Update doc

_sources/apiref.txt

@@ -709,7 +709,9 @@ Types (structs, unions and typedefs)
     not used and always 0. It must return the number of bytes sent if
     it succeeds.  If it cannot send any single byte without blocking,
     it must return :macro:`NGHTTP2_ERR_WOULDBLOCK`. For other errors, it
-    must return :macro:`NGHTTP2_ERR_CALLBACK_FAILURE`.
+    must return :macro:`NGHTTP2_ERR_CALLBACK_FAILURE`. The *user_data*
+    pointer is the third argument passed in to the call to
+    `nghttp2_session_client_new()` or `nghttp2_session_server_new()`.
 
 .. type:: typedef ssize_t (*nghttp2_recv_callback) (nghttp2_session *session, uint8_t *buf, size_t length, int flags, void *user_data)
 
@@ -723,13 +725,17 @@ Types (structs, unions and typedefs)
     it gets EOF before it reads any single byte, it must return
     :macro:`NGHTTP2_ERR_EOF`. For other errors, it must return
     :macro:`NGHTTP2_ERR_CALLBACK_FAILURE`. Returning 0 is treated as
-    :macro:`NGHTTP2_ERR_WOULDBLOCK`.
+    :macro:`NGHTTP2_ERR_WOULDBLOCK`. The *user_data* pointer is the
+    third argument passed in to the call to
+    `nghttp2_session_client_new()` or `nghttp2_session_server_new()`.
 
 .. type:: typedef int (*nghttp2_on_frame_recv_callback) (nghttp2_session *session, const nghttp2_frame *frame, void *user_data)
 
     
     Callback function invoked by `nghttp2_session_recv()` when a
-    non-DATA frame is received.
+    non-DATA frame is received. The *user_data* pointer is the third
+    argument passed in to the call to `nghttp2_session_client_new()` or
+    `nghttp2_session_server_new()`.
     
     The implementation of this function must return 0 if it
     succeeds. If nonzero is returned, it is treated as fatal error and
@@ -743,7 +749,9 @@ Types (structs, unions and typedefs)
     invalid non-DATA frame is received. The *error_code* is one of the
     :macro:`nghttp2_error_code` and indicates the error. When this
     callback function is invoked, the library automatically submits
-    either RST_STREAM or GOAWAY frame.
+    either RST_STREAM or GOAWAY frame. The *user_data* pointer is the
+    third argument passed in to the call to
+    `nghttp2_session_client_new()` or `nghttp2_session_server_new()`.
     
     The implementation of this function must return 0 if it
     succeeds. If nonzero is returned, it is treated as fatal error and
@@ -759,7 +767,9 @@ Types (structs, unions and typedefs)
     contained. ``(flags & NGHTTP2_FLAG_END_STREAM) != 0`` does not
     necessarily mean this chunk of data is the last one in the
     stream. You should use :type:`nghttp2_on_data_recv_callback` to
-    know all data frames are received.
+    know all data frames are received. The *user_data* pointer is the
+    third argument passed in to the call to
+    `nghttp2_session_client_new()` or `nghttp2_session_server_new()`.
     
     The implementation of this function must return 0 if it
     succeeds. If nonzero is returned, it is treated as fatal error and
@@ -771,7 +781,9 @@ Types (structs, unions and typedefs)
     
     Callback function invoked when DATA frame is received. The actual
     data it contains are received by
-    :type:`nghttp2_on_data_chunk_recv_callback`.
+    :type:`nghttp2_on_data_chunk_recv_callback`. The *user_data*
+    pointer is the third argument passed in to the call to
+    `nghttp2_session_client_new()` or `nghttp2_session_server_new()`.
     
     The implementation of this function must return 0 if it
     succeeds. If nonzero is returned, it is treated as fatal error and
@@ -785,7 +797,9 @@ Types (structs, unions and typedefs)
     sent. This may be useful, for example, to know the stream ID of
     HEADERS and PUSH_PROMISE frame (see also
     `nghttp2_session_get_stream_user_data()`), which is not assigned
-    when it was queued.
+    when it was queued. The *user_data* pointer is the third argument
+    passed in to the call to `nghttp2_session_client_new()` or
+    `nghttp2_session_server_new()`.
     
     The implementation of this function must return 0 if it
     succeeds. If nonzero is returned, it is treated as fatal error and
@@ -796,6 +810,9 @@ Types (structs, unions and typedefs)
 
     
     Callback function invoked after the non-DATA frame *frame* is sent.
+    The *user_data* pointer is the third argument passed in to the call
+    to `nghttp2_session_client_new()` or
+    `nghttp2_session_server_new()`.
     
     The implementation of this function must return 0 if it
     succeeds. If nonzero is returned, it is treated as fatal error and
@@ -808,7 +825,9 @@ Types (structs, unions and typedefs)
     Callback function invoked after the non-DATA frame *frame* is not
     sent because of the error. The error is indicated by the
     *lib_error_code*, which is one of the values defined in
-    :type:`nghttp2_error`.
+    :type:`nghttp2_error`. The *user_data* pointer is the third
+    argument passed in to the call to `nghttp2_session_client_new()` or
+    `nghttp2_session_server_new()`.
     
     The implementation of this function must return 0 if it
     succeeds. If nonzero is returned, it is treated as fatal error and
@@ -818,7 +837,9 @@ Types (structs, unions and typedefs)
 .. type:: typedef int (*nghttp2_on_data_send_callback) (nghttp2_session *session, uint16_t length, uint8_t flags, int32_t stream_id, void *user_data)
 
     
-    Callback function invoked after DATA frame is sent.
+    Callback function invoked after DATA frame is sent. The *user_data*
+    pointer is the third argument passed in to the call to
+    `nghttp2_session_client_new()` or `nghttp2_session_server_new()`.
     
     The implementation of this function must return 0 if it
     succeeds. If nonzero is returned, it is treated as fatal error and
@@ -829,10 +850,12 @@ Types (structs, unions and typedefs)
 
     
     Callback function invoked when the stream *stream_id* is
-    closed. The reason of closure is indicated by the
-    *error_code*. The stream_user_data, which was specified in
-    `nghttp2_submit_request()` or `nghttp2_submit_headers()`, is
-    still available in this function.
+    closed. The reason of closure is indicated by the *error_code*. The
+    stream_user_data, which was specified in `nghttp2_submit_request()`
+    or `nghttp2_submit_headers()`, is still available in this
+    function. The *user_data* pointer is the third argument passed in
+    to the call to `nghttp2_session_client_new()` or
+    `nghttp2_session_server_new()`.
     
     The implementation of this function must return 0 if it
     succeeds. If nonzero is returned, it is treated as fatal error and
@@ -845,7 +868,9 @@ Types (structs, unions and typedefs)
     Callback function invoked when the request from the remote peer is
     received.  In other words, the frame with END_STREAM flag set is
     received.  In HTTP, this means HTTP request, including request
-    body, is fully received.
+    body, is fully received. The *user_data* pointer is the third
+    argument passed in to the call to `nghttp2_session_client_new()` or
+    `nghttp2_session_server_new()`.
     
     The implementation of this function must return 0 if it
     succeeds. If nonzero is returned, it is treated as fatal error and
@@ -863,8 +888,10 @@ Types (structs, unions and typedefs)
     words, the *head* is the first 8 bytes of the received frame.  The
     *payload* is the pointer to the data portion of the received frame.
     The *payloadlen* is the length of the *payload*. This is the data
-    after the length field. The *lib_error_code* is one of the error code
-    defined in :macro:`nghttp2_error` and indicates the error.
+    after the length field. The *lib_error_code* is one of the error
+    code defined in :macro:`nghttp2_error` and indicates the error. The
+    *user_data* pointer is the third argument passed in to the call to
+    `nghttp2_session_client_new()` or `nghttp2_session_server_new()`.
     
     The implementation of this function must return 0 if it
     succeeds. If nonzero is returned, it is treated as fatal error and
@@ -880,7 +907,10 @@ Types (structs, unions and typedefs)
     spec, the *headlen* is always 8. In other words, the *head* is the
     first 8 bytes of the received frame.  The *payload* is the pointer
     to the data portion of the received frame.  The *payloadlen* is the
-    length of the *payload*. This is the data after the length field.
+    length of the *payload*. This is the data after the length
+    field. The *user_data* pointer is the third argument passed in to
+    the call to `nghttp2_session_client_new()` or
+    `nghttp2_session_server_new()`.
     
     The implementation of this function must return 0 if it
     succeeds. If nonzero is returned, it is treated as fatal error and
@@ -1278,7 +1308,7 @@ Functions
     to hold serialized data. The required space for the *niv* entries
     are ``8*niv`` bytes. This function is used mainly for creating
     SETTINGS payload to be sent with ``HTTP2-Settings`` header field in
-    HTTP Upgrade request. The data written in *buf* is not still
+    HTTP Upgrade request. The data written in *buf* is NOT
     base64url encoded and the application is responsible for encoding.
     
     This function returns the number of bytes written in *buf*, or one