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/* Copyright (C) 2023 Aryadev Chavali
* You may distribute and modify this code under the terms of the
* GPLv2 license. You should have received a copy of the GPLv2
* license with this file. If not, please write to:
* aryadev@aryadevchavali.com.
* Created: 2023-10-15
* Author: Aryadev Chavali
* Description: Dynamically sized byte array
*/
#ifndef DARR_H
#define DARR_H
#include <stdio.h>
#include <stdlib.h>
#include "./base.h"
/**
* A dynamically sized buffer of bytes which may be used for a
* variety of purposes.
* @prop data: Buffer of bytes (may be reallocated)
* @prop used: Number of bytes currently used
* @prop available: Number of bytes currently allocated
*/
typedef struct
{
byte *data;
size_t used, available;
} darr_t;
/* Some useful constants for dynamic array work. */
#define DARR_DEFAULT_SIZE 8
#define DARR_REALLOC_MULT 1.5
/** Get the INDth item in a darr, where the buffer of bytes is
* considerd an array of type TYPE.
* Unsafe operation as safety checks are not done (in particular if
* the dynamic array has IND items or is big enough to store an
* element of TYPE) so it is presumed the caller will.
*/
#define DARR_AT(TYPE, DARR_DATA, IND) ((TYPE *)(DARR_DATA))[(IND)]
/** Initialise a dynamic array (darr) with n elements.
* If n == 0 then initialise with DARR_DEFAULT_SIZE elements.
*/
void darr_init(darr_t *darr, size_t n);
/** Ensure the dynamic array (darr) has at least n elements free.
* If the dynamic array has less than n elements free it will
* reallocate.
*/
void darr_ensure_capacity(darr_t *darr, size_t n);
/** Append a byte (b) to the dynamic array (darr).
* If the dynamic array doesn't have enough space it will reallocate
* to ensure it can fit it in.
*/
void darr_append_byte(darr_t *darr, byte b);
/** Append an array of n bytes (b) to the dynamic array (darr).
* If the dynamic array doesn't have enough space to fit all n bytes
* it will reallocate to ensure it can fit it in.
*/
void darr_append_bytes(darr_t *darr, byte *b, size_t n);
/** Safely get the nth byte of the dynamic array (darr)
* If the dynamic array has less than n bytes used, it will return 0
* as a default value.
*/
byte darr_at(darr_t *darr, size_t n);
/** Write the dynamic array (darr) to the file pointer (fp) as a
* buffer of bytes.
* Assumes fp is a valid file pointer and in write mode.
*/
void darr_write_file(darr_t *, FILE *);
/** Read a file pointer (fp) in its entirety, converting the bytes
* into a tightly fitted dynamic array.
* Say the file pointer is a file of n bytes. Then the dynamic array
* returned will have available set to n and used set to 0.
*/
darr_t darr_read_file(FILE *);
#endif
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