Reflog support (libgit2#467)

reflog.go

@@ -0,0 +1,175 @@
+package git
+
+/*
+#include <git2.h>
+*/
+import "C"
+import (
+	"runtime"
+	"unsafe"
+)
+
+// RefLog is a log of changes for a reference
+type RefLog struct {
+	ptr  *C.git_reflog
+	repo *Repository
+	name string
+}
+
+func newRefLogFromC(ptr *C.git_reflog, repo *Repository, name string) *RefLog {
+	l := &RefLog{
+		ptr:  ptr,
+		repo: repo,
+		name: name,
+	}
+	runtime.SetFinalizer(l, (*RefLog).Free)
+	return l
+}
+
+func (repo *Repository) ReadRefLog(name string) (*RefLog, error) {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	cname := C.CString(name)
+	defer C.free(unsafe.Pointer(cname))
+
+	var ptr *C.git_reflog
+
+	ecode := C.git_reflog_read(&ptr, repo.ptr, cname)
+	runtime.KeepAlive(repo)
+	if ecode < 0 {
+		return nil, MakeGitError(ecode)
+	}
+
+	return newRefLogFromC(ptr, repo, name), nil
+}
+
+func (repo *Repository) DeleteReflog(name string) error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	cname := C.CString(name)
+	defer C.free(unsafe.Pointer(cname))
+
+	ecode := C.git_reflog_delete(repo.ptr, cname)
+	runtime.KeepAlive(repo)
+	if ecode < 0 {
+		return MakeGitError(ecode)
+	}
+
+	return nil
+}
+
+func (repo *Repository) RenameReflog(oldName, newName string) error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	cOldName := C.CString(oldName)
+	defer C.free(unsafe.Pointer(cOldName))
+
+	cNewName := C.CString(newName)
+	defer C.free(unsafe.Pointer(cNewName))
+
+	ecode := C.git_reflog_rename(repo.ptr, cOldName, cNewName)
+	runtime.KeepAlive(repo)
+	if ecode < 0 {
+		return MakeGitError(ecode)
+	}
+
+	return nil
+}
+
+func (l *RefLog) Write() error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	ecode := C.git_reflog_write(l.ptr)
+	runtime.KeepAlive(l)
+	if ecode < 0 {
+		return MakeGitError(ecode)
+	}
+	return nil
+}
+
+func (l *RefLog) EntryCount() uint {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	count := C.git_reflog_entrycount(l.ptr)
+	runtime.KeepAlive(l)
+	return uint(count)
+}
+
+// RefLogEntry specifies a reference change
+type RefLogEntry struct {
+	Old       *Oid
+	New       *Oid
+	Committer *Signature
+	Message   string // may be empty
+}
+
+func newRefLogEntry(entry *C.git_reflog_entry) *RefLogEntry {
+	return &RefLogEntry{
+		New:       newOidFromC(C.git_reflog_entry_id_new(entry)),
+		Old:       newOidFromC(C.git_reflog_entry_id_old(entry)),
+		Committer: newSignatureFromC(C.git_reflog_entry_committer(entry)),
+		Message:   C.GoString(C.git_reflog_entry_message(entry)),
+	}
+}
+
+func (l *RefLog) EntryByIndex(index uint) *RefLogEntry {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	entry := C.git_reflog_entry_byindex(l.ptr, C.size_t(index))
+	if entry == nil {
+		return nil
+	}
+
+	goEntry := newRefLogEntry(entry)
+	runtime.KeepAlive(l)
+
+	return goEntry
+}
+
+func (l *RefLog) DropEntry(index uint, rewriteHistory bool) error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	var rewriteHistoryInt int
+	if rewriteHistory {
+		rewriteHistoryInt = 1
+	}
+
+	ecode := C.git_reflog_drop(l.ptr, C.size_t(index), C.int(rewriteHistoryInt))
+	runtime.KeepAlive(l)
+	if ecode < 0 {
+		return MakeGitError(ecode)
+	}
+
+	return nil
+}
+
+func (l *RefLog) AppendEntry(oid *Oid, committer *Signature, message string) error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	cSignature, err := committer.toC()
+	if err != nil {
+		return err
+	}
+	defer C.git_signature_free(cSignature)
+
+	cMsg := C.CString(message)
+	defer C.free(unsafe.Pointer(cMsg))
+
+	C.git_reflog_append(l.ptr, oid.toC(), cSignature, cMsg)
+	runtime.KeepAlive(l)
+
+	return nil
+}
+
+func (l *RefLog) Free() {
+	runtime.SetFinalizer(l, nil)
+	C.git_reflog_free(l.ptr)
+}

reflog_test.go

@@ -0,0 +1,162 @@
+package git
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+	"time"
+)
+
+func allReflogEntries(t *testing.T, repo *Repository, refName string) (entries []*RefLogEntry) {
+	rl, err := repo.ReadRefLog(refName)
+	checkFatal(t, err)
+	defer rl.Free()
+
+	for i := uint(0); i < rl.EntryCount(); i++ {
+		entries = append(entries, rl.EntryByIndex(i))
+	}
+	return entries
+}
+
+// assertEntriesEqual will assert that the reflogs match with the exception of
+// the signature time (it is not reliably deterministic to predict the
+// signature time during many reference updates)
+func assertEntriesEqual(t *testing.T, got, want []*RefLogEntry) {
+	if len(got) != len(want) {
+		t.Fatalf("got %d length, wanted %d length", len(got), len(want))
+	}
+
+	for i := 0; i < len(got); i++ {
+		gi := got[i]
+		wi := want[i]
+		// remove the signature time to make the results deterministic
+		gi.Committer.When = time.Time{}
+		wi.Committer.When = time.Time{}
+		// check committer separately to print results clearly
+		if !reflect.DeepEqual(gi.Committer, wi.Committer) {
+			t.Fatalf("got committer %v, want committer %v",
+				gi.Committer, wi.Committer)
+		}
+		if !reflect.DeepEqual(gi, wi) {
+			t.Fatalf("got %v, want %v", gi, wi)
+		}
+	}
+}
+
+func TestReflog(t *testing.T) {
+	t.Parallel()
+	repo := createTestRepo(t)
+	defer cleanupTestRepo(t, repo)
+
+	commitID, treeId := seedTestRepo(t, repo)
+
+	testRefName := "refs/heads/test"
+
+	// configure committer for deterministic reflog entries
+	cfg, err := repo.Config()
+	checkFatal(t, err)
+
+	sig := &Signature{
+		Name:  "Rand Om Hacker",
+		Email: "[email protected]",
+	}
+
+	checkFatal(t, cfg.SetString("user.name", sig.Name))
+	checkFatal(t, cfg.SetString("user.email", sig.Email))
+
+	checkFatal(t, repo.References.EnsureLog(testRefName))
+	_, err = repo.References.Create(testRefName, commitID, true, "first update")
+	checkFatal(t, err)
+	got := allReflogEntries(t, repo, testRefName)
+	want := []*RefLogEntry{
+		&RefLogEntry{
+			New:       commitID,
+			Old:       &Oid{},
+			Committer: sig,
+			Message:   "first update",
+		},
+	}
+
+	// create additional commits and verify they are added to reflog
+	tree, err := repo.LookupTree(treeId)
+	checkFatal(t, err)
+	for i := 0; i < 10; i++ {
+		nextEntry := &RefLogEntry{
+			Old:       commitID,
+			Committer: sig,
+			Message:   fmt.Sprintf("commit: %d", i),
+		}
+
+		commit, err := repo.LookupCommit(commitID)
+		checkFatal(t, err)
+
+		commitID, err = repo.CreateCommit(testRefName, sig, sig, fmt.Sprint(i), tree, commit)
+		checkFatal(t, err)
+
+		nextEntry.New = commitID
+
+		want = append([]*RefLogEntry{nextEntry}, want...)
+	}
+	got = allReflogEntries(t, repo, testRefName)
+
+	t.Run("ReadReflog", func(t *testing.T) {
+		assertEntriesEqual(t, got, want)
+	})
+
+	t.Run("DropEntry", func(t *testing.T) {
+		rl, err := repo.ReadRefLog(testRefName)
+		checkFatal(t, err)
+		defer rl.Free()
+
+		gotBefore := allReflogEntries(t, repo, testRefName)
+
+		checkFatal(t, rl.DropEntry(0, false))
+		checkFatal(t, rl.Write())
+
+		gotAfter := allReflogEntries(t, repo, testRefName)
+
+		assertEntriesEqual(t, gotAfter, gotBefore[1:])
+	})
+
+	t.Run("AppendEntry", func(t *testing.T) {
+		logs := allReflogEntries(t, repo, testRefName)
+
+		rl, err := repo.ReadRefLog(testRefName)
+		checkFatal(t, err)
+		defer rl.Free()
+
+		newOID := NewOidFromBytes([]byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})
+		checkFatal(t, rl.AppendEntry(newOID, sig, "synthetic"))
+		checkFatal(t, rl.Write())
+
+		want := append([]*RefLogEntry{
+			&RefLogEntry{
+				New:       newOID,
+				Old:       logs[0].New,
+				Committer: sig,
+				Message:   "synthetic",
+			},
+		}, logs...)
+		got := allReflogEntries(t, repo, testRefName)
+		assertEntriesEqual(t, got, want)
+	})
+
+	t.Run("RenameReflog", func(t *testing.T) {
+		logs := allReflogEntries(t, repo, testRefName)
+		newRefName := "refs/heads/new"
+
+		checkFatal(t, repo.RenameReflog(testRefName, newRefName))
+		assertEntriesEqual(t, allReflogEntries(t, repo, testRefName), nil)
+		assertEntriesEqual(t, allReflogEntries(t, repo, newRefName), logs)
+
+		checkFatal(t, repo.RenameReflog(newRefName, testRefName))
+		assertEntriesEqual(t, allReflogEntries(t, repo, testRefName), logs)
+		assertEntriesEqual(t, allReflogEntries(t, repo, newRefName), nil)
+	})
+
+	t.Run("DeleteReflog", func(t *testing.T) {
+		checkFatal(t, repo.DeleteReflog(testRefName))
+		assertEntriesEqual(t, allReflogEntries(t, repo, testRefName), nil)
+	})
+
+}