3 * Copyright 2015 gRPC authors.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
19 #ifndef GRPC_CORE_LIB_JSON_JSON_READER_H
20 #define GRPC_CORE_LIB_JSON_JSON_READER_H
22 #include <grpc/support/port_platform.h>
24 #include "src/core/lib/json/json_common.h"
27 GRPC_JSON_STATE_OBJECT_KEY_BEGIN,
28 GRPC_JSON_STATE_OBJECT_KEY_STRING,
29 GRPC_JSON_STATE_OBJECT_KEY_END,
30 GRPC_JSON_STATE_VALUE_BEGIN,
31 GRPC_JSON_STATE_VALUE_STRING,
32 GRPC_JSON_STATE_STRING_ESCAPE,
33 GRPC_JSON_STATE_STRING_ESCAPE_U1,
34 GRPC_JSON_STATE_STRING_ESCAPE_U2,
35 GRPC_JSON_STATE_STRING_ESCAPE_U3,
36 GRPC_JSON_STATE_STRING_ESCAPE_U4,
37 GRPC_JSON_STATE_VALUE_NUMBER,
38 GRPC_JSON_STATE_VALUE_NUMBER_WITH_DECIMAL,
39 GRPC_JSON_STATE_VALUE_NUMBER_ZERO,
40 GRPC_JSON_STATE_VALUE_NUMBER_DOT,
41 GRPC_JSON_STATE_VALUE_NUMBER_E,
42 GRPC_JSON_STATE_VALUE_NUMBER_EPM,
43 GRPC_JSON_STATE_VALUE_TRUE_R,
44 GRPC_JSON_STATE_VALUE_TRUE_U,
45 GRPC_JSON_STATE_VALUE_TRUE_E,
46 GRPC_JSON_STATE_VALUE_FALSE_A,
47 GRPC_JSON_STATE_VALUE_FALSE_L,
48 GRPC_JSON_STATE_VALUE_FALSE_S,
49 GRPC_JSON_STATE_VALUE_FALSE_E,
50 GRPC_JSON_STATE_VALUE_NULL_U,
51 GRPC_JSON_STATE_VALUE_NULL_L1,
52 GRPC_JSON_STATE_VALUE_NULL_L2,
53 GRPC_JSON_STATE_VALUE_END,
55 } grpc_json_reader_state;
58 /* The first non-unicode value is 0x110000. But let's pick
59 * a value high enough to start our error codes from. These
60 * values are safe to return from the read_char function.
62 GRPC_JSON_READ_CHAR_EOF = 0x7ffffff0,
63 GRPC_JSON_READ_CHAR_EAGAIN,
64 GRPC_JSON_READ_CHAR_ERROR
67 struct grpc_json_reader;
69 typedef struct grpc_json_reader_vtable {
70 /* Clears your internal string scratchpad. */
71 void (*string_clear)(void* userdata);
72 /* Adds a char to the string scratchpad. */
73 void (*string_add_char)(void* userdata, uint32_t c);
74 /* Adds a utf32 char to the string scratchpad. */
75 void (*string_add_utf32)(void* userdata, uint32_t c);
76 /* Reads a character from your input. May be utf-8, 16 or 32. */
77 uint32_t (*read_char)(void* userdata);
78 /* Starts a container of type GRPC_JSON_ARRAY or GRPC_JSON_OBJECT. */
79 void (*container_begins)(void* userdata, grpc_json_type type);
80 /* Ends the current container. Must return the type of its parent. */
81 grpc_json_type (*container_ends)(void* userdata);
82 /* Your internal string scratchpad is an object's key. */
83 void (*set_key)(void* userdata);
84 /* Your internal string scratchpad is a string value. */
85 void (*set_string)(void* userdata);
86 /* Your internal string scratchpad is a numerical value. Return 1 if valid. */
87 int (*set_number)(void* userdata);
88 /* Sets the values true, false or null. */
89 void (*set_true)(void* userdata);
90 void (*set_false)(void* userdata);
91 void (*set_null)(void* userdata);
92 } grpc_json_reader_vtable;
94 typedef struct grpc_json_reader {
95 /* That structure is fully private, and initialized by grpc_json_reader_init.
96 * The definition is public so you can put it on your stack.
100 grpc_json_reader_vtable* vtable;
104 int escaped_string_was_key;
105 int container_just_begun;
106 uint16_t unicode_char, unicode_high_surrogate;
107 grpc_json_reader_state state;
110 /* The return type of the parser. */
112 GRPC_JSON_DONE, /* The parser finished successfully. */
113 GRPC_JSON_EAGAIN, /* The parser yields to get more data. */
114 GRPC_JSON_READ_ERROR, /* The parser passes through a read error. */
115 GRPC_JSON_PARSE_ERROR, /* The parser found an error in the json stream. */
116 GRPC_JSON_INTERNAL_ERROR /* The parser got an internal error. */
117 } grpc_json_reader_status;
119 /* Call this function to start parsing the input. It will return the following:
120 * . GRPC_JSON_DONE if the input got eof, and the parsing finished
122 * . GRPC_JSON_EAGAIN if the read_char function returned again. Call the
123 * parser again as needed. It is okay to call the parser in polling mode,
124 * although a bit dull.
125 * . GRPC_JSON_READ_ERROR if the read_char function returned an error. The
126 * state isn't broken however, and the function can be called again if the
127 * error has been corrected. But please use the EAGAIN feature instead for
129 * . GRPC_JSON_PARSE_ERROR if the input was somehow invalid.
130 * . GRPC_JSON_INTERNAL_ERROR if the parser somehow ended into an invalid
133 grpc_json_reader_status grpc_json_reader_run(grpc_json_reader* reader);
135 /* Call this function to initialize the reader structure. */
136 void grpc_json_reader_init(grpc_json_reader* reader,
137 grpc_json_reader_vtable* vtable, void* userdata);
139 /* You may call this from the read_char callback if you don't know where is the
140 * end of your input stream, and you'd like the json reader to hint you that it
141 * has completed reading its input, so you can return an EOF to it. Note that
142 * there might still be trailing whitespaces after that point.
144 int grpc_json_reader_is_complete(grpc_json_reader* reader);
146 #endif /* GRPC_CORE_LIB_JSON_JSON_READER_H */