// Package memory is a storage backend base on memory
package memory
import (
"fmt"
"gopkg.in/src-d/go-git.v4/config"
"gopkg.in/src-d/go-git.v4/plumbing"
"gopkg.in/src-d/go-git.v4/plumbing/format/index"
"gopkg.in/src-d/go-git.v4/plumbing/storer"
"gopkg.in/src-d/go-git.v4/storage"
)
var ErrUnsupportedObjectType = fmt.Errorf("unsupported object type")
var ErrRefHasChanged = fmt.Errorf("reference has changed concurrently")
// Storage is an implementation of git.Storer that stores data on memory, being
// ephemeral. The use of this storage should be done in controlled envoriments,
// since the representation in memory of some repository can fill the machine
// memory. in the other hand this storage has the best performance.
type Storage struct {
ConfigStorage
ObjectStorage
ShallowStorage
IndexStorage
ReferenceStorage
ModuleStorage
}
// NewStorage returns a new Storage base on memory
func NewStorage() *Storage {
return &Storage{
ReferenceStorage: make(ReferenceStorage, 0),
ConfigStorage: ConfigStorage{},
ShallowStorage: ShallowStorage{},
ObjectStorage: ObjectStorage{
Objects: make(map[plumbing.Hash]plumbing.EncodedObject, 0),
Commits: make(map[plumbing.Hash]plumbing.EncodedObject, 0),
Trees: make(map[plumbing.Hash]plumbing.EncodedObject, 0),
Blobs: make(map[plumbing.Hash]plumbing.EncodedObject, 0),
Tags: make(map[plumbing.Hash]plumbing.EncodedObject, 0),
},
ModuleStorage: make(ModuleStorage, 0),
}
}
type ConfigStorage struct {
config *config.Config
}
func (c *ConfigStorage) SetConfig(cfg *config.Config) error {
if err := cfg.Validate(); err != nil {
return err
}
c.config = cfg
return nil
}
func (c *ConfigStorage) Config() (*config.Config, error) {
if c.config == nil {
c.config = config.NewConfig()
}
return c.config, nil
}
type IndexStorage struct {
index *index.Index
}
func (c *IndexStorage) SetIndex(idx *index.Index) error {
c.index = idx
return nil
}
func (c *IndexStorage) Index() (*index.Index, error) {
if c.index == nil {
c.index = &index.Index{Version: 2}
}
return c.index, nil
}
type ObjectStorage struct {
Objects map[plumbing.Hash]plumbing.EncodedObject
Commits map[plumbing.Hash]plumbing.EncodedObject
Trees map[plumbing.Hash]plumbing.EncodedObject
Blobs map[plumbing.Hash]plumbing.EncodedObject
Tags map[plumbing.Hash]plumbing.EncodedObject
}
func (o *ObjectStorage) NewEncodedObject() plumbing.EncodedObject {
return &plumbing.MemoryObject{}
}
func (o *ObjectStorage) SetEncodedObject(obj plumbing.EncodedObject) (plumbing.Hash, error) {
h := obj.Hash()
o.Objects[h] = obj
switch obj.Type() {
case plumbing.CommitObject:
o.Commits[h] = o.Objects[h]
case plumbing.TreeObject:
o.Trees[h] = o.Objects[h]
case plumbing.BlobObject:
o.Blobs[h] = o.Objects[h]
case plumbing.TagObject:
o.Tags[h] = o.Objects[h]
default:
return h, ErrUnsupportedObjectType
}
return h, nil
}
func (o *ObjectStorage) EncodedObject(t plumbing.ObjectType, h plumbing.Hash) (plumbing.EncodedObject, error) {
obj, ok := o.Objects[h]
if !ok || (plumbing.AnyObject != t && obj.Type() != t) {
return nil, plumbing.ErrObjectNotFound
}
return obj, nil
}
func (o *ObjectStorage) IterEncodedObjects(t plumbing.ObjectType) (storer.EncodedObjectIter, error) {
var series []plumbing.EncodedObject
switch t {
case plumbing.AnyObject:
series = flattenObjectMap(o.Objects)
case plumbing.CommitObject:
series = flattenObjectMap(o.Commits)
case plumbing.TreeObject:
series = flattenObjectMap(o.Trees)
case plumbing.BlobObject:
series = flattenObjectMap(o.Blobs)
case plumbing.TagObject:
series = flattenObjectMap(o.Tags)
}
return storer.NewEncodedObjectSliceIter(series), nil
}
func flattenObjectMap(m map[plumbing.Hash]plumbing.EncodedObject) []plumbing.EncodedObject {
objects := make([]plumbing.EncodedObject, 0, len(m))
for _, obj := range m {
objects = append(objects, obj)
}
return objects
}
func (o *ObjectStorage) Begin() storer.Transaction {
return &TxObjectStorage{
Storage: o,
Objects: make(map[plumbing.Hash]plumbing.EncodedObject, 0),
}
}
type TxObjectStorage struct {
Storage *ObjectStorage
Objects map[plumbing.Hash]plumbing.EncodedObject
}
func (tx *TxObjectStorage) SetEncodedObject(obj plumbing.EncodedObject) (plumbing.Hash, error) {
h := obj.Hash()
tx.Objects[h] = obj
return h, nil
}
func (tx *TxObjectStorage) EncodedObject(t plumbing.ObjectType, h plumbing.Hash) (plumbing.EncodedObject, error) {
obj, ok := tx.Objects[h]
if !ok || (plumbing.AnyObject != t && obj.Type() != t) {
return nil, plumbing.ErrObjectNotFound
}
return obj, nil
}
func (tx *TxObjectStorage) Commit() error {
for h, obj := range tx.Objects {
delete(tx.Objects, h)
if _, err := tx.Storage.SetEncodedObject(obj); err != nil {
return err
}
}
return nil
}
func (tx *TxObjectStorage) Rollback() error {
tx.Objects = make(map[plumbing.Hash]plumbing.EncodedObject, 0)
return nil
}
type ReferenceStorage map[plumbing.ReferenceName]*plumbing.Reference
func (r ReferenceStorage) SetReference(ref *plumbing.Reference) error {
if ref != nil {
r[ref.Name()] = ref
}
return nil
}
func (r ReferenceStorage) CheckAndSetReference(ref, old *plumbing.Reference) error {
if ref != nil {
if old != nil {
tmp := r[ref.Name()]
if tmp != nil && tmp.Hash() != old.Hash() {
return ErrRefHasChanged
}
}
r[ref.Name()] = ref
}
return nil
}
func (r ReferenceStorage) Reference(n plumbing.ReferenceName) (*plumbing.Reference, error) {
ref, ok := r[n]
if !ok {
return nil, plumbing.ErrReferenceNotFound
}
return ref, nil
}
func (r ReferenceStorage) IterReferences() (storer.ReferenceIter, error) {
var refs []*plumbing.Reference
for _, ref := range r {
refs = append(refs, ref)
}
return storer.NewReferenceSliceIter(refs), nil
}
func (r ReferenceStorage) RemoveReference(n plumbing.ReferenceName) error {
delete(r, n)
return nil
}
type ShallowStorage []plumbing.Hash
func (s *ShallowStorage) SetShallow(commits []plumbing.Hash) error {
*s = commits
return nil
}
func (s ShallowStorage) Shallow() ([]plumbing.Hash, error) {
return s, nil
}
type ModuleStorage map[string]*Storage
func (s ModuleStorage) Module(name string) (storage.Storer, error) {
if m, ok := s[name]; ok {
return m, nil
}
m := NewStorage()
s[name] = m
return m, nil
}
