files for previous commit

internal/rpc/deps.go

@@ -941,6 +941,10 @@ type FilesService interface {
 	GetFile(ctx context.Context, req domain.FileDownloadRequest) (domain.FileChunk, bool, error)
 	// CreateEncryptedFileFromUpload 把密聊上传分片组装成盲 blob 并铸造 EncryptedFile 快照（P2）。
 	CreateEncryptedFileFromUpload(ctx context.Context, file domain.UploadedFileRef, keyFingerprint int) (domain.EncryptedFileRef, error)
+	// DeleteEncryptedFileBlob deletes a secret-chat encrypted file's blob
+	// bytes once fully downloaded (TELESRV_SECRET_CHAT_DELETE_FILE_AFTER_DOWNLOAD,
+	// no-op otherwise) -- see internal/app/files.Service.DeleteEncryptedFileBlob.
+	DeleteEncryptedFileBlob(ctx context.Context, locationKey string) error
 	// GeoMapTile 渲染 geo 消息地图缩略占位图（upload.getWebFile），确定性、无外部依赖。
 	GeoMapTile(lat, long float64, w, h, zoom, scale int) ([]byte, string)
 	// 资源读取（reaction / sticker / document）。

internal/rpc/send_media_test.go

@@ -73,6 +73,9 @@ func (f *fakeFiles) GetFile(_ context.Context, req domain.FileDownloadRequest) (
 func (f *fakeFiles) CreateEncryptedFileFromUpload(context.Context, domain.UploadedFileRef, int) (domain.EncryptedFileRef, error) {
 	return domain.EncryptedFileRef{ID: 9001, AccessHash: 9002, Size: 16, DCID: 2, KeyFingerprint: 7}, nil
 }
+func (f *fakeFiles) DeleteEncryptedFileBlob(context.Context, string) error {
+	return nil
+}
 func (f *fakeFiles) GeoMapTile(lat, long float64, w, h, zoom, scale int) ([]byte, string) {
 	return []byte{0x89, 'P', 'N', 'G', 0x0D, 0x0A, 0x1A, 0x0A, 1, 2, 3, 4}, "image/png"
 }

internal/rpc/upload.go

@@ -104,6 +104,19 @@ func (r *Router) onUploadGetFile(ctx context.Context, req *tg.UploadGetFileReque
 		return nil, internalErr()
 	}
 	if found {
+		if isSecretChatFileFullyDownloaded(key, req.Offset, len(chunk.Bytes), chunk.Total) {
+			// The recipient has now received every byte of this secret-chat
+			// file. Best-effort, fire-and-forget: DeleteEncryptedFileBlob is
+			// itself a no-op unless TELESRV_SECRET_CHAT_DELETE_FILE_AFTER_DOWNLOAD
+			// is enabled, and must never delay or fail this download response
+			// -- use a detached context since ctx may be canceled the moment
+			// this handler returns.
+			go func(locationKey string) {
+				if err := r.deps.Files.DeleteEncryptedFileBlob(context.Background(), locationKey); err != nil && r.log != nil {
+					r.log.Warn("delete secret chat file after download failed", zap.String("location_key", locationKey), zap.Error(err))
+				}
+			}(key)
+		}
 		return &tg.UploadFile{
 			Type:  storageFileType(chunk.MimeType, chunk.Bytes),
 			Mtime: 0,
@@ -113,6 +126,19 @@ func (r *Router) onUploadGetFile(ctx context.Context, req *tg.UploadGetFileReque
 	return nil, locationInvalidErr()
 }
 
+// isSecretChatFileFullyDownloaded reports whether a getFile response for
+// location key key just delivered the last byte of a secret-chat encrypted
+// file (location_key "enc:<id>") -- the signal onUploadGetFile uses to
+// fire-and-forget DeleteEncryptedFileBlob. total<=0 (unknown size) never
+// counts as fully downloaded -- there is nothing to compare against, so
+// treating that as "done" could delete a file mid-transfer.
+func isSecretChatFileFullyDownloaded(key string, offset int64, chunkLen int, total int64) bool {
+	if !strings.HasPrefix(key, "enc:") || total <= 0 {
+		return false
+	}
+	return offset+int64(chunkLen) >= total
+}
+
 // authorizedFileLocationKey applies the authorization/capability checks which cannot be
 // expressed by a plain location-key conversion. Secret-chat blobs are addressed internally by
 // id, but the wire capability is the pair (id, access_hash); accepting id alone would let any

internal/rpc/upload_test.go

@@ -10,6 +10,37 @@ import (
 	"telesrv/internal/domain"
 )
 
+// TestIsSecretChatFileFullyDownloaded covers the fire-and-forget
+// delete-after-download trigger in onUploadGetFile: only an "enc:"-prefixed
+// (secret-chat) location key, with a known total size, whose chunk reaches
+// the end of the file, counts as fully downloaded.
+func TestIsSecretChatFileFullyDownloaded(t *testing.T) {
+	cases := []struct {
+		name     string
+		key      string
+		offset   int64
+		chunkLen int
+		total    int64
+		want     bool
+	}{
+		{"secret chat, last chunk reaches exact end", "enc:123", 900, 100, 1000, true},
+		{"secret chat, last chunk overlaps past end", "enc:123", 950, 100, 1000, true},
+		{"secret chat, still mid-file", "enc:123", 0, 100, 1000, false},
+		{"secret chat, unknown total must never look done", "enc:123", 0, 100, 0, false},
+		{"secret chat, negative total must never look done", "enc:123", 0, 100, -1, false},
+		{"ordinary document key, even if it would otherwise look complete", "doc:123", 900, 100, 1000, false},
+		{"ordinary photo key", "photo:123:x", 0, 1000, 1000, false},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			if got := isSecretChatFileFullyDownloaded(c.key, c.offset, c.chunkLen, c.total); got != c.want {
+				t.Fatalf("isSecretChatFileFullyDownloaded(%q, %d, %d, %d) = %v, want %v",
+					c.key, c.offset, c.chunkLen, c.total, got, c.want)
+			}
+		})
+	}
+}
+
 func TestFileSaveErrMapsStorageCapacityWithoutFloodWait(t *testing.T) {
 	err := fileSaveErr(domain.ErrStorageFull)
 	if !tgerr.Is(err, "STORAGE_FULL") {

internal/store/media.go

@@ -34,6 +34,12 @@ type MediaStore interface {
 	// 供低磁盘空间守卫的周期性用量刷新使用（尤其是 s3 backend 的预算模式，没有
 	// 操作系统级"剩余空间"概念，只能靠这个累计值和配置的预算比较）。
 	SumFileBlobBytes(ctx context.Context) (int64, error)
+	// DeleteFileBlobRow deletes exactly one file_blobs row by its exact
+	// location_key -- no prefix matching (unlike the doc:/photo: sweep
+	// primitives, since callers of this method, e.g. secret-chat
+	// delete-after-download, already know the precise key and it never has
+	// sibling thumbnail/rendition rows to also clean up).
+	DeleteFileBlobRow(ctx context.Context, locationKey string) error
 
 	// seed 状态。只记录静态资源 catalog 的内容 hash，用于启动时跳过未变化的重复导入；
 	// 真实可服务性仍由 documents/file_blobs 校验保证，不能只相信这里的 hash。

internal/store/postgres/media.go

@@ -238,6 +238,12 @@ func (s *MediaStore) PutFileBlob(ctx context.Context, blob domain.FileBlob) erro
 	})
 }
 
+// DeleteFileBlobRow deletes exactly one file_blobs row by its exact
+// location_key -- see the store.MediaStore interface doc comment.
+func (s *MediaStore) DeleteFileBlobRow(ctx context.Context, locationKey string) error {
+	return s.q.DeleteFileBlobRow(ctx, locationKey)
+}
+
 func (s *MediaStore) GetFileBlob(ctx context.Context, locationKey string) (domain.FileBlob, bool, error) {
 	row, err := s.q.GetFileBlob(ctx, locationKey)
 	if err != nil {