forgejo/modules/uploader/repo.go

// Copyright 2019 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.

package uploader

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"os"
	"os/exec"
	"path"
	"strings"
	"time"

	"code.gitea.io/gitea/models"
	"code.gitea.io/gitea/modules/process"
	"code.gitea.io/gitea/modules/setting"

	"github.com/Unknwon/com"
)

// TemporaryUploadRepository is a type to wrap our upload repositories
type TemporaryUploadRepository struct {
	repo     *models.Repository
	basePath string
}

// NewTemporaryUploadRepository creates a new temporary upload repository
func NewTemporaryUploadRepository(repo *models.Repository) (*TemporaryUploadRepository, error) {
	timeStr := com.ToStr(time.Now().Nanosecond()) // SHOULD USE SOMETHING UNIQUE
	basePath := path.Join(models.LocalCopyPath(), "upload-"+timeStr+".git")
	if err := os.MkdirAll(path.Dir(basePath), os.ModePerm); err != nil {
		return nil, fmt.Errorf("Failed to create dir %s: %v", basePath, err)
	}
	t := &TemporaryUploadRepository{repo: repo, basePath: basePath}
	return t, nil
}

// Close the repository cleaning up all files
func (t *TemporaryUploadRepository) Close() {
	if _, err := os.Stat(t.basePath); !os.IsNotExist(err) {
		os.RemoveAll(t.basePath)
	}
}

// Clone the base repository to our path and set branch as the HEAD
func (t *TemporaryUploadRepository) Clone(branch string) error {
	if _, stderr, err := process.GetManager().ExecTimeout(5*time.Minute,
		fmt.Sprintf("Clone (git clone -s --bare): %s", t.basePath),
		"git", "clone", "-s", "--bare", "-b", branch, t.repo.RepoPath(), t.basePath); err != nil {
		return fmt.Errorf("Clone: %v %s", err, stderr)
	}
	return nil
}

// SetDefaultIndex sets the git index to our HEAD
func (t *TemporaryUploadRepository) SetDefaultIndex() error {
	if _, stderr, err := process.GetManager().ExecDir(5*time.Minute,
		t.basePath,
		fmt.Sprintf("SetDefaultIndex (git read-tree HEAD): %s", t.basePath),
		"git", "read-tree", "HEAD"); err != nil {
		return fmt.Errorf("SetDefaultIndex: %v %s", err, stderr)
	}
	return nil
}

// LsFiles checks if the given filename arguments are in the index
func (t *TemporaryUploadRepository) LsFiles(filenames ...string) ([]string, error) {
	stdOut := new(bytes.Buffer)
	stdErr := new(bytes.Buffer)

	timeout := 5 * time.Minute
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	cmdArgs := []string{"ls-files", "-z", "--"}
	for _, arg := range filenames {
		if arg != "" {
			cmdArgs = append(cmdArgs, arg)
		}
	}

	cmd := exec.CommandContext(ctx, "git", cmdArgs...)
	desc := fmt.Sprintf("lsFiles: (git ls-files) %v", cmdArgs)
	cmd.Dir = t.basePath
	cmd.Stdout = stdOut
	cmd.Stderr = stdErr

	if err := cmd.Start(); err != nil {
		return nil, fmt.Errorf("exec(%s) failed: %v(%v)", desc, err, ctx.Err())
	}

	pid := process.GetManager().Add(desc, cmd)
	err := cmd.Wait()
	process.GetManager().Remove(pid)

	if err != nil {
		err = fmt.Errorf("exec(%d:%s) failed: %v(%v) stdout: %v stderr: %v", pid, desc, err, ctx.Err(), stdOut, stdErr)
		return nil, err
	}

	filelist := make([]string, len(filenames))
	for _, line := range bytes.Split(stdOut.Bytes(), []byte{'\000'}) {
		filelist = append(filelist, string(line))
	}

	return filelist, err
}

// RemoveFilesFromIndex removes the given files from the index
func (t *TemporaryUploadRepository) RemoveFilesFromIndex(filenames ...string) error {
	stdOut := new(bytes.Buffer)
	stdErr := new(bytes.Buffer)
	stdIn := new(bytes.Buffer)
	for _, file := range filenames {
		if file != "" {
			stdIn.WriteString("0 0000000000000000000000000000000000000000\t")
			stdIn.WriteString(file)
			stdIn.WriteByte('\000')
		}
	}

	timeout := 5 * time.Minute
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	cmdArgs := []string{"update-index", "--remove", "-z", "--index-info"}
	cmd := exec.CommandContext(ctx, "git", cmdArgs...)
	desc := fmt.Sprintf("removeFilesFromIndex: (git update-index) %v", filenames)
	cmd.Dir = t.basePath
	cmd.Stdout = stdOut
	cmd.Stderr = stdErr
	cmd.Stdin = bytes.NewReader(stdIn.Bytes())

	if err := cmd.Start(); err != nil {
		return fmt.Errorf("exec(%s) failed: %v(%v)", desc, err, ctx.Err())
	}

	pid := process.GetManager().Add(desc, cmd)
	err := cmd.Wait()
	process.GetManager().Remove(pid)

	if err != nil {
		err = fmt.Errorf("exec(%d:%s) failed: %v(%v) stdout: %v stderr: %v", pid, desc, err, ctx.Err(), stdOut, stdErr)
	}

	return err
}

// HashObject writes the provided content to the object db and returns its hash
func (t *TemporaryUploadRepository) HashObject(content io.Reader) (string, error) {
	timeout := 5 * time.Minute
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	hashCmd := exec.CommandContext(ctx, "git", "hash-object", "-w", "--stdin")
	hashCmd.Dir = t.basePath
	hashCmd.Stdin = content
	stdOutBuffer := new(bytes.Buffer)
	stdErrBuffer := new(bytes.Buffer)
	hashCmd.Stdout = stdOutBuffer
	hashCmd.Stderr = stdErrBuffer
	desc := fmt.Sprintf("hashObject: (git hash-object)")
	if err := hashCmd.Start(); err != nil {
		return "", fmt.Errorf("git hash-object: %s", err)
	}

	pid := process.GetManager().Add(desc, hashCmd)
	err := hashCmd.Wait()
	process.GetManager().Remove(pid)

	if err != nil {
		err = fmt.Errorf("exec(%d:%s) failed: %v(%v) stdout: %v stderr: %v", pid, desc, err, ctx.Err(), stdOutBuffer, stdErrBuffer)
		return "", err
	}

	return strings.TrimSpace(stdOutBuffer.String()), nil
}

// AddObjectToIndex adds the provided object hash to the index with the provided mode and path
func (t *TemporaryUploadRepository) AddObjectToIndex(mode, objectHash, objectPath string) error {
	if _, stderr, err := process.GetManager().ExecDir(5*time.Minute,
		t.basePath,
		fmt.Sprintf("addObjectToIndex (git update-index): %s", t.basePath),
		"git", "update-index", "--add", "--replace", "--cacheinfo", mode, objectHash, objectPath); err != nil {
		return fmt.Errorf("git update-index: %s", stderr)
	}
	return nil
}

// WriteTree writes the current index as a tree to the object db and returns its hash
func (t *TemporaryUploadRepository) WriteTree() (string, error) {
	treeHash, stderr, err := process.GetManager().ExecDir(5*time.Minute,
		t.basePath,
		fmt.Sprintf("WriteTree (git write-tree): %s", t.basePath),
		"git", "write-tree")
	if err != nil {
		return "", fmt.Errorf("git write-tree: %s", stderr)
	}
	return strings.TrimSpace(treeHash), nil

}

// CommitTree creates a commit from a given tree for the user with provided message
func (t *TemporaryUploadRepository) CommitTree(doer *models.User, treeHash string, message string) (string, error) {
	commitTimeStr := time.Now().Format(time.UnixDate)
	sig := doer.NewGitSig()

	// FIXME: Should we add SSH_ORIGINAL_COMMAND to this
	// Because this may call hooks we should pass in the environment
	env := append(os.Environ(),
		"GIT_AUTHOR_NAME="+sig.Name,
		"GIT_AUTHOR_EMAIL="+sig.Email,
		"GIT_AUTHOR_DATE="+commitTimeStr,
		"GIT_COMMITTER_NAME="+sig.Name,
		"GIT_COMMITTER_EMAIL="+sig.Email,
		"GIT_COMMITTER_DATE="+commitTimeStr,
	)
	commitHash, stderr, err := process.GetManager().ExecDirEnv(5*time.Minute,
		t.basePath,
		fmt.Sprintf("commitTree (git commit-tree): %s", t.basePath),
		env,
		"git", "commit-tree", treeHash, "-p", "HEAD", "-m", message)
	if err != nil {
		return "", fmt.Errorf("git commit-tree: %s", stderr)
	}
	return strings.TrimSpace(commitHash), nil
}

// Push the provided commitHash to the repository branch by the provided user
func (t *TemporaryUploadRepository) Push(doer *models.User, commitHash string, branch string) error {
	isWiki := "false"
	if strings.HasSuffix(t.repo.Name, ".wiki") {
		isWiki = "true"
	}

	sig := doer.NewGitSig()

	// FIXME: Should we add SSH_ORIGINAL_COMMAND to this
	// Because calls hooks we need to pass in the environment
	env := append(os.Environ(),
		"GIT_AUTHOR_NAME="+sig.Name,
		"GIT_AUTHOR_EMAIL="+sig.Email,
		"GIT_COMMITTER_NAME="+sig.Name,
		"GIT_COMMITTER_EMAIL="+sig.Email,
		models.EnvRepoName+"="+t.repo.Name,
		models.EnvRepoUsername+"="+t.repo.OwnerName,
		models.EnvRepoIsWiki+"="+isWiki,
		models.EnvPusherName+"="+doer.Name,
		models.EnvPusherID+"="+fmt.Sprintf("%d", doer.ID),
		models.ProtectedBranchRepoID+"="+fmt.Sprintf("%d", t.repo.ID),
	)

	if _, stderr, err := process.GetManager().ExecDirEnv(5*time.Minute,
		t.basePath,
		fmt.Sprintf("actuallyPush (git push): %s", t.basePath),
		env,
		"git", "push", t.repo.RepoPath(), strings.TrimSpace(commitHash)+":refs/heads/"+strings.TrimSpace(branch)); err != nil {
		return fmt.Errorf("git push: %s", stderr)
	}
	return nil
}

// DiffIndex returns a Diff of the current index to the head
func (t *TemporaryUploadRepository) DiffIndex() (diff *models.Diff, err error) {
	timeout := 5 * time.Minute
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	stdErr := new(bytes.Buffer)

	cmd := exec.CommandContext(ctx, "git", "diff-index", "--cached", "-p", "HEAD")
	cmd.Dir = t.basePath
	cmd.Stderr = stdErr

	stdout, err := cmd.StdoutPipe()
	if err != nil {
		return nil, fmt.Errorf("StdoutPipe: %v stderr %s", err, stdErr.String())
	}

	if err = cmd.Start(); err != nil {
		return nil, fmt.Errorf("Start: %v stderr %s", err, stdErr.String())
	}

	pid := process.GetManager().Add(fmt.Sprintf("diffIndex [repo_path: %s]", t.repo.RepoPath()), cmd)
	defer process.GetManager().Remove(pid)

	diff, err = models.ParsePatch(setting.Git.MaxGitDiffLines, setting.Git.MaxGitDiffLineCharacters, setting.Git.MaxGitDiffFiles, stdout)
	if err != nil {
		return nil, fmt.Errorf("ParsePatch: %v", err)
	}

	if err = cmd.Wait(); err != nil {
		return nil, fmt.Errorf("Wait: %v", err)
	}

	return diff, nil
}

// CheckAttribute checks the given attribute of the provided files
func (t *TemporaryUploadRepository) CheckAttribute(attribute string, args ...string) (map[string]map[string]string, error) {
	stdOut := new(bytes.Buffer)
	stdErr := new(bytes.Buffer)

	timeout := 5 * time.Minute
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	cmdArgs := []string{"check-attr", "-z", attribute, "--cached", "--"}
	for _, arg := range args {
		if arg != "" {
			cmdArgs = append(cmdArgs, arg)
		}
	}

	cmd := exec.CommandContext(ctx, "git", cmdArgs...)
	desc := fmt.Sprintf("checkAttr: (git check-attr) %s %v", attribute, cmdArgs)
	cmd.Dir = t.basePath
	cmd.Stdout = stdOut
	cmd.Stderr = stdErr

	if err := cmd.Start(); err != nil {
		return nil, fmt.Errorf("exec(%s) failed: %v(%v)", desc, err, ctx.Err())
	}

	pid := process.GetManager().Add(desc, cmd)
	err := cmd.Wait()
	process.GetManager().Remove(pid)

	if err != nil {
		err = fmt.Errorf("exec(%d:%s) failed: %v(%v) stdout: %v stderr: %v", pid, desc, err, ctx.Err(), stdOut, stdErr)
		return nil, err
	}

	fields := bytes.Split(stdOut.Bytes(), []byte{'\000'})

	if len(fields)%3 != 1 {
		return nil, fmt.Errorf("Wrong number of fields in return from check-attr")
	}

	var name2attribute2info = make(map[string]map[string]string)

	for i := 0; i < (len(fields) / 3); i++ {
		filename := string(fields[3*i])
		attribute := string(fields[3*i+1])
		info := string(fields[3*i+2])
		attribute2info := name2attribute2info[filename]
		if attribute2info == nil {
			attribute2info = make(map[string]string)
		}
		attribute2info[attribute] = info
		name2attribute2info[filename] = attribute2info
	}

	return name2attribute2info, err
}