初始提交: Gitea 项目代码

modules/lfs/pointer_scanner_nogogit.go

@@ -0,0 +1,98 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+//go:build !gogit
+
+package lfs
+
+import (
+	"bufio"
+	"context"
+	"errors"
+	"io"
+	"strconv"
+	"strings"
+
+	"gitea.dev/modules/git"
+	"gitea.dev/modules/git/gitcmd"
+	"gitea.dev/modules/git/pipeline"
+	"gitea.dev/modules/util"
+
+	"golang.org/x/sync/errgroup"
+)
+
+// SearchPointerBlobs scans the whole repository for LFS pointer files
+func SearchPointerBlobs(ctx context.Context, repo *git.Repository, pointerChan chan<- PointerBlob) error {
+	cmd1AllObjs, cmd3BatchContent := gitcmd.NewCommand(), gitcmd.NewCommand()
+
+	cmd1AllObjsStdout, cmd1AllObjsStdoutClose := cmd1AllObjs.MakeStdoutPipe()
+	defer cmd1AllObjsStdoutClose()
+
+	cmd3BatchContentIn, cmd3BatchContentOut, cmd3BatchContentClose := cmd3BatchContent.MakeStdinStdoutPipe()
+	defer cmd3BatchContentClose()
+
+	// Create the go-routines in reverse order (update: the order is not needed any more, the pipes are properly prepared)
+	wg := errgroup.Group{}
+	// 4. Take the output of cat-file --batch and check if each file in turn
+	// to see if they're pointers to files in the LFS store
+	wg.Go(func() error {
+		return createPointerResultsFromCatFileBatch(cmd3BatchContentOut, pointerChan)
+	})
+
+	// 3. Take the shas of the blobs and batch read them
+	wg.Go(func() error {
+		return pipeline.CatFileBatch(ctx, cmd3BatchContent, repo.Path)
+	})
+
+	// 2. From the provided objects restrict to blobs <=1k
+	wg.Go(func() error {
+		return pipeline.BlobsLessThan1024FromCatFileBatchCheck(cmd1AllObjsStdout, cmd3BatchContentIn)
+	})
+
+	// 1. Run batch-check on all objects in the repository
+	wg.Go(func() error {
+		return pipeline.CatFileBatchCheckAllObjects(ctx, cmd1AllObjs, repo.Path)
+	})
+	err := wg.Wait()
+	close(pointerChan)
+	return err
+}
+
+func createPointerResultsFromCatFileBatch(catFileBatchReader io.ReadCloser, pointerChan chan<- PointerBlob) error {
+	defer catFileBatchReader.Close()
+
+	bufferedReader := bufio.NewReader(catFileBatchReader)
+	buf := make([]byte, 1025)
+
+	for {
+		// File descriptor line: sha
+		sha, err := bufferedReader.ReadString(' ')
+		if err != nil {
+			return util.Iif(errors.Is(err, io.EOF), nil, err)
+		}
+		sha = strings.TrimSpace(sha)
+		// Throw away the blob
+		if _, err := bufferedReader.ReadString(' '); err != nil {
+			return err
+		}
+		sizeStr, err := bufferedReader.ReadString('\n')
+		if err != nil {
+			return err
+		}
+		size, err := strconv.Atoi(sizeStr[:len(sizeStr)-1])
+		if err != nil {
+			return err
+		}
+		pointerBuf := buf[:size+1]
+		if _, err := io.ReadFull(bufferedReader, pointerBuf); err != nil {
+			return err
+		}
+		pointerBuf = pointerBuf[:size]
+		// Now we need to check if the pointerBuf is an LFS pointer
+		pointer, _ := ReadPointerFromBuffer(pointerBuf)
+		if !pointer.IsValid() {
+			continue
+		}
+		pointerChan <- PointerBlob{Hash: sha, Pointer: pointer}
+	}
+}