nghttp2_data_source_read_callback: Replace eof with uint32_t *data_flags

Replace int *eof with uint32_t *data_flags so that we can easily
extend functionality if we have to (but we don't do if possible).

examples/libevent-server.c

@@ -328,7 +328,7 @@ static char* percent_decode(const uint8_t *value, size_t valuelen)
 
 static ssize_t file_read_callback
 (nghttp2_session *session, int32_t stream_id,
- uint8_t *buf, size_t length, int *eof,
+ uint8_t *buf, size_t length, uint32_t *data_flags,
  nghttp2_data_source *source, void *user_data)
 {
   int fd = source->fd;
@@ -338,7 +338,7 @@ static ssize_t file_read_callback
     return NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE;
   }
   if(r == 0) {
-    *eof = 1;
+    *data_flags |= NGHTTP2_DATA_FLAG_EOF;
   }
   return r;
 }

lib/includes/nghttp2/nghttp2.h

@@ -621,6 +621,23 @@ typedef union {
   void *ptr;
 } nghttp2_data_source;
 
+/**
+ * @enum
+ *
+ * The flags used to set in |data_flags| output parameter in
+ * :type:`nghttp2_data_source_read_callback`.
+ */
+typedef enum {
+  /**
+   * No flag set.
+   */
+  NGHTTP2_DATA_FLAG_NONE = 0,
+  /**
+   * Indicates EOF was sensed.
+   */
+  NGHTTP2_DATA_FLAG_EOF = 0x01
+} nghttp2_data_flag;
+
 /**
  * @functypedef
  *
@@ -629,21 +646,22 @@ typedef union {
  * implementation of this function must read at most |length| bytes of
  * data from |source| (or possibly other places) and store them in
  * |buf| and return number of data stored in |buf|. If EOF is reached,
- * set |*eof| to 1.  If the application wants to postpone DATA frames,
+ * set :enum:`NGHTTP2_DATA_FLAG_EOF` flag in |*data_falgs|.  If the
- * (e.g., asynchronous I/O, or reading data blocks for long time), it
+ * application wants to postpone DATA frames, (e.g., asynchronous I/O,
- * is achieved by returning :enum:`NGHTTP2_ERR_DEFERRED` without
+ * or reading data blocks for long time), it is achieved by returning
- * reading any data in this invocation.  The library removes DATA
+ * :enum:`NGHTTP2_ERR_DEFERRED` without reading any data in this
- * frame from the outgoing queue temporarily.  To move back deferred
+ * invocation.  The library removes DATA frame from the outgoing queue
- * DATA frame to outgoing queue, call `nghttp2_session_resume_data()`.
+ * temporarily.  To move back deferred DATA frame to outgoing queue,
- * In case of error, there are 2 choices. Returning
+ * call `nghttp2_session_resume_data()`.  In case of error, there are
- * :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE` will close the stream
+ * 2 choices. Returning :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`
- * by issuing RST_STREAM with :enum:`NGHTTP2_INTERNAL_ERROR`.
+ * will close the stream by issuing RST_STREAM with
- * Returning :enum:`NGHTTP2_ERR_CALLBACK_FAILURE` will signal the
+ * :enum:`NGHTTP2_INTERNAL_ERROR`.  Returning
- * entire session failure.
+ * :enum:`NGHTTP2_ERR_CALLBACK_FAILURE` will signal the entire session
+ * failure.
  */
 typedef ssize_t (*nghttp2_data_source_read_callback)
 (nghttp2_session *session, int32_t stream_id,
- uint8_t *buf, size_t length, int *eof,
+ uint8_t *buf, size_t length, uint32_t *data_flags,
  nghttp2_data_source *source, void *user_data);
 
 /**

lib/nghttp2_session.c

@@ -5388,7 +5388,7 @@ int nghttp2_session_pack_data(nghttp2_session *session,
                               nghttp2_private_data *frame)
 {
   ssize_t rv;
-  int eof_flags;
+  uint32_t data_flags;
   uint8_t flags;
   ssize_t payloadlen;
   ssize_t padded_payloadlen;
@@ -5404,10 +5404,10 @@ int nghttp2_session_pack_data(nghttp2_session *session,
   /* Current max DATA length is less then buffer chunk size */
   assert(nghttp2_buf_avail(buf) >= (ssize_t)datamax);
 
-  eof_flags = 0;
+  data_flags = NGHTTP2_DATA_FLAG_NONE;
   payloadlen = frame->data_prd.read_callback
     (session, frame->hd.stream_id, buf->pos, datamax,
-     &eof_flags, &frame->data_prd.source, session->user_data);
+     &data_flags, &frame->data_prd.source, session->user_data);
 
   if(payloadlen == NGHTTP2_ERR_DEFERRED ||
      payloadlen == NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE) {
@@ -5430,7 +5430,7 @@ int nghttp2_session_pack_data(nghttp2_session *session,
   frame->hd.flags &= (NGHTTP2_FLAG_END_STREAM | NGHTTP2_FLAG_END_SEGMENT);
   flags = NGHTTP2_FLAG_NONE;
 
-  if(eof_flags) {
+  if(data_flags & NGHTTP2_DATA_FLAG_EOF) {
     frame->eof = 1;
     if(frame->hd.flags & NGHTTP2_FLAG_END_STREAM) {
       flags |= NGHTTP2_FLAG_END_STREAM;

src/HttpServer.cc

@@ -922,7 +922,7 @@ void Http2Handler::terminate_session(nghttp2_error_code error_code)
 
 ssize_t file_read_callback
 (nghttp2_session *session, int32_t stream_id,
- uint8_t *buf, size_t length, int *eof,
+ uint8_t *buf, size_t length, uint32_t *data_flags,
  nghttp2_data_source *source, void *user_data)
 {
   auto hd = static_cast<Http2Handler*>(user_data);
@@ -942,7 +942,7 @@ ssize_t file_read_callback
   }
 
   if(r == 0) {
-    *eof = 1;
+    *data_flags |= NGHTTP2_DATA_FLAG_EOF;
   }
 
   return r;

src/nghttp.cc

@@ -1669,7 +1669,7 @@ int communicate(const std::string& scheme, const std::string& host,
 namespace {
 ssize_t file_read_callback
 (nghttp2_session *session, int32_t stream_id,
- uint8_t *buf, size_t length, int *eof,
+ uint8_t *buf, size_t length, uint32_t *data_flags,
  nghttp2_data_source *source, void *user_data)
 {
   auto req = (Request*)nghttp2_session_get_stream_user_data
@@ -1683,7 +1683,7 @@ ssize_t file_read_callback
     return NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE;
   } else {
     if(r == 0) {
-      *eof = 1;
+      *data_flags |= NGHTTP2_DATA_FLAG_EOF;
     } else {
       req->data_offset += r;
     }

src/shrpx_http2_downstream_connection.cc

@@ -154,7 +154,7 @@ namespace {
 ssize_t http2_data_read_callback(nghttp2_session *session,
                                  int32_t stream_id,
                                  uint8_t *buf, size_t length,
-                                 int *eof,
+                                 uint32_t *data_flags,
                                  nghttp2_data_source *source,
                                  void *user_data)
 {
@@ -183,7 +183,7 @@ ssize_t http2_data_read_callback(nghttp2_session *session,
         if(!downstream->get_upgrade_request() ||
            (downstream->get_response_state() == Downstream::HEADER_COMPLETE &&
             !downstream->get_upgraded())) {
-          *eof = 1;
+          *data_flags |= NGHTTP2_DATA_FLAG_EOF;
         } else {
           return NGHTTP2_ERR_DEFERRED;
         }
@@ -204,7 +204,7 @@ ssize_t http2_data_read_callback(nghttp2_session *session,
         if(evbuffer_get_length(body) == 0) {
           // Check get_request_state() == MSG_COMPLETE just in case
           if(downstream->get_request_state() == Downstream::MSG_COMPLETE) {
-            *eof = 1;
+            *data_flags |= NGHTTP2_DATA_FLAG_EOF;
             break;
           }
           return NGHTTP2_ERR_DEFERRED;

src/shrpx_http2_upstream.cc

@@ -891,7 +891,7 @@ namespace {
 ssize_t downstream_data_read_callback(nghttp2_session *session,
                                       int32_t stream_id,
                                       uint8_t *buf, size_t length,
-                                      int *eof,
+                                      uint32_t *data_flags,
                                       nghttp2_data_source *source,
                                       void *user_data)
 {
@@ -910,7 +910,7 @@ ssize_t downstream_data_read_callback(nghttp2_session *session,
   if(nread == 0 &&
      downstream->get_response_state() == Downstream::MSG_COMPLETE) {
     if(!downstream->get_upgraded()) {
-      *eof = 1;
+      *data_flags |= NGHTTP2_DATA_FLAG_EOF;
     } else {
       // For tunneling, issue RST_STREAM to finish the stream.
       if(LOG_ENABLED(INFO)) {
@@ -923,14 +923,14 @@ ssize_t downstream_data_read_callback(nghttp2_session *session,
   }
   // Send WINDOW_UPDATE before buffer is empty to avoid delay because
   // of RTT.
-  if(*eof != 1 &&
+  if(((*data_flags) & NGHTTP2_DATA_FLAG_EOF) == 0 &&
      handler->get_outbuf_length() + evbuffer_get_length(body) <
      OUTBUF_MAX_THRES) {
     if(downstream->resume_read(SHRPX_NO_BUFFER) != 0) {
       return NGHTTP2_ERR_CALLBACK_FAILURE;
     }
   }
-  if(nread == 0 && *eof != 1) {
+  if(nread == 0 && ((*data_flags) & NGHTTP2_DATA_FLAG_EOF) == 0) {
     return NGHTTP2_ERR_DEFERRED;
   }
   return nread;

tests/nghttp2_session_test.c

@@ -232,7 +232,7 @@ static ssize_t select_padding_callback(nghttp2_session *session,
 
 static ssize_t fixed_length_data_source_read_callback
 (nghttp2_session *session, int32_t stream_id,
- uint8_t *buf, size_t len, int *eof,
+ uint8_t *buf, size_t len, uint32_t *data_flags,
  nghttp2_data_source *source, void *user_data)
 {
   my_user_data *ud = (my_user_data*)user_data;
@@ -244,14 +244,14 @@ static ssize_t fixed_length_data_source_read_callback
   }
   ud->data_source_length -= wlen;
   if(ud->data_source_length == 0) {
-    *eof = 1;
+    *data_flags |= NGHTTP2_DATA_FLAG_EOF;
   }
   return wlen;
 }
 
 static ssize_t temporal_failure_data_source_read_callback
 (nghttp2_session *session, int32_t stream_id,
- uint8_t *buf, size_t len, int *eof,
+ uint8_t *buf, size_t len, uint32_t *data_flags,
  nghttp2_data_source *source, void *user_data)
 {
   return NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE;
@@ -259,7 +259,7 @@ static ssize_t temporal_failure_data_source_read_callback
 
 static ssize_t fail_data_source_read_callback
 (nghttp2_session *session, int32_t stream_id,
- uint8_t *buf, size_t len, int *eof,
+ uint8_t *buf, size_t len, uint32_t *data_flags,
  nghttp2_data_source *source, void *user_data)
 {
   return NGHTTP2_ERR_CALLBACK_FAILURE;
@@ -332,7 +332,7 @@ static int on_begin_headers_callback(nghttp2_session *session,
 
 static ssize_t defer_data_source_read_callback
 (nghttp2_session *session, int32_t stream_id,
- uint8_t *buf, size_t len, int *eof,
+ uint8_t *buf, size_t len, uint32_t *data_flags,
  nghttp2_data_source *source, void *user_data)
 {
   return NGHTTP2_ERR_DEFERRED;