snapshot of https://github.com/go-gitea/gitea.git (main, 2026-09-15; blobs > 131072B omitted)

modules/git/compare.go

@@ -0,0 +1,70 @@
+// Copyright 2025 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package git
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"gitea.dev/modules/git/gitcmd"
+)
+
+// DivergeObject represents commit count diverging commits
+type DivergeObject struct {
+	Ahead  int
+	Behind int
+}
+
+// GetDivergingCommits returns the number of commits a targetBranch is ahead or behind a baseBranch
+func GetDivergingCommits(ctx context.Context, repo RepositoryFacade, baseBranch, targetBranch string) (*DivergeObject, error) {
+	cmd := gitcmd.NewCommand("rev-list", "--count", "--left-right").
+		AddDynamicArguments(baseBranch + "..." + targetBranch).AddArguments("--")
+	stdout, _, err1 := cmd.WithRepo(repo).RunStdString(ctx)
+	if err1 != nil {
+		return nil, err1
+	}
+
+	left, right, found := strings.Cut(strings.Trim(stdout, "\n"), "\t")
+	if !found {
+		return nil, fmt.Errorf("git rev-list output is missing a tab: %q", stdout)
+	}
+
+	behind, err := strconv.Atoi(left)
+	if err != nil {
+		return nil, err
+	}
+	ahead, err := strconv.Atoi(right)
+	if err != nil {
+		return nil, err
+	}
+	return &DivergeObject{Ahead: ahead, Behind: behind}, nil
+}
+
+// GetCommitIDsBetweenReverse returns the last commit IDs between two commits in reverse order (from old to new) with limit.
+// If the result exceeds the limit, the old commits IDs will be ignored
+func GetCommitIDsBetweenReverse(ctx context.Context, repo RepositoryFacade, startRef, endRef, notRef string, limit int) ([]string, error) {
+	genCmd := func(reversions ...string) *gitcmd.Command {
+		cmd := gitcmd.NewCommand("rev-list", "--reverse").
+			AddArguments("-n").AddDynamicArguments(strconv.Itoa(limit)).
+			AddDynamicArguments(reversions...)
+		if notRef != "" { // --not should be kept as the last parameter of git command, otherwise the result will be wrong
+			cmd.AddOptionValues("--not", notRef)
+		}
+		return cmd
+	}
+	stdout, _, err := genCmd(startRef + ".." + endRef).WithRepo(repo).RunStdString(ctx)
+	if gitcmd.IsStderr(err, gitcmd.StderrNoMergeBase) {
+		// if the start and end are not related (no merge base), just get all commits pushed by "end ref"
+		// previously it would return the results of git rev-list before last so let's try that...
+		stdout, _, err = genCmd(endRef).WithRepo(repo).RunStdString(ctx)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	commitIDs := strings.Fields(strings.TrimSpace(stdout))
+	return commitIDs, nil
+}