core: new MemoryObject, move from memory.Object, packfile.Parser, base on new ObjectStorage interface

1 files changed, 65 insertions, 0 deletions

diff --git a/core/memory.go b/core/memory.go
new file mode 100644
index 0000000..6477f74
--- /dev/null
+++ b/core/memory.go
@@ -0,0 +1,65 @@
+package core
+
+import (
+	"bytes"
+	"io/ioutil"
+)
+
+// MemoryObject on memory Object implementation
+type MemoryObject struct {
+	t    ObjectType
+	h    Hash
+	cont []byte
+	sz   int64
+}
+
+// NewMemoryObject creates a new MemoryObject
+func NewMemoryObject(t ObjectType, len int64, cont []byte) *MemoryObject {
+	return &MemoryObject{t: t, sz: len, cont: cont}
+}
+
+// Hash return the object Hash, the hash is calculated on-the-fly the first
+// time is called, the subsequent calls the same Hash is returned even if the
+// type or the content has changed. The Hash is only generated if the size of
+// the content is exactly the Object.Size
+func (o *MemoryObject) Hash() Hash {
+	if o.h == ZeroHash && int64(len(o.cont)) == o.sz {
+		o.h = ComputeHash(o.t, o.cont)
+	}
+
+	return o.h
+}
+
+// Type return the ObjectType
+func (o *MemoryObject) Type() ObjectType { return o.t }
+
+// SetType sets the ObjectType
+func (o *MemoryObject) SetType(t ObjectType) { o.t = t }
+
+// Size return the size of the object
+func (o *MemoryObject) Size() int64 { return o.sz }
+
+// SetSize set the object size, the given size should be written afterwards
+func (o *MemoryObject) SetSize(s int64) { o.sz = s }
+
+// Content returns the contents of the object
+func (o *MemoryObject) Content() []byte { return o.cont }
+
+// Reader returns a ObjectReader used to read the object's content.
+func (o *MemoryObject) Reader() (ObjectReader, 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) {
+	return o, nil
+}
+
+func (o *MemoryObject) Write(p []byte) (n int, err error) {
+	o.cont = append(o.cont, p...)
+	return len(p), nil
+}
+
+// Close releases any resources consumed by the object when it is acting as a
+// ObjectWriter.
+func (o *MemoryObject) Close() error { return nil }