global storage interface refactor (#112)

* core: ObjectStorage, ReferenceStorage renamed to ObjectStorer and
ReferenceStorer

* rebase

* general, changes request by @alcortes

* general, changes request by @alcortes

5 files changed, 55 insertions, 65 deletions

diff --git a/core/memory.go b/core/memory.go
index 97b1b9b..dabee3a 100644
--- a/core/memory.go
+++ b/core/memory.go
@@ -1,7 +1,8 @@
-package core 
+package core
 
 import (
 	"bytes"
+	"io"
 	"io/ioutil"
 )
 
@@ -39,12 +40,12 @@ func (o *MemoryObject) Size() int64 { return o.sz }
 func (o *MemoryObject) SetSize(s int64) { o.sz = s }
 
 // Reader returns a ObjectReader used to read the object's content.
-func (o *MemoryObject) Reader() (ObjectReader, error) {
+func (o *MemoryObject) Reader() (io.ReadCloser, error) {
 	return ioutil.NopCloser(bytes.NewBuffer(o.cont)), nil
 }
 
 // Writer returns a ObjectWriter used to write the object's content.
-func (o *MemoryObject) Writer() (ObjectWriter, error) {
+func (o *MemoryObject) Writer() (io.WriteCloser, error) {
 	return o, nil
 }
 
diff --git a/core/object.go b/core/object.go
index 30beff8..8125465 100644
--- a/core/object.go
+++ b/core/object.go
@@ -12,21 +12,6 @@ var (
 	ErrInvalidType = errors.New("invalid object type")
 )
 
-// TODO: Consider adding a Hash function to the ObjectReader and ObjectWriter
-//       interfaces that returns the hash calculated for the reader or writer.
-
-// ObjectReader is a generic representation of an object reader.
-//
-// ObjectReader implements io.ReadCloser. Close should be called when finished
-// with it.
-type ObjectReader io.ReadCloser
-
-// ObjectWriter is a generic representation of an object writer.
-//
-// ObjectWriter implements io.WriterCloser. Close should be called when finished
-// with it.
-type ObjectWriter io.WriteCloser
-
 // Object is a generic representation of any git object
 type Object interface {
 	Hash() Hash
@@ -34,8 +19,8 @@ type Object interface {
 	SetType(ObjectType)
 	Size() int64
 	SetSize(int64)
-	Reader() (ObjectReader, error)
-	Writer() (ObjectWriter, error)
+	Reader() (io.ReadCloser, error)
+	Writer() (io.WriteCloser, error)
 }
 
 // ObjectType internal object type
@@ -116,7 +101,7 @@ func ParseObjectType(value string) (typ ObjectType, err error) {
 // The ObjectLookupIter must be closed with a call to Close() when it is no
 // longer needed.
 type ObjectLookupIter struct {
-	storage ObjectStorage
+	storage ObjectStorer
 	series  []Hash
 	t       ObjectType
 	pos     int
@@ -124,7 +109,7 @@ type ObjectLookupIter struct {
 
 // NewObjectLookupIter returns an object iterator given an object storage and
 // a slice of object hashes.
-func NewObjectLookupIter(storage ObjectStorage, t ObjectType, series []Hash) *ObjectLookupIter {
+func NewObjectLookupIter(storage ObjectStorer, t ObjectType, series []Hash) *ObjectLookupIter {
 	return &ObjectLookupIter{
 		storage: storage,
 		series:  series,
@@ -142,7 +127,7 @@ func (iter *ObjectLookupIter) Next() (Object, error) {
 	}
 
 	hash := iter.series[iter.pos]
-	obj, err := iter.storage.Get(iter.t, hash)
+	obj, err := iter.storage.Object(iter.t, hash)
 	if err == nil {
 		iter.pos++
 	}
diff --git a/core/object_test.go b/core/object_test.go
index d087aae..5ebf26a 100644
--- a/core/object_test.go
+++ b/core/object_test.go
@@ -159,18 +159,18 @@ func (o *MockObjectStorage) NewObject() Object {
 	return nil
 }
 
-func (o *MockObjectStorage) Set(obj Object) (Hash, error) {
+func (o *MockObjectStorage) SetObject(obj Object) (Hash, error) {
 	return ZeroHash, nil
 }
 
-func (o *MockObjectStorage) Get(t ObjectType, h Hash) (Object, error) {
+func (o *MockObjectStorage) Object(t ObjectType, h Hash) (Object, error) {
 	return &MemoryObject{h: h}, nil
 }
 
-func (o *MockObjectStorage) Iter(t ObjectType) (ObjectIter, error) {
+func (o *MockObjectStorage) IterObjects(t ObjectType) (ObjectIter, error) {
 	return nil, nil
 }
 
-func (o *MockObjectStorage) Begin() TxObjectStorage {
+func (o *MockObjectStorage) Begin() Transaction {
 	return nil
 }
diff --git a/core/reference.go b/core/reference.go
index 16b60ac..ee55a6a 100644
--- a/core/reference.go
+++ b/core/reference.go
@@ -203,15 +203,15 @@ func (iter *ReferenceSliceIter) Close() {
 	iter.pos = len(iter.series)
 }
 
-func ResolveReference(s ReferenceStorage, n ReferenceName) (*Reference, error) {
-	r, err := s.Get(n)
+func ResolveReference(s ReferenceStorer, n ReferenceName) (*Reference, error) {
+	r, err := s.Reference(n)
 	if err != nil || r == nil {
 		return r, err
 	}
 	return resolveReference(s, r, 0)
 }
 
-func resolveReference(s ReferenceStorage, r *Reference, recursion int) (*Reference, error) {
+func resolveReference(s ReferenceStorer, r *Reference, recursion int) (*Reference, error) {
 	if r.Type() != SymbolicReference {
 		return r, nil
 	}
@@ -220,7 +220,7 @@ func resolveReference(s ReferenceStorage, r *Reference, recursion int) (*Referen
 		return nil, ErrMaxResolveRecursion
 	}
 
-	t, err := s.Get(r.Target())
+	t, err := s.Reference(r.Target())
 	if err != nil {
 		return nil, err
 	}
diff --git a/core/storage.go b/core/storage.go
index 739dfb6..101115b 100644
--- a/core/storage.go
+++ b/core/storage.go
@@ -7,45 +7,49 @@ import (
 
 var (
 	//ErrStop is used to stop a ForEach function in an Iter
-	ErrStop           = errors.New("stop iter")
-	ErrNotImplemented = errors.New("method not-implemented")
+	ErrStop = errors.New("stop iter")
 )
 
-// ObjectStorage generic storage of objects
-type ObjectStorage interface {
+// ObjectStorer generic storage of objects
+type ObjectStorer interface {
 	// NewObject returns a new Object, the real type of the object can be a
 	// custom implementation or the defaul one, MemoryObject
 	NewObject() Object
-	// Set save an object into the storage, the object shuld be create with
-	// the NewObject, method, and file if the type is not supported.
-	Set(Object) (Hash, error)
-	// Get an object by hash with the given ObjectType. Implementors should
-	// return (nil, ErrObjectNotFound) if an object doesn't exist with both the
-	// given hash and object type.
+	// SetObject save an object into the storage, the object shuld be create
+	// with the NewObject, method, and file if the type is not supported.
+	SetObject(Object) (Hash, error)
+	// Object an object by hash with the given ObjectType. Implementors
+	// should return (nil, ErrObjectNotFound) if an object doesn't exist with
+	// both the given hash and object type.
 	//
 	// Valid ObjectType values are CommitObject, BlobObject, TagObject,
-	// TreeObject and AnyObject.
-	//
-	// If AnyObject is given, the object must be looked up regardless of its type.
-	Get(ObjectType, Hash) (Object, error)
-	// Iter returns a custom ObjectIter over all the object on the storage.
+	// TreeObject and AnyObject. If AnyObject is given, the object must be
+	// looked up regardless of its type.
+	Object(ObjectType, Hash) (Object, error)
+	// IterObjects returns a custom ObjectIter over all the object on the
+	// storage.
 	//
 	// Valid ObjectType values are CommitObject, BlobObject, TagObject,
-	Iter(ObjectType) (ObjectIter, error)
+	IterObjects(ObjectType) (ObjectIter, error)
+}
+
+// Transactioner is a optional method for ObjectStorer, it enable transaction
+// base write and read operations in the storage
+type Transactioner interface {
 	// Begin starts a transaction.
-	Begin() TxObjectStorage
+	Begin() Transaction
 }
 
-// ObjectStorageWrite is a optional method for ObjectStorage, it enable direct
-// write of packfile to the storage
-type ObjectStorageWrite interface {
-	// Writer retuns a writer for writing a packfile to the Storage, this method
-	// is optional, if not implemented the ObjectStorage should return a
-	// ErrNotImplemented error.
+// PackfileWriter is a optional method for ObjectStorer, it enable direct write
+// of packfile to the storage
+type PackfileWriter interface {
+	// PackfileWriter retuns a writer for writing a packfile to the Storage,
+	// this method is optional, if not implemented the ObjectStorer should
+	// return a ErrNotImplemented error.
 	//
 	// If the implementation not implements Writer the objects should be written
 	// using the Set method.
-	Writer() (io.WriteCloser, error)
+	PackfileWriter() (io.WriteCloser, error)
 }
 
 // ObjectIter is a generic closable interface for iterating over objects.
@@ -55,20 +59,20 @@ type ObjectIter interface {
 	Close()
 }
 
-// TxObjectStorage is an in-progress storage transaction.
-// A transaction must end with a call to Commit or Rollback.
-type TxObjectStorage interface {
-	Set(Object) (Hash, error)
-	Get(ObjectType, Hash) (Object, error)
+// Transaction is an in-progress storage transaction. A transaction must end
+// with a call to Commit or Rollback.
+type Transaction interface {
+	SetObject(Object) (Hash, error)
+	Object(ObjectType, Hash) (Object, error)
 	Commit() error
 	Rollback() error
 }
 
-// ReferenceStorage generic storage of references
-type ReferenceStorage interface {
-	Set(*Reference) error
-	Get(ReferenceName) (*Reference, error)
-	Iter() (ReferenceIter, error)
+// ReferenceStorer generic storage of references
+type ReferenceStorer interface {
+	SetReference(*Reference) error
+	Reference(ReferenceName) (*Reference, error)
+	IterReferences() (ReferenceIter, error)
 }
 
 // ReferenceIter is a generic closable interface for iterating over references