nghttp2_mem structure is introduced to hold custom memory allocator
functions and user supplied pointer. nghttp2_mem object can be passed
to nghttp2_session_client_new3(), nghttp2_session_server_new3(),
nghttp2_hd_deflate_new2() and nghttp2_hd_inflate_new2() to replace
standard malloc(), free(), calloc() and realloc(). nghttp2_mem
structure has user supplied pointer mem_user_data which can be used as
per session/object memory pool.
h2-14 now allows extensions to define new error codes. To allow
application callback to access such error codes, we uses uint32_t as
error_code type for structs and function parameters. Previously we
treated unknown error code as INTERNAL_ERROR, but this change removes
this and unknown error code is passed to application callback as is.
ALTSVC and BLOCKED frames are now extension frames. To add new
extension frame without modifying nghttp2_frame union, which causes so
name bump, we separated extension frames from core frames.
nghttp2_frame includes generic nghttp2_extension. The payload member
of nghttp2_extension will point to the structure of extension frame
payload. The frame types of extension frames are defined in
nghttp2_ext_frame_type.
Previously we use 2 separate buffer for each name and value. The
problem is we would waste buffer space for name because it is usually
small. Also tuning buffer size for each buffer separately is not
elegant and current HTTP server practice is that one buffer for 1
name/value pair. This commit unifies 2 buffers into 1.
Previously stream ID was assigned just before HEADERS or PUSH_PROMISE
was serialized and nghttp2_submit_{request, headers, push_promise} did
not return stream ID. The application has to check assigned stream ID
using before_frame_send_callback. Now it is apparent that priority is
meant to DATA transfer only. Also application can reorder the
requests if it wants. Therefore we can assign stream ID in
nghttp2_submit_* functions and return stream ID from them. With this
change, now application does not have to check stream ID using
before_frame_send_callback and its code will be simplified.
The library interface supports compressed DATA. The library does not
deflate nor inflate data payload. When sending data, an application
has to compress data and set NGHTTP2_DATA_FLAG_COMPRESSED to
data_flags parameter in nghttp2_data_source_read_callback. On
receiving, flags parameter in nghttp2_on_data_chunk_recv_callback
includes NGHTTP2_FLAG_COMPRESSED. An application should check the
flags and inflate data as necessary. Since compression context is per
frame, when DATA is seen in nghttp2_on_frame_recv_callback, an
application should reset compression context.
* Use 1 Huffman code table for both request and response
* Remove complicated deflater side table size management
* Add encoding context update
* Fix memory leak in inflater
Now previous padding options are removed and instead we added
select_padding_callback to select padding length for each frame
by application. If this callback is not implemented by application,
no padding is added.
This change also fixes the broken session_detect_idle_stream()
if stream_id is our side.
Tatsuhiro Tsujikawa