toys/sww/source/dynamic_buffer.c

#include "dynamic_buffer.h"

int DynamicBuffer_Reserve(DynamicBuffer *o, size_t new_capacity) {
  int succ = 0;

  if (o->capacity < new_capacity) {
    void *tmp_buffer = realloc(o->buffer, new_capacity);

    if (tmp_buffer == NULL) {
      goto func_end;
    }

    o->capacity = new_capacity;
    o->buffer = tmp_buffer;
  }

  succ = 1;

func_end:

  return succ;
}

int DynamicBuffer_ResetBuffer(DynamicBuffer *o, size_t position) {
  int succ = 0;

  /// position should never larger than buffer size!
  assert(position <= o->size);

  if (position > o->size) {
    printf("[E] Failed to reset buffer: position is larger than buffer size!");
    goto func_end;
  }

  if (position != o->size) {
    memmove(o->buffer, (uint8_t *)o->buffer + position, o->size - position);
  }

  o->size -= position;

  succ = 1;

func_end:

  return succ;
}

int DynamicBuffer_Resize(DynamicBuffer *o, size_t new_size) {
  if (o->size <= new_size) {
    o->size = new_size;
    return 1;
  }

  if (!DynamicBuffer_Reserve(o, new_size)) {
    return 0;
  }

  o->size = new_size;

  return 1;
}

/// FIXME(anjingyu): Assume never overflow!
void DynamicBuffer_Append(DynamicBuffer *o, const void *buffer, size_t size) {
  size_t new_size = o->capacity;

  while (o->size + size > new_size) {
    new_size <<= 1;
  }

  DynamicBuffer_Reserve(o, new_size);

  memmove((uint8_t *)o->buffer + o->size, buffer, size);
  o->size += size;
}

void *AutoReleasePool_Alloc(AutoReleasePool *o, size_t size) {
  size_t new_size = o->capacity;
  void *r = NULL;

  while (o->size + size > new_size) {
    new_size <<= 1;
  }

  DynamicBuffer_Reserve(o, new_size);

  r = (uint8_t *)o->buffer + o->size;
  o->size += size;

  return r;
}