1
0
forked from MTSR/mapserver
mapserver/db/sqlite.go
2019-01-09 11:11:45 +01:00

117 lines
2.4 KiB
Go

package db
import (
"database/sql"
_ "github.com/mattn/go-sqlite3"
"github.com/sirupsen/logrus"
"mapserver/coords"
"time"
"errors"
)
var log *logrus.Entry
func init(){
log = logrus.WithFields(logrus.Fields{"prefix": "db/sqlite.Migrate"})
}
const migrateScript = `
alter table blocks add mtime timestamp default NULL;
update blocks set mtime = current_timestamp;
create index blocks_mtime on blocks(mtime);
CREATE TRIGGER update_blocks_mtime_insert after insert on blocks for each row
begin
update blocks set mtime = current_timestamp where pos = new.pos;
end;
CREATE TRIGGER update_blocks_mtime_update after update on blocks for each row
begin
update blocks set mtime = current_timestamp where pos = old.pos;
end;
`
type Sqlite3Accessor struct {
db *sql.DB
filename string
}
func (db *Sqlite3Accessor) Migrate() error {
//RW connection
rwdb, err := sql.Open("sqlite3", db.filename + "?mode=rw")
if err != nil {
return err
}
defer rwdb.Close()
hasMtime := true
_, err = rwdb.Query("select max(mtime) from blocks")
if err != nil {
hasMtime = false
}
if !hasMtime {
log.WithFields(logrus.Fields{"filename":db.filename}).Info("Migrating database")
start := time.Now()
_, err = rwdb.Exec(migrateScript)
if err != nil {
return err
}
t := time.Now()
elapsed := t.Sub(start)
log.WithFields(logrus.Fields{"elapsed":elapsed}).Info("Migration completed")
}
return nil
}
func (db *Sqlite3Accessor) FindLatestBlocks(mintime int64, limit int) ([]Block, error) {
return make([]Block, 0), nil
}
func (db *Sqlite3Accessor) FindBlocks(pos1, pos2 coords.MapBlockCoords) ([]Block, error) {
return make([]Block, 0), nil
}
const countBlockQuery = `
select count(*) from blocks b
where b.pos >= ? and b.pos <= ?
`
func (db *Sqlite3Accessor) CountBlocks(pos1, pos2 coords.MapBlockCoords) (int, error) {
ppos1 := coords.CoordToPlain(pos1)
ppos2 := coords.CoordToPlain(pos2)
if ppos1 > ppos2 {
ppos1, ppos2 = ppos2, ppos1
}
rows, err := db.db.Query(countBlockQuery, ppos1, ppos2)
if err != nil {
return 0, err
}
if !rows.Next() {
return 0, errors.New("No results")
}
var count int
err = rows.Scan(&count)
if err != nil {
return 0, err
}
return count, nil
}
func NewSqliteAccessor(filename string) (*Sqlite3Accessor, error) {
db, err := sql.Open("sqlite3", filename + "?mode=ro")
if err != nil {
return nil, err
}
sq := &Sqlite3Accessor{db: db, filename: filename}
return sq, nil
}