pocketlang/src/buffers.h

/*
 *  Copyright (c) 2021 Thakee Nathees
 *  Licensed under: MIT License
 */

#ifndef BUFFERS_TEMPLATE_H
#define BUFFERS_TEMPLATE_H

#include "common.h"

// The macro 'DECLARE_BUFFER()' emulate the C++ template to declare and define
// different types of buffer objects.

// A buffer of type 'T' will contain a heap allocated array of 'T' with the
// capacity of 'Tbuffer.capacity' as 'T* Tbuffer.data'. When the capacity is
// filled with 'T' values (ie. Tbuffer.count == Tbuffer.capacity) the buffer's
// internal data array will be reallocate to a capacity of 'GROW_FACTOR' times
// it's last capacity.


#define DECLARE_BUFFER(M__NAME, M__NAME_L, M__TYPE)                            \
  typedef struct {                                                             \
    M__TYPE* data;                                                             \
    uint32_t count;                                                            \
    uint32_t capacity;                                                         \
  } M__NAME##Buffer;                                                           \
                                                                               \
  /* Initialize a new buffer int instance. */                                  \
  void M__NAME_L##BufferInit(M__NAME##Buffer* self);                           \
                                                                               \
  /* Clears the allocated elementes from the VM's realloc function. */         \
  void M__NAME_L##BufferClear(M__NAME##Buffer* self, PKVM* vm);                \
                                                                               \
  /* Ensure the capacity is greater than [size], if not resize. */             \
  void M__NAME_L##BufferReserve(M__NAME##Buffer* self, PKVM* vm, size_t size); \
                                                                               \
  /* Fill the buffer at the end of it with provided data if the capacity */    \
  /*  isn't enough using VM's realloc function. */                             \
  void M__NAME_L##BufferFill(M__NAME##Buffer* self, PKVM* vm,                  \
                             M__TYPE data, int count);                         \
                                                                               \
  /* Write to the buffer with provided data at the end of the buffer.*/        \
  void M__NAME_L##BufferWrite(M__NAME##Buffer* self,                           \
                              PKVM* vm, M__TYPE data);                         \


DECLARE_BUFFER(Uint, uint, uint32_t)
DECLARE_BUFFER(Byte, byte, uint8_t)
DECLARE_BUFFER(Var, var, Var)
DECLARE_BUFFER(String, string, String*)
DECLARE_BUFFER(Function, function, Function*)

// Add all the characters to the buffer, byte buffer can also be used as a
// buffer to write string (like a string stream).
void ByteBufferAddString(ByteBuffer* self, PKVM* vm, const char* str,
                         uint32_t length);

#undef DECLARE_BUFFER

#endif // BUFFERS_TEMPLATE_H