modules/lfstransfer: add locking support

modules/lfstransfer/backend/backend.go

@@ -25,7 +25,7 @@ const Version = "1"
 // Capabilities is a list of Git LFS capabilities supported by this package.
 var Capabilities = []string{
 	"version=" + Version,
-	// "locking",
+	"locking",
 }
 
 var _ transfer.Backend = &GiteaBackend{}
@@ -291,5 +291,5 @@ func (g *GiteaBackend) Verify(oid string, size int64, args transfer.Args) (trans
 
 // LockBackend implements transfer.Backend.
 func (g *GiteaBackend) LockBackend(_ transfer.Args) transfer.LockBackend {
-	return (transfer.LockBackend)(nil)
+	return newGiteaLockBackend(g)
 }

modules/lfstransfer/backend/lock.go

@@ -0,0 +1,292 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package backend
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strconv"
+	"time"
+
+	"code.gitea.io/gitea/modules/json"
+	lfslock "code.gitea.io/gitea/modules/structs"
+
+	"github.com/charmbracelet/git-lfs-transfer/transfer"
+)
+
+var _ transfer.LockBackend = &giteaLockBackend{}
+
+type giteaLockBackend struct {
+	ctx    context.Context
+	g      *GiteaBackend
+	server *url.URL
+	token  string
+	logger transfer.Logger
+}
+
+func newGiteaLockBackend(g *GiteaBackend) transfer.LockBackend {
+	server := g.server.JoinPath("locks")
+	return &giteaLockBackend{ctx: g.ctx, g: g, server: server, token: g.token, logger: g.logger}
+}
+
+// Create implements transfer.LockBackend
+func (g *giteaLockBackend) Create(path, refname string) (transfer.Lock, error) {
+	reqBody := lfslock.LFSLockRequest{Path: path}
+
+	bodyBytes, err := json.Marshal(reqBody)
+	if err != nil {
+		g.logger.Log("json marshal error", err)
+		return nil, err
+	}
+	url := g.server.String()
+	headers := map[string]string{
+		headerAuthorisation: g.token,
+		headerAccept:        mimeGitLFS,
+		headerContentType:   mimeGitLFS,
+	}
+	req := newInternalRequest(g.ctx, url, http.MethodPost, headers, bodyBytes)
+	resp, err := req.Response()
+	if err != nil {
+		g.logger.Log("http request error", err)
+		return nil, err
+	}
+	defer resp.Body.Close()
+	respBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		g.logger.Log("http read error", err)
+		return nil, err
+	}
+	if resp.StatusCode != http.StatusCreated {
+		g.logger.Log("http statuscode error", resp.StatusCode, statusCodeToErr(resp.StatusCode))
+		return nil, statusCodeToErr(resp.StatusCode)
+	}
+	var respBody lfslock.LFSLockResponse
+	err = json.Unmarshal(respBytes, &respBody)
+	if err != nil {
+		g.logger.Log("json umarshal error", err)
+		return nil, err
+	}
+
+	if respBody.Lock == nil {
+		g.logger.Log("api returned nil lock")
+		return nil, fmt.Errorf("api returned nil lock")
+	}
+	respLock := respBody.Lock
+	owner := userUnknown
+	if respLock.Owner != nil {
+		owner = respLock.Owner.Name
+	}
+	lock := newGiteaLock(g, respLock.ID, respLock.Path, respLock.LockedAt, owner)
+	return lock, nil
+}
+
+// Unlock implements transfer.LockBackend
+func (g *giteaLockBackend) Unlock(lock transfer.Lock) error {
+	reqBody := lfslock.LFSLockDeleteRequest{}
+
+	bodyBytes, err := json.Marshal(reqBody)
+	if err != nil {
+		g.logger.Log("json marshal error", err)
+		return err
+	}
+	url := g.server.JoinPath(lock.ID(), "unlock").String()
+	headers := map[string]string{
+		headerAuthorisation: g.token,
+		headerAccept:        mimeGitLFS,
+		headerContentType:   mimeGitLFS,
+	}
+	req := newInternalRequest(g.ctx, url, http.MethodPost, headers, bodyBytes)
+	resp, err := req.Response()
+	if err != nil {
+		g.logger.Log("http request error", err)
+		return err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		g.logger.Log("http statuscode error", resp.StatusCode, statusCodeToErr(resp.StatusCode))
+		return statusCodeToErr(resp.StatusCode)
+	}
+	// no need to read response
+
+	return nil
+}
+
+// FromPath implements transfer.LockBackend
+func (g *giteaLockBackend) FromPath(path string) (transfer.Lock, error) {
+	v := url.Values{
+		argPath: []string{path},
+	}
+
+	respLocks, _, err := g.queryLocks(v)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(respLocks) == 0 {
+		return nil, transfer.ErrNotFound
+	}
+	return respLocks[0], nil
+}
+
+// FromID implements transfer.LockBackend
+func (g *giteaLockBackend) FromID(id string) (transfer.Lock, error) {
+	v := url.Values{
+		argID: []string{id},
+	}
+
+	respLocks, _, err := g.queryLocks(v)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(respLocks) == 0 {
+		return nil, transfer.ErrNotFound
+	}
+	return respLocks[0], nil
+}
+
+// Range implements transfer.LockBackend
+func (g *giteaLockBackend) Range(cursor string, limit int, iter func(transfer.Lock) error) (string, error) {
+	v := url.Values{
+		argLimit: []string{strconv.FormatInt(int64(limit), 10)},
+	}
+	if cursor != "" {
+		v[argCursor] = []string{cursor}
+	}
+
+	respLocks, cursor, err := g.queryLocks(v)
+	if err != nil {
+		return "", err
+	}
+
+	for _, lock := range respLocks {
+		err := iter(lock)
+		if err != nil {
+			return "", err
+		}
+	}
+	return cursor, nil
+}
+
+func (g *giteaLockBackend) queryLocks(v url.Values) ([]transfer.Lock, string, error) {
+	urlq := g.server.JoinPath() // get a copy
+	urlq.RawQuery = v.Encode()
+	url := urlq.String()
+	headers := map[string]string{
+		headerAuthorisation: g.token,
+		headerAccept:        mimeGitLFS,
+		headerContentType:   mimeGitLFS,
+	}
+	req := newInternalRequest(g.ctx, url, http.MethodGet, headers, nil)
+	resp, err := req.Response()
+	if err != nil {
+		g.logger.Log("http request error", err)
+		return nil, "", err
+	}
+	defer resp.Body.Close()
+	respBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		g.logger.Log("http read error", err)
+		return nil, "", err
+	}
+	if resp.StatusCode != http.StatusOK {
+		g.logger.Log("http statuscode error", resp.StatusCode, statusCodeToErr(resp.StatusCode))
+		return nil, "", statusCodeToErr(resp.StatusCode)
+	}
+	var respBody lfslock.LFSLockList
+	err = json.Unmarshal(respBytes, &respBody)
+	if err != nil {
+		g.logger.Log("json umarshal error", err)
+		return nil, "", err
+	}
+
+	respLocks := make([]transfer.Lock, 0, len(respBody.Locks))
+	for _, respLock := range respBody.Locks {
+		owner := userUnknown
+		if respLock.Owner != nil {
+			owner = respLock.Owner.Name
+		}
+		lock := newGiteaLock(g, respLock.ID, respLock.Path, respLock.LockedAt, owner)
+		respLocks = append(respLocks, lock)
+	}
+	return respLocks, respBody.Next, nil
+}
+
+var _ transfer.Lock = &giteaLock{}
+
+type giteaLock struct {
+	g        *giteaLockBackend
+	id       string
+	path     string
+	lockedAt time.Time
+	owner    string
+}
+
+func newGiteaLock(g *giteaLockBackend, id, path string, lockedAt time.Time, owner string) transfer.Lock {
+	return &giteaLock{g: g, id: id, path: path, lockedAt: lockedAt, owner: owner}
+}
+
+// Unlock implements transfer.Lock
+func (g *giteaLock) Unlock() error {
+	return g.g.Unlock(g)
+}
+
+// ID implements transfer.Lock
+func (g *giteaLock) ID() string {
+	return g.id
+}
+
+// Path implements transfer.Lock
+func (g *giteaLock) Path() string {
+	return g.path
+}
+
+// FormattedTimestamp implements transfer.Lock
+func (g *giteaLock) FormattedTimestamp() string {
+	return g.lockedAt.UTC().Format(time.RFC3339)
+}
+
+// OwnerName implements transfer.Lock
+func (g *giteaLock) OwnerName() string {
+	return g.owner
+}
+
+func (g *giteaLock) CurrentUser() (string, error) {
+	return userSelf, nil
+}
+
+// AsLockSpec implements transfer.Lock
+func (g *giteaLock) AsLockSpec(ownerID bool) ([]string, error) {
+	msgs := []string{
+		fmt.Sprintf("lock %s", g.ID()),
+		fmt.Sprintf("path %s %s", g.ID(), g.Path()),
+		fmt.Sprintf("locked-at %s %s", g.ID(), g.FormattedTimestamp()),
+		fmt.Sprintf("ownername %s %s", g.ID(), g.OwnerName()),
+	}
+	if ownerID {
+		user, err := g.CurrentUser()
+		if err != nil {
+			return nil, fmt.Errorf("error getting current user: %w", err)
+		}
+		who := "theirs"
+		if user == g.OwnerName() {
+			who = "ours"
+		}
+		msgs = append(msgs, fmt.Sprintf("owner %s %s", g.ID(), who))
+	}
+	return msgs, nil
+}
+
+// AsArguments implements transfer.Lock
+func (g *giteaLock) AsArguments() []string {
+	return []string{
+		fmt.Sprintf("id=%s", g.ID()),
+		fmt.Sprintf("path=%s", g.Path()),
+		fmt.Sprintf("locked-at=%s", g.FormattedTimestamp()),
+		fmt.Sprintf("ownername=%s", g.OwnerName()),
+	}
+}

modules/lfstransfer/backend/util.go

@@ -41,13 +41,22 @@ const (
 
 // SSH protocol argument keys
 const (
+	argCursor    = "cursor"
 	argExpiresAt = "expires-at"
 	argID        = "id"
+	argLimit     = "limit"
+	argPath      = "path"
 	argRefname   = "refname"
 	argToken     = "token"
 	argTransfer  = "transfer"
 )
 
+// Default username constants
+const (
+	userSelf    = "(self)"
+	userUnknown = "(unknown)"
+)
+
 // Operations enum
 const (
 	opNone = iota