/*
* 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"
/*
* 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 and not opened
yet. */
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;
/* HTTP related flags to enforce HTTP semantics */
typedef enum {
NGHTTP2_HTTP_FLAG_NONE = 0,
/* header field seen so far */
NGHTTP2_HTTP_FLAG__AUTHORITY = 1,
NGHTTP2_HTTP_FLAG__PATH = 1 << 1,
NGHTTP2_HTTP_FLAG__METHOD = 1 << 2,
NGHTTP2_HTTP_FLAG__SCHEME = 1 << 3,
/* host is not pseudo header, but we require either host or
:authority */
NGHTTP2_HTTP_FLAG_HOST = 1 << 4,
NGHTTP2_HTTP_FLAG__STATUS = 1 << 5,
/* required header fields for HTTP request except for CONNECT
method. */
NGHTTP2_HTTP_FLAG_REQ_HEADERS = NGHTTP2_HTTP_FLAG__METHOD |
NGHTTP2_HTTP_FLAG__PATH |
NGHTTP2_HTTP_FLAG__SCHEME,
NGHTTP2_HTTP_FLAG_PSEUDO_HEADER_DISALLOWED = 1 << 6,
/* HTTP method flags */
NGHTTP2_HTTP_FLAG_METH_CONNECT = 1 << 7,
NGHTTP2_HTTP_FLAG_METH_HEAD = 1 << 8,
NGHTTP2_HTTP_FLAG_METH_OPTIONS = 1 << 9,
NGHTTP2_HTTP_FLAG_METH_UPGRADE_WORKAROUND = 1 << 10,
NGHTTP2_HTTP_FLAG_METH_ALL = NGHTTP2_HTTP_FLAG_METH_CONNECT |
NGHTTP2_HTTP_FLAG_METH_HEAD |
NGHTTP2_HTTP_FLAG_METH_OPTIONS |
NGHTTP2_HTTP_FLAG_METH_UPGRADE_WORKAROUND,
/* :path category */
/* path starts with "/" */
NGHTTP2_HTTP_FLAG_PATH_REGULAR = 1 << 11,
/* path "*" */
NGHTTP2_HTTP_FLAG_PATH_ASTERISK = 1 << 12,
/* scheme */
/* "http" or "https" scheme */
NGHTTP2_HTTP_FLAG_SCHEME_HTTP = 1 << 13,
/* set if final response is expected */
NGHTTP2_HTTP_FLAG_EXPECT_FINAL_RESPONSE = 1 << 14
} nghttp2_http_flag;
struct nghttp2_stream {
/* Intrusive Map */
nghttp2_map_entry map_entry;
/* Entry for dep_prev->obq */
nghttp2_pq_entry pq_entry;
/* Priority Queue storing direct descendant (nghttp2_stream). Only
streams which itself has some data to send, or has a descendant
which has some data to sent. */
nghttp2_pq obq;
/* Content-Length of request/response body. -1 if unknown. */
int64_t content_length;
/* Received body so far */
int64_t recv_content_length;
/* Base last_cycle for direct descendent streams. */
uint32_t descendant_last_cycle;
/* Next scheduled time to sent item */
uint32_t cycle;
/* Next seq used for direct descendant streams */
uint64_t descendant_next_seq;
/* Secondary key for prioritization to break a tie for cycle. This
value is monotonically increased for single parent stream. */
uint64_t seq;
/* 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;
/* 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;
/* The arbitrary data provided by user for this stream. */
void *stream_user_data;
/* Item to send */
nghttp2_outbound_item *item;
/* Last written length of frame payload */
size_t last_writelen;
/* stream ID */
int32_t stream_id;
/* 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;
/* This is unpaid penalty (offset) when calculating cycle. */
uint32_t pending_penalty;
/* sum of weight of direct descendants */
int32_t sum_dep_weight;
nghttp2_stream_state state;
/* status code from remote server */
int16_t status_code;
/* Bitwise OR of zero or more nghttp2_http_flag values */
uint16_t http_flags;
/* 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;
/* Nonzero if this stream has been queued to stream pointed by
dep_prev. We maintain the invariant that if a stream is queued,
then its ancestors, except for root, are also queued. This
invariant may break in fatal error condition. */
uint8_t queued;
/* This flag is used to reduce excessive queuing of WINDOW_UPDATE to
this stream. The nonzero does not necessarily mean WINDOW_UPDATE
is not queued. */
uint8_t window_update_queued;
};
void nghttp2_stream_init(nghttp2_stream *stream, int32_t stream_id,
uint8_t flags, nghttp2_stream_state initial_state,
int32_t weight, int32_t remote_initial_window_size,
int32_t local_initial_window_size,
void *stream_user_data, nghttp2_mem *mem);
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->item|. We won't call this function in the situation
* where |stream->item| == NULL. The |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_item(nghttp2_stream *stream, uint8_t flags);
/*
* 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.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory
*/
int nghttp2_stream_resume_deferred_item(nghttp2_stream *stream, uint8_t flags);
/*
* Returns nonzero if item is deferred by whatever reason.
*/
int nghttp2_stream_check_deferred_item(nghttp2_stream *stream);
/*
* Returns nonzero if 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 nonzero if |target| is an ancestor of |stream|.
*/
int nghttp2_stream_dep_find_ancestor(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.
*/
int32_t nghttp2_stream_dep_distributed_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->item| is NULL.
*
* 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(nghttp2_stream *dep_stream,
nghttp2_stream *stream);
/*
* Makes the |stream| depend on the |dep_stream|. This dependency is
* not exclusive. This function assumes |stream->item| is NULL.
*/
void nghttp2_stream_dep_add(nghttp2_stream *dep_stream, nghttp2_stream *stream);
/*
* Removes the |stream| from the current dependency tree. This
* function assumes |stream->item| is NULL.
*/
int nghttp2_stream_dep_remove(nghttp2_stream *stream);
/*
* Attaches |item| to |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_attach_item(nghttp2_stream *stream,
nghttp2_outbound_item *item);
/*
* Detaches |stream->item|. This function does not free
* |stream->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_item(nghttp2_stream *stream);
/*
* Makes the |stream| depend on the |dep_stream|. This dependency is
* exclusive.
*
* 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);
/*
* Makes the |stream| depend on the |dep_stream|. This dependency is
* not exclusive.
*
* 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);
/*
* Removes subtree whose root stream is |stream|. 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);
/*
* Returns nonzero if |stream| is in any dependency tree.
*/
int nghttp2_stream_in_dep_tree(nghttp2_stream *stream);
/*
* Schedules transmission of |stream|'s item, assuming stream->item is
* attached, and stream->last_writelen was updated.
*/
void nghttp2_stream_reschedule(nghttp2_stream *stream);
/*
* Changes |stream|'s weight to |weight|. If |stream| is queued, it
* will be rescheduled based on new weight.
*/
void nghttp2_stream_change_weight(nghttp2_stream *stream, int32_t weight);
/*
* Returns a stream which has highest priority, updating
* descendant_last_cycle of selected stream's ancestors.
*/
nghttp2_outbound_item *
nghttp2_stream_next_outbound_item(nghttp2_stream *stream);
#endif /* NGHTTP2_STREAM */