storage: transactional, new storage with transactional capabilities (WIP)

Signed-off-by: Máximo Cuadros <mcuadros@gmail.com>

Author: mcuadros

plumbing/storer/object.go

@@ -222,7 +222,7 @@ type MultiEncodedObjectIter struct {
 }
 
 // NewMultiEncodedObjectIter returns an object iterator for the given slice of
-// objects.
+// EncodedObjectIters.
 func NewMultiEncodedObjectIter(iters []EncodedObjectIter) EncodedObjectIter {
 	return &MultiEncodedObjectIter{iters: iters}
 }

storage/transactional/config.go

@@ -0,0 +1,36 @@
+package transactional
+
+import "gopkg.in/src-d/go-git.v4/config"
+
+type ConfigStorage struct {
+	config.ConfigStorer
+	temporal config.ConfigStorer
+
+	set bool
+}
+
+func NewConfigStorage(s, temporal config.ConfigStorer) *ConfigStorage {
+	return &ConfigStorage{ConfigStorer: s, temporal: temporal}
+}
+
+func (c *ConfigStorage) SetConfig(cfg *config.Config) error {
+	if err := c.temporal.SetConfig(cfg); err != nil {
+		return err
+	}
+
+	c.set = true
+	return nil
+}
+
+func (c *ConfigStorage) Commit() error {
+	if !c.set {
+		return nil
+	}
+
+	cfg, err := c.temporal.Config()
+	if err != nil {
+		return err
+	}
+
+	return c.ConfigStorer.SetConfig(cfg)
+}

storage/transactional/config_test.go

@@ -0,0 +1,70 @@
+package transactional
+
+import (
+	"testing"
+
+	. "gopkg.in/check.v1"
+	"gopkg.in/src-d/go-git.v4/config"
+	"gopkg.in/src-d/go-git.v4/storage/memory"
+)
+
+func Test(t *testing.T) { TestingT(t) }
+
+var _ = Suite(&ConfigSuite{})
+
+type ConfigSuite struct{}
+
+func (s *ConfigSuite) TestSetConfig(c *C) {
+	cfg := config.NewConfig()
+	cfg.Core.Worktree = "foo"
+
+	base := memory.NewStorage()
+	err := base.SetConfig(cfg)
+	c.Assert(err, IsNil)
+
+	temporal := memory.NewStorage()
+
+	cfg = config.NewConfig()
+	cfg.Core.Worktree = "bar"
+
+	cs := NewConfigStorage(base, temporal)
+	err = cs.SetConfig(cfg)
+	c.Assert(err, IsNil)
+
+	baseCfg, err := base.Config()
+	c.Assert(err, IsNil)
+	c.Assert(baseCfg.Core.Worktree, Equals, "foo")
+
+	temporalCfg, err := temporal.Config()
+	c.Assert(err, IsNil)
+	c.Assert(temporalCfg.Core.Worktree, Equals, "bar")
+
+	cfg, err = cs.Config()
+	c.Assert(err, IsNil)
+	c.Assert(temporalCfg.Core.Worktree, Equals, "bar")
+}
+
+func (s *ConfigSuite) TestCommit(c *C) {
+	cfg := config.NewConfig()
+	cfg.Core.Worktree = "foo"
+
+	base := memory.NewStorage()
+	err := base.SetConfig(cfg)
+	c.Assert(err, IsNil)
+
+	temporal := memory.NewStorage()
+
+	cfg = config.NewConfig()
+	cfg.Core.Worktree = "bar"
+
+	cs := NewConfigStorage(base, temporal)
+	err = cs.SetConfig(cfg)
+	c.Assert(err, IsNil)
+
+	err = cs.Commit()
+	c.Assert(err, IsNil)
+
+	baseCfg, err := base.Config()
+	c.Assert(err, IsNil)
+	c.Assert(baseCfg.Core.Worktree, Equals, "bar")
+}

storage/transactional/object.go

@@ -0,0 +1,63 @@
+package transactional
+
+import (
+	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/storer"
+)
+
+type ObjectStorage struct {
+	storer.EncodedObjectStorer
+	temporal storer.EncodedObjectStorer
+}
+
+func NewObjectStorage(s, temporal storer.EncodedObjectStorer) *ObjectStorage {
+	return &ObjectStorage{EncodedObjectStorer: s, temporal: temporal}
+}
+
+func (o *ObjectStorage) SetEncodedObject(obj plumbing.EncodedObject) (plumbing.Hash, error) {
+	return o.temporal.SetEncodedObject(obj)
+}
+
+func (o *ObjectStorage) HasEncodedObject(h plumbing.Hash) error {
+	err := o.EncodedObjectStorer.HasEncodedObject(h)
+	if err == plumbing.ErrObjectNotFound {
+		return o.temporal.HasEncodedObject(h)
+	}
+
+	return err
+}
+
+func (o *ObjectStorage) EncodedObjectSize(h plumbing.Hash) (int64, error) {
+	sz, err := o.EncodedObjectStorer.EncodedObjectSize(h)
+	if err == plumbing.ErrObjectNotFound {
+		return o.temporal.EncodedObjectSize(h)
+	}
+
+	return sz, err
+}
+
+func (o *ObjectStorage) EncodedObject(t plumbing.ObjectType, h plumbing.Hash) (plumbing.EncodedObject, error) {
+	obj, err := o.EncodedObjectStorer.EncodedObject(t, h)
+	if err == plumbing.ErrObjectNotFound {
+		return o.temporal.EncodedObject(t, h)
+	}
+
+	return obj, err
+}
+
+func (o *ObjectStorage) IterEncodedObjects(t plumbing.ObjectType) (storer.EncodedObjectIter, error) {
+	baseIter, err := o.EncodedObjectStorer.IterEncodedObjects(t)
+	if err != nil {
+		return nil, err
+	}
+
+	temporalIter, err := o.temporal.IterEncodedObjects(t)
+	if err != nil {
+		return nil, err
+	}
+
+	return storer.NewMultiEncodedObjectIter([]storer.EncodedObjectIter{
+		baseIter,
+		temporalIter,
+	}), nil
+}

storage/transactional/object_test.go

@@ -0,0 +1,119 @@
+package transactional
+
+import (
+	. "gopkg.in/check.v1"
+	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/storage/memory"
+)
+
+var _ = Suite(&ObjectSuite{})
+
+type ObjectSuite struct{}
+
+func (s *ObjectSuite) TestHasEncodedObject(c *C) {
+	base := memory.NewStorage()
+	temporal := memory.NewStorage()
+
+	os := NewObjectStorage(base, temporal)
+
+	commit := base.NewEncodedObject()
+	commit.SetType(plumbing.CommitObject)
+
+	ch, err := base.SetEncodedObject(commit)
+	c.Assert(ch.IsZero(), Equals, false)
+	c.Assert(err, IsNil)
+
+	tree := base.NewEncodedObject()
+	tree.SetType(plumbing.TreeObject)
+
+	th, err := os.SetEncodedObject(tree)
+	c.Assert(th.IsZero(), Equals, false)
+	c.Assert(err, IsNil)
+
+	err = os.HasEncodedObject(th)
+	c.Assert(err, IsNil)
+
+	err = os.HasEncodedObject(ch)
+	c.Assert(err, IsNil)
+
+	err = base.HasEncodedObject(th)
+	c.Assert(err, Equals, plumbing.ErrObjectNotFound)
+}
+
+func (s *ObjectSuite) TestEncodedObjectAndEncodedObjectSize(c *C) {
+	base := memory.NewStorage()
+	temporal := memory.NewStorage()
+
+	os := NewObjectStorage(base, temporal)
+
+	commit := base.NewEncodedObject()
+	commit.SetType(plumbing.CommitObject)
+
+	ch, err := base.SetEncodedObject(commit)
+	c.Assert(ch.IsZero(), Equals, false)
+	c.Assert(err, IsNil)
+
+	tree := base.NewEncodedObject()
+	tree.SetType(plumbing.TreeObject)
+
+	th, err := os.SetEncodedObject(tree)
+	c.Assert(th.IsZero(), Equals, false)
+	c.Assert(err, IsNil)
+
+	otree, err := os.EncodedObject(plumbing.TreeObject, th)
+	c.Assert(err, IsNil)
+	c.Assert(otree.Hash(), Equals, tree.Hash())
+
+	treeSz, err := os.EncodedObjectSize(th)
+	c.Assert(err, IsNil)
+	c.Assert(treeSz, Equals, int64(0))
+
+	ocommit, err := os.EncodedObject(plumbing.CommitObject, ch)
+	c.Assert(err, IsNil)
+	c.Assert(ocommit.Hash(), Equals, commit.Hash())
+
+	commitSz, err := os.EncodedObjectSize(ch)
+	c.Assert(err, IsNil)
+	c.Assert(commitSz, Equals, int64(0))
+
+	_, err = base.EncodedObject(plumbing.TreeObject, th)
+	c.Assert(err, Equals, plumbing.ErrObjectNotFound)
+
+	_, err = base.EncodedObjectSize(th)
+	c.Assert(err, Equals, plumbing.ErrObjectNotFound)
+}
+
+func (s *ObjectSuite) TestIterEncodedObjects(c *C) {
+	base := memory.NewStorage()
+	temporal := memory.NewStorage()
+
+	os := NewObjectStorage(base, temporal)
+
+	commit := base.NewEncodedObject()
+	commit.SetType(plumbing.CommitObject)
+
+	ch, err := base.SetEncodedObject(commit)
+	c.Assert(ch.IsZero(), Equals, false)
+	c.Assert(err, IsNil)
+
+	tree := base.NewEncodedObject()
+	tree.SetType(plumbing.TreeObject)
+
+	th, err := os.SetEncodedObject(tree)
+	c.Assert(th.IsZero(), Equals, false)
+	c.Assert(err, IsNil)
+
+	iter, err := os.IterEncodedObjects(plumbing.AnyObject)
+	c.Assert(err, IsNil)
+
+	var hashes []plumbing.Hash
+	err = iter.ForEach(func(obj plumbing.EncodedObject) error {
+		hashes = append(hashes, obj.Hash())
+		return nil
+	})
+
+	c.Assert(err, IsNil)
+	c.Assert(hashes, HasLen, 2)
+	c.Assert(hashes[0], Equals, ch)
+	c.Assert(hashes[1], Equals, th)
+}

storage/transactional/storage.go

@@ -0,0 +1 @@
+package transactional