nghttp2/lib/nghttp2_session.h

717 lines
25 KiB
C

/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2012 Tatsuhiro Tsujikawa
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef NGHTTP2_SESSION_H
#define NGHTTP2_SESSION_H
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif /* HAVE_CONFIG_H */
#include <nghttp2/nghttp2.h>
#include "nghttp2_pq.h"
#include "nghttp2_map.h"
#include "nghttp2_frame.h"
#include "nghttp2_hd.h"
#include "nghttp2_stream.h"
#include "nghttp2_outbound_item.h"
#include "nghttp2_int.h"
#include "nghttp2_buf.h"
/*
* Option flags.
*/
typedef enum {
NGHTTP2_OPTMASK_NO_AUTO_STREAM_WINDOW_UPDATE = 1 << 0,
NGHTTP2_OPTMASK_NO_AUTO_CONNECTION_WINDOW_UPDATE = 1 << 1
} nghttp2_optmask;
typedef enum {
NGHTTP2_OB_POP_ITEM,
NGHTTP2_OB_SEND_DATA
} nghttp2_outbound_state;
typedef struct {
nghttp2_outbound_item *item;
nghttp2_bufs framebufs;
nghttp2_outbound_state state;
} nghttp2_active_outbound_item;
/* Buffer length for inbound raw byte stream used in
nghttp2_session_recv(). */
#define NGHTTP2_INBOUND_BUFFER_LENGTH 16384
/* Internal state when receiving incoming frame */
typedef enum {
/* Receiving frame header */
NGHTTP2_IB_READ_HEAD,
NGHTTP2_IB_READ_NBYTE,
NGHTTP2_IB_READ_HEADER_BLOCK,
NGHTTP2_IB_IGN_HEADER_BLOCK,
NGHTTP2_IB_IGN_PAYLOAD,
NGHTTP2_IB_FRAME_SIZE_ERROR,
NGHTTP2_IB_READ_SETTINGS,
NGHTTP2_IB_READ_GOAWAY_DEBUG,
NGHTTP2_IB_READ_ALTSVC,
NGHTTP2_IB_EXPECT_CONTINUATION,
NGHTTP2_IB_IGN_CONTINUATION,
NGHTTP2_IB_READ_PAD_CONTINUATION,
NGHTTP2_IB_IGN_PAD_CONTINUATION,
NGHTTP2_IB_READ_PAD_DATA,
NGHTTP2_IB_READ_DATA,
NGHTTP2_IB_IGN_DATA
} nghttp2_inbound_state;
typedef struct {
nghttp2_frame frame;
/* The received SETTINGS entry. The protocol says that we only cares
about the defined settings ID. If unknown ID is received, it is
subject to connection error */
nghttp2_settings_entry iv[5];
/* buffer pointers to small buffer, raw_sbuf */
nghttp2_buf sbuf;
/* buffer pointers to large buffer, raw_lbuf */
nghttp2_buf lbuf;
/* Large buffer, malloced on demand */
uint8_t *raw_lbuf;
/* The number of entry filled in |iv| */
size_t niv;
/* How many bytes we still need to receive for current frame */
size_t payloadleft;
/* padding length for the current frame */
size_t padlen;
nghttp2_inbound_state state;
uint8_t raw_sbuf[8];
} nghttp2_inbound_frame;
typedef enum {
NGHTTP2_GOAWAY_NONE = 0,
/* Flag means GOAWAY frame is sent to the remote peer. */
NGHTTP2_GOAWAY_SEND = 0x1,
/* Flag means GOAWAY frame is received from the remote peer. */
NGHTTP2_GOAWAY_RECV = 0x2,
/* Flag means connection should be dropped after sending GOAWAY. */
NGHTTP2_GOAWAY_FAIL_ON_SEND = 0x4
} nghttp2_goaway_flag;
struct nghttp2_session {
nghttp2_map /* <nghttp2_stream*> */ streams;
nghttp2_map /* <nghttp2_stream_group*> */ stream_groups;
/* Queue for outbound frames other than stream-creating HEADERS */
nghttp2_pq /* <nghttp2_outbound_item*> */ ob_pq;
/* Queue for outbound stream-creating HEADERS frame */
nghttp2_pq /* <nghttp2_outbound_item*> */ ob_ss_pq;
nghttp2_active_outbound_item aob;
nghttp2_inbound_frame iframe;
nghttp2_hd_deflater hd_deflater;
nghttp2_hd_inflater hd_inflater;
nghttp2_session_callbacks callbacks;
/* Sequence number of outbound frame to maintain the order of
enqueue if priority is equal. */
int64_t next_seq;
void *user_data;
/* Points to the latest closed stream. NULL if there is no closed
stream. */
nghttp2_stream *closed_stream_head;
/* Points to the oldest closed stream. NULL if there is no closed
stream. */
nghttp2_stream *closed_stream_tail;
/* In-flight SETTINGS values. NULL does not necessarily mean there
is no in-flight SETTINGS. */
nghttp2_settings_entry *inflight_iv;
/* The number of entries in |inflight_iv|. -1 if there is no
in-flight SETTINGS. */
ssize_t inflight_niv;
/* The number of outgoing streams. This will be capped by
remote_settings[NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS]. */
size_t num_outgoing_streams;
/* The number of incoming streams. This will be capped by
local_settings[NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS]. */
size_t num_incoming_streams;
/* The number of closed streams still kept in |streams| hash. The
closed streams can be accessed through single linked list
|closed_stream_head|. The current implementation only keeps
incoming streams and session is initialized as server. */
size_t num_closed_streams;
/* The number of bytes allocated for nvbuf */
size_t nvbuflen;
/* Next Stream ID. Made unsigned int to detect >= (1 << 31). */
uint32_t next_stream_id;
/* The largest stream ID received so far */
int32_t last_recv_stream_id;
/* The largest stream ID which has been processed in some way. This
value will be used as last-stream-id when sending GOAWAY
frame. */
int32_t last_proc_stream_id;
/* Counter of unique ID of PING. Wraps when it exceeds
NGHTTP2_MAX_UNIQUE_ID */
uint32_t next_unique_id;
/* This is the value in GOAWAY frame received from remote endpoint. */
int32_t last_stream_id;
/* Current sender window size. This value is computed against the
current initial window size of remote endpoint. */
int32_t remote_window_size;
/* Keep track of the number of bytes received without
WINDOW_UPDATE. This could be negative after submitting negative
value to WINDOW_UPDATE. */
int32_t recv_window_size;
/* The amount of recv_window_size cut using submitting negative
value to WINDOW_UPDATE */
int32_t recv_reduction;
/* window size for local flow control. It is initially set to
NGHTTP2_INITIAL_CONNECTION_WINDOW_SIZE and could be
increased/decreased by submitting WINDOW_UPDATE. See
nghttp2_submit_window_update(). */
int32_t local_window_size;
/* Settings value received from the remote endpoint. We just use ID
as index. The index = 0 is unused. */
uint32_t remote_settings[NGHTTP2_SETTINGS_MAX+1];
/* Settings value of the local endpoint. */
uint32_t local_settings[NGHTTP2_SETTINGS_MAX+1];
/* Option flags. This is bitwise-OR of 0 or more of nghttp2_optmask. */
uint32_t opt_flags;
/* Unacked local SETTINGS_MAX_CONCURRENT_STREAMS value. We use this
to refuse the incoming stream if it exceeds this value. */
uint32_t pending_local_max_concurrent_stream;
/* Nonzero if the session is server side. */
uint8_t server;
/* Flags indicating GOAWAY is sent and/or recieved. The flags are
composed by bitwise OR-ing nghttp2_goaway_flag. */
uint8_t goaway_flags;
};
/* Struct used when updating initial window size of each active
stream. */
typedef struct {
nghttp2_session *session;
int32_t new_window_size, old_window_size;
} nghttp2_update_window_size_arg;
/* TODO stream timeout etc */
/*
* Returns nonzero value if |stream_id| is initiated by local
* endpoint.
*/
int nghttp2_session_is_my_stream_id(nghttp2_session *session,
int32_t stream_id);
/*
* Adds frame |frame| to the outbound queue in |session|. The
* |frame_cat| must be either NGHTTP2_CTRL or NGHTTP2_DATA. If the
* |frame_cat| is NGHTTP2_CTRL, the |frame| must be a pointer to
* nghttp2_frame. If the |frame_cat| is NGHTTP2_DATA, it must be a
* pointer to nghttp2_private_data. |aux_data| is a pointer to the arbitrary
* data. Its interpretation is defined per the type of the frame. When
* this function succeeds, it takes ownership of |frame| and
* |aux_data|, so caller must not free them on success.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
*/
int nghttp2_session_add_frame(nghttp2_session *session,
nghttp2_frame_category frame_cat,
void *abs_frame, void *aux_data);
/*
* Adds RST_STREAM frame for the stream |stream_id| with the error
* code |error_code|. This is a convenient function built on top of
* nghttp2_session_add_frame() to add RST_STREAM easily.
*
* This function simply returns 0 without adding RST_STREAM frame if
* given stream is in NGHTTP2_STREAM_CLOSING state, because multiple
* RST_STREAM for a stream is redundant.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
*/
int nghttp2_session_add_rst_stream(nghttp2_session *session,
int32_t stream_id,
nghttp2_error_code error_code);
/*
* Adds PING frame. This is a convenient functin built on top of
* nghttp2_session_add_frame() to add PING easily.
*
* If the |opaque_data| is not NULL, it must point to 8 bytes memory
* region of data. The data pointed by |opaque_data| is copied. It can
* be NULL. In this case, 8 bytes NULL is used.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
*/
int nghttp2_session_add_ping(nghttp2_session *session, uint8_t flags,
uint8_t *opaque_data);
/*
* Adds GOAWAY frame with the last-stream-ID |last_stream_id| and the
* error code |error_code|. This is a convenient function built on top
* of nghttp2_session_add_frame() to add GOAWAY easily.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
* NGHTTP2_ERR_INVALID_ARGUMENT
* The |opaque_data_len| is too large.
*/
int nghttp2_session_add_goaway(nghttp2_session *session,
int32_t last_stream_id,
nghttp2_error_code error_code,
const uint8_t *opaque_data,
size_t opaque_data_len);
/*
* Adds WINDOW_UPDATE frame with stream ID |stream_id| and
* window-size-increment |window_size_increment|. This is a convenient
* function built on top of nghttp2_session_add_frame() to add
* WINDOW_UPDATE easily.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
*/
int nghttp2_session_add_window_update(nghttp2_session *session, uint8_t flags,
int32_t stream_id,
int32_t window_size_increment);
/*
* Adds SETTINGS frame.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
*/
int nghttp2_session_add_settings(nghttp2_session *session, uint8_t flags,
const nghttp2_settings_entry *iv, size_t niv);
/*
* Creates new stream in |session| with stream ID |stream_id|,
* priority |pri_spec| and flags |flags|. The |flags| is bitwise OR
* of nghttp2_stream_flag. Since this function is called when initial
* HEADERS is sent or received, these flags are taken from it. The
* state of stream is set to |initial_state|. The |stream_user_data|
* is a pointer to the arbitrary user supplied data to be associated
* to this stream.
*
* This function returns a pointer to created new stream object, or
* NULL.
*/
nghttp2_stream* nghttp2_session_open_stream(nghttp2_session *session,
int32_t stream_id,
uint8_t flags,
nghttp2_priority_spec *pri_spec,
nghttp2_stream_state initial_state,
void *stream_user_data);
/*
* Closes stream whose stream ID is |stream_id|. The reason of closure
* is indicated by the |error_code|. When closing the stream,
* on_stream_close_callback will be called.
*
* If the session is initialized as server and |stream| is incoming
* stream, stream is just marked closed and this function calls
* nghttp2_session_keep_closed_stream() with |stream|. Otherwise,
* |stream| will be deleted from memory.
*
* This function returns 0 if it succeeds, or one the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
* NGHTTP2_ERR_INVALID_ARGUMENT
* The specified stream does not exist.
* NGHTTP2_ERR_CALLBACK_FAILURE
* The callback function failed.
*/
int nghttp2_session_close_stream(nghttp2_session *session, int32_t stream_id,
nghttp2_error_code error_code);
/*
* Deletes |stream| from memory. After this function returns, stream
* cannot be accessed.
*
*/
void nghttp2_session_destroy_stream(nghttp2_session *session,
nghttp2_stream *stream);
/*
* Tries to keep incoming closed stream |stream|. Due to the
* limitation of maximum number of streams in memory, |stream| is not
* closed and just deleted from memory (see
* nghttp2_session_destroy_stream).
*/
void nghttp2_session_keep_closed_stream(nghttp2_session *session,
nghttp2_stream *stream);
/*
* Deletes closed stream to ensure that number of incoming streams
* including active and closed is in the maximum number of allowed
* stream. If |offset| is nonzero, it is decreased from the maximum
* number of allowed stream when comparing number of active and closed
* stream and the maximum number.
*/
void nghttp2_session_adjust_closed_stream(nghttp2_session *session,
ssize_t offset);
/*
* If further receptions and transmissions over the stream |stream_id|
* are disallowed, close the stream with error code NGHTTP2_NO_ERROR.
*
* This function returns 0 if it
* succeeds, or one of the following negative error codes:
*
* NGHTTP2_ERR_INVALID_ARGUMENT
* The specified stream does not exist.
*/
int nghttp2_session_close_stream_if_shut_rdwr(nghttp2_session *session,
nghttp2_stream *stream);
int nghttp2_session_end_request_headers_received(nghttp2_session *session,
nghttp2_frame *frame,
nghttp2_stream *stream);
int nghttp2_session_end_response_headers_received(nghttp2_session *session,
nghttp2_frame *frame,
nghttp2_stream *stream);
int nghttp2_session_end_headers_received(nghttp2_session *session,
nghttp2_frame *frame,
nghttp2_stream *stream);
int nghttp2_session_on_request_headers_received(nghttp2_session *session,
nghttp2_frame *frame);
int nghttp2_session_on_response_headers_received(nghttp2_session *session,
nghttp2_frame *frame,
nghttp2_stream *stream);
int nghttp2_session_on_push_response_headers_received(nghttp2_session *session,
nghttp2_frame *frame,
nghttp2_stream *stream);
/*
* Called when HEADERS is received, assuming |frame| is properly
* initialized. This function does first validate received frame and
* then open stream and call callback functions.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
* NGHTTP2_ERR_IGN_HEADER_BLOCK
* Frame was rejected and header block must be decoded but
* result must be ignored.
* NGHTTP2_ERR_CALLBACK_FAILURE
* The read_callback failed
*/
int nghttp2_session_on_headers_received(nghttp2_session *session,
nghttp2_frame *frame,
nghttp2_stream *stream);
/*
* Called when PRIORITY is received, assuming |frame| is properly
* initialized.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
* NGHTTP2_ERR_CALLBACK_FAILURE
* The read_callback failed
*/
int nghttp2_session_on_priority_received(nghttp2_session *session,
nghttp2_frame *frame);
/*
* Called when RST_STREAM is received, assuming |frame| is properly
* initialized.
*
* This function returns 0 if it succeeds, or one the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
* NGHTTP2_ERR_CALLBACK_FAILURE
* The read_callback failed
*/
int nghttp2_session_on_rst_stream_received(nghttp2_session *session,
nghttp2_frame *frame);
/*
* Called when SETTINGS is received, assuming |frame| is properly
* initialized. If |noack| is non-zero, SETTINGS with ACK will not be
* submitted. If |frame| has NGHTTP2_FLAG_ACK flag set, no SETTINGS
* with ACK will not be submitted regardless of |noack|.
*
* This function returns 0 if it succeeds, or one the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
* NGHTTP2_ERR_CALLBACK_FAILURE
* The read_callback failed
*/
int nghttp2_session_on_settings_received(nghttp2_session *session,
nghttp2_frame *frame,
int noack);
/*
* Called when PUSH_PROMISE is received, assuming |frame| is properly
* initialized.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
* NGHTTP2_ERR_IGN_HEADER_BLOCK
* Frame was rejected and header block must be decoded but
* result must be ignored.
* NGHTTP2_ERR_CALLBACK_FAILURE
* The read_callback failed
*/
int nghttp2_session_on_push_promise_received(nghttp2_session *session,
nghttp2_frame *frame);
/*
* Called when PING is received, assuming |frame| is properly
* initialized.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
* NGHTTP2_ERR_CALLBACK_FAILURE
* The callback function failed.
*/
int nghttp2_session_on_ping_received(nghttp2_session *session,
nghttp2_frame *frame);
/*
* Called when GOAWAY is received, assuming |frame| is properly
* initialized.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
* NGHTTP2_ERR_CALLBACK_FAILURE
* The callback function failed.
*/
int nghttp2_session_on_goaway_received(nghttp2_session *session,
nghttp2_frame *frame);
/*
* Called when WINDOW_UPDATE is recieved, assuming |frame| is properly
* initialized.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
* NGHTTP2_ERR_CALLBACK_FAILURE
* The callback function failed.
*/
int nghttp2_session_on_window_update_received(nghttp2_session *session,
nghttp2_frame *frame);
/*
* Called when ALTSVC is received, assuming |frame| is properly
* initialized.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
* NGHTTP2_ERR_CALLBACK_FAILURE
* The callback function failed.
*/
int nghttp2_session_on_altsvc_received(nghttp2_session *session,
nghttp2_frame *frame);
/*
* Called when DATA is received, assuming |frame| is properly
* initialized.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
* NGHTTP2_ERR_CALLBACK_FAILURE
* The callback function failed.
*/
int nghttp2_session_on_data_received(nghttp2_session *session,
nghttp2_frame *frame);
/*
* Returns nghttp2_stream* object whose stream ID is |stream_id|. It
* could be NULL if such stream does not exist. This function returns
* NULL if stream is marked as closed.
*/
nghttp2_stream* nghttp2_session_get_stream(nghttp2_session *session,
int32_t stream_id);
/*
* This function behaves like nghttp2_session_get_stream(), but it
* returns stream object even if it is marked as closed.
*/
nghttp2_stream* nghttp2_session_get_stream_raw(nghttp2_session *session,
int32_t stream_id);
/*
* Returns nghttp2_stream_group* object whose priority group ID is
* |pri_group_id|. It could be NULL if such priority group does not
* exist.
*/
nghttp2_stream_group* nghttp2_session_get_stream_group
(nghttp2_session *session, int32_t pri_group_id);
/*
* Packs DATA frame |frame| in wire frame format and stores it in
* |*buf_ptr|. The capacity of |*buf_ptr| is |*buflen_ptr|
* length. This function expands |*buf_ptr| as necessary to store
* given |frame|. It packs header in first 8 bytes starting
* |*bufoff_ptr| offset. The |*bufoff_ptr| is calculated based on
* usage of padding. Remaining bytes are the DATA apyload and are
* filled using |frame->data_prd|. The length of payload is at most
* |datamax| bytes.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_DEFERRED
* The DATA frame is postponed.
* NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE
* The read_callback failed (stream error).
* NGHTTP2_ERR_NOMEM
* Out of memory.
* NGHTTP2_ERR_CALLBACK_FAILURE
* The read_callback failed (session error).
*/
int nghttp2_session_pack_data(nghttp2_session *session,
nghttp2_bufs *bufs,
size_t datamax,
nghttp2_private_data *frame);
/*
* Returns top of outbound frame queue. This function returns NULL if
* queue is empty.
*/
nghttp2_outbound_item* nghttp2_session_get_ob_pq_top(nghttp2_session *session);
/*
* Pops and returns next item to send. If there is no such item,
* returns NULL. This function takes into account max concurrent
* streams. That means if session->ob_pq is empty but
* session->ob_ss_pq has item and max concurrent streams is reached,
* then this function returns NULL.
*/
nghttp2_outbound_item* nghttp2_session_pop_next_ob_item
(nghttp2_session *session);
/*
* Returns next item to send. If there is no such item, this function
* returns NULL. This function takes into account max concurrent
* streams. That means if session->ob_pq is empty but
* session->ob_ss_pq has item and max concurrent streams is reached,
* then this function returns NULL.
*/
nghttp2_outbound_item* nghttp2_session_get_next_ob_item
(nghttp2_session *session);
/*
* Updates local settings with the |iv|. The number of elements in the
* array pointed by the |iv| is given by the |niv|. This function
* assumes that the all settings_id member in |iv| are in range 1 to
* NGHTTP2_SETTINGS_MAX, inclusive.
*
* While updating individual stream's local window size, if the window
* size becomes strictly larger than NGHTTP2_MAX_WINDOW_SIZE,
* RST_STREAM is issued against such a stream.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
*/
int nghttp2_session_update_local_settings(nghttp2_session *session,
nghttp2_settings_entry *iv,
size_t niv);
/*
* Re-prioritize |stream|. The new priority specification is
* |pri_spec|.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
*/
int nghttp2_session_reprioritize_stream
(nghttp2_session *session, nghttp2_stream *stream,
const nghttp2_priority_spec *pri_spec);
/*
* Creates new priority group using given values.
*
* This function returns created priority group if it succeeds, or
* NULL.
*/
nghttp2_stream_group* nghttp2_session_open_stream_group
(nghttp2_session *session, int32_t pri_group_id, int32_t weight);
/*
* Closes priority group if it does not include any streams.
*/
void nghttp2_session_close_stream_group_if_empty
(nghttp2_session *session, nghttp2_stream_group *stream_group);
#endif /* NGHTTP2_SESSION_H */