aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/core/transport/stream_op.h
blob: 227320cf2a889af6afdee7c44d66ecdcc536f8fe (plain)
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
/*
 *
 * Copyright 2015, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#ifndef GRPC_INTERNAL_CORE_TRANSPORT_STREAM_OP_H
#define GRPC_INTERNAL_CORE_TRANSPORT_STREAM_OP_H

#include <grpc/grpc.h>
#include <grpc/support/port_platform.h>
#include <grpc/support/slice.h>
#include <grpc/support/time.h>
#include "src/core/transport/metadata.h"

/* this many stream ops are inlined into a sopb before allocating */
#define GRPC_SOPB_INLINE_ELEMENTS 4

/* Operations that can be performed on a stream.
   Used by grpc_stream_op. */
typedef enum grpc_stream_op_code {
  /* Do nothing code. Useful if rewriting a batch to exclude some operations.
     Must be ignored by receivers */
  GRPC_NO_OP,
  GRPC_OP_METADATA,
  /* Begin a message/metadata element/status - as defined by
     grpc_message_type. */
  GRPC_OP_BEGIN_MESSAGE,
  /* Add a slice of data to the current message/metadata element/status.
     Must not overflow the forward declared length. */
  GRPC_OP_SLICE
} grpc_stream_op_code;

/** Internal bit flag for grpc_begin_message's \a flags signaling the use of
 * compression for the message */
#define GRPC_WRITE_INTERNAL_COMPRESS (0x80000000u)
/** Mask of all valid internal flags. */
#define GRPC_WRITE_INTERNAL_USED_MASK (GRPC_WRITE_INTERNAL_COMPRESS)

/* Arguments for GRPC_OP_BEGIN_MESSAGE */
typedef struct grpc_begin_message {
  /* How many bytes of data will this message contain */
  gpr_uint32 length;
  /* Write flags for the message: see grpc.h GRPC_WRITE_* for the public bits,
   * GRPC_WRITE_INTERNAL_* for the internal ones. */
  gpr_uint32 flags;
} grpc_begin_message;

typedef struct grpc_linked_mdelem {
  grpc_mdelem *md;
  struct grpc_linked_mdelem *next;
  struct grpc_linked_mdelem *prev;
} grpc_linked_mdelem;

typedef struct grpc_mdelem_list {
  grpc_linked_mdelem *head;
  grpc_linked_mdelem *tail;
} grpc_mdelem_list;

typedef struct grpc_metadata_batch {
  /** Metadata elements in this batch */
  grpc_mdelem_list list;
  /** Elements that have been removed from the batch, but have
      not yet been unreffed - used to allow collecting garbage
      under a single metadata context lock */
  grpc_mdelem_list garbage;
  /** Used to calculate grpc-timeout at the point of sending,
      or gpr_inf_future if this batch does not need to send a
      grpc-timeout */
  gpr_timespec deadline;
} grpc_metadata_batch;

void grpc_metadata_batch_init(grpc_metadata_batch *batch);
void grpc_metadata_batch_destroy(grpc_metadata_batch *batch);
void grpc_metadata_batch_merge(grpc_metadata_batch *target,
                               grpc_metadata_batch *add);

/** Moves the metadata information from \a src to \a dst. Upon return, \a src is
 * zeroed. */
void grpc_metadata_batch_move(grpc_metadata_batch *dst,
                              grpc_metadata_batch *src);

/** Add \a storage to the beginning of \a batch. storage->md is
    assumed to be valid.
    \a storage is owned by the caller and must survive for the
    lifetime of batch. This usually means it should be around
    for the lifetime of the call. */
void grpc_metadata_batch_link_head(grpc_metadata_batch *batch,
                                   grpc_linked_mdelem *storage);
/** Add \a storage to the end of \a batch. storage->md is
    assumed to be valid.
    \a storage is owned by the caller and must survive for the
    lifetime of batch. This usually means it should be around
    for the lifetime of the call. */
void grpc_metadata_batch_link_tail(grpc_metadata_batch *batch,
                                   grpc_linked_mdelem *storage);

/** Add \a elem_to_add as the first element in \a batch, using
    \a storage as backing storage for the linked list element.
    \a storage is owned by the caller and must survive for the
    lifetime of batch. This usually means it should be around
    for the lifetime of the call.
    Takes ownership of \a elem_to_add */
void grpc_metadata_batch_add_head(grpc_metadata_batch *batch,
                                  grpc_linked_mdelem *storage,
                                  grpc_mdelem *elem_to_add);
/** Add \a elem_to_add as the last element in \a batch, using
    \a storage as backing storage for the linked list element.
    \a storage is owned by the caller and must survive for the
    lifetime of batch. This usually means it should be around
    for the lifetime of the call.
    Takes ownership of \a elem_to_add */
void grpc_metadata_batch_add_tail(grpc_metadata_batch *batch,
                                  grpc_linked_mdelem *storage,
                                  grpc_mdelem *elem_to_add);

/** For each element in \a batch, execute \a filter.
    The return value from \a filter will be substituted for the
    grpc_mdelem passed to \a filter. If \a filter returns NULL,
    the element will be moved to the garbage list. */
void grpc_metadata_batch_filter(grpc_metadata_batch *batch,
                                grpc_mdelem *(*filter)(void *user_data,
                                                       grpc_mdelem *elem),
                                void *user_data);

#ifndef NDEBUG
void grpc_metadata_batch_assert_ok(grpc_metadata_batch *comd);
#else
#define grpc_metadata_batch_assert_ok(comd) \
  do {                                      \
  } while (0)
#endif

/* Represents a single operation performed on a stream/transport */
typedef struct grpc_stream_op {
  /* the operation to be applied */
  enum grpc_stream_op_code type;
  /* the arguments to this operation. union fields are named according to the
     associated op-code */
  union {
    grpc_begin_message begin_message;
    grpc_metadata_batch metadata;
    gpr_slice slice;
  } data;
} grpc_stream_op;

/** A stream op buffer is a wrapper around stream operations that is
 * dynamically extendable. */
typedef struct grpc_stream_op_buffer {
  grpc_stream_op *ops;
  size_t nops;
  size_t capacity;
  grpc_stream_op inlined_ops[GRPC_SOPB_INLINE_ELEMENTS];
} grpc_stream_op_buffer;

/* Initialize a stream op buffer */
void grpc_sopb_init(grpc_stream_op_buffer *sopb);
/* Destroy a stream op buffer */
void grpc_sopb_destroy(grpc_stream_op_buffer *sopb);
/* Reset a sopb to no elements */
void grpc_sopb_reset(grpc_stream_op_buffer *sopb);
/* Swap two sopbs */
void grpc_sopb_swap(grpc_stream_op_buffer *a, grpc_stream_op_buffer *b);

void grpc_stream_ops_unref_owned_objects(grpc_stream_op *ops, size_t nops);

/* Append a GRPC_NO_OP to a buffer */
void grpc_sopb_add_no_op(grpc_stream_op_buffer *sopb);
/* Append a GRPC_OP_BEGIN to a buffer */
void grpc_sopb_add_begin_message(grpc_stream_op_buffer *sopb, gpr_uint32 length,
                                 gpr_uint32 flags);
void grpc_sopb_add_metadata(grpc_stream_op_buffer *sopb,
                            grpc_metadata_batch metadata);
/* Append a GRPC_SLICE to a buffer - does not ref/unref the slice */
void grpc_sopb_add_slice(grpc_stream_op_buffer *sopb, gpr_slice slice);
/* Append a buffer to a buffer - does not ref/unref any internal objects */
void grpc_sopb_append(grpc_stream_op_buffer *sopb, grpc_stream_op *ops,
                      size_t nops);

void grpc_sopb_move_to(grpc_stream_op_buffer *src, grpc_stream_op_buffer *dst);

char *grpc_sopb_string(grpc_stream_op_buffer *sopb);

#endif /* GRPC_INTERNAL_CORE_TRANSPORT_STREAM_OP_H */