func randURI(base string) rdf.URI {
n := rnd.Intn(100)
if n > 70 {
// 70% using base uri
base = "http://"
}
letters := []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-..///")
l := rnd.Intn(100) + 1
r := make([]rune, l)
for i := range r {
r[i] = letters[rand.Intn(len(letters))]
}
if r[0] == '/' {
r[0] = letters[rand.Intn(len(letters)-3)]
}
return rdf.NewURI(base + string(r))
}
func (db *DB) decode(b []byte) (rdf.Term, error) {
// We control the encoding, so the only way for this method to fail to decode
// into a RDF term is if the underlying stoarge has been corrupted on the file system level.
if len(b) == 0 {
return nil, errors.New("cannot decode empty byte slice into RDF term")
}
var dt rdf.URI
switch b[0] {
case 0x00:
return rdf.URI(db.base + string(b[1:])), nil
case 0x01:
return rdf.URI(string(b[1:])), nil
case 0x02:
return rdf.NewTypedLiteral(string(b[1:]), rdf.XSDstring), nil
case 0x03:
if len(b) < 2 {
return nil, fmt.Errorf("cannot decode as rdf:langString: %v", b)
}
ll := int(b[1])
if len(b) < ll+2 {
return nil, fmt.Errorf("cannot decode as rdf:langString: %v", b)
}
return rdf.NewLangLiteral(string(b[ll+2:]), string(b[2:2+ll])), nil
case 0x04:
dt = rdf.XSDboolean
case 0x05:
dt = rdf.XSDbyte
case 0x06:
dt = rdf.XSDint
case 0x07:
dt = rdf.XSDshort
case 0x08:
dt = rdf.XSDlong
case 0x09:
dt = rdf.XSDinteger
case 0x0A:
dt = rdf.XSDunsignedShort
case 0x0B:
dt = rdf.XSDunsignedInt
case 0x0C:
dt = rdf.XSDunsignedLong
case 0x0D:
dt = rdf.XSDunsignedByte
case 0x0E:
dt = rdf.XSDfloat
case 0x0F:
dt = rdf.XSDdouble
case 0x10:
dt = rdf.XSDdateTimeStamp
case 0xFF:
if len(b) < 2 {
return nil, fmt.Errorf("cannot decode as literal: %v", b)
}
ll := int(b[1])
if len(b) < ll {
return nil, fmt.Errorf("cannot decode as literal: %v", b)
}
return rdf.NewTypedLiteral(string(b[ll+2:]), rdf.NewURI(string(b[2:2+ll]))), nil
default:
return nil, fmt.Errorf("cannot decode RDF term: %v", b)
}
return rdf.NewTypedLiteral(string(b[1:]), dt), nil
}