move code.gitea.io/git to code.gitea.io/gitea/modules/git (#6364)

* move code.gitea.io/git to code.gitea.io/gitea/modules/git

* fix imports

* fix fmt

* fix misspell

* remove wrong tests data

* fix unit tests

* fix tests

* fix tests

* fix tests

* fix tests

* fix tests

* enable Debug to trace the failure tests

* fix tests

* fix tests

* fix tests

* fix tests

* fix tests

* comment commit count tests since git clone depth is 50

* fix tests

* update from code.gitea.io/git

* revert change to makefile

modules/git/blob.go

@@ -0,0 +1,73 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+)
+
+// Blob represents a Git object.
+type Blob struct {
+	repo *Repository
+	*TreeEntry
+}
+
+// Data gets content of blob all at once and wrap it as io.Reader.
+// This can be very slow and memory consuming for huge content.
+func (b *Blob) Data() (io.Reader, error) {
+	stdout := new(bytes.Buffer)
+	stderr := new(bytes.Buffer)
+
+	// Preallocate memory to save ~50% memory usage on big files.
+	stdout.Grow(int(b.Size() + 2048))
+
+	if err := b.DataPipeline(stdout, stderr); err != nil {
+		return nil, concatenateError(err, stderr.String())
+	}
+	return stdout, nil
+}
+
+// DataPipeline gets content of blob and write the result or error to stdout or stderr
+func (b *Blob) DataPipeline(stdout, stderr io.Writer) error {
+	return NewCommand("show", b.ID.String()).RunInDirPipeline(b.repo.Path, stdout, stderr)
+}
+
+type cmdReadCloser struct {
+	cmd    *exec.Cmd
+	stdout io.Reader
+}
+
+func (c cmdReadCloser) Read(p []byte) (int, error) {
+	return c.stdout.Read(p)
+}
+
+func (c cmdReadCloser) Close() error {
+	io.Copy(ioutil.Discard, c.stdout)
+	return c.cmd.Wait()
+}
+
+// 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) {
+	cmd := exec.Command("git", "show", b.ID.String())
+	cmd.Dir = b.repo.Path
+	cmd.Stderr = os.Stderr
+
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		return nil, fmt.Errorf("StdoutPipe: %v", err)
+	}
+
+	if err = cmd.Start(); err != nil {
+		return nil, fmt.Errorf("Start: %v", err)
+	}
+
+	return cmdReadCloser{stdout: stdout, cmd: cmd}, nil
+}