libcpp.cpp

来自「Thinking_in_C___2.rar」· C++ 代码 · 共 58 行

//: C04:Libcpp.cpp {O}
// From Thinking in C++, 2nd Edition
// at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// C library converted to C++
// Declare structure and functions:
#include <cstdlib> // Dynamic memory
#include <cstring> // memcpy()
#include <cstdio>
#include "../require.h" // Error testing code
#include "Libcpp.h"
using namespace std;

void Stash::initialize(int Size) {
  size = Size;
  quantity = 0;
  storage = 0;
  next = 0;
}

void Stash::cleanup() {
  if(storage) {
    puts("freeing storage");
    free(storage);
  }
}

int Stash::add(void* element) {
  if(next >= quantity) // Enough space left?
    inflate(100);
  // Copy element into storage,
  // starting at next empty space:
  memcpy(&(storage[next * size]),
         element, size);
  next++;
  return(next - 1); // Index number
}

void* Stash::fetch(int index) {
  if(index >= next || index < 0)
    return 0;  // Not out of bounds?
  // Produce pointer to desired element:
  return &(storage[index * size]);
}

int Stash::count() {
  return next; // Number of elements in Stash
}

void Stash::inflate(int increase) {
  void* v =
    realloc(storage, (quantity+increase)*size);
  require(v != 0);  // Was it successful?
  storage = (unsigned char*)v;
  quantity += increase;
} ///:~