/**************************************************************************//**
* @file
* Source module relating to internal EVEL_JSON_BUFFER manipulation functions.
*
* License
* -------
*
* Copyright © 2017 AT&T Intellectual Property. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*****************************************************************************/
#include <assert.h>
#include <string.h>
#include "evel_throttle.h"
/*****************************************************************************/
/* Local prototypes. */
/*****************************************************************************/
static char * evel_json_kv_comma(EVEL_JSON_BUFFER * jbuf);
/**************************************************************************//**
* Initialize a ::EVEL_JSON_BUFFER.
*
* @param jbuf Pointer to the ::EVEL_JSON_BUFFER to initialise.
* @param json Pointer to the underlying working buffer to use.
* @param max_size Size of storage available in the JSON buffer.
* @param throttle_spec Pointer to throttle specification. Can be NULL.
*****************************************************************************/
void evel_json_buffer_init(EVEL_JSON_BUFFER * jbuf,
char * const json,
const int max_size,
EVEL_THROTTLE_SPEC * throttle_spec)
{
EVEL_ENTER();
assert(jbuf != NULL);
assert(json != NULL);
jbuf->json = json;
jbuf->max_size = max_size;
jbuf->offset = 0;
jbuf->throttle_spec = throttle_spec;
jbuf->depth = 0;
jbuf->checkpoint = -1;
EVEL_EXIT();
}
/**************************************************************************//**
* Encode an integer value to a JSON buffer.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param value The integer to add to it.
*****************************************************************************/
void evel_enc_int(EVEL_JSON_BUFFER * jbuf,
const int value)
{
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"%d", value);
EVEL_EXIT();
}
/**************************************************************************//**
* Encode a string key and string value to a ::EVEL_JSON_BUFFER.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @param option Pointer to holder of the corresponding value to encode.
* @return true if the key, value was added, false if it was suppressed.
*****************************************************************************/
bool evel_enc_kv_opt_string(EVEL_JSON_BUFFER * jbuf,
const char * const key,
const EVEL_OPTION_STRING * const option)
{
bool added = false;
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(option != NULL);
if (option->is_set)
{
if ((jbuf->depth == EVEL_THROTTLE_FIELD_DEPTH) &&
(jbuf->throttle_spec != NULL) &&
evel_throttle_suppress_field(jbuf->throttle_spec, key))
{
EVEL_INFO("Suppressed: %s, %s", key, option->value);
}
else
{
EVEL_DEBUG("Encoded: %s, %s", key, option->value);
evel_enc_kv_string(jbuf, key, option->value);
added = true;
}
}
EVEL_EXIT();
return added;
}
/**************************************************************************//**
* Encode a string key and string value to a ::EVEL_JSON_BUFFER.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @param value Pointer to the corresponding value to encode.
*****************************************************************************/
void evel_enc_kv_string(EVEL_JSON_BUFFER * jbuf,
const char * const key,
const char * const value)
{
int index;
int length;
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
assert(key != NULL);
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"%s\"%s\": \"",
evel_json_kv_comma(jbuf),
key);
/***************************************************************************/
/* We need to escape quotation marks and backslashes in the value. */
/***************************************************************************/
length = strlen(value);
for (index = 0; index < length; index++)
{
/*************************************************************************/
/* Drop out if no more space. */
/*************************************************************************/
if (jbuf->max_size - jbuf->offset < 2)
{
break;
}
/*************************************************************************/
/* Add an escape character if necessary, then write the character */
/* itself. */
/*************************************************************************/
if ((value[index] == '\"') || (value[index] == '\\'))
{
jbuf->json[jbuf->offset] = '\\';
jbuf->offset++;
}
jbuf->json[jbuf->offset] = value[index];
jbuf->offset++;
}
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"\"");
EVEL_EXIT();
}
/**************************************************************************//**
* Encode a string key and integer value to a ::EVEL_JSON_BUFFER.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @param option Pointer to holder of the corresponding value to encode.
* @return true if the key, value was added, false if it was suppressed.
*****************************************************************************/
bool evel_enc_kv_opt_int(EVEL_JSON_BUFFER * jbuf,
const char * const key,
const EVEL_OPTION_INT * const option)
{
bool added = false;
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(option != NULL);
if (option->is_set)
{
if ((jbuf->depth == EVEL_THROTTLE_FIELD_DEPTH) &&
(jbuf->throttle_spec != NULL) &&
evel_throttle_suppress_field(jbuf->throttle_spec, key))
{
EVEL_INFO("Suppressed: %s, %d", key, option->value);
}
else
{
EVEL_DEBUG("Encoded: %s, %d", key, option->value);
evel_enc_kv_int(jbuf, key, option->value);
added = true;
}
}
EVEL_EXIT();
return added;
}
/**************************************************************************//**
* Encode a string key and integer value to a ::EVEL_JSON_BUFFER.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @param value The corresponding value to encode.
*****************************************************************************/
void evel_enc_kv_int(EVEL_JSON_BUFFER * jbuf,
const char * const key,
const int value)
{
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
assert(key != NULL);
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"%s\"%s\": %d",
evel_json_kv_comma(jbuf),
key,
value);
EVEL_EXIT();
}
/**************************************************************************//**
* Encode a string key and double value to a ::EVEL_JSON_BUFFER.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @param option Pointer to holder of the corresponding value to encode.
* @return true if the key, value was added, false if it was suppressed.
*****************************************************************************/
bool evel_enc_kv_opt_double(EVEL_JSON_BUFFER * jbuf,
const char * const key,
const EVEL_OPTION_DOUBLE * const option)
{
bool added = false;
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(option != NULL);
if (option->is_set)
{
if ((jbuf->depth == EVEL_THROTTLE_FIELD_DEPTH) &&
(jbuf->throttle_spec != NULL) &&
evel_throttle_suppress_field(jbuf->throttle_spec, key))
{
EVEL_INFO("Suppressed: %s, %1f", key, option->value);
}
else
{
EVEL_DEBUG("Encoded: %s, %1f", key, option->value);
evel_enc_kv_double(jbuf, key, option->value);
added = true;
}
}
EVEL_EXIT();
return added;
}
/**************************************************************************//**
* Encode a string key and double value to a ::EVEL_JSON_BUFFER.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @param value The corresponding value to encode.
*****************************************************************************/
void evel_enc_kv_double(EVEL_JSON_BUFFER * jbuf,
const char * const key,
const double value)
{
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
assert(key != NULL);
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"%s\"%s\": %1f",
evel_json_kv_comma(jbuf),
key,
value);
EVEL_EXIT();
}
/**************************************************************************//**
* Encode a string key and unsigned long long value to a ::EVEL_JSON_BUFFER.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @param option Pointer to holder of the corresponding value to encode.
* @return true if the key, value was added, false if it was suppressed.
*****************************************************************************/
bool evel_enc_kv_opt_ull(EVEL_JSON_BUFFER * jbuf,
const char * const key,
const EVEL_OPTION_ULL * const option)
{
bool added = false;
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(option != NULL);
if (option->is_set)
{
if ((jbuf->depth == EVEL_THROTTLE_FIELD_DEPTH) &&
(jbuf->throttle_spec != NULL) &&
evel_throttle_suppress_field(jbuf->throttle_spec, key))
{
EVEL_INFO("Suppressed: %s, %1lu", key, option->value);
}
else
{
EVEL_DEBUG("Encoded: %s, %1lu", key, option->value);
evel_enc_kv_ull(jbuf, key, option->value);
added = true;
}
}
EVEL_EXIT();
return added;
}
/**************************************************************************//**
* Encode a string key and unsigned long long value to a ::EVEL_JSON_BUFFER.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @param value The corresponding value to encode.
*****************************************************************************/
void evel_enc_kv_ull(EVEL_JSON_BUFFER * jbuf,
const char * const key,
const unsigned long long value)
{
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
assert(key != NULL);
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"%s\"%s\": %llu",
evel_json_kv_comma(jbuf),
key,
value);
EVEL_EXIT();
}
/**************************************************************************//**
* Encode a string key and time value to a ::EVEL_JSON_BUFFER.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @param option Pointer to holder of the corresponding value to encode.
* @return true if the key, value was added, false if it was suppressed.
*****************************************************************************/
bool evel_enc_kv_opt_time(EVEL_JSON_BUFFER * jbuf,
const char * const key,
const EVEL_OPTION_TIME * const option)
{
bool added = false;
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(option != NULL);
if (option->is_set)
{
if ((jbuf->depth == EVEL_THROTTLE_FIELD_DEPTH) &&
(jbuf->throttle_spec != NULL) &&
evel_throttle_suppress_field(jbuf->throttle_spec, key))
{
EVEL_INFO("Suppressed time: %s", key);
}
else
{
EVEL_DEBUG("Encoded time: %s", key);
evel_enc_kv_time(jbuf, key, &option->value);
added = true;
}
}
EVEL_EXIT();
return added;
}
/**************************************************************************//**
* Encode a string key and time value to a ::EVEL_JSON_BUFFER.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @param time Pointer to the time to encode.
*****************************************************************************/
void evel_enc_kv_time(EVEL_JSON_BUFFER * jbuf,
const char * const key,
const time_t * time)
{
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
assert(key != NULL);
assert(time != NULL);
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"%s\"%s\": \"",
evel_json_kv_comma(jbuf),
key);
jbuf->offset += strftime(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
EVEL_RFC2822_STRFTIME_FORMAT,
localtime(time));
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"\"");
EVEL_EXIT();
}
/**************************************************************************//**
* Encode a key and version.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @param major_version The major version to encode.
* @param minor_version The minor version to encode.
*****************************************************************************/
void evel_enc_version(EVEL_JSON_BUFFER * jbuf,
const char * const key,
const int major_version,
const int minor_version)
{
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
assert(key != NULL);
evel_enc_kv_int(jbuf, key, major_version);
if (minor_version != 0)
{
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
".%d",
minor_version);
}
EVEL_EXIT();
}
/**************************************************************************//**
* Add the key and opening bracket of an optional named list to a JSON buffer.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @return true if the list was opened, false if it was suppressed.
*****************************************************************************/
bool evel_json_open_opt_named_list(EVEL_JSON_BUFFER * jbuf,
const char * const key)
{
bool opened = false;
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
assert(key != NULL);
if ((jbuf->depth == EVEL_THROTTLE_FIELD_DEPTH) &&
(jbuf->throttle_spec != NULL) &&
evel_throttle_suppress_field(jbuf->throttle_spec, key))
{
EVEL_INFO("Suppressed: %s", key);
opened = false;
}
else
{
evel_json_open_named_list(jbuf, key);
opened = true;
}
EVEL_EXIT();
return opened;
}
/**************************************************************************//**
* Add the key and opening bracket of a named list to a JSON buffer.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
*****************************************************************************/
void evel_json_open_named_list(EVEL_JSON_BUFFER * jbuf,
const char * const key)
{
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
assert(key != NULL);
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"%s\"%s\": [",
evel_json_kv_comma(jbuf),
key);
jbuf->depth++;
EVEL_EXIT();
}
/**************************************************************************//**
* Add the closing bracket of a list to a JSON buffer.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
*****************************************************************************/
void evel_json_close_list(EVEL_JSON_BUFFER * jbuf)
{
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"]");
jbuf->depth--;
EVEL_EXIT();
}
/**************************************************************************//**
* Encode a list item with format and param list to a ::EVEL_JSON_BUFFER.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param format Format string in standard printf format.
* @param ... Variable parameters for format string.
*****************************************************************************/
void evel_enc_list_item(EVEL_JSON_BUFFER * jbuf,
const char * const format,
...)
{
va_list largs;
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
assert(format != NULL);
/***************************************************************************/
/* Add a comma unless we're at the start of the list. */
/***************************************************************************/
if (jbuf->json[jbuf->offset - 1] != '[')
{
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
", ");
}
va_start(largs, format);
jbuf->offset += vsnprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
format,
largs);
va_end(largs);
EVEL_EXIT();
}
/**************************************************************************//**
* Add the opening bracket of an optional named object to a JSON buffer.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
*****************************************************************************/
bool evel_json_open_opt_named_object(EVEL_JSON_BUFFER * jbuf,
const char * const key)
{
bool opened = false;
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
assert(key != NULL);
if ((jbuf->depth == EVEL_THROTTLE_FIELD_DEPTH) &&
(jbuf->throttle_spec != NULL) &&
evel_throttle_suppress_field(jbuf->throttle_spec, key))
{
EVEL_INFO("Suppressed: %s", key);
opened = false;
}
else
{
evel_json_open_named_object(jbuf, key);
opened = true;
}
EVEL_EXIT();
return opened;
}
/**************************************************************************//**
* Add the opening bracket of an object to a JSON buffer.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @param key Pointer to the key to encode.
* @return true if the object was opened, false if it was suppressed.
*****************************************************************************/
void evel_json_open_named_object(EVEL_JSON_BUFFER * jbuf,
const char * const key)
{
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
assert(key != NULL);
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"%s\"%s\": {",
evel_json_kv_comma(jbuf),
key);
jbuf->depth++;
EVEL_EXIT();
}
/**************************************************************************//**
* Add the opening bracket of an object to a JSON buffer.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
*****************************************************************************/
void evel_json_open_object(EVEL_JSON_BUFFER * jbuf)
{
char * comma;
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
if ((jbuf->offset != 0) && (jbuf->json[jbuf->offset-1] == '}'))
{
comma = ", ";
}
else
{
comma = "";
}
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"%s{",
comma);
jbuf->depth++;
EVEL_EXIT();
}
/**************************************************************************//**
* Add the closing bracket of an object to a JSON buffer.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
*****************************************************************************/
void evel_json_close_object(EVEL_JSON_BUFFER * jbuf)
{
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
jbuf->offset += snprintf(jbuf->json + jbuf->offset,
jbuf->max_size - jbuf->offset,
"}");
jbuf->depth--;
EVEL_EXIT();
}
/**************************************************************************//**
* Determine whether to add a comma when adding a key-value pair.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
* @returns A string containing the comma if it is required.
*****************************************************************************/
char * evel_json_kv_comma(EVEL_JSON_BUFFER * jbuf)
{
char * result;
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
if ((jbuf->offset == 0) ||
(jbuf->json[jbuf->offset-1] == '{') ||
(jbuf->json[jbuf->offset-1] == '['))
{
result = "";
}
else
{
result = ", ";
}
EVEL_EXIT();
return result;
}
/**************************************************************************//**
* Add a checkpoint - a stake in the ground to which we can rewind.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
*****************************************************************************/
void evel_json_checkpoint(EVEL_JSON_BUFFER * jbuf)
{
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
/***************************************************************************/
/* Store the current offset. */
/***************************************************************************/
jbuf->checkpoint = jbuf->offset;
EVEL_EXIT();
}
/**************************************************************************//**
* Rewind to the latest checkoint.
*
* @param jbuf Pointer to working ::EVEL_JSON_BUFFER.
*****************************************************************************/
void evel_json_rewind(EVEL_JSON_BUFFER * jbuf)
{
EVEL_ENTER();
/***************************************************************************/
/* Check preconditions. */
/***************************************************************************/
assert(jbuf != NULL);
assert(jbuf->checkpoint >= 0);
assert(jbuf->checkpoint <= jbuf->offset);
/***************************************************************************/
/* Reinstate the offset from the last checkpoint. */
/***************************************************************************/
jbuf->offset = jbuf->checkpoint;
jbuf->checkpoint = -1;
EVEL_EXIT();
}