aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/core/lib/json/json_reader.h
blob: 37a838889da26ba0816f7189f718e920f87a76d8 (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
/*
 *
 * Copyright 2015-2016, 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_CORE_LIB_JSON_JSON_READER_H
#define GRPC_CORE_LIB_JSON_JSON_READER_H

#include <grpc/support/port_platform.h>
#include "src/core/lib/json/json_common.h"

typedef enum {
  GRPC_JSON_STATE_OBJECT_KEY_BEGIN,
  GRPC_JSON_STATE_OBJECT_KEY_STRING,
  GRPC_JSON_STATE_OBJECT_KEY_END,
  GRPC_JSON_STATE_VALUE_BEGIN,
  GRPC_JSON_STATE_VALUE_STRING,
  GRPC_JSON_STATE_STRING_ESCAPE,
  GRPC_JSON_STATE_STRING_ESCAPE_U1,
  GRPC_JSON_STATE_STRING_ESCAPE_U2,
  GRPC_JSON_STATE_STRING_ESCAPE_U3,
  GRPC_JSON_STATE_STRING_ESCAPE_U4,
  GRPC_JSON_STATE_VALUE_NUMBER,
  GRPC_JSON_STATE_VALUE_NUMBER_WITH_DECIMAL,
  GRPC_JSON_STATE_VALUE_NUMBER_ZERO,
  GRPC_JSON_STATE_VALUE_NUMBER_DOT,
  GRPC_JSON_STATE_VALUE_NUMBER_E,
  GRPC_JSON_STATE_VALUE_NUMBER_EPM,
  GRPC_JSON_STATE_VALUE_TRUE_R,
  GRPC_JSON_STATE_VALUE_TRUE_U,
  GRPC_JSON_STATE_VALUE_TRUE_E,
  GRPC_JSON_STATE_VALUE_FALSE_A,
  GRPC_JSON_STATE_VALUE_FALSE_L,
  GRPC_JSON_STATE_VALUE_FALSE_S,
  GRPC_JSON_STATE_VALUE_FALSE_E,
  GRPC_JSON_STATE_VALUE_NULL_U,
  GRPC_JSON_STATE_VALUE_NULL_L1,
  GRPC_JSON_STATE_VALUE_NULL_L2,
  GRPC_JSON_STATE_VALUE_END,
  GRPC_JSON_STATE_END
} grpc_json_reader_state;

enum {
  /* The first non-unicode value is 0x110000. But let's pick
   * a value high enough to start our error codes from. These
   * values are safe to return from the read_char function.
   */
  GRPC_JSON_READ_CHAR_EOF = 0x7ffffff0,
  GRPC_JSON_READ_CHAR_EAGAIN,
  GRPC_JSON_READ_CHAR_ERROR
};

struct grpc_json_reader;

typedef struct grpc_json_reader_vtable {
  /* Clears your internal string scratchpad. */
  void (*string_clear)(void *userdata);
  /* Adds a char to the string scratchpad. */
  void (*string_add_char)(void *userdata, uint32_t c);
  /* Adds a utf32 char to the string scratchpad. */
  void (*string_add_utf32)(void *userdata, uint32_t c);
  /* Reads a character from your input. May be utf-8, 16 or 32. */
  uint32_t (*read_char)(void *userdata);
  /* Starts a container of type GRPC_JSON_ARRAY or GRPC_JSON_OBJECT. */
  void (*container_begins)(void *userdata, grpc_json_type type);
  /* Ends the current container. Must return the type of its parent. */
  grpc_json_type (*container_ends)(void *userdata);
  /* Your internal string scratchpad is an object's key. */
  void (*set_key)(void *userdata);
  /* Your internal string scratchpad is a string value. */
  void (*set_string)(void *userdata);
  /* Your internal string scratchpad is a numerical value. Return 1 if valid. */
  int (*set_number)(void *userdata);
  /* Sets the values true, false or null. */
  void (*set_true)(void *userdata);
  void (*set_false)(void *userdata);
  void (*set_null)(void *userdata);
} grpc_json_reader_vtable;

typedef struct grpc_json_reader {
  /* That structure is fully private, and initialized by grpc_json_reader_init.
   * The definition is public so you can put it on your stack.
   */

  void *userdata;
  grpc_json_reader_vtable *vtable;
  int depth;
  int in_object;
  int in_array;
  int escaped_string_was_key;
  int container_just_begun;
  uint16_t unicode_char, unicode_high_surrogate;
  grpc_json_reader_state state;
} grpc_json_reader;

/* The return type of the parser. */
typedef enum {
  GRPC_JSON_DONE,          /* The parser finished successfully. */
  GRPC_JSON_EAGAIN,        /* The parser yields to get more data. */
  GRPC_JSON_READ_ERROR,    /* The parser passes through a read error. */
  GRPC_JSON_PARSE_ERROR,   /* The parser found an error in the json stream. */
  GRPC_JSON_INTERNAL_ERROR /* The parser got an internal error. */
} grpc_json_reader_status;

/* Call this function to start parsing the input. It will return the following:
 *    . GRPC_JSON_DONE if the input got eof, and the parsing finished
 *      successfully.
 *    . GRPC_JSON_EAGAIN if the read_char function returned again. Call the
 *      parser again as needed. It is okay to call the parser in polling mode,
 *      although a bit dull.
 *    . GRPC_JSON_READ_ERROR if the read_char function returned an error. The
 *      state isn't broken however, and the function can be called again if the
 *      error has been corrected. But please use the EAGAIN feature instead for
 *      consistency.
 *    . GRPC_JSON_PARSE_ERROR if the input was somehow invalid.
 *    . GRPC_JSON_INTERNAL_ERROR if the parser somehow ended into an invalid
 *      internal state.
 */
grpc_json_reader_status grpc_json_reader_run(grpc_json_reader *reader);

/* Call this function to initialize the reader structure. */
void grpc_json_reader_init(grpc_json_reader *reader,
                           grpc_json_reader_vtable *vtable, void *userdata);

/* You may call this from the read_char callback if you don't know where is the
 * end of your input stream, and you'd like the json reader to hint you that it
 * has completed reading its input, so you can return an EOF to it. Note that
 * there might still be trailing whitespaces after that point.
 */
int grpc_json_reader_is_complete(grpc_json_reader *reader);

#endif /* GRPC_CORE_LIB_JSON_JSON_READER_H */