first-commit

modules/git/blob_nogogit.go

@@ -0,0 +1,125 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+//go:build !gogit
+
+package git
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+
+	"code.gitea.io/gitea/modules/log"
+)
+
+// Blob represents a Git object.
+type Blob struct {
+	ID ObjectID
+
+	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, err := b.repo.CatFileBatch(b.repo.Ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	_, 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, err := b.repo.CatFileBatchCheck(b.repo.Ctx)
+	if err != nil {
+		log.Debug("error whilst reading size for %s in %s. Error: %v", b.ID.String(), b.repo.Path, err)
+		return 0
+	}
+	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 n, err
+}
+
+// Close implements io.Closer
+func (b *blobReader) Close() error {
+	if b.rd == nil {
+		return nil
+	}
+
+	defer b.cancel()
+
+	if err := DiscardFull(b.rd, b.n+1); err != nil {
+		return err
+	}
+
+	b.rd = nil
+
+	return nil
+}