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-rw-r--r--plumbing/format/packfile/fsobject.go15
-rw-r--r--plumbing/format/packfile/packfile.go73
-rw-r--r--plumbing/format/packfile/patch_delta.go210
-rw-r--r--plumbing/format/packfile/scanner.go15
4 files changed, 313 insertions, 0 deletions
diff --git a/plumbing/format/packfile/fsobject.go b/plumbing/format/packfile/fsobject.go
index c5edaf5..4aa3c8e 100644
--- a/plumbing/format/packfile/fsobject.go
+++ b/plumbing/format/packfile/fsobject.go
@@ -7,6 +7,7 @@ import (
"github.com/go-git/go-git/v5/plumbing"
"github.com/go-git/go-git/v5/plumbing/cache"
"github.com/go-git/go-git/v5/plumbing/format/idxfile"
+ "github.com/go-git/go-git/v5/utils/ioutil"
)
// FSObject is an object from the packfile on the filesystem.
@@ -63,6 +64,20 @@ func (o *FSObject) Reader() (io.ReadCloser, error) {
}
p := NewPackfileWithCache(o.index, nil, f, o.cache)
+ if o.size > LargeObjectThreshold {
+ // We have a big object
+ h, err := p.objectHeaderAtOffset(o.offset)
+ if err != nil {
+ return nil, err
+ }
+
+ r, err := p.getReaderDirect(h)
+ if err != nil {
+ _ = f.Close()
+ return nil, err
+ }
+ return ioutil.NewReadCloserWithCloser(r, f.Close), nil
+ }
r, err := p.getObjectContent(o.offset)
if err != nil {
_ = f.Close()
diff --git a/plumbing/format/packfile/packfile.go b/plumbing/format/packfile/packfile.go
index ddd7f62..77861d2 100644
--- a/plumbing/format/packfile/packfile.go
+++ b/plumbing/format/packfile/packfile.go
@@ -32,6 +32,12 @@ var (
// wrapped in FSObject.
const smallObjectThreshold = 16 * 1024
+// Conversely there are large objects that should not be cached and kept
+// in memory as they're too large to be reasonably cached. Objects larger
+// than this threshold are now always never read into memory to be stored
+// in the cache
+const LargeObjectThreshold = 1024 * 1024
+
// Packfile allows retrieving information from inside a packfile.
type Packfile struct {
idxfile.Index
@@ -282,6 +288,37 @@ func (p *Packfile) getObjectContent(offset int64) (io.ReadCloser, error) {
return obj.Reader()
}
+func (p *Packfile) getReaderDirect(h *ObjectHeader) (io.ReadCloser, error) {
+ switch h.Type {
+ case plumbing.CommitObject, plumbing.TreeObject, plumbing.BlobObject, plumbing.TagObject:
+ return p.s.ReadObject()
+ case plumbing.REFDeltaObject:
+ deltaRC, err := p.s.ReadObject()
+ if err != nil {
+ return nil, err
+ }
+ r, err := p.readREFDeltaObjectContent(h, deltaRC)
+ if err != nil {
+ _ = deltaRC.Close()
+ return nil, err
+ }
+ return r, nil
+ case plumbing.OFSDeltaObject:
+ deltaRC, err := p.s.ReadObject()
+ if err != nil {
+ return nil, err
+ }
+ r, err := p.readOFSDeltaObjectContent(h, deltaRC)
+ if err != nil {
+ _ = deltaRC.Close()
+ return nil, err
+ }
+ return r, nil
+ default:
+ return nil, ErrInvalidObject.AddDetails("type %q", h.Type)
+ }
+}
+
func (p *Packfile) getNextMemoryObject(h *ObjectHeader) (plumbing.EncodedObject, error) {
var obj = new(plumbing.MemoryObject)
obj.SetSize(h.Length)
@@ -334,6 +371,20 @@ func (p *Packfile) fillREFDeltaObjectContent(obj plumbing.EncodedObject, ref plu
return p.fillREFDeltaObjectContentWithBuffer(obj, ref, buf)
}
+func (p *Packfile) readREFDeltaObjectContent(h *ObjectHeader, deltaRC io.ReadCloser) (io.ReadCloser, error) {
+ var err error
+
+ base, ok := p.cacheGet(h.Reference)
+ if !ok {
+ base, err = p.Get(h.Reference)
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ return ReaderFromDelta(h, base, deltaRC)
+}
+
func (p *Packfile) fillREFDeltaObjectContentWithBuffer(obj plumbing.EncodedObject, ref plumbing.Hash, buf *bytes.Buffer) error {
var err error
@@ -364,6 +415,28 @@ func (p *Packfile) fillOFSDeltaObjectContent(obj plumbing.EncodedObject, offset
return p.fillOFSDeltaObjectContentWithBuffer(obj, offset, buf)
}
+func (p *Packfile) readOFSDeltaObjectContent(h *ObjectHeader, deltaRC io.ReadCloser) (io.ReadCloser, error) {
+ hash, err := p.FindHash(h.OffsetReference)
+ if err != nil {
+ return nil, err
+ }
+
+ base, err := p.objectAtOffset(h.OffsetReference, hash)
+ if err != nil {
+ return nil, err
+ }
+
+ base, ok := p.cacheGet(h.Reference)
+ if !ok {
+ base, err = p.Get(h.Reference)
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ return ReaderFromDelta(h, base, deltaRC)
+}
+
func (p *Packfile) fillOFSDeltaObjectContentWithBuffer(obj plumbing.EncodedObject, offset int64, buf *bytes.Buffer) error {
hash, err := p.FindHash(offset)
if err != nil {
diff --git a/plumbing/format/packfile/patch_delta.go b/plumbing/format/packfile/patch_delta.go
index 9e90f30..76fef4a 100644
--- a/plumbing/format/packfile/patch_delta.go
+++ b/plumbing/format/packfile/patch_delta.go
@@ -1,9 +1,11 @@
package packfile
import (
+ "bufio"
"bytes"
"errors"
"io"
+ "math"
"github.com/go-git/go-git/v5/plumbing"
"github.com/go-git/go-git/v5/utils/ioutil"
@@ -73,6 +75,131 @@ func PatchDelta(src, delta []byte) ([]byte, error) {
return b.Bytes(), nil
}
+func ReaderFromDelta(h *ObjectHeader, base plumbing.EncodedObject, deltaRC io.ReadCloser) (io.ReadCloser, error) {
+ deltaBuf := bufio.NewReaderSize(deltaRC, 1024)
+ srcSz, err := decodeLEB128ByteReader(deltaBuf)
+ if err != nil {
+ if err == io.EOF {
+ return nil, ErrInvalidDelta
+ }
+ return nil, err
+ }
+ if srcSz != uint(base.Size()) {
+ return nil, ErrInvalidDelta
+ }
+
+ targetSz, err := decodeLEB128ByteReader(deltaBuf)
+ if err != nil {
+ if err == io.EOF {
+ return nil, ErrInvalidDelta
+ }
+ return nil, err
+ }
+ remainingTargetSz := targetSz
+
+ dstRd, dstWr := io.Pipe()
+
+ go func() {
+ baseRd, err := base.Reader()
+ if err != nil {
+ _ = dstWr.CloseWithError(ErrInvalidDelta)
+ return
+ }
+ defer baseRd.Close()
+
+ baseBuf := bufio.NewReader(baseRd)
+ basePos := uint(0)
+
+ for {
+ cmd, err := deltaBuf.ReadByte()
+ if err == io.EOF {
+ _ = dstWr.CloseWithError(ErrInvalidDelta)
+ return
+ }
+ if err != nil {
+ _ = dstWr.CloseWithError(err)
+ return
+ }
+
+ if isCopyFromSrc(cmd) {
+ offset, err := decodeOffsetByteReader(cmd, deltaBuf)
+ if err != nil {
+ _ = dstWr.CloseWithError(err)
+ return
+ }
+ sz, err := decodeSizeByteReader(cmd, deltaBuf)
+ if err != nil {
+ _ = dstWr.CloseWithError(err)
+ return
+ }
+
+ if invalidSize(sz, targetSz) ||
+ invalidOffsetSize(offset, sz, srcSz) {
+ _ = dstWr.Close()
+ return
+ }
+
+ discard := offset - basePos
+ if discard < 0 {
+ _ = baseRd.Close()
+ baseRd, err = base.Reader()
+ if err != nil {
+ _ = dstWr.CloseWithError(ErrInvalidDelta)
+ return
+ }
+ baseBuf.Reset(baseRd)
+ discard = offset
+ }
+ for discard > math.MaxInt32 {
+ n, err := baseBuf.Discard(math.MaxInt32)
+ if err != nil {
+ _ = dstWr.CloseWithError(err)
+ return
+ }
+ basePos += uint(n)
+ discard -= uint(n)
+ }
+ for discard > 0 {
+ n, err := baseBuf.Discard(int(discard))
+ if err != nil {
+ _ = dstWr.CloseWithError(err)
+ return
+ }
+ basePos += uint(n)
+ discard -= uint(n)
+ }
+ if _, err := io.Copy(dstWr, io.LimitReader(baseBuf, int64(sz))); err != nil {
+ _ = dstWr.CloseWithError(err)
+ return
+ }
+ remainingTargetSz -= sz
+ basePos += sz
+ } else if isCopyFromDelta(cmd) {
+ sz := uint(cmd) // cmd is the size itself
+ if invalidSize(sz, targetSz) {
+ _ = dstWr.CloseWithError(ErrInvalidDelta)
+ return
+ }
+ if _, err := io.Copy(dstWr, io.LimitReader(deltaBuf, int64(sz))); err != nil {
+ _ = dstWr.CloseWithError(err)
+ return
+ }
+
+ remainingTargetSz -= sz
+ } else {
+ _ = dstWr.CloseWithError(ErrDeltaCmd)
+ return
+ }
+ if remainingTargetSz <= 0 {
+ _ = dstWr.Close()
+ return
+ }
+ }
+ }()
+
+ return dstRd, nil
+}
+
func patchDelta(dst *bytes.Buffer, src, delta []byte) error {
if len(delta) < deltaSizeMin {
return ErrInvalidDelta
@@ -161,6 +288,25 @@ func decodeLEB128(input []byte) (uint, []byte) {
return num, input[sz:]
}
+func decodeLEB128ByteReader(input io.ByteReader) (uint, error) {
+ var num, sz uint
+ for {
+ b, err := input.ReadByte()
+ if err != nil {
+ return 0, err
+ }
+
+ num |= (uint(b) & payload) << (sz * 7) // concats 7 bits chunks
+ sz++
+
+ if uint(b)&continuation == 0 {
+ break
+ }
+ }
+
+ return num, nil
+}
+
const (
payload = 0x7f // 0111 1111
continuation = 0x80 // 1000 0000
@@ -174,6 +320,40 @@ func isCopyFromDelta(cmd byte) bool {
return (cmd&0x80) == 0 && cmd != 0
}
+func decodeOffsetByteReader(cmd byte, delta io.ByteReader) (uint, error) {
+ var offset uint
+ if (cmd & 0x01) != 0 {
+ next, err := delta.ReadByte()
+ if err != nil {
+ return 0, err
+ }
+ offset = uint(next)
+ }
+ if (cmd & 0x02) != 0 {
+ next, err := delta.ReadByte()
+ if err != nil {
+ return 0, err
+ }
+ offset |= uint(next) << 8
+ }
+ if (cmd & 0x04) != 0 {
+ next, err := delta.ReadByte()
+ if err != nil {
+ return 0, err
+ }
+ offset |= uint(next) << 16
+ }
+ if (cmd & 0x08) != 0 {
+ next, err := delta.ReadByte()
+ if err != nil {
+ return 0, err
+ }
+ offset |= uint(next) << 24
+ }
+
+ return offset, nil
+}
+
func decodeOffset(cmd byte, delta []byte) (uint, []byte, error) {
var offset uint
if (cmd & 0x01) != 0 {
@@ -208,6 +388,36 @@ func decodeOffset(cmd byte, delta []byte) (uint, []byte, error) {
return offset, delta, nil
}
+func decodeSizeByteReader(cmd byte, delta io.ByteReader) (uint, error) {
+ var sz uint
+ if (cmd & 0x10) != 0 {
+ next, err := delta.ReadByte()
+ if err != nil {
+ return 0, err
+ }
+ sz = uint(next)
+ }
+ if (cmd & 0x20) != 0 {
+ next, err := delta.ReadByte()
+ if err != nil {
+ return 0, err
+ }
+ sz |= uint(next) << 8
+ }
+ if (cmd & 0x40) != 0 {
+ next, err := delta.ReadByte()
+ if err != nil {
+ return 0, err
+ }
+ sz |= uint(next) << 16
+ }
+ if sz == 0 {
+ sz = 0x10000
+ }
+
+ return sz, nil
+}
+
func decodeSize(cmd byte, delta []byte) (uint, []byte, error) {
var sz uint
if (cmd & 0x10) != 0 {
diff --git a/plumbing/format/packfile/scanner.go b/plumbing/format/packfile/scanner.go
index 6e6a687..5d9e8fb 100644
--- a/plumbing/format/packfile/scanner.go
+++ b/plumbing/format/packfile/scanner.go
@@ -320,6 +320,21 @@ func (s *Scanner) NextObject(w io.Writer) (written int64, crc32 uint32, err erro
return
}
+// ReadObject returns a reader for the object content and an error
+func (s *Scanner) ReadObject() (io.ReadCloser, error) {
+ s.pendingObject = nil
+ zr := zlibReaderPool.Get().(io.ReadCloser)
+
+ if err := zr.(zlib.Resetter).Reset(s.r, nil); err != nil {
+ return nil, fmt.Errorf("zlib reset error: %s", err)
+ }
+
+ return ioutil.NewReadCloserWithCloser(zr, func() error {
+ zlibReaderPool.Put(zr)
+ return nil
+ }), nil
+}
+
// ReadRegularObject reads and write a non-deltified object
// from it zlib stream in an object entry in the packfile.
func (s *Scanner) copyObject(w io.Writer) (n int64, err error) {
generated by cgit (git 2.34.1) at 2024-09-27 19:25:03 +0000