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out-of-tree/daemon/db/db.go

124 lines
2.1 KiB
Go

package db
import (
"database/sql"
"fmt"
"strconv"
_ "github.com/mattn/go-sqlite3"
)
// Change on ANY database update
const currentDatabaseVersion = 1
const versionField = "db_version"
func createMetadataTable(db *sql.DB) (err error) {
_, err = db.Exec(`
CREATE TABLE IF NOT EXISTS metadata (
id INTEGER PRIMARY KEY,
key TEXT UNIQUE,
value TEXT
)`)
return
}
func metaChkValue(db *sql.DB, key string) (exist bool, err error) {
sql := "SELECT EXISTS(SELECT id FROM metadata WHERE key = $1)"
stmt, err := db.Prepare(sql)
if err != nil {
return
}
defer stmt.Close()
err = stmt.QueryRow(key).Scan(&exist)
return
}
func metaGetValue(db *sql.DB, key string) (value string, err error) {
stmt, err := db.Prepare("SELECT value FROM metadata " +
"WHERE key = $1")
if err != nil {
return
}
defer stmt.Close()
err = stmt.QueryRow(key).Scan(&value)
return
}
func metaSetValue(db *sql.DB, key, value string) (err error) {
stmt, err := db.Prepare("INSERT OR REPLACE INTO metadata " +
"(key, value) VALUES ($1, $2)")
if err != nil {
return
}
defer stmt.Close()
_, err = stmt.Exec(key, value)
return
}
func getVersion(db *sql.DB) (version int, err error) {
s, err := metaGetValue(db, versionField)
if err != nil {
return
}
version, err = strconv.Atoi(s)
return
}
func createSchema(db *sql.DB) (err error) {
err = createMetadataTable(db)
if err != nil {
return
}
err = createJobTable(db)
if err != nil {
return
}
err = createRepoTable(db)
if err != nil {
return
}
return
}
func OpenDatabase(path string) (db *sql.DB, err error) {
db, err = sql.Open("sqlite3", path)
if err != nil {
return
}
db.SetMaxOpenConns(1)
exists, _ := metaChkValue(db, versionField)
if !exists {
err = createSchema(db)
if err != nil {
return
}
err = metaSetValue(db, versionField,
strconv.Itoa(currentDatabaseVersion))
return
}
version, err := getVersion(db)
if err != nil {
return
}
if version != currentDatabaseVersion {
err = fmt.Errorf("database is not supported (%d instead of %d)",
version, currentDatabaseVersion)
return
}
return
}