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package packfile
import (
"bytes"
"errors"
"io"
"sync"
"gopkg.in/src-d/go-git.v4/plumbing"
"gopkg.in/src-d/go-git.v4/plumbing/storer"
"gopkg.in/src-d/go-git.v4/utils/ioutil"
)
var signature = []byte{'P', 'A', 'C', 'K'}
const (
// VersionSupported is the packfile version supported by this package
VersionSupported uint32 = 2
firstLengthBits = uint8(4) // the first byte into object header has 4 bits to store the length
lengthBits = uint8(7) // subsequent bytes has 7 bits to store the length
maskFirstLength = 15 // 0000 1111
maskContinue = 0x80 // 1000 0000
maskLength = uint8(127) // 0111 1111
maskType = uint8(112) // 0111 0000
)
// UpdateObjectStorage updates the storer with the objects in the given
// packfile.
func UpdateObjectStorage(s storer.Storer, packfile io.Reader) error {
if pw, ok := s.(storer.PackfileWriter); ok {
return WritePackfileToObjectStorage(pw, packfile)
}
updater := newPackfileStorageUpdater(s)
_, err := NewParser(NewScanner(packfile), updater).Parse()
return err
}
// WritePackfileToObjectStorage writes all the packfile objects into the given
// object storage.
func WritePackfileToObjectStorage(
sw storer.PackfileWriter,
packfile io.Reader,
) (err error) {
w, err := sw.PackfileWriter()
if err != nil {
return err
}
defer ioutil.CheckClose(w, &err)
_, err = io.Copy(w, packfile)
return err
}
var bufPool = sync.Pool{
New: func() interface{} {
return bytes.NewBuffer(nil)
},
}
var errMissingObjectContent = errors.New("missing object content")
type packfileStorageUpdater struct {
storer.Storer
lastSize int64
lastType plumbing.ObjectType
}
func newPackfileStorageUpdater(s storer.Storer) *packfileStorageUpdater {
return &packfileStorageUpdater{Storer: s}
}
func (p *packfileStorageUpdater) OnHeader(count uint32) error {
return nil
}
func (p *packfileStorageUpdater) OnInflatedObjectHeader(
t plumbing.ObjectType,
objSize int64,
pos int64,
) error {
if p.lastSize > 0 || p.lastType != plumbing.InvalidObject {
return errMissingObjectContent
}
p.lastType = t
p.lastSize = objSize
return nil
}
func (p *packfileStorageUpdater) OnInflatedObjectContent(
h plumbing.Hash,
pos int64,
crc uint32,
content []byte,
) error {
obj := new(plumbing.MemoryObject)
obj.SetSize(p.lastSize)
obj.SetType(p.lastType)
if _, err := obj.Write(content); err != nil {
return err
}
_, err := p.SetEncodedObject(obj)
p.lastSize = 0
p.lastType = plumbing.InvalidObject
return err
}
func (p *packfileStorageUpdater) OnFooter(h plumbing.Hash) error {
return nil
}
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