/
odb.go
196 lines (171 loc) · 4.35 KB
/
odb.go
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package git4go
import (
"bufio"
"errors"
"fmt"
"os"
"path/filepath"
"sort"
)
const (
GitLoosePriority = 1
GitPackedPriority = 2
GitAlternatesMaxDepth = 5
GitAlternatesFile = "info/alternates"
)
func (r *Repository) Odb() (odb *Odb, err error) {
if r.odb == nil {
odb, err := OdbOpen(filepath.Join(r.pathRepository, GitObjectsDir))
if err != nil {
return nil, err
}
r.odb = odb
}
return r.odb, nil
}
// Odb type and its methods
type Odb struct {
backends []OdbBackend
}
func OdbOpen(objectsDir string) (*Odb, error) {
odb := &Odb{}
err := odb.AddDefaultBackends(objectsDir, false, 0)
return odb, err
}
func (o *Odb) AddDefaultBackends(objectsDir string, asAlternates bool, alternateDepth int) error {
info, err := os.Stat(objectsDir)
if err != nil {
return errors.New(fmt.Sprintf("Failed to load object database in '%s'", objectsDir))
}
for _, backend := range o.backends {
if backend.SameDirectory(info) {
return nil
}
}
loose := NewOdbBackendLoose(objectsDir, -1, false, 0, 0)
o.addBackendInternal(loose, GitLoosePriority, asAlternates, info)
packed := NewOdbBackendPacked(objectsDir)
if packed != nil {
o.addBackendInternal(packed, GitPackedPriority, asAlternates, info)
}
o.loadAlternates(objectsDir, alternateDepth)
return nil
}
func (v *Odb) Hash(data []byte, objType ObjectType) (*Oid, error) {
return hash(data, objType)
}
func (o *Odb) Exists(oid *Oid) bool {
for _, backend := range o.backends {
if backend.Exists(oid) {
return true
}
}
return false
}
func (o *Odb) ExistsPrefix(oid *Oid, length int) (*Oid, error) {
var foundId *Oid
var err error
for _, backend := range o.backends {
foundId, err = backend.ExistsPrefix(oid, length)
if foundId != nil {
return foundId, nil
}
}
return nil, err
}
func (o *Odb) Read(oid *Oid) (*OdbObject, error) {
for _, backend := range o.backends {
odbObject, err := backend.Read(oid)
if err == nil {
return odbObject, nil
}
}
return nil, errors.New(fmt.Sprintf("no match for id: %s", oid.String()))
}
func (o *Odb) ReadPrefix(oid *Oid, length int) (*Oid, *OdbObject, error) {
var foundId *Oid
var foundObject *OdbObject
var err error
for _, backend := range o.backends {
foundId, foundObject, err = backend.ReadPrefix(oid, length)
if err == nil {
return foundId, foundObject, nil
}
}
return nil, nil, errors.New(fmt.Sprintf("no match for id: %s", oid.String()))
}
func (o *Odb) ReadHeader(oid *Oid) (ObjectType, uint64, error) {
for _, backend := range o.backends {
objType, size, err := backend.ReadHeader(oid)
if err == nil {
return objType, size, nil
}
}
return ObjectBad, 0, errors.New(fmt.Sprintf("no match for id: %s", oid.String()))
}
func (o *Odb) Write(data []byte, objType ObjectType) (*Oid, error) {
for _, backend := range o.backends {
if backend.IsAlternate() {
continue
}
oid, err := backend.Write(data, objType)
if err == nil {
return oid, nil
}
}
return nil, errors.New("Odb.Write: no backend write data")
}
type OdbForEachCallback func(id *Oid) error
func (o *Odb) ForEach(callback OdbForEachCallback) error {
for _, backend := range o.backends {
err := backend.ForEach(callback)
if err != nil {
return err
}
}
return nil
}
func (o *Odb) GetAllObjects() ([]*Oid, error) {
var oids []*Oid
err := o.ForEach(func(oid *Oid) error {
oids = append(oids, oid)
return nil
})
return oids, err
}
// internal functions and methods
func (o *Odb) addBackendInternal(backend OdbBackend, priority int, asAlternates bool, dirInfo os.FileInfo) {
backend.InitBackend(priority, asAlternates, dirInfo)
o.backends = append(o.backends, backend)
var backends OdbBackends = o.backends
sort.Sort(backends)
}
func (o *Odb) loadAlternates(objectsDir string, alternateDepth int) error {
if alternateDepth > GitAlternatesMaxDepth {
return nil
}
alternatePath := filepath.Join(objectsDir, GitAlternatesFile)
_, err := os.Stat(alternatePath)
if os.IsNotExist(err) {
return nil
}
file, err := os.Open(alternatePath)
if err != nil {
return err
}
scanner := bufio.NewScanner(file)
for scanner.Scan() {
line := scanner.Text()
if len(line) == 0 || line[0] == '#' {
continue
}
if line[0] == '.' && alternateDepth > 0 {
alternatesPath2 := filepath.Join(objectsDir, line)
err = o.AddDefaultBackends(alternatesPath2, true, alternateDepth+1)
if err != nil {
return err
}
}
}
return nil
}