PenguinBuffer/CircularBuffer/inc/PCircularBuffer.h

// Resource/Inspiration: https://embedjournal.com/implementing-circular-buffer-embedded-c/

/*
	Penguin's Circular Buffer -- a simple floating queue designed for low memory usage (mainly for embedded)

	This is a ring buffer with limited capabilities. It is meant as a container for moving data.
	Normally included features such as checks to see if the buffer is full or empty have been omitted
	because this type of buffer is being implemented mainly for sensor data usage. Data is almost never read
   individually, and even if it is, it isn't meant to be cleared on read. It is a simple moving buffer that
   automatically writes over old data for the purpose of keeping track of the most up to date data.

	Notes:
	 - Initialization is mandatory using p_cb_<type>_init.
	 - If a circular buffer is not initialized, you will run into a LOT of hard-to-debug problems. Just initialize it.
	 - By default, all cb types should be defined as disabled. This is to save on size. Enable the ones you want to use.

	Behavior:
	 - Oldest data is overwritten
	 - popping of data isn't implemented. If this feature is required, use a ring buffer.

	Acronyms:
	 - p: penguin
	 - pb: penguin buffer
	 - cb: circular buffer
	 - uX, where X is bit size: unsigned X bit integer
	 - iX, where X is bit size: signed X bit integer
*/

#ifndef _PCIRCULARBUFFER_H_
#define _PCIRCULARBUFFER_H_

#include <stdbool.h>
#include <stdint.h>

// comment this out for release builds
//#define PB_CB_DEBUG

// Making these PB_EN/DIS rather than just ENABLE/DISABLE because
// some enable/disable definition might already exist that is
// inversely active (enabled = 0, disable = 1)
// this way our en/dis definitions are explicit
#ifndef PB_ENABLE
#define PB_ENABLE (1)
#endif

#ifndef PB_DISABLE
#define PB_DISABLE (0)
#endif

// Max size is 65535 (2^16 - 1) so variables can be safely set 16 bits (unsigned)
// If you want to change this, you'll need to change the sizes of all heads and max lengths
#define PB_CB_MAX_BUFFER_SIZE (65535)

// Config
// Disable or Enable types needed here
// We can save code size this way
// While there are better ways to do this, this is the most accessible for anyone imo
#define PB_CB_FLOAT PB_DISABLE
#define PB_CB_DOUBLE PB_ENABLE
#define PB_CB_U8 PB_DISABLE
#define PB_CB_U16 PB_DISABLE
#define PB_CB_U32 PB_DISABLE
#define PB_CB_U64 PB_DISABLE
#define PB_CB_I8 PB_DISABLE
#define PB_CB_I16 PB_DISABLE
#define PB_CB_I32 PB_DISABLE
#define PB_CB_I64 PB_DISABLE

typedef enum PB_CB_STATUS
{
	PB_CB_GOOD = 0,
	PB_CB_BAD = 1,
	PB_CB_BAD_BUFFER_SIZE = 2,
	PB_CB_NULL_BUFFER = 3,
	PB_CB_NULL_CBUFFER = 4
} PB_CB_STATUS;

#if PB_CB_U8
typedef struct p_cb_u8
{
	uint8_t *buffer;
	uint16_t head;
	uint16_t max_len;
	// Signifies the buffer being filled at least once.
	// Useful for initializing sensor data
	bool b_filled;
	// Signifies the buffer being empty
	// Useful for knowing if data is being received
	bool b_empty;

	PB_CB_STATUS (*push)(struct p_cb_u8 *cbuffer, uint8_t value);
	PB_CB_STATUS (*empty)(struct p_cb_u8 *cbuffer);
} p_cb_u8;

PB_CB_STATUS p_cb_u8_init(p_cb_u8 *circ_buffer, uint8_t *buff, uint32_t max_length);
#endif

#if PB_CB_U16
typedef struct p_cb_u16
{
	uint16_t *buffer;
	uint16_t head;
	uint16_t max_len;
	// Signifies the buffer being filled at least once.
	// Useful for initializing sensor data
	bool b_filled;
	// Signifies the buffer being empty
	// Useful for knowing if data is being received
	bool b_empty;

	PB_CB_STATUS (*push)(struct p_cb_u16 *cbuffer, uint16_t value);
	PB_CB_STATUS (*empty)(struct p_cb_u16 *cbuffer);
} p_cb_u16;

PB_CB_STATUS p_cb_u16_init(p_cb_u16 *circ_buffer, uint16_t *buff, uint32_t max_length);
#endif

#if PB_CB_U32
typedef struct p_cb_u32
{
	uint32_t *buffer;
	uint16_t head;
	uint16_t max_len;
	// Signifies the buffer being filled at least once.
	// Useful for initializing sensor data
	bool b_filled;
	// Signifies the buffer being empty
	// Useful for knowing if data is being received
	bool b_empty;

	PB_CB_STATUS (*push)(struct p_cb_u32 *cbuffer, uint32_t value);
	PB_CB_STATUS (*empty)(struct p_cb_u32 *cbuffer);
} p_cb_u32;

PB_CB_STATUS p_cb_u32_init(p_cb_u32 *circ_buffer, uint32_t *buff, uint32_t max_length);
#endif

#if PB_CB_U64
typedef struct p_cb_u64
{
	uint64_t *buffer;
	uint16_t head;
	uint16_t max_len;
	// Signifies the buffer being filled at least once.
	// Useful for initializing sensor data
	bool b_filled;
	// Signifies the buffer being empty
	// Useful for knowing if data is being received
	bool b_empty;

	PB_CB_STATUS (*push)(struct p_cb_u64 *cbuffer, uint64_t value);
	PB_CB_STATUS (*empty)(struct p_cb_u64 *cbuffer);
} p_cb_u64;

PB_CB_STATUS p_cb_u64_init(p_cb_u64 *circ_buffer, uint64_t *buff, uint32_t max_length);
#endif

#if PB_CB_FLOAT
typedef struct p_cb_float
{
	float *buffer;
	uint16_t head;
	uint16_t max_len;
	// Signifies the buffer being filled at least once.
	// Useful for initializing sensor data
	bool b_filled;
	// Signifies the buffer being empty
	// Useful for knowing if data is being received
	bool b_empty;

	PB_CB_STATUS (*push)(struct p_cb_float *cbuffer, float value);
	PB_CB_STATUS (*empty)(struct p_cb_float *cbuffer);
} p_cb_float;

PB_CB_STATUS p_cb_float_init(p_cb_float *circ_buffer, float *buff, uint32_t max_length);
#endif

#if PB_CB_DOUBLE
typedef struct p_cb_double
{
	double *buffer;
	uint16_t head;
	uint16_t max_len;
	// Signifies the buffer being filled at least once.
	// Useful for initializing sensor data
	bool b_filled;
	// Signifies the buffer being empty
	// Useful for knowing if data is being received
	bool b_empty;

	PB_CB_STATUS (*push)(struct p_cb_double *cbuffer, double value);
	PB_CB_STATUS (*empty)(struct p_cb_double *cbuffer);
} p_cb_double;

PB_CB_STATUS p_cb_double_init(p_cb_double *circ_buffer, double *buff, uint32_t max_length);
#endif

#endif