rtl_433/include/data.h
2019-02-13 16:36:32 +01:00

195 lines
7.1 KiB
C

/** @file
A general structure for extracting hierarchical data from the devices;
typically key-value pairs, but allows for more rich data as well.
Copyright (C) 2015 by Erkki Seppälä <flux@modeemi.fi>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef INCLUDE_DATA_H_
#define INCLUDE_DATA_H_
#include <stdio.h>
#if defined(_MSC_VER) && !defined(__clang__)
/*
* MSVC have no support for "Variable Length Arrays"
* But compiling using 'clang-cl', '_MSC_VER' is a built-in. Hence use VLA
* for Clang in that case.
* With no VLAs, we need 'alloca()' which is in '<malloc.h>' etc.
*/
#include <malloc.h>
#define RTL_433_NO_VLAs
// MSVC has something like C99 restrict as __restrict
#ifndef restrict
#define restrict __restrict
#endif
#endif
/*
* The only place '<strings.h>' is currenly needed is in 'src/devices/flex.c'.
* But it's cleaner to keep such trivia here.
*/
#ifdef _MSC_VER
#include <string.h>
#define strcasecmp(s1,s2) _stricmp(s1,s2)
#define strncasecmp(s1,s2,n) _strnicmp(s1,s2,n)
#else
#include <strings.h>
#endif
typedef enum {
DATA_DATA, /**< pointer to data is stored */
DATA_INT, /**< pointer to integer is stored */
DATA_DOUBLE, /**< pointer to a double is stored */
DATA_STRING, /**< pointer to a string is stored */
DATA_ARRAY, /**< pointer to an array of values is stored */
DATA_COUNT, /**< invalid */
DATA_FORMAT /**< indicates the following value is formatted */
} data_type_t;
typedef struct data_array {
int num_values;
data_type_t type;
void *values;
} data_array_t;
typedef struct data {
char *key;
char *pretty_key; /**< the name used for displaying data to user in with a nicer name */
data_type_t type;
char *format; /**< if not null, contains special formatting string */
void *value;
unsigned retain; /**< incremented on data_retain, data_free only frees if this is zero */
struct data *next; /**< chaining to the next element in the linked list; NULL indicates end-of-list */
} data_t;
/** Constructs a structured data object.
Example:
data_make(
"key", "Pretty key", DATA_INT, 42,
"others", "More data", DATA_DATA, data_make("foo", DATA_DOUBLE, 42.0, NULL),
"zoom", NULL, data_array(2, DATA_STRING, (char*[]){"hello", "World"}),
"double", "Double", DATA_DOUBLE, 10.0/3,
NULL);
Most of the time the function copies perhaps what you expect it to. Things
it copies:
- string contents for keys and values
- numerical arrays
- string arrays (copied deeply)
Things it moves:
- recursive data_t* and data_array_t* values
The rule is: if an object is boxed (look at the dmt structure in the data.c)
and it has a array_elementwise_import in the same structure, then it is
copied deeply. Otherwise, it is copied shallowly.
@param key Name of the first value to put in.
@param pretty_key Pretty name for the key. Use "" if to omit pretty label for this field completely,
or NULL if to use key name for it.
@param type Type of the first value to put in.
@param ... The value of the first value to put in, followed by the rest of the
key-type-values. The list is terminated with a NULL.
@return A constructed data_t* object or NULL if there was a memory allocation error.
*/
data_t *data_make(const char *key, const char *pretty_key, ...);
/** Adds to a structured data object, by appending data.
@see data_make()
*/
data_t *data_append(data_t *first, const char *key, const char *pretty_key, ...);
/** Adds to a structured data object, by prepending data.
@see data_make()
*/
data_t *data_prepend(data_t *first, const char *key, const char *pretty_key, ...);
/** Constructs an array from given data of the given uniform type.
@param ptr The contents pointed by the argument are copied in.
@return The constructed data array object, typically placed inside a data_t or NULL
if there was a memory allocation error.
*/
data_array_t *data_array(int num_values, data_type_t type, void *ptr);
/** Releases a data array. */
void data_array_free(data_array_t *array);
/** Retain a structure object, returns the structure object passed in. */
data_t *data_retain(data_t *data);
/** Releases a structure object if retain is zero, decrement retain otherwise. */
void data_free(data_t *data);
struct data_output;
typedef struct data_output {
void (*print_data)(struct data_output *output, data_t *data, char *format);
void (*print_array)(struct data_output *output, data_array_t *data, char *format);
void (*print_string)(struct data_output *output, const char *data, char *format);
void (*print_double)(struct data_output *output, double data, char *format);
void (*print_int)(struct data_output *output, int data, char *format);
void (*output_start)(struct data_output *output, const char **fields, int num_fields);
void (*output_poll)(struct data_output *output);
void (*output_free)(struct data_output *output);
FILE *file;
} data_output_t;
/** Construct data output for CSV printer.
@param file the output stream
@return The auxiliary data to pass along with data_csv_printer to data_print.
You must release this object with data_output_free once you're done with it.
*/
struct data_output *data_output_csv_create(FILE *file);
struct data_output *data_output_json_create(FILE *file);
struct data_output *data_output_kv_create(FILE *file);
struct data_output *data_output_syslog_create(const char *host, const char *port);
/** Setup known field keys and start output, used by CSV only.
@param output the data_output handle from data_output_x_create
@param fields the list of fields to accept and expect. Array is copied, but the actual
strings not. The list may contain duplicates and they are eliminated.
@param num_fields number of fields
*/
void data_output_start(struct data_output *output, const char **fields, int num_fields);
/** Prints a structured data object. */
void data_output_print(struct data_output *output, data_t *data);
/** Allows to polls an event loop, if necessary. */
void data_output_poll(struct data_output *output);
void data_output_free(struct data_output *output);
/* data output helpers */
void print_value(data_output_t *output, data_type_t type, void *value, char *format);
void print_array_value(data_output_t *output, data_array_t *array, char *format, int idx);
#endif // INCLUDE_DATA_H_