := os.Stat(assetsDir + "/style.css")
errLog("", err)
indexStat, err := os.Stat(assetsDir + "/tmpl/index.html")
errLog("", err)
staticCache.mu.RLock()
indexMod := staticCache.indexMod
cssMod := staticCache.cssMod
staticCache.mu.RUnlock()
if !indexMod.Equal(indexStat.ModTime()) {
tmpls = initTemplates()
var b []byte
buf := bytes.NewBuffer(b)
confObj.Mu.RLock()
err = tmpls.ExecuteTemplate(buf, "index.html", confObj.Instance)
confObj.Mu.RUnlock()
errLog("", err)
staticCache.mu.Lock()
staticCache.index = buf.Bytes()
staticCache.indexMod = indexStat.ModTime()
staticCache.mu.Unlock()
}
if !cssMod.Equal(cssStat.ModTime()) {
css, err := ioutil.ReadFile(assetsDir + "/style.css")
errLog("", err)
staticCache.mu.Lock()
staticCache.css = css
staticCache.cssMod = cssStat.ModTime()
staticCache.mu.Unlock()
}
}
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