keytransform ds

Godeps/Godeps.json

@@ -64,7 +64,7 @@
 		},
 		{
 			"ImportPath": "github.com/jbenet/datastore.go",
-			"Rev": "e7d6f7cb9e3c207a04c5397c449d10a6f9d403a0"
+			"Rev": "60ebc56447b5a8264cfed3ae3ff48deb984d7cf1"
 		},
 		{
 			"ImportPath": "github.com/jbenet/go-base58",

Godeps/_workspace/src/github.com/jbenet/datastore.go/keytransform/keytransform.go

@@ -0,0 +1,88 @@
+package keytransform
+
+import ds "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/datastore.go"
+
+// KeyTransform is a function that transforms one key into another.
+type KeyTransform func(ds.Key) ds.Key
+
+// Datastore is a keytransform.Datastore
+type Datastore interface {
+	ds.Shim
+
+	// Transform runs the transformation function
+	Transform(ds.Key) ds.Key
+
+	// TransformFunc returns the KeyTransform function
+	TransformFunc() KeyTransform
+}
+
+// ktds keeps a KeyTransform function
+type ktds struct {
+	child ds.Datastore
+	xform KeyTransform
+}
+
+// WrapDatastore wraps a given datastore with a KeyTransform function.
+// The resulting wrapped datastore will use the transform on all Datastore
+// operations.
+func WrapDatastore(child ds.Datastore, f KeyTransform) Datastore {
+	if f == nil {
+		panic("f (KeyTransform) is nil")
+	}
+
+	if child == nil {
+		panic("child (ds.Datastore) is nil")
+	}
+
+	return &ktds{child, f}
+}
+
+// TransformFunc returns the KeyTransform function
+func (d *ktds) TransformFunc() KeyTransform {
+	return d.xform
+}
+
+// Transform runs the KeyTransform function
+func (d *ktds) Transform(k ds.Key) ds.Key {
+	return d.xform(k)
+}
+
+// Children implements ds.Shim
+func (d *ktds) Children() []ds.Datastore {
+	return []ds.Datastore{d.child}
+}
+
+// Put stores the given value, transforming the key first.
+func (d *ktds) Put(key ds.Key, value interface{}) (err error) {
+	return d.child.Put(d.Transform(key), value)
+}
+
+// Get returns the value for given key, transforming the key first.
+func (d *ktds) Get(key ds.Key) (value interface{}, err error) {
+	return d.child.Get(d.Transform(key))
+}
+
+// Has returns whether the datastore has a value for a given key, transforming
+// the key first.
+func (d *ktds) Has(key ds.Key) (exists bool, err error) {
+	return d.child.Has(d.Transform(key))
+}
+
+// Delete removes the value for given key
+func (d *ktds) Delete(key ds.Key) (err error) {
+	return d.child.Delete(d.Transform(key))
+}
+
+// KeyList returns a list of all keys in the datastore, transforming keys out.
+func (d *ktds) KeyList() ([]ds.Key, error) {
+
+	keys, err := d.child.KeyList()
+	if err != nil {
+		return nil, err
+	}
+
+	for i, k := range keys {
+		keys[i] = d.Transform(k)
+	}
+	return keys, nil
+}

Godeps/_workspace/src/github.com/jbenet/datastore.go/keytransform/keytransform_test.go

@@ -0,0 +1,60 @@
+package keytransform_test
+
+import (
+	"bytes"
+	"testing"
+
+	ds "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/datastore.go"
+	kt "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/datastore.go/keytransform"
+	. "launchpad.net/gocheck"
+)
+
+// Hook up gocheck into the "go test" runner.
+func Test(t *testing.T) { TestingT(t) }
+
+type DSSuite struct {
+	dir string
+	ds  ds.Datastore
+}
+
+var _ = Suite(&DSSuite{})
+
+func (ks *DSSuite) TestBasic(c *C) {
+
+	mpds := ds.NewMapDatastore()
+	ktds := kt.WrapDatastore(mpds, func(k ds.Key) ds.Key {
+		return k.Reverse()
+	})
+
+	keys := strsToKeys([]string{
+		"foo",
+		"foo/bar",
+		"foo/bar/baz",
+		"foo/barb",
+		"foo/bar/bazb",
+		"foo/bar/baz/barb",
+	})
+
+	for _, k := range keys {
+		err := ktds.Put(k, []byte(k.String()))
+		c.Check(err, Equals, nil)
+	}
+
+	for _, k := range keys {
+		v1, err := ktds.Get(k)
+		c.Check(err, Equals, nil)
+		c.Check(bytes.Equal(v1.([]byte), []byte(k.String())), Equals, true)
+
+		v2, err := mpds.Get(k.Reverse())
+		c.Check(err, Equals, nil)
+		c.Check(bytes.Equal(v2.([]byte), []byte(k.String())), Equals, true)
+	}
+}
+
+func strsToKeys(strs []string) []ds.Key {
+	keys := make([]ds.Key, len(strs))
+	for i, s := range strs {
+		keys[i] = ds.NewKey(s)
+	}
+	return keys
+}