Initial commit

2024-07-19 12:50:57 +02:00
commit ff0811bf90
7 changed files with 448 additions and 0 deletions
--- a/cache.go
+++ b/cache.go
@@ -0,0 +1,137 @@
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+	"time"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+// region DB
+type DB struct {
+	path      string
+	readConn  *sql.DB
+	writeConn *sql.DB
+}
+
+func (db *DB) Open() error {
+	if db.path == "" {
+		return fmt.Errorf("database path not set")
+	}
+
+	writeConn, err := sql.Open("sqlite3", db.path+"?_journal=WAL&_synchronous=NORMAL")
+	if err != nil {
+		Error.Printf("%++v", err)
+		return err
+	}
+	writeConn.SetMaxOpenConns(1)
+	writeConn.SetConnMaxIdleTime(30 * time.Second)
+	writeConn.SetConnMaxLifetime(30 * time.Second)
+	db.writeConn = writeConn
+
+	readConn, err := sql.Open("sqlite3", db.path+"?mode=ro&_journal=WAL&_synchronous=NORMAL&_mode=ro")
+	if err != nil {
+		Error.Printf("%++v", err)
+		return err
+	}
+	readConn.SetMaxOpenConns(4)
+	readConn.SetConnMaxIdleTime(30 * time.Second)
+	readConn.SetConnMaxLifetime(30 * time.Second)
+	db.readConn = readConn
+
+	return nil
+}
+
+func (db *DB) Close() error {
+	err := db.writeConn.Close()
+	if err != nil {
+		return err
+	}
+
+	err = db.readConn.Close()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+type DBCache interface {
+	Get(key string) (any, error)
+	Set(key string, value any) error
+	Tidy() error
+	Init() error
+}
+
+// region Cache
+type Cache struct {
+	db     *DB
+	hits   int
+	misses int
+}
+type CacheEntry struct {
+	Key string
+	Value string
+	Date time.Time
+}
+
+func (cache *Cache) Get(key string) (CacheEntry, error) {
+	ret := CacheEntry{}
+	var rkey, rvalue string
+	var date time.Time
+	err := cache.db.readConn.QueryRow("SELECT key, value, date FROM cache WHERE key = ?", key).Scan(&rkey, &rvalue, &date)
+	if err != nil {
+		log.Printf("Cache miss for %s: %v", key, err)
+		cache.misses++
+		return ret, err
+	}
+
+	ret.Key = rkey
+	ret.Value = rvalue
+	ret.Date = date
+	
+	cache.hits++
+	log.Printf("Cache hit for %s", key)
+	return ret, nil
+}
+
+func (cache *Cache) Set(key string, value string) error {
+	_, err := cache.db.writeConn.Exec("INSERT INTO cache (key, value) VALUES (?, ?)", key, value)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (cache *Cache) Init() error {
+	_, err := cache.db.writeConn.Exec("CREATE TABLE IF NOT EXISTS cache (key TEXT, value TEXT, date DATE DEFAULT CURRENT_TIMESTAMP)")
+	if err != nil {
+		return err
+	}
+
+	_, err = cache.db.writeConn.Exec("CREATE INDEX IF NOT EXISTS idx_cache_key ON cache (key)")
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (cache *Cache) Tidy() error {
+	_, err := cache.db.writeConn.Exec("DELETE FROM cache WHERE date < datetime('now', '-1 day')")
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (cache *Cache) Rate() float32 {
+	return float32(cache.hits) / float32(cache.hits+cache.misses)
+}
+func (cache *Cache) RatePerc() string {
+	return fmt.Sprintf("%.2f%%", cache.Rate()*100)
+}