prologic revised this gist . Go to revision
2 files changed, 15 insertions, 10 deletions
collection.go
| @@ -4,6 +4,7 @@ import ( | |||
| 4 | 4 | "encoding/json" | |
| 5 | 5 | "errors" | |
| 6 | 6 | "fmt" | |
| 7 | + | "reflect" | |
| 7 | 8 | ) | |
| 8 | 9 | ||
| 9 | 10 | var ( | |
| @@ -62,22 +63,26 @@ func (c *Collection) Get(id string, obj any) error { | |||
| 62 | 63 | } | |
| 63 | 64 | ||
| 64 | 65 | // List returns a list of all objects in this collection. | |
| 65 | - | func (c *Collection) List(objects []any) error { | |
| 66 | + | func (c *Collection) List(objects any) error { | |
| 66 | 67 | tx := c.db.Transaction() | |
| 67 | 68 | defer tx.Discard() | |
| 68 | 69 | ||
| 70 | + | value := reflect.ValueOf(objects).Elem() | |
| 71 | + | elem := reflect.TypeOf(objects).Elem() | |
| 72 | + | ||
| 69 | 73 | return tx.Scan(c.makePrefix(), func(k Key) error { | |
| 70 | 74 | data, err := tx.Get(k) | |
| 71 | 75 | if err != nil { | |
| 72 | 76 | return err | |
| 73 | 77 | } | |
| 74 | 78 | ||
| 75 | - | var obj any | |
| 76 | - | if err := json.Unmarshal(data, obj); err != nil { | |
| 79 | + | obj := reflect.New(elem) | |
| 80 | + | ||
| 81 | + | if err := json.Unmarshal(data, &obj); err != nil { | |
| 77 | 82 | return err | |
| 78 | 83 | } | |
| 79 | 84 | ||
| 80 | - | objects = append(objects, obj) | |
| 85 | + | value.Set(reflect.Append(value, reflect.ValueOf(obj))) | |
| 81 | 86 | ||
| 82 | 87 | return nil | |
| 83 | 88 | }) | |
| @@ -117,4 +122,4 @@ func (c *Collection) Drop() error { | |||
| 117 | 122 | // Count() > 0. | |
| 118 | 123 | func (c *Collection) Exists() bool { | |
| 119 | 124 | return c.Count() > 0 | |
| 120 | - | } | |
| 125 | + | } | |
collection_test.go
| @@ -99,7 +99,7 @@ func TestCollection(t *testing.T) { | |||
| 99 | 99 | c := db.Collection("users") | |
| 100 | 100 | ||
| 101 | 101 | var actual []User | |
| 102 | - | expected := []User{} | |
| 102 | + | var expected []User | |
| 103 | 103 | // cannot use actual (variable of type []User) as []any value in argument to c.List | |
| 104 | 104 | assert.NoError(t, c.List(actual)) | |
| 105 | 105 | assert.Equal(t, expected, actual) | |
| @@ -110,13 +110,13 @@ func TestCollection(t *testing.T) { | |||
| 110 | 110 | ||
| 111 | 111 | actual = []User{} | |
| 112 | 112 | expected = []User{ | |
| 113 | - | User{"James", 21}, | |
| 114 | - | User{"Bob", 99}, | |
| 115 | - | User{"frank", 37}, | |
| 113 | + | {"James", 21}, | |
| 114 | + | {"Bob", 99}, | |
| 115 | + | {"frank", 37}, | |
| 116 | 116 | } | |
| 117 | 117 | ||
| 118 | 118 | // cannot use actual (variable of type []User) as []any value in argument to c.List | |
| 119 | 119 | assert.NoError(t, c.List(actual)) | |
| 120 | 120 | assert.Equal(t, expected, actual) | |
| 121 | 121 | }) | |
| 122 | - | } | |
| 122 | + | } | |
prologic revised this gist . Go to revision
2 files changed, 242 insertions
collection.go(file created)
| @@ -0,0 +1,120 @@ | |||
| 1 | + | package bitcask | |
| 2 | + | ||
| 3 | + | import ( | |
| 4 | + | "encoding/json" | |
| 5 | + | "errors" | |
| 6 | + | "fmt" | |
| 7 | + | ) | |
| 8 | + | ||
| 9 | + | var ( | |
| 10 | + | // ErrObjectNotFound is the error returned when an object is not found in the collection. | |
| 11 | + | ErrObjectNotFound = errors.New("error: object not found") | |
| 12 | + | ) | |
| 13 | + | ||
| 14 | + | func (b *bitcask) Collection(name string) *Collection { | |
| 15 | + | return &Collection{db: b, name: name} | |
| 16 | + | } | |
| 17 | + | ||
| 18 | + | // Collection allows you to manage a collection of objects encoded as JSON | |
| 19 | + | // documents with a path-based key based on the provided name. This is convenient | |
| 20 | + | // for storing complex normalized collections of objects. | |
| 21 | + | type Collection struct { | |
| 22 | + | db DB | |
| 23 | + | name string | |
| 24 | + | } | |
| 25 | + | ||
| 26 | + | func (c *Collection) makeKey(id string) Key { | |
| 27 | + | return Key(fmt.Sprintf("%s/%s", c.name, id)) | |
| 28 | + | } | |
| 29 | + | ||
| 30 | + | func (c *Collection) makePrefix() Key { | |
| 31 | + | return Key(c.name) | |
| 32 | + | } | |
| 33 | + | ||
| 34 | + | // Add adds a new object to the collection | |
| 35 | + | func (c *Collection) Add(id string, obj any) error { | |
| 36 | + | k := c.makeKey(id) | |
| 37 | + | v, err := json.Marshal(obj) | |
| 38 | + | if err != nil { | |
| 39 | + | return err | |
| 40 | + | } | |
| 41 | + | ||
| 42 | + | return c.db.Put(k, v) | |
| 43 | + | } | |
| 44 | + | ||
| 45 | + | // Delete deletes an object from the collection | |
| 46 | + | func (c *Collection) Delete(id string) error { | |
| 47 | + | return c.db.Delete(c.makeKey(id)) | |
| 48 | + | } | |
| 49 | + | ||
| 50 | + | // Get returns an object from the collection | |
| 51 | + | func (c *Collection) Get(id string, obj any) error { | |
| 52 | + | k := c.makeKey(id) | |
| 53 | + | data, err := c.db.Get(k) | |
| 54 | + | if err != nil { | |
| 55 | + | if err == ErrKeyNotFound { | |
| 56 | + | return ErrObjectNotFound | |
| 57 | + | } | |
| 58 | + | return err | |
| 59 | + | } | |
| 60 | + | ||
| 61 | + | return json.Unmarshal(data, obj) | |
| 62 | + | } | |
| 63 | + | ||
| 64 | + | // List returns a list of all objects in this collection. | |
| 65 | + | func (c *Collection) List(objects []any) error { | |
| 66 | + | tx := c.db.Transaction() | |
| 67 | + | defer tx.Discard() | |
| 68 | + | ||
| 69 | + | return tx.Scan(c.makePrefix(), func(k Key) error { | |
| 70 | + | data, err := tx.Get(k) | |
| 71 | + | if err != nil { | |
| 72 | + | return err | |
| 73 | + | } | |
| 74 | + | ||
| 75 | + | var obj any | |
| 76 | + | if err := json.Unmarshal(data, obj); err != nil { | |
| 77 | + | return err | |
| 78 | + | } | |
| 79 | + | ||
| 80 | + | objects = append(objects, obj) | |
| 81 | + | ||
| 82 | + | return nil | |
| 83 | + | }) | |
| 84 | + | } | |
| 85 | + | ||
| 86 | + | // Has returns true if an object exists by the provided id. | |
| 87 | + | func (c *Collection) Has(id string) bool { | |
| 88 | + | return c.db.Has(c.makeKey(id)) | |
| 89 | + | } | |
| 90 | + | ||
| 91 | + | // Count returns the number of objects in this collection. | |
| 92 | + | func (c *Collection) Count() int { | |
| 93 | + | n := 0 | |
| 94 | + | c.db.Scan(c.makePrefix(), func(k Key) error { | |
| 95 | + | n++ | |
| 96 | + | return nil | |
| 97 | + | }) | |
| 98 | + | return n | |
| 99 | + | } | |
| 100 | + | ||
| 101 | + | // Drop deletes the entire collection | |
| 102 | + | func (c *Collection) Drop() error { | |
| 103 | + | tx := c.db.Transaction() | |
| 104 | + | defer tx.Discard() | |
| 105 | + | ||
| 106 | + | if err := tx.Scan(c.makePrefix(), func(k Key) error { | |
| 107 | + | return tx.Delete(k) | |
| 108 | + | }); err != nil { | |
| 109 | + | return err | |
| 110 | + | } | |
| 111 | + | ||
| 112 | + | return tx.Commit() | |
| 113 | + | } | |
| 114 | + | ||
| 115 | + | // Exists returns true if the collection exists at all, which really just means | |
| 116 | + | // whether there are any objects in the collection, so this is the same as calling | |
| 117 | + | // Count() > 0. | |
| 118 | + | func (c *Collection) Exists() bool { | |
| 119 | + | return c.Count() > 0 | |
| 120 | + | } | |
collection_test.go(file created)
| @@ -0,0 +1,122 @@ | |||
| 1 | + | package bitcask | |
| 2 | + | ||
| 3 | + | import ( | |
| 4 | + | "os" | |
| 5 | + | "testing" | |
| 6 | + | ||
| 7 | + | "github.com/stretchr/testify/assert" | |
| 8 | + | "github.com/stretchr/testify/require" | |
| 9 | + | ) | |
| 10 | + | ||
| 11 | + | func setupDB(t *testing.T) DB { | |
| 12 | + | t.Helper() | |
| 13 | + | ||
| 14 | + | testDir, err := os.MkdirTemp("", "bitcask") | |
| 15 | + | assert.NoError(t, err) | |
| 16 | + | ||
| 17 | + | db, err := Open(testDir) | |
| 18 | + | assert.NoError(t, err) | |
| 19 | + | ||
| 20 | + | return db | |
| 21 | + | } | |
| 22 | + | ||
| 23 | + | func TestCollection(t *testing.T) { | |
| 24 | + | type User struct { | |
| 25 | + | Name string | |
| 26 | + | Age int | |
| 27 | + | } | |
| 28 | + | ||
| 29 | + | t.Run("AddGetDelete", func(t *testing.T) { | |
| 30 | + | db := setupDB(t) | |
| 31 | + | defer db.Close() | |
| 32 | + | c := db.Collection("users") | |
| 33 | + | ||
| 34 | + | err := c.Add("prologic", &User{"James", 21}) | |
| 35 | + | assert.NoError(t, err) | |
| 36 | + | ||
| 37 | + | var actual User | |
| 38 | + | expected := User{"James", 21} | |
| 39 | + | require.NoError(t, c.Get("prologic", &actual)) | |
| 40 | + | assert.EqualValues(t, expected, actual) | |
| 41 | + | ||
| 42 | + | actual = User{} | |
| 43 | + | expected = User{} | |
| 44 | + | require.NoError(t, c.Delete("prologic")) | |
| 45 | + | err = c.Get("prologic", &actual) | |
| 46 | + | require.Error(t, err) | |
| 47 | + | assert.EqualValues(t, expected, actual) | |
| 48 | + | }) | |
| 49 | + | ||
| 50 | + | t.Run("GetError", func(t *testing.T) { | |
| 51 | + | db := setupDB(t) | |
| 52 | + | defer db.Close() | |
| 53 | + | c := db.Collection("users") | |
| 54 | + | ||
| 55 | + | var actual User | |
| 56 | + | err := c.Get("foo", &actual) | |
| 57 | + | require.Error(t, err) | |
| 58 | + | assert.ErrorIs(t, err, ErrObjectNotFound) | |
| 59 | + | assert.EqualError(t, err, ErrObjectNotFound.Error()) | |
| 60 | + | }) | |
| 61 | + | ||
| 62 | + | t.Run("CountExistsEmpty", func(t *testing.T) { | |
| 63 | + | db := setupDB(t) | |
| 64 | + | defer db.Close() | |
| 65 | + | c := db.Collection("users") | |
| 66 | + | ||
| 67 | + | assert.Zero(t, c.Count()) | |
| 68 | + | assert.False(t, c.Exists()) | |
| 69 | + | }) | |
| 70 | + | ||
| 71 | + | t.Run("CountNonZero", func(t *testing.T) { | |
| 72 | + | db := setupDB(t) | |
| 73 | + | defer db.Close() | |
| 74 | + | c := db.Collection("users") | |
| 75 | + | ||
| 76 | + | assert.Zero(t, c.Count()) | |
| 77 | + | assert.False(t, c.Exists()) | |
| 78 | + | ||
| 79 | + | require.NoError(t, c.Add("prologic", User{"James", 21})) | |
| 80 | + | assert.Equal(t, 1, c.Count()) | |
| 81 | + | assert.True(t, c.Exists()) | |
| 82 | + | ||
| 83 | + | }) | |
| 84 | + | ||
| 85 | + | t.Run("Has", func(t *testing.T) { | |
| 86 | + | db := setupDB(t) | |
| 87 | + | defer db.Close() | |
| 88 | + | c := db.Collection("users") | |
| 89 | + | ||
| 90 | + | assert.False(t, c.Has("prologic")) | |
| 91 | + | ||
| 92 | + | require.NoError(t, c.Add("prologic", User{"James", 21})) | |
| 93 | + | assert.True(t, c.Has("prologic")) | |
| 94 | + | }) | |
| 95 | + | ||
| 96 | + | t.Run("List", func(t *testing.T) { | |
| 97 | + | db := setupDB(t) | |
| 98 | + | defer db.Close() | |
| 99 | + | c := db.Collection("users") | |
| 100 | + | ||
| 101 | + | var actual []User | |
| 102 | + | expected := []User{} | |
| 103 | + | // cannot use actual (variable of type []User) as []any value in argument to c.List | |
| 104 | + | assert.NoError(t, c.List(actual)) | |
| 105 | + | assert.Equal(t, expected, actual) | |
| 106 | + | ||
| 107 | + | require.NoError(t, c.Add("prologic", User{"James", 21})) | |
| 108 | + | require.NoError(t, c.Add("bob", User{"Bob", 99})) // name is made-up | |
| 109 | + | require.NoError(t, c.Add("frank", User{"Frank", 37})) // name is made-up | |
| 110 | + | ||
| 111 | + | actual = []User{} | |
| 112 | + | expected = []User{ | |
| 113 | + | User{"James", 21}, | |
| 114 | + | User{"Bob", 99}, | |
| 115 | + | User{"frank", 37}, | |
| 116 | + | } | |
| 117 | + | ||
| 118 | + | // cannot use actual (variable of type []User) as []any value in argument to c.List | |
| 119 | + | assert.NoError(t, c.List(actual)) | |
| 120 | + | assert.Equal(t, expected, actual) | |
| 121 | + | }) | |
| 122 | + | } | |
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