磁盘非跨盘访问算法实现

1. 背景说明

本算法基于已将磁盘分布合并并排序为升序线性表。实现示例为：磁盘扇区大小：32（可自定义），待拆分磁盘内存： [0 - 50]，[60 - 100]（可增加）。示意图如下：

2. 示例代码

allocateAddr.c

/* 地址分配算法 */
 
#include 
#include 
 
#define MAX_SIZE 10
#define SEC_SIZE 32
 
typedef struct {
	int startAddr;
	int endAddr;
} IoAddr;
 
int GetUpBound(const IoAddr *addr)
{
	int i;
	for (i = 1; i <= SEC_SIZE; ++i) {
		if ((addr->startAddr + i) % SEC_SIZE == 0) {
			return i - 1;
		}
	}
 
	return 0;
}
 
int GetMin(int a, int b)
{
	return (a <= b) ? a : b;
}
 
IoAddr *Process(int addrSize, int *detaSize, IoAddr *addr)
{
	IoAddr *detatch = (IoAddr *)malloc(sizeof(IoAddr) * MAX_SIZE);
	int secLength;
	int upBound;
	*detaSize = 0;
	int min;
	for (int i = 0; i < addrSize; ++i) {
		secLength = (addr + i)->endAddr - (addr + i)->startAddr + 1;
		while (secLength) {
			upBound = GetUpBound(addr + i);
			min = GetMin(upBound, secLength - 1);
			detatch[*detaSize].startAddr = (addr + i)->startAddr;
			detatch[*detaSize].endAddr = (addr + i)->startAddr + min;
			++(*detaSize);
			(addr + i)->startAddr += (min + 1);
			if ((addr + i)->startAddr > (addr + i)->endAddr) {
				break;
			}
 
			secLength = (addr + i)->endAddr - (addr + i)->startAddr + 1;
		}
	}
 
	return detatch;
}
 
int main(void)
{
	IoAddr *memory = (IoAddr *)malloc(sizeof(IoAddr) * 2);
	memory[0].startAddr = 0;
	memory[0].endAddr = 50;
	memory[1].startAddr = 60;
	memory[1].endAddr = 100;
	int detaSize;
	IoAddr *detatch = Process(2, &detaSize, memory);
	printf("The allocation is as follows:\n\n");
	for (int i = 0; i < detaSize; ++i) {
		printf("[%-3d %-3d]\n", detatch[i].startAddr, detatch[i].endAddr);
	}
 
	free(memory);
	free(detatch);
 
	return 0;
}

3. 运行结果