fix: make p2phttp work for deleted and recreated repositories (#86)

The issue was that the caching mechanism for the UUID to repository path
association tried to be too smart and ended up buggy. This removes the
parts that skip updating the UUIDs for already-in-cache repository
paths. This change makes updating the cache more expensive, but since
https://codeberg.org/forgejo-aneksajo/forgejo-aneksajo/pulls/65 is
merged it should be fast enough to be fine.

Fixes #83.

Reviewed-on: https://codeberg.org/forgejo-aneksajo/forgejo-aneksajo/pulls/86
Co-authored-by: Matthias Riße <m.risse@fz-juelich.de>
Co-committed-by: Matthias Riße <m.risse@fz-juelich.de>

modules/annex/annex.go

@@ -152,10 +152,7 @@ func IsAnnexRepo(repo *git.Repository) bool {
 	return err == nil
 }
 
-var (
-	uuid2repoPathCache = make(map[string]string)
-	repoPath2uuidCache = make(map[string]string)
-)
+var uuid2repoPathCache = make(map[string]string)
 
 func Init() error {
 	if !setting.Annex.Enabled {
@@ -179,10 +176,6 @@ func updateUUID2RepoPathCache() error {
 	}
 	for _, configFile := range configFiles {
 		repoPath := strings.TrimSuffix(configFile, "/config")
-		_, ok := repoPath2uuidCache[repoPath]
-		if ok {
-			continue
-		}
 		config, err := ini.Load(configFile)
 		if err != nil {
 			continue
@@ -190,7 +183,6 @@ func updateUUID2RepoPathCache() error {
 		repoUUID := config.Section("annex").Key("uuid").Value()
 		if repoUUID != "" {
 			uuid2repoPathCache[repoUUID] = repoPath
-			repoPath2uuidCache[repoPath] = repoUUID
 		}
 	}
 	return nil
@@ -219,11 +211,6 @@ func checkValidity(uuid, repoPath string) (bool, error) {
 	return uuid == repoUUID, nil
 }
 
-func removeCachedEntries(uuid, repoPath string) {
-	delete(uuid2repoPathCache, uuid)
-	delete(repoPath2uuidCache, repoPath)
-}
-
 func UUID2RepoPath(uuid string) (string, error) {
 	// Get the current cache entry for the UUID
 	repoPath, err := repoPathFromUUIDCache(uuid)
@@ -237,7 +224,7 @@ func UUID2RepoPath(uuid string) (string, error) {
 	}
 	if !valid {
 		// If it isn't, remove the cache entry and try again
-		removeCachedEntries(uuid, repoPath)
+		delete(uuid2repoPathCache, uuid)
 		return UUID2RepoPath(uuid)
 	}
 	// Otherwise just return the cached entry

routers/web/repo/annex.go

@@ -36,6 +36,7 @@ func AnnexP2PHTTP(ctx *services_context.Context) {
 	uuid := ctx.Params(":uuid")
 	repoPath, err := annex.UUID2RepoPath(uuid)
 	if err != nil {
+		log.Error("%v", err)
 		ctx.PlainText(http.StatusNotFound, "Repository not found")
 		return
 	}
@@ -45,12 +46,14 @@ func AnnexP2PHTTP(ctx *services_context.Context) {
 	owner := parts[len(parts)-2]
 	repo, err := repo_model.GetRepositoryByOwnerAndName(ctx, owner, repoName)
 	if err != nil {
+		log.Error("%v", err)
 		ctx.PlainText(http.StatusNotFound, "Repository not found")
 		return
 	}
 
 	p, err := access_model.GetUserRepoPermission(ctx, repo, ctx.Doer)
 	if err != nil {
+		log.Error("%v", err)
 		ctx.ServerError("GetUserRepoPermission", err)
 		return
 	}

routers/web/repo/githttp.go

@@ -243,8 +243,9 @@ func httpBase(ctx *context.Context) *serviceHandler {
 		}
 	}
 
+	isRequestToConfig := strings.HasSuffix(ctx.Req.URL.Path, "/config")
 	if !repoExist {
-		if !receivePack {
+		if !receivePack && !isRequestToConfig {
 			ctx.PlainText(http.StatusNotFound, "Repository not found")
 			return nil
 		}
@@ -264,7 +265,7 @@ func httpBase(ctx *context.Context) *serviceHandler {
 		}
 
 		// Return dummy payload if GET receive-pack
-		if ctx.Req.Method == http.MethodGet {
+		if ctx.Req.Method == http.MethodGet && !isRequestToConfig {
 			dummyInfoRefs(ctx)
 			return nil
 		}
@@ -551,6 +552,21 @@ func GetConfig(ctx *context.Context) {
 	h := httpBase(ctx)
 	if h != nil {
 		setHeaderNoCache(ctx)
+		if setting.Annex.Enabled && strings.HasPrefix(ctx.Req.UserAgent(), "git-annex/") {
+			p, err := access_model.GetUserRepoPermission(ctx, h.repo, ctx.Doer)
+			if err != nil {
+				ctx.ServerError("GetUserRepoPermission", err)
+				return
+			}
+
+			if p.CanAccess(perm.AccessModeWrite, unit.TypeCode) {
+				_, _, err := git.NewCommand(ctx, "annex", "init").RunStdString(&git.RunOpts{Dir: h.getRepoDir()})
+				if err != nil {
+					ctx.Resp.WriteHeader(http.StatusInternalServerError)
+					return
+				}
+			}
+		}
 		config, err := os.ReadFile(filepath.Join(h.getRepoDir(), "config"))
 		if err != nil {
 			log.Error("Failed to read git config file: %v", err)