func ExampleKey() {
var a1 int16 = 42
var a2 float32 = 9.2
x, _ := lex.Key(a1)
y, _ := lex.Key(a2)
z, _ := lex.Key(a1, a2)
fmt.Printf("%v %v\n%v", x, y, z)
// Output:
// [128 42] [193 19 51 51]
// [128 42 193 19 51 51]
}
func TestKey_alias(t *testing.T) {
var a1 aliasedInt = 42
expected := make([]byte, 8)
lex.PutInt(expected, int(a1))
actual, err := lex.Key(a1)
assert.Nil(t, err)
assert.True(t, bytes.Equal(expected, actual))
}
func TestKey(t *testing.T) {
var a1 int16 = 42
var a2 float32 = 9.2
expected := make([]byte, 6)
lex.PutInt16(expected, a1)
lex.PutFloat32(expected[2:], a2)
actual, err := lex.Key(a1, a2)
assert.Nil(t, err)
assert.True(t, bytes.Equal(expected, actual))
}
func Example() {
//from http://www.imdb.com/chart/top
movies := []Movie{
{1, "The Shawshank Redemption", 1994, 9.2},
{2, "The Godfather", 1972, 9.2},
{3, "The Godfather: Part II", 1974, 9.0},
{4, "The Dark Knight", 2008, 8.9},
{5, "12 Angry Men", 1957, 8.9},
{6, "Schindler's List", 1993, 8.9},
{7, "Pulp Fiction", 1994, 8.9},
{8, "The Good, the Bad and the Ugly", 1966, 8.9},
{9, "The Lord of the Rings: The Return of the King", 2003, 8.9},
{10, "Fight Club", 1999, 8.8},
}
db := setup_bolt()
defer clean_bolt(db)
//index of {year,rating} => title
db.Update(func(tx *bolt.Tx) error {
b, _ := tx.CreateBucket([]byte("year,rating"))
for _, m := range movies {
k, _ := lex.Key(m.Year, m.Rating)
v := []byte(m.Title)
b.Put(k, v)
}
//range seek on first part of key
//year >= 1950 && year < 1970
min, _ := lex.Key(int16(1950))
max, _ := lex.Key(int16(1970))
c := b.Cursor()
for k, v := c.Seek(min); bytes.Compare(k, max) <= 0; k, v = c.Next() {
fmt.Printf("%v (%v)\n", string(v), lex.Int16(k))
}
//exact match on first + range seek on second part of key
//year == 1994 && rating >= 9.0
start, _ := lex.Key(int16(1994), float32(9.0))
prefix, _ := lex.Key(int16(1994))
c = b.Cursor()
for k, v := c.Seek(start); bytes.HasPrefix(k, prefix); k, v = c.Next() {
fmt.Println(string(v))
}
return nil
})
//index of {title} => rating
db.Update(func(tx *bolt.Tx) error {
b, _ := tx.CreateBucket([]byte("title"))
for _, m := range movies {
k, _ := lex.Key(m.Title)
v := []byte(strconv.FormatFloat(float64(m.Rating), 'f', 1, 32))
b.Put(k, v)
}
//title Equals "The Godfather"
eq, _ := lex.Key("The Godfather")
v := b.Get(eq)
fmt.Println(string(v))
//title HasPrefix "The Godfather"
prefix := []byte("The Godfather") //note that this isn't NUL terminated
c := b.Cursor()
for k, v := c.Seek(prefix); bytes.HasPrefix(k, prefix); k, v = c.Next() {
fmt.Printf("%v %v\n", lex.String(k), string(v))
}
return nil
})
// Output:
//12 Angry Men (1957)
//The Good, the Bad and the Ugly (1966)
//The Shawshank Redemption
//9.2
//The Godfather 9.2
//The Godfather: Part II 9.0
}
func TestKey_invalidnilptr(t *testing.T) {
var m map[string]int
b, err := lex.Key(&m)
assert.Nil(t, b)
assert.NotNil(t, err)
}
func TestKey_nilptr(t *testing.T) {
var p *int = nil
b, err := lex.Key(p)
assert.Nil(t, b)
assert.NotNil(t, err)
}
func TestKey_nil(t *testing.T) {
b, err := lex.Key(nil)
assert.Nil(t, b)
assert.NotNil(t, err)
}
func TestKey_noargs(t *testing.T) {
b, err := lex.Key()
assert.Nil(t, b)
assert.NotNil(t, err)
}