gitea/modules/git/blob_nogogit.go

131 lines
2.4 KiB
Go

// Copyright 2020 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
//go:build !gogit
// +build !gogit
package git
import (
"bufio"
"bytes"
"io"
"math"
"code.gitea.io/gitea/modules/log"
)
// Blob represents a Git object.
type Blob struct {
ID SHA1
gotSize bool
size int64
name string
repo *Repository
}
// DataAsync gets a ReadCloser for the contents of a blob without reading it all.
// Calling the Close function on the result will discard all unread output.
func (b *Blob) DataAsync() (io.ReadCloser, error) {
wr, rd, cancel := b.repo.CatFileBatch(b.repo.Ctx)
_, err := wr.Write([]byte(b.ID.String() + "\n"))
if err != nil {
cancel()
return nil, err
}
_, _, size, err := ReadBatchLine(rd)
if err != nil {
cancel()
return nil, err
}
b.gotSize = true
b.size = size
if size < 4096 {
bs, err := io.ReadAll(io.LimitReader(rd, size))
defer cancel()
if err != nil {
return nil, err
}
_, err = rd.Discard(1)
return io.NopCloser(bytes.NewReader(bs)), err
}
return &blobReader{
rd: rd,
n: size,
cancel: cancel,
}, nil
}
// Size returns the uncompressed size of the blob
func (b *Blob) Size() int64 {
if b.gotSize {
return b.size
}
wr, rd, cancel := b.repo.CatFileBatchCheck(b.repo.Ctx)
defer cancel()
_, err := wr.Write([]byte(b.ID.String() + "\n"))
if err != nil {
log.Debug("error whilst reading size for %s in %s. Error: %v", b.ID.String(), b.repo.Path, err)
return 0
}
_, _, b.size, err = ReadBatchLine(rd)
if err != nil {
log.Debug("error whilst reading size for %s in %s. Error: %v", b.ID.String(), b.repo.Path, err)
return 0
}
b.gotSize = true
return b.size
}
type blobReader struct {
rd *bufio.Reader
n int64
cancel func()
}
func (b *blobReader) Read(p []byte) (n int, err error) {
if b.n <= 0 {
return 0, io.EOF
}
if int64(len(p)) > b.n {
p = p[0:b.n]
}
n, err = b.rd.Read(p)
b.n -= int64(n)
return
}
// Close implements io.Closer
func (b *blobReader) Close() error {
defer b.cancel()
if b.n > 0 {
for b.n > math.MaxInt32 {
n, err := b.rd.Discard(math.MaxInt32)
b.n -= int64(n)
if err != nil {
return err
}
b.n -= math.MaxInt32
}
n, err := b.rd.Discard(int(b.n))
b.n -= int64(n)
if err != nil {
return err
}
}
if b.n == 0 {
_, err := b.rd.Discard(1)
b.n--
return err
}
return nil
}