1 files changed, 86 insertions, 0 deletions
diff --git a/modules/git/pipeline/revlist.go b/modules/git/pipeline/revlist.go
new file mode 100644
index 0000000..d88ebe7
--- /dev/null
+++ b/modules/git/pipeline/revlist.go
@@ -0,0 +1,86 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package pipeline
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"strings"
+	"sync"
+
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/log"
+)
+
+// RevListAllObjects runs rev-list --objects --all and writes to a pipewriter
+func RevListAllObjects(ctx context.Context, revListWriter *io.PipeWriter, wg *sync.WaitGroup, basePath string, errChan chan<- error) {
+	defer wg.Done()
+	defer revListWriter.Close()
+
+	stderr := new(bytes.Buffer)
+	var errbuf strings.Builder
+	cmd := git.NewCommand(ctx, "rev-list", "--objects", "--all")
+	if err := cmd.Run(&git.RunOpts{
+		Dir:    basePath,
+		Stdout: revListWriter,
+		Stderr: stderr,
+	}); err != nil {
+		log.Error("git rev-list --objects --all [%s]: %v - %s", basePath, err, errbuf.String())
+		err = fmt.Errorf("git rev-list --objects --all [%s]: %w - %s", basePath, err, errbuf.String())
+		_ = revListWriter.CloseWithError(err)
+		errChan <- err
+	}
+}
+
+// RevListObjects run rev-list --objects from headSHA to baseSHA
+func RevListObjects(ctx context.Context, revListWriter *io.PipeWriter, wg *sync.WaitGroup, tmpBasePath, headSHA, baseSHA string, errChan chan<- error) {
+	defer wg.Done()
+	defer revListWriter.Close()
+	stderr := new(bytes.Buffer)
+	var errbuf strings.Builder
+	cmd := git.NewCommand(ctx, "rev-list", "--objects").AddDynamicArguments(headSHA)
+	if baseSHA != "" {
+		cmd = cmd.AddArguments("--not").AddDynamicArguments(baseSHA)
+	}
+	if err := cmd.Run(&git.RunOpts{
+		Dir:    tmpBasePath,
+		Stdout: revListWriter,
+		Stderr: stderr,
+	}); err != nil {
+		log.Error("git rev-list [%s]: %v - %s", tmpBasePath, err, errbuf.String())
+		errChan <- fmt.Errorf("git rev-list [%s]: %w - %s", tmpBasePath, err, errbuf.String())
+	}
+}
+
+// BlobsFromRevListObjects reads a RevListAllObjects and only selects blobs
+func BlobsFromRevListObjects(revListReader *io.PipeReader, shasToCheckWriter *io.PipeWriter, wg *sync.WaitGroup) {
+	defer wg.Done()
+	defer revListReader.Close()
+	scanner := bufio.NewScanner(revListReader)
+	defer func() {
+		_ = shasToCheckWriter.CloseWithError(scanner.Err())
+	}()
+	for scanner.Scan() {
+		line := scanner.Text()
+		if len(line) == 0 {
+			continue
+		}
+		fields := strings.Split(line, " ")
+		if len(fields) < 2 || len(fields[1]) == 0 {
+			continue
+		}
+		toWrite := []byte(fields[0] + "\n")
+		for len(toWrite) > 0 {
+			n, err := shasToCheckWriter.Write(toWrite)
+			if err != nil {
+				_ = revListReader.CloseWithError(err)
+				break
+			}
+			toWrite = toWrite[n:]
+		}
+	}
+}