summary refs log tree commit diff stats
path: root/svc/cache.go
blob: fb6a9ab96f129ed8a6f5331a92a1779a127c4a89 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
package svc // import "github.com/getwtxt/getwtxt/svc"

import (
	"bytes"
	"io/ioutil"
	"log"
	"os"
	"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() {
			if err := pushDB(); err != nil {
				log.Printf("Error pushing cache to database: %v\n", err.Error())
			}
		}
		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)
		if err != nil {
			log.Printf("%v\n", err.Error())
		}
		twtxtCache.Mu.RLock()
	}
	twtxtCache.Mu.RUnlock()

	remoteRegistries.Mu.RLock()
	for _, v := range remoteRegistries.List {
		err := twtxtCache.CrawlRemoteRegistry(v)
		if err != nil {
			log.Printf("Error while refreshing local copy of remote registry user data: %v\n", err.Error())
		}
	}
	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")
	if err != nil {
		log.Printf("%v\n", err.Error())
	}

	indexStat, err := os.Stat(assetsDir + "/tmpl/index.html")
	if err != nil {
		log.Printf("%v\n", err.Error())
	}

	indexMod := staticCache.indexMod
	cssMod := staticCache.cssMod

	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()
		if err != nil {
			log.Printf("%v\n", err.Error())
		}

		staticCache.index = buf.Bytes()
		staticCache.indexMod = indexStat.ModTime()
	}

	if !cssMod.Equal(cssStat.ModTime()) {

		css, err := ioutil.ReadFile(assetsDir + "/style.css")
		if err != nil {
			log.Printf("%v\n", err.Error())
		}

		staticCache.css = css
		staticCache.cssMod = cssStat.ModTime()
	}
}