1 files changed, 66 insertions, 0 deletions
diff --git a/cmd/generate/gitcache.go b/cmd/generate/gitcache.go
new file mode 100644
index 0000000..7caf024
--- /dev/null
+++ b/cmd/generate/gitcache.go
@@ -0,0 +1,66 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+
+	"git.mothstuff.lol/lukeshu/eclipse/lib/gitcache"
+)
+
+var gitFetched = map[string]struct{}{}
+
+var gitCache = &gitcache.Cache{
+	Dir: ".git-cache",
+}
+
+func withGit(u string, fn func(dir string) error) error {
+	if _, ok := gitFetched[u]; !ok {
+		if err := gitCache.Fetch(os.Stderr, u); err != nil {
+			return err
+		}
+	}
+	return gitCache.WithFastClone(os.Stderr, u, fn)
+}
+
+func getGitTagThatContainsAll(gitURL string, gitHashes ...string) (string, error) {
+	if len(gitHashes) == 0 {
+		return "", nil
+	}
+	var tag string
+	err := withGit(gitURL, func(dir string) error {
+		gitHash := gitHashes[0]
+		if len(gitHashes) > 1 {
+			cmdline := append([]string{"git", "merge-base", "--independent", "--"}, gitHashes...)
+			cmd := exec.Command(cmdline[0], cmdline[1:]...)
+			cmd.Dir = dir
+			var stdout strings.Builder
+			cmd.Stdout = &stdout
+			cmd.Stderr = os.Stderr
+			if err := cmd.Run(); err != nil {
+				return err
+			}
+			gitHash = strings.TrimSpace(stdout.String())
+		}
+		cmd := exec.Command("git", "for-each-ref",
+			"--count=1",
+			"--format=%(refname:lstrip=2)",
+			"--contains="+gitHash,
+			"refs/tags/",
+		)
+		cmd.Dir = dir
+		var stdout strings.Builder
+		cmd.Stdout = &stdout
+		cmd.Stderr = os.Stderr
+		if err := cmd.Run(); err != nil {
+			return err
+		}
+		tag = strings.TrimSpace(stdout.String())
+		return nil
+	})
+	if err != nil {
+		return "", fmt.Errorf("%q: %w", gitURL, err)
+	}
+	return tag, nil
+}