summaryrefslogtreecommitdiffstats
path: root/VES5.0/evel/evel-library/code/evel_library/evel_throttle.h
blob: 5f02cd2fd9321265b4472f2215ec4faddcbd35d3 (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
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
#ifndef EVEL_THROTTLE_INCLUDED
#define EVEL_THROTTLE_INCLUDED

/**************************************************************************//**
 * @file
 * EVEL throttle definitions.
 *
 * These are internal definitions related to throttling specicications, which
 * are required within the library but are not intended for external
 * consumption.
 *
 * License
 * -------
 *
 * Copyright(c) <2016>, AT&T Intellectual Property.  All other rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:  This product includes
 *    software developed by the AT&T.
 * 4. Neither the name of AT&T 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 AT&T INTELLECTUAL PROPERTY ''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 AT&T INTELLECTUAL PROPERTY 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.
 *****************************************************************************/

#include "evel_internal.h"
#include "jsmn.h"

/*****************************************************************************/
/* Maximum depth of JSON response that we can handle.                        */
/*****************************************************************************/
#define EVEL_JSON_STACK_DEPTH           10

/**************************************************************************//**
 * Maximum number of tokens that we allow for in a JSON response.
 *****************************************************************************/
#define EVEL_MAX_RESPONSE_TOKENS        1024

/**************************************************************************//**
 * The nature of the next token that we are iterating through.  Within an
 * object, we alternate between collecting keys and values.  Within an array,
 * we only collect items.
 *****************************************************************************/
typedef enum {
  EVEL_JSON_KEY,
  EVEL_JSON_VALUE,
  EVEL_JSON_ITEM
} EVEL_JSON_STATE;

/**************************************************************************//**
 * States which we move through during JSON processing, tracking our way
 * through the supported JSON structure.
 *****************************************************************************/
typedef enum
{
  /***************************************************************************/
  /* Initial state.                                                          */
  /***************************************************************************/
  EVEL_JCS_START,

  /***************************************************************************/
  /* {"commandList": [                                                       */
  /***************************************************************************/
  EVEL_JCS_COMMAND_LIST,

  /***************************************************************************/
  /* {"commandList": [{                                                      */
  /***************************************************************************/
  EVEL_JCS_COMMAND_LIST_ENTRY,

  /***************************************************************************/
  /* {"commandList": [{"command": {                                          */
  /***************************************************************************/
  EVEL_JCS_COMMAND,

  /***************************************************************************/
  /* ... "eventDomainThrottleSpecification": {                               */
  /***************************************************************************/
  EVEL_JCS_SPEC,

  /***************************************************************************/
  /* ... "suppressedFieldNames": [                                           */
  /***************************************************************************/
  EVEL_JCS_FIELD_NAMES,

  /***************************************************************************/
  /* ... "suppressedNvPairsList": [                                          */
  /***************************************************************************/
  EVEL_JCS_PAIRS_LIST,

  /***************************************************************************/
  /* ... "suppressedNvPairsList": [{                                         */
  /***************************************************************************/
  EVEL_JCS_PAIRS_LIST_ENTRY,

  /***************************************************************************/
  /* ... "suppressedNvPairNames": [                                          */
  /***************************************************************************/
  EVEL_JCS_NV_PAIR_NAMES,

  EVEL_JCS_MAX
} EVEL_JSON_COMMAND_STATE;

/**************************************************************************//**
 * An entry in the JSON stack.
 *****************************************************************************/
typedef struct evel_json_stack_entry {

  /***************************************************************************/
  /* The number of elements required at this level.                          */
  /***************************************************************************/
  int num_required;

  /***************************************************************************/
  /* The number of elements collected at this level.                         */
  /***************************************************************************/
  int json_count;

  /***************************************************************************/
  /* The collection state at this level in the JSON stack.                   */
  /***************************************************************************/
  EVEL_JSON_STATE json_state;

  /***************************************************************************/
  /* The key being collected (if json_state is EVEL_JSON_VALUE), or NULL.    */
  /***************************************************************************/
  char * json_key;

} EVEL_JSON_STACK_ENTRY;

/**************************************************************************//**
 * The JSON stack.
 *****************************************************************************/
typedef struct evel_json_stack {

  /***************************************************************************/
  /* The current position of the stack - starting at zero.                   */
  /***************************************************************************/
  int level;

  /***************************************************************************/
  /* The stack itself.                                                       */
  /***************************************************************************/
  EVEL_JSON_STACK_ENTRY entry[EVEL_JSON_STACK_DEPTH];

  /***************************************************************************/
  /* The underlying memory chunk.                                            */
  /***************************************************************************/
  const MEMORY_CHUNK * chunk;

} EVEL_JSON_STACK;

/**************************************************************************//**
 * Initialize event throttling to the default state.
 *
 * Called from ::evel_initialize.
 *****************************************************************************/
void evel_throttle_initialize();

/**************************************************************************//**
 * Clean up event throttling.
 *
 * Called from ::evel_terminate.
 *****************************************************************************/
void evel_throttle_terminate();

/**************************************************************************//**
 * Handle a JSON response from the listener, as a list of tokens from JSMN.
 *
 * @param chunk         Memory chunk containing the JSON buffer.
 * @param json_tokens   Array of tokens to handle.
 * @param num_tokens    The number of tokens to handle.
 * @param post          The memory chunk in which to place any resulting POST.
 * @return true if the command was handled, false otherwise.
 *****************************************************************************/
bool evel_handle_command_list(const MEMORY_CHUNK * const chunk,
                              const jsmntok_t * const json_tokens,
                              const int num_tokens,
                              MEMORY_CHUNK * const post);

/**************************************************************************//**
 * Return the ::EVEL_THROTTLE_SPEC for a given domain.
 *
 * @param domain        The domain for which to return state.
 *****************************************************************************/
EVEL_THROTTLE_SPEC * evel_get_throttle_spec(EVEL_EVENT_DOMAINS domain);

/**************************************************************************//**
 * Determine whether a field_name should be suppressed.
 *
 * @param throttle_spec Throttle specification for the domain being encoded.
 * @param field_name    The field name to encoded or suppress.
 * @return true if the field_name should be suppressed, false otherwise.
 *****************************************************************************/
bool evel_throttle_suppress_field(EVEL_THROTTLE_SPEC * throttle_spec,
                                  const char * const field_name);

/**************************************************************************//**
 * Determine whether a name-value pair should be allowed (not suppressed).
 *
 * @param throttle_spec Throttle specification for the domain being encoded.
 * @param field_name    The field name holding the name-value pairs.
 * @param name          The name of the name-value pair to encoded or suppress.
 * @return true if the name-value pair should be suppressed, false otherwise.
 *****************************************************************************/
bool evel_throttle_suppress_nv_pair(EVEL_THROTTLE_SPEC * throttle_spec,
                                    const char * const field_name,
                                    const char * const name);

#endif