nghttp2/lib/nghttp2_stream.h

444 lines
15 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_STREAM_H
#define NGHTTP2_STREAM_H
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /* HAVE_CONFIG_H */
#include <nghttp2/nghttp2.h>
#include "nghttp2_outbound_item.h"
#include "nghttp2_map.h"
#include "nghttp2_pq.h"
#include "nghttp2_int.h"
/*
* Maximum number of streams in one dependency tree.
*/
#define NGHTTP2_MAX_DEP_TREE_LENGTH 100
/*
* If local peer is stream initiator:
* NGHTTP2_STREAM_OPENING : upon sending request HEADERS
* NGHTTP2_STREAM_OPENED : upon receiving response HEADERS
* NGHTTP2_STREAM_CLOSING : upon queuing RST_STREAM
*
* If remote peer is stream initiator:
* NGHTTP2_STREAM_OPENING : upon receiving request HEADERS
* NGHTTP2_STREAM_OPENED : upon sending response HEADERS
* NGHTTP2_STREAM_CLOSING : upon queuing RST_STREAM
*/
typedef enum {
/* Initial state */
NGHTTP2_STREAM_INITIAL,
/* For stream initiator: request HEADERS has been sent, but response
HEADERS has not been received yet. For receiver: request HEADERS
has been received, but it does not send response HEADERS yet. */
NGHTTP2_STREAM_OPENING,
/* For stream initiator: response HEADERS is received. For receiver:
response HEADERS is sent. */
NGHTTP2_STREAM_OPENED,
/* RST_STREAM is received, but somehow we need to keep stream in
memory. */
NGHTTP2_STREAM_CLOSING,
/* PUSH_PROMISE is received or sent */
NGHTTP2_STREAM_RESERVED,
/* Stream is created in this state if it is used as anchor in
dependency tree. */
NGHTTP2_STREAM_IDLE
} nghttp2_stream_state;
typedef enum {
NGHTTP2_SHUT_NONE = 0,
/* Indicates further receptions will be disallowed. */
NGHTTP2_SHUT_RD = 0x01,
/* Indicates further transmissions will be disallowed. */
NGHTTP2_SHUT_WR = 0x02,
/* Indicates both further receptions and transmissions will be
disallowed. */
NGHTTP2_SHUT_RDWR = NGHTTP2_SHUT_RD | NGHTTP2_SHUT_WR
} nghttp2_shut_flag;
typedef enum {
NGHTTP2_STREAM_FLAG_NONE = 0,
/* Indicates that this stream is pushed stream */
NGHTTP2_STREAM_FLAG_PUSH = 0x01,
/* Indicates that this stream was closed */
NGHTTP2_STREAM_FLAG_CLOSED = 0x02,
/* Indicates the item is deferred due to flow control. */
NGHTTP2_STREAM_FLAG_DEFERRED_FLOW_CONTROL = 0x04,
/* Indicates the item is deferred by user callback */
NGHTTP2_STREAM_FLAG_DEFERRED_USER = 0x08,
/* bitwise OR of NGHTTP2_STREAM_FLAG_DEFERRED_FLOW_CONTROL and
NGHTTP2_STREAM_FLAG_DEFERRED_USER. */
NGHTTP2_STREAM_FLAG_DEFERRED_ALL = 0x0c
} nghttp2_stream_flag;
typedef enum {
NGHTTP2_STREAM_DPRI_NONE = 0,
NGHTTP2_STREAM_DPRI_NO_DATA = 0x01,
NGHTTP2_STREAM_DPRI_TOP = 0x02,
NGHTTP2_STREAM_DPRI_REST = 0x04
} nghttp2_stream_dpri;
struct nghttp2_stream_roots;
typedef struct nghttp2_stream_roots nghttp2_stream_roots;
struct nghttp2_stream;
typedef struct nghttp2_stream nghttp2_stream;
struct nghttp2_stream {
/* Intrusive Map */
nghttp2_map_entry map_entry;
/* pointers to form dependency tree. If multiple streams depend on
a stream, only one stream (left most) has non-NULL dep_prev which
points to the stream it depends on. The remaining streams are
linked using sib_prev and sib_next. The stream which has
non-NULL dep_prev always NULL sib_prev. The right most stream
has NULL sib_next. If this stream is a root of dependency tree,
dep_prev and sib_prev are NULL. */
nghttp2_stream *dep_prev, *dep_next;
nghttp2_stream *sib_prev, *sib_next;
/* pointers to track dependency tree root streams. This is
doubly-linked list and first element is pointed by
roots->head. */
nghttp2_stream *root_prev, *root_next;
/* When stream is kept after closure, it may be kept in doubly
linked list pointed by nghttp2_session closed_stream_head.
closed_next points to the next stream object if it is the element
of the list. */
nghttp2_stream *closed_prev, *closed_next;
/* pointer to roots, which tracks dependency tree roots */
nghttp2_stream_roots *roots;
/* The arbitrary data provided by user for this stream. */
void *stream_user_data;
/* Item to send */
nghttp2_outbound_item *data_item;
/* stream ID */
int32_t stream_id;
/* categorized priority of this stream. Only stream bearing
NGHTTP2_STREAM_DPRI_TOP can send item. */
nghttp2_stream_dpri dpri;
/* the number of streams in subtree */
size_t num_substreams;
/* Current remote 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 number of bytes consumed by the application and now is
subject to WINDOW_UPDATE. This is only used when auto
WINDOW_UPDATE is turned off. */
int32_t consumed_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_WINDOW_SIZE and could be increased/decreased by
submitting WINDOW_UPDATE. See nghttp2_submit_window_update(). */
int32_t local_window_size;
/* weight of this stream */
int32_t weight;
/* effective weight of this stream in belonging dependency tree */
int32_t effective_weight;
/* sum of weight (not effective_weight) of direct descendants */
int32_t sum_dep_weight;
/* sum of weight of direct descendants which have at least one
descendant with dpri == NGHTTP2_STREAM_DPRI_TOP. We use this
value to calculate effective weight. */
int32_t sum_norest_weight;
/* sum of weight of direct descendants whose dpri value is
NGHTTP2_STREAM_DPRI_TOP */
int32_t sum_top_weight;
nghttp2_stream_state state;
/* This is bitwise-OR of 0 or more of nghttp2_stream_flag. */
uint8_t flags;
/* Bitwise OR of zero or more nghttp2_shut_flag values */
uint8_t shut_flags;
};
void nghttp2_stream_init(nghttp2_stream *stream, int32_t stream_id,
uint8_t flags, nghttp2_stream_state initial_state,
int32_t weight, nghttp2_stream_roots *roots,
int32_t remote_initial_window_size,
int32_t local_initial_window_size,
void *stream_user_data);
void nghttp2_stream_free(nghttp2_stream *stream);
/*
* Disallow either further receptions or transmissions, or both.
* |flag| is bitwise OR of one or more of nghttp2_shut_flag.
*/
void nghttp2_stream_shutdown(nghttp2_stream *stream, nghttp2_shut_flag flag);
/*
* Defer |stream->data_item|. We won't call this function in the
* situation where |stream->data_item| == NULL. If |flags| is bitwise
* OR of zero or more of NGHTTP2_STREAM_FLAG_DEFERRED_USER and
* NGHTTP2_STREAM_FLAG_DEFERRED_FLOW_CONTROL. The |flags| indicates
* the reason of this action.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
*/
int nghttp2_stream_defer_data(nghttp2_stream *stream, uint8_t flags,
nghttp2_session *session);
/*
* Put back deferred data in this stream to active state. The |flags|
* are one or more of bitwise OR of the following values:
* NGHTTP2_STREAM_FLAG_DEFERRED_USER and
* NGHTTP2_STREAM_FLAG_DEFERRED_FLOW_CONTROL and given masks are
* cleared if they are set. So even if this function is called, if
* one of flag is still set, data does not become active.
*/
int nghttp2_stream_resume_deferred_data(nghttp2_stream *stream, uint8_t flags,
nghttp2_session *session);
/*
* Returns nonzero if data item is deferred by whatever reason.
*/
int nghttp2_stream_check_deferred_data(nghttp2_stream *stream);
/*
* Returns nonzero if data item is deferred by flow control.
*/
int nghttp2_stream_check_deferred_by_flow_control(nghttp2_stream *stream);
/*
* Updates the remote window size with the new value
* |new_initial_window_size|. The |old_initial_window_size| is used to
* calculate the current window size.
*
* This function returns 0 if it succeeds or -1. The failure is due to
* overflow.
*/
int nghttp2_stream_update_remote_initial_window_size(
nghttp2_stream *stream, int32_t new_initial_window_size,
int32_t old_initial_window_size);
/*
* Updates the local window size with the new value
* |new_initial_window_size|. The |old_initial_window_size| is used to
* calculate the current window size.
*
* This function returns 0 if it succeeds or -1. The failure is due to
* overflow.
*/
int nghttp2_stream_update_local_initial_window_size(
nghttp2_stream *stream, int32_t new_initial_window_size,
int32_t old_initial_window_size);
/*
* Call this function if promised stream |stream| is replied with
* HEADERS. This function makes the state of the |stream| to
* NGHTTP2_STREAM_OPENED.
*/
void nghttp2_stream_promise_fulfilled(nghttp2_stream *stream);
/*
* Returns the stream positioned in root of the dependency tree the
* |stream| belongs to.
*/
nghttp2_stream *nghttp2_stream_get_dep_root(nghttp2_stream *stream);
/*
* Returns nonzero if |target| is found in subtree of |stream|.
*/
int nghttp2_stream_dep_subtree_find(nghttp2_stream *stream,
nghttp2_stream *target);
/*
* Computes distributed weight of a stream of the |weight| under the
* |stream| if |stream| is removed from a dependency tree. The result
* is computed using stream->weight rather than
* stream->effective_weight.
*/
int32_t nghttp2_stream_dep_distributed_weight(nghttp2_stream *stream,
int32_t weight);
/*
* Computes effective weight of a stream of the |weight| under the
* |stream|. The result is computed using stream->effective_weight
* rather than stream->weight. This function is used to determine
* weight in dependency tree.
*/
int32_t nghttp2_stream_dep_distributed_effective_weight(nghttp2_stream *stream,
int32_t weight);
/*
* Makes the |stream| depend on the |dep_stream|. This dependency is
* exclusive. All existing direct descendants of |dep_stream| become
* the descendants of the |stream|. This function assumes
* |stream->data| is NULL and no dpri members are changed in this
* dependency tree.
*/
void nghttp2_stream_dep_insert(nghttp2_stream *dep_stream,
nghttp2_stream *stream);
/*
* Makes the |stream| depend on the |dep_stream|. This dependency is
* not exclusive. This function assumes |stream->data| is NULL and no
* dpri members are changed in this dependency tree.
*/
void nghttp2_stream_dep_add(nghttp2_stream *dep_stream, nghttp2_stream *stream);
/*
* Removes the |stream| from the current dependency tree. This
* function assumes |stream->data| is NULL.
*/
void nghttp2_stream_dep_remove(nghttp2_stream *stream);
/*
* Attaches |data_item| to |stream|. Updates dpri members in this
* dependency tree.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
*/
int nghttp2_stream_attach_data(nghttp2_stream *stream,
nghttp2_outbound_item *data_item,
nghttp2_session *session);
/*
* Detaches |stream->data_item|. Updates dpri members in this
* dependency tree. This function does not free |stream->data_item|.
* The caller must free it.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
*/
int nghttp2_stream_detach_data(nghttp2_stream *stream,
nghttp2_session *session);
/*
* Makes the |stream| depend on the |dep_stream|. This dependency is
* exclusive. Updates dpri members in this dependency tree.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
*/
int nghttp2_stream_dep_insert_subtree(nghttp2_stream *dep_stream,
nghttp2_stream *stream,
nghttp2_session *session);
/*
* Makes the |stream| depend on the |dep_stream|. This dependency is
* not exclusive. Updates dpri members in this dependency tree.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
*/
int nghttp2_stream_dep_add_subtree(nghttp2_stream *dep_stream,
nghttp2_stream *stream,
nghttp2_session *session);
/*
* Removes subtree whose root stream is |stream|. Removing subtree
* does not change dpri values. The effective_weight of streams in
* removed subtree is not updated.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
*/
void nghttp2_stream_dep_remove_subtree(nghttp2_stream *stream);
/*
* Makes the |stream| as root. Updates dpri members in this
* dependency tree.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
*/
int nghttp2_stream_dep_make_root(nghttp2_stream *stream,
nghttp2_session *session);
/*
* Makes the |stream| as root and all existing root streams become
* direct children of |stream|.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
*/
int
nghttp2_stream_dep_all_your_stream_are_belong_to_us(nghttp2_stream *stream,
nghttp2_session *session);
/*
* Returns nonzero if |stream| is in any dependency tree.
*/
int nghttp2_stream_in_dep_tree(nghttp2_stream *stream);
struct nghttp2_stream_roots {
nghttp2_stream *head;
int32_t num_streams;
};
void nghttp2_stream_roots_init(nghttp2_stream_roots *roots);
void nghttp2_stream_roots_free(nghttp2_stream_roots *roots);
void nghttp2_stream_roots_add(nghttp2_stream_roots *roots,
nghttp2_stream *stream);
void nghttp2_stream_roots_remove(nghttp2_stream_roots *roots,
nghttp2_stream *stream);
void nghttp2_stream_roots_remove_all(nghttp2_stream_roots *roots);
#endif /* NGHTTP2_STREAM */