libmicrohttpd2

commit 7f786eb527a18836b3937b1b1c7a47f53edc92c1
parent 5224f4454e596343c5dda48172e958451f6dc003
Author: Evgeny Grin (Karlson2k) <k2k@drgrin.dev>
Date:   Sun, 16 Aug 2026 14:27:43 +0200

MHD_response_from_fd(): implemented support for automatic file size

Diffstat:
M
src/include/microhttpd2.h
 | 
20
++++++++++++--------
M
src/include/microhttpd2_main.h.in
 | 
20
++++++++++++--------
M
src/mhd2/stream_process_reply.c
 | 
16
++++++++++++++++

3 files changed, 40 insertions(+), 16 deletions(-)
diff --git a/src/include/microhttpd2.h b/src/include/microhttpd2.h
@@ -6558,14 +6558,18 @@ MHD_response_from_iovec (
  *
  * @param sc status code to return
  * @param fd file descriptor referring to a file on disk with the
- *        data; will be closed when response is destroyed;
- *        fd should be in 'blocking' mode
- * @param offset offset to start reading from in the file;
- *        reading file beyond 2 GiB may be not supported by OS or
- *        MHD build; see #MHD_LIB_INFO_FIXED_HAS_LARGE_FILE
- * @param size size of the data portion of the response;
- *        sizes larger than 2 GiB may be not supported by OS or
- *        MHD build; see #MHD_LIB_INFO_FIXED_HAS_LARGE_FILE
+ *           data; will be closed when response is destroyed;
+ *           fd should be in 'blocking' mode
+ * @param offset offset to start reading from in the file,
+ *               must not be #MHD_SIZE_UNKNOWN;
+ *               reading file beyond 2 GiB may be not supported by OS or
+ *               MHD build; see #MHD_LIB_INFO_FIXED_HAS_LARGE_FILE
+ * @param size size of the data portion of the response,
+ *             #MHD_SIZE_UNKNOWN to send the file to its end; with the
+ *             unknown size and @p offset beyond the end of the file the
+ *             body is empty;
+ *             sizes larger than 2 GiB may be not supported by OS or
+ *             MHD build; see #MHD_LIB_INFO_FIXED_HAS_LARGE_FILE
  * @return new response object on success,
  *         NULL on failure (i.e. invalid arguments, out of memory),
  *         @p fd is closed automatically in case of failure
diff --git a/src/include/microhttpd2_main.h.in b/src/include/microhttpd2_main.h.in
@@ -1640,14 +1640,18 @@ MHD_response_from_iovec (
  *
  * @param sc status code to return
  * @param fd file descriptor referring to a file on disk with the
- *        data; will be closed when response is destroyed;
- *        fd should be in 'blocking' mode
- * @param offset offset to start reading from in the file;
- *        reading file beyond 2 GiB may be not supported by OS or
- *        MHD build; see #MHD_LIB_INFO_FIXED_HAS_LARGE_FILE
- * @param size size of the data portion of the response;
- *        sizes larger than 2 GiB may be not supported by OS or
- *        MHD build; see #MHD_LIB_INFO_FIXED_HAS_LARGE_FILE
+ *           data; will be closed when response is destroyed;
+ *           fd should be in 'blocking' mode
+ * @param offset offset to start reading from in the file,
+ *               must not be #MHD_SIZE_UNKNOWN;
+ *               reading file beyond 2 GiB may be not supported by OS or
+ *               MHD build; see #MHD_LIB_INFO_FIXED_HAS_LARGE_FILE
+ * @param size size of the data portion of the response,
+ *             #MHD_SIZE_UNKNOWN to send the file to its end; with the
+ *             unknown size and @p offset beyond the end of the file the
+ *             body is empty;
+ *             sizes larger than 2 GiB may be not supported by OS or
+ *             MHD build; see #MHD_LIB_INFO_FIXED_HAS_LARGE_FILE
  * @return new response object on success,
  *         NULL on failure (i.e. invalid arguments, out of memory),
  *         @p fd is closed automatically in case of failure
diff --git a/src/mhd2/stream_process_reply.c b/src/mhd2/stream_process_reply.c
@@ -1129,6 +1129,8 @@ read_response_file (struct MHD_Connection *restrict c,
                       "for this platform.");
     return false;
   case mhd_FILE_READ_EOF:
+    if (MHD_SIZE_UNKNOWN == r->cntn_size)
+      return true;
     mhd_STREAM_ABORT (c, \
                       mhd_CONN_CLOSE_FILE_TOO_SHORT, \
                       "The file for file-backed response is smaller " \
@@ -1243,6 +1245,13 @@ mhd_stream_prep_unchunked_body (struct MHD_Connection *restrict c)
                                c->write_buffer + c->write_buffer_append_offset,
                                &filled))
         return true; /* Error, the stream is closed */
+      if (0u == filled)
+      {
+        mhd_assert (MHD_SIZE_UNKNOWN == r->cntn_size);
+        c->stage = mhd_HTTP_STAGE_FULL_REPLY_SENT;
+
+        return true;
+      }
 
       c->rp.rsp_cntn_read_pos += filled;
       c->write_buffer_append_offset += filled;
@@ -1411,6 +1420,13 @@ mhd_stream_prep_chunked_body (struct MHD_Connection *restrict c)
                              c->write_buffer + max_chunk_hdr_len,
                              &filled))
       return true; /* Error, the stream is closed */
+    if (0u == filled)
+    {
+      mhd_assert (MHD_SIZE_UNKNOWN == r->cntn_size);
+      c->stage = mhd_HTTP_STAGE_CHUNKED_BODY_SENT;
+
+      return true;
+    }
   }
   else
   {