func gdbmOpen(file string) (*gdbm, error) {
cstr := C.CString(file)
defer C.free(unsafe.Pointer(cstr))
dbf := C.gdbm_open(cstr, 0, C.GDBM_WRCREAT, 0644, nil)
if dbf == nil {
return nil, err()
}
return &gdbm{
dbf: dbf,
}, nil
}
// Opens a database using the given configuration options.
func OpenConfig(config *Config) (*Database, error) {
cname := C.CString(config.File)
defer C.free(unsafe.Pointer(cname))
mode := C.int(config.Mode)
if config.Sync {
mode |= C.GDBM_SYNC
}
if config.DontLock {
mode |= C.GDBM_NOLOCK
}
dbf, err := C.gdbm_open(cname, C.int(config.BlockSize), mode, C.int(config.Perm), nil)
if dbf != nil {
if config.CacheSize != 0 {
val := C.int(config.CacheSize)
C.gdbm_setopt(dbf, C.GDBM_CACHESIZE, &val, C.int(unsafe.Sizeof(val)))
}
return &Database{config.File, dbf}, nil
}
return nil, err
}
// More complex database initialization function that takes in a `DatabaseCfg`
// struct to allow more fine-grained control over database settings.
func OpenWithCfg(filename string, cfg DatabaseCfg) (db *Database, err error) {
db = new(Database)
// Convert a human-readable mode string into a libgdbm-usable constant.
switch cfg.Mode {
case "r":
db.mode = C.GDBM_READER
case "w":
db.mode = C.GDBM_WRITER
case "c":
db.mode = C.GDBM_WRCREAT
case "n":
db.mode = C.GDBM_NEWDB
}
cs := C.CString(filename)
defer C.free(unsafe.Pointer(cs))
db.dbf = C.gdbm_open(cs, C.int(cfg.BlockSize), C.int(db.mode), C.int(cfg.Permissions), nil)
if db.dbf == nil {
err = lastError()
}
return db, err
}