File: http2_internal.h

package info (click to toggle)
h2o 2.2.5+dfsg2-3~bpo9+1
  • links: PTS, VCS
  • area: main
  • in suites: stretch-backports
  • size: 56,568 kB
  • sloc: ansic: 130,776; cpp: 35,914; ruby: 19,541; sh: 11,844; yacc: 5,964; perl: 3,732; python: 2,658; asm: 2,259; makefile: 525; objc: 385; pascal: 382; php: 13
file content (504 lines) | stat: -rw-r--r-- 20,653 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
/*
 * Copyright (c) 2014,2015 DeNA Co., Ltd.
 *
 * 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 h2o__http2__internal_h
#define h2o__http2__internal_h

#include <assert.h>
#include <stdint.h>
#include "khash.h"
#include "h2o/cache.h"
#include "h2o/http2_casper.h"
#include "h2o/cache_digests.h"
#include "h2o/http2_scheduler.h"

typedef struct st_h2o_http2_conn_t h2o_http2_conn_t;
typedef struct st_h2o_http2_stream_t h2o_http2_stream_t;

#define H2O_HTTP2_DEFAULT_OUTBUF_SIZE 81920 /* the target size of each write call; connection flow control window + alpha */
#define H2O_HTTP2_DEFAULT_OUTBUF_SOFT_MAX_SIZE 524288 /* 512KB; stops reading if size exceeds this value */

/* hpack */

#define H2O_HTTP2_ENCODE_INT_MAX_LENGTH 5

typedef struct st_h2o_hpack_header_table_t {
    /* ring buffer */
    struct st_h2o_hpack_header_table_entry_t *entries;
    size_t num_entries, entry_capacity, entry_start_index;
    /* size and capacities are 32+name_len+value_len (as defined by hpack spec.) */
    size_t hpack_size;
    size_t hpack_capacity;     /* the value set by SETTINGS_HEADER_TABLE_SIZE _and_ dynamic table size update */
    size_t hpack_max_capacity; /* the value set by SETTINGS_HEADER_TABLE_SIZE */
} h2o_hpack_header_table_t;

typedef struct st_h2o_hpack_header_table_entry_t {
    h2o_iovec_t *name;
    h2o_iovec_t *value;
    const char *err_desc; /* the recorded soft error description */
} h2o_hpack_header_table_entry_t;

#define H2O_HPACK_PARSE_HEADERS_METHOD_EXISTS 1
#define H2O_HPACK_PARSE_HEADERS_SCHEME_EXISTS 2
#define H2O_HPACK_PARSE_HEADERS_PATH_EXISTS 4
#define H2O_HPACK_PARSE_HEADERS_AUTHORITY_EXISTS 8

void h2o_hpack_dispose_header_table(h2o_hpack_header_table_t *header_table);
int h2o_hpack_parse_headers(h2o_req_t *req, h2o_hpack_header_table_t *header_table, const uint8_t *src, size_t len,
                            int *pseudo_header_exists_map, size_t *content_length, h2o_cache_digests_t **digests,
                            const char **err_desc);
size_t h2o_hpack_encode_string(uint8_t *dst, const char *s, size_t len);
void h2o_hpack_flatten_request(h2o_buffer_t **buf, h2o_hpack_header_table_t *header_table, uint32_t stream_id,
                               size_t max_frame_size, h2o_req_t *req, uint32_t parent_stream_id);
void h2o_hpack_flatten_response(h2o_buffer_t **buf, h2o_hpack_header_table_t *header_table, uint32_t stream_id,
                                size_t max_frame_size, h2o_res_t *res, h2o_timestamp_t *ts, const h2o_iovec_t *server_name,
                                size_t content_length);
static h2o_hpack_header_table_entry_t *h2o_hpack_header_table_get(h2o_hpack_header_table_t *table, size_t index);

/* frames */

#define H2O_HTTP2_FRAME_HEADER_SIZE 9

#define H2O_HTTP2_FRAME_TYPE_DATA 0
#define H2O_HTTP2_FRAME_TYPE_HEADERS 1
#define H2O_HTTP2_FRAME_TYPE_PRIORITY 2
#define H2O_HTTP2_FRAME_TYPE_RST_STREAM 3
#define H2O_HTTP2_FRAME_TYPE_SETTINGS 4
#define H2O_HTTP2_FRAME_TYPE_PUSH_PROMISE 5
#define H2O_HTTP2_FRAME_TYPE_PING 6
#define H2O_HTTP2_FRAME_TYPE_GOAWAY 7
#define H2O_HTTP2_FRAME_TYPE_WINDOW_UPDATE 8
#define H2O_HTTP2_FRAME_TYPE_CONTINUATION 9

#define H2O_HTTP2_FRAME_FLAG_END_STREAM 0x1
#define H2O_HTTP2_FRAME_FLAG_ACK 0x1
#define H2O_HTTP2_FRAME_FLAG_END_HEADERS 0x4
#define H2O_HTTP2_FRAME_FLAG_PADDED 0x8
#define H2O_HTTP2_FRAME_FLAG_PRIORITY 0x20

typedef struct st_h2o_http2_frame_t {
    uint32_t length;
    uint8_t type;
    uint8_t flags;
    uint32_t stream_id;
    const uint8_t *payload;
} h2o_http2_frame_t;

typedef struct st_h2o_http2_data_payload_t {
    const uint8_t *data;
    size_t length;
} h2o_http2_data_payload_t;

typedef struct st_h2o_http2_headers_payload_t {
    h2o_http2_priority_t priority;
    const uint8_t *headers;
    size_t headers_len;
} h2o_http2_headers_payload_t;

typedef struct st_h2o_http2_rst_stream_payload_t {
    uint32_t error_code;
} h2o_http2_rst_stream_payload_t;

typedef struct st_h2o_http2_ping_payload_t {
    uint8_t data[8];
} h2o_http2_ping_payload_t;

typedef struct st_h2o_http2_goaway_payload_t {
    uint32_t last_stream_id;
    uint32_t error_code;
    h2o_iovec_t debug_data;
} h2o_http2_goaway_payload_t;

typedef struct st_h2o_http2_window_update_payload_t {
    uint32_t window_size_increment;
} h2o_http2_window_update_payload_t;

typedef struct st_h2o_http2_window_t {
    ssize_t _avail;
} h2o_http2_window_t;

typedef enum enum_h2o_http2_stream_state_t {
    H2O_HTTP2_STREAM_STATE_IDLE,
    H2O_HTTP2_STREAM_STATE_RECV_HEADERS,
    H2O_HTTP2_STREAM_STATE_RECV_BODY,
    H2O_HTTP2_STREAM_STATE_REQ_PENDING,
    H2O_HTTP2_STREAM_STATE_SEND_HEADERS,
    H2O_HTTP2_STREAM_STATE_SEND_BODY,
    H2O_HTTP2_STREAM_STATE_SEND_BODY_IS_FINAL,
    H2O_HTTP2_STREAM_STATE_END_STREAM
} h2o_http2_stream_state_t;

typedef struct st_h2o_http2_conn_num_streams_t {
    uint32_t open;
    uint32_t half_closed;
    uint32_t send_body;
} h2o_http2_conn_num_streams_t;

struct st_h2o_http2_stream_t {
    uint32_t stream_id;
    h2o_ostream_t _ostr_final;
    h2o_http2_stream_state_t state;
    h2o_http2_window_t output_window;
    h2o_http2_window_t input_window;
    h2o_http2_priority_t received_priority;
    h2o_buffer_t *_req_body;         /* NULL unless request body IS expected */
    size_t _expected_content_length; /* SIZE_MAX if unknown */
    H2O_VECTOR(h2o_iovec_t) _data;
    h2o_ostream_pull_cb _pull_cb;
    h2o_http2_conn_num_streams_t *_num_streams_slot; /* points http2_conn_t::num_streams::* in which the stream is counted */
    h2o_cache_digests_t *cache_digests;
    union {
        struct {
            uint32_t parent_stream_id;
            unsigned promise_sent : 1;
        } push;
        struct {
            unsigned casper_is_ready : 1;
        } pull;
    };
    /* references governed by connection.c for handling various things */
    struct {
        h2o_linklist_t link;
        h2o_http2_scheduler_openref_t scheduler;
    } _refs;
    h2o_send_state_t send_state; /* state of the ostream, only used in push mode */
    /* placed at last since it is large and has it's own ctor */
    h2o_req_t req;
};

KHASH_MAP_INIT_INT64(h2o_http2_stream_t, h2o_http2_stream_t *)

typedef enum enum_h2o_http2_conn_state_t {
    H2O_HTTP2_CONN_STATE_OPEN,        /* accepting new connections */
    H2O_HTTP2_CONN_STATE_HALF_CLOSED, /* no more accepting new streams */
    H2O_HTTP2_CONN_STATE_IS_CLOSING   /* nothing should be sent */
} h2o_http2_conn_state_t;

struct st_h2o_http2_conn_t {
    h2o_conn_t super;
    h2o_socket_t *sock;
    /* settings */
    h2o_http2_settings_t peer_settings;
    /* streams */
    khash_t(h2o_http2_stream_t) * streams;
    struct {
        uint32_t max_open;
        uint32_t max_processed;
    } pull_stream_ids;
    struct {
        uint32_t max_open;
    } push_stream_ids;
    struct {
        h2o_http2_conn_num_streams_t priority;
        h2o_http2_conn_num_streams_t pull;
        h2o_http2_conn_num_streams_t push;
    } num_streams;
    /* internal */
    h2o_http2_scheduler_node_t scheduler;
    h2o_http2_conn_state_t state;
    h2o_linklist_t _conns; /* linklist to h2o_context_t::http2._conns */
    ssize_t (*_read_expect)(h2o_http2_conn_t *conn, const uint8_t *src, size_t len, const char **err_desc);
    h2o_buffer_t *_http1_req_input; /* contains data referred to by original request via HTTP/1.1 */
    h2o_hpack_header_table_t _input_header_table;
    h2o_http2_window_t _input_window;
    h2o_hpack_header_table_t _output_header_table;
    h2o_linklist_t _pending_reqs; /* list of h2o_http2_stream_t that contain pending requests */
    h2o_timeout_entry_t _timeout_entry;
    h2o_buffer_t *_headers_unparsed; /* for temporary storing HEADERS|CONTINUATION frames without END_HEADERS flag set */
    struct {
        h2o_buffer_t *buf;
        h2o_buffer_t *buf_in_flight;
        h2o_linklist_t streams_to_proceed;
        h2o_timeout_entry_t timeout_entry;
        h2o_http2_window_t window;
    } _write;
    h2o_cache_t *push_memo;
    h2o_http2_casper_t *casper;
};

int h2o_http2_update_peer_settings(h2o_http2_settings_t *settings, const uint8_t *src, size_t len, const char **err_desc);

/* frames */
uint8_t *h2o_http2_encode_frame_header(uint8_t *dst, size_t length, uint8_t type, uint8_t flags, int32_t stream_id);

#define h2o_http2_encode_rst_stream_frame(buf, stream_id, errnum)                                                                  \
    h2o_http2__encode_rst_stream_frame(buf, stream_id, (H2O_BUILD_ASSERT((errnum) > 0), errnum))

void h2o_http2__encode_rst_stream_frame(h2o_buffer_t **buf, uint32_t stream_id, int errnum);
void h2o_http2_encode_ping_frame(h2o_buffer_t **buf, int is_ack, const uint8_t *data);
void h2o_http2_encode_goaway_frame(h2o_buffer_t **buf, uint32_t last_stream_id, int errnum, h2o_iovec_t additional_data);
void h2o_http2_encode_window_update_frame(h2o_buffer_t **buf, uint32_t stream_id, int32_t window_size_increment);
ssize_t h2o_http2_decode_frame(h2o_http2_frame_t *frame, const uint8_t *src, size_t len, const h2o_http2_settings_t *host_settings,
                               const char **err_desc);
int h2o_http2_decode_data_payload(h2o_http2_data_payload_t *payload, const h2o_http2_frame_t *frame, const char **err_desc);
int h2o_http2_decode_headers_payload(h2o_http2_headers_payload_t *payload, const h2o_http2_frame_t *frame, const char **err_desc);
int h2o_http2_decode_priority_payload(h2o_http2_priority_t *payload, const h2o_http2_frame_t *frame, const char **err_desc);
int h2o_http2_decode_rst_stream_payload(h2o_http2_rst_stream_payload_t *payload, const h2o_http2_frame_t *frame,
                                        const char **err_desc);
int h2o_http2_decode_ping_payload(h2o_http2_ping_payload_t *payload, const h2o_http2_frame_t *frame, const char **err_desc);
int h2o_http2_decode_goaway_payload(h2o_http2_goaway_payload_t *payload, const h2o_http2_frame_t *frame, const char **err_desc);
int h2o_http2_decode_window_update_payload(h2o_http2_window_update_payload_t *paylaod, const h2o_http2_frame_t *frame,
                                           const char **err_desc, int *err_is_stream_level);

/* connection */
void h2o_http2_conn_register_stream(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream);
void h2o_http2_conn_unregister_stream(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream);
static h2o_http2_stream_t *h2o_http2_conn_get_stream(h2o_http2_conn_t *conn, uint32_t stream_id);
void h2o_http2_conn_push_path(h2o_http2_conn_t *conn, h2o_iovec_t path, h2o_http2_stream_t *src_stream);
void h2o_http2_conn_request_write(h2o_http2_conn_t *conn);
void h2o_http2_conn_register_for_proceed_callback(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream);
static ssize_t h2o_http2_conn_get_buffer_window(h2o_http2_conn_t *conn);
static void h2o_http2_conn_init_casper(h2o_http2_conn_t *conn, unsigned capacity_bits);

/* stream */
static int h2o_http2_stream_is_push(uint32_t stream_id);
h2o_http2_stream_t *h2o_http2_stream_open(h2o_http2_conn_t *conn, uint32_t stream_id, h2o_req_t *src_req,
                                          const h2o_http2_priority_t *received_priority);
static void h2o_http2_stream_update_open_slot(h2o_http2_stream_t *stream, h2o_http2_conn_num_streams_t *slot);
static void h2o_http2_stream_set_state(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream, h2o_http2_stream_state_t new_state);
static void h2o_http2_stream_prepare_for_request(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream);
void h2o_http2_stream_close(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream);
void h2o_http2_stream_reset(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream);
void h2o_http2_stream_send_pending_data(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream);
static int h2o_http2_stream_has_pending_data(h2o_http2_stream_t *stream);
void h2o_http2_stream_proceed(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream);
static void h2o_http2_stream_send_push_promise(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream);

/* misc */
static void h2o_http2_window_init(h2o_http2_window_t *window, const h2o_http2_settings_t *peer_settings);
static int h2o_http2_window_update(h2o_http2_window_t *window, ssize_t delta);
static ssize_t h2o_http2_window_get_window(h2o_http2_window_t *window);
static void h2o_http2_window_consume_window(h2o_http2_window_t *window, size_t bytes);

static uint16_t h2o_http2_decode16u(const uint8_t *src);
static uint32_t h2o_http2_decode24u(const uint8_t *src);
static uint32_t h2o_http2_decode32u(const uint8_t *src);
static uint8_t *h2o_http2_encode24u(uint8_t *dst, uint32_t value);
static uint8_t *h2o_http2_encode32u(uint8_t *dst, uint32_t value);

h2o_http2_debug_state_t *h2o_http2_get_debug_state(h2o_req_t *req, int hpack_enabled);

/* inline definitions */

inline void h2o_http2_window_init(h2o_http2_window_t *window, const h2o_http2_settings_t *peer_settings)
{
    window->_avail = peer_settings->initial_window_size;
}

inline int h2o_http2_window_update(h2o_http2_window_t *window, ssize_t delta)
{
    ssize_t v = window->_avail + delta;
    if (v > INT32_MAX)
        return -1;
    window->_avail = v;
    return 0;
}

inline ssize_t h2o_http2_window_get_window(h2o_http2_window_t *window)
{
    return window->_avail;
}

inline void h2o_http2_window_consume_window(h2o_http2_window_t *window, size_t bytes)
{
    window->_avail -= bytes;
}

inline h2o_http2_stream_t *h2o_http2_conn_get_stream(h2o_http2_conn_t *conn, uint32_t stream_id)
{
    khiter_t iter = kh_get(h2o_http2_stream_t, conn->streams, stream_id);
    if (iter != kh_end(conn->streams))
        return kh_val(conn->streams, iter);
    return NULL;
}

inline int h2o_http2_stream_is_push(uint32_t stream_id)
{
    return stream_id % 2 == 0;
}

inline ssize_t h2o_http2_conn_get_buffer_window(h2o_http2_conn_t *conn)
{
    ssize_t ret, winsz;
    size_t capacity, cwnd_left;

    capacity = conn->_write.buf->capacity;
    if ((cwnd_left = h2o_socket_prepare_for_latency_optimized_write(
             conn->sock, &conn->super.ctx->globalconf->http2.latency_optimization)) < capacity) {
        capacity = cwnd_left;
        if (capacity < conn->_write.buf->size)
            return 0;
    }

    ret = capacity - conn->_write.buf->size;
    if (ret < H2O_HTTP2_FRAME_HEADER_SIZE)
        return 0;
    ret -= H2O_HTTP2_FRAME_HEADER_SIZE;
    winsz = h2o_http2_window_get_window(&conn->_write.window);
    if (winsz < ret)
        ret = winsz;
    return ret;
}

inline void h2o_http2_conn_init_casper(h2o_http2_conn_t *conn, unsigned capacity_bits)
{
    assert(conn->casper == NULL);
    conn->casper = h2o_http2_casper_create(capacity_bits, 6);
}

inline void h2o_http2_stream_update_open_slot(h2o_http2_stream_t *stream, h2o_http2_conn_num_streams_t *slot)
{
    --stream->_num_streams_slot->open;
    ++slot->open;
    stream->_num_streams_slot = slot;
}

inline void h2o_http2_stream_set_state(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream, h2o_http2_stream_state_t new_state)
{
    switch (new_state) {
    case H2O_HTTP2_STREAM_STATE_IDLE:
        assert(!"FIXME");
        break;
    case H2O_HTTP2_STREAM_STATE_RECV_HEADERS:
        assert(stream->state == H2O_HTTP2_STREAM_STATE_IDLE);
        if (h2o_http2_stream_is_push(stream->stream_id))
            h2o_http2_stream_update_open_slot(stream, &conn->num_streams.push);
        else
            h2o_http2_stream_update_open_slot(stream, &conn->num_streams.pull);
        stream->state = new_state;
        stream->req.timestamps.request_begin_at = *h2o_get_timestamp(conn->super.ctx, NULL, NULL);
        break;
    case H2O_HTTP2_STREAM_STATE_RECV_BODY:
        stream->state = new_state;
        stream->req.timestamps.request_body_begin_at = *h2o_get_timestamp(conn->super.ctx, NULL, NULL);
        break;
    case H2O_HTTP2_STREAM_STATE_REQ_PENDING:
        stream->state = new_state;
        break;
    case H2O_HTTP2_STREAM_STATE_SEND_HEADERS:
        assert(stream->state == H2O_HTTP2_STREAM_STATE_REQ_PENDING);
        ++stream->_num_streams_slot->half_closed;
        stream->state = new_state;
        break;
    case H2O_HTTP2_STREAM_STATE_SEND_BODY:
        stream->state = new_state;
        ++stream->_num_streams_slot->send_body;
        stream->req.timestamps.response_start_at = *h2o_get_timestamp(conn->super.ctx, NULL, NULL);
        break;
    case H2O_HTTP2_STREAM_STATE_SEND_BODY_IS_FINAL:
        assert(stream->state == H2O_HTTP2_STREAM_STATE_SEND_BODY);
        stream->state = new_state;
        break;
    case H2O_HTTP2_STREAM_STATE_END_STREAM:
        switch (stream->state) {
        case H2O_HTTP2_STREAM_STATE_IDLE:
        case H2O_HTTP2_STREAM_STATE_RECV_BODY:
        case H2O_HTTP2_STREAM_STATE_RECV_HEADERS:
            break;
        case H2O_HTTP2_STREAM_STATE_REQ_PENDING:
            break;
        case H2O_HTTP2_STREAM_STATE_SEND_HEADERS:
            --stream->_num_streams_slot->half_closed;
            break;
        case H2O_HTTP2_STREAM_STATE_SEND_BODY:
        case H2O_HTTP2_STREAM_STATE_SEND_BODY_IS_FINAL:
            --stream->_num_streams_slot->half_closed;
            --stream->_num_streams_slot->send_body;
            break;
        case H2O_HTTP2_STREAM_STATE_END_STREAM:
            assert(!"FIXME");
            break;
        }
        stream->state = new_state;
        stream->req.timestamps.response_end_at = *h2o_get_timestamp(conn->super.ctx, NULL, NULL);
        --stream->_num_streams_slot->open;
        stream->_num_streams_slot = NULL;
        break;
    }
}

inline void h2o_http2_stream_prepare_for_request(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream)
{
    assert(h2o_http2_scheduler_is_open(&stream->_refs.scheduler));

    /* adjust max-open */
    uint32_t *max_open =
        h2o_http2_stream_is_push(stream->stream_id) ? &conn->push_stream_ids.max_open : &conn->pull_stream_ids.max_open;
    if (*max_open < stream->stream_id)
        *max_open = stream->stream_id;
    h2o_http2_stream_set_state(conn, stream, H2O_HTTP2_STREAM_STATE_RECV_HEADERS);
    h2o_http2_window_init(&stream->output_window, &conn->peer_settings);
}

inline int h2o_http2_stream_has_pending_data(h2o_http2_stream_t *stream)
{
    return stream->_data.size != 0;
}

inline void h2o_http2_stream_send_push_promise(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream)
{
    assert(!stream->push.promise_sent);
    h2o_hpack_flatten_request(&conn->_write.buf, &conn->_output_header_table, stream->stream_id, conn->peer_settings.max_frame_size,
                              &stream->req, stream->push.parent_stream_id);
    stream->push.promise_sent = 1;
}

inline uint16_t h2o_http2_decode16u(const uint8_t *src)
{
    return (uint16_t)src[0] << 8 | src[1];
}

inline uint32_t h2o_http2_decode24u(const uint8_t *src)
{
    return (uint32_t)src[0] << 16 | (uint32_t)src[1] << 8 | src[2];
}

inline uint32_t h2o_http2_decode32u(const uint8_t *src)
{
    return (uint32_t)src[0] << 24 | (uint32_t)src[1] << 16 | (uint32_t)src[2] << 8 | src[3];
}

inline uint8_t *h2o_http2_encode24u(uint8_t *dst, uint32_t value)
{
    *dst++ = value >> 16;
    *dst++ = value >> 8;
    *dst++ = value;
    return dst;
}

inline uint8_t *h2o_http2_encode32u(uint8_t *dst, uint32_t value)
{
    *dst++ = value >> 24;
    *dst++ = value >> 16;
    *dst++ = value >> 8;
    *dst++ = value;
    return dst;
}

inline h2o_hpack_header_table_entry_t *h2o_hpack_header_table_get(h2o_hpack_header_table_t *table, size_t index)
{
    size_t entry_index = (index + table->entry_start_index) % table->entry_capacity;
    struct st_h2o_hpack_header_table_entry_t *entry = table->entries + entry_index;
    assert(entry->name != NULL);
    return entry;
}

#endif