#include <stdio.h>
#include <string.h>
#include <fstream.h>

#include "cbuffer.h"


ostream& operator<<(ostream& o, cbuffer& b)
{
	size_t maxitem = 5;
	for(size_t i=0; i<b.len(); i++) {
		o << b[i] << '\t';
		if(((i+1) % maxitem)==0)
			o << endl;
	}
	o << endl;
	return o;
}

// 將第n個值設為d，如果引用數大于1，則克隆出一個新的
// 復數緩存區，再作設置，返回作了設置的緩存區指針
cbuffer* cbuffer::set(size_t n, COMPLEX d)
{
	DOUBLE x,y;
	if(doadjust) {
		x = real(d);
		y = imag(d);
		d = COMPLEX(adjust(x),adjust(y));
	}
	if(refnum == 1) {
		retrieve(n) = d;
		return this;
	}
	refnum --;
	cbuffer * b;
	b = clone();
	(b->retrieve(n)) = d;
	return b;
}

// 克隆一個完全一樣的緩存區
cbuffer* memcbuffer::clone()
{
	cbuffer* b;
	b = new memcbuffer(length);
	if(length > 0)
		for(size_t i=0; i<length; i++)
			(b->retrieve(i)) = (*this)[i];
	return b;
}

// 磁盤緩存區構造函數，打開臨時文件
diskcbuffer::diskcbuffer(size_t lth):cbuffer(),length(lth),n(0)
{
	tempfp = tmpfile();
}


// 析構函數，關閉臨時文件
diskcbuffer::~diskcbuffer()
{
	fclose(tempfp);
}

// 將緩存區尺寸改為num
void diskcbuffer::alloc(size_t num)
{
	length = num;
	if(!tempfp)
		tempfp = tmpfile();
	n = 0;
}

// 釋放緩存區，關閉臨時文件
void diskcbuffer::release()
{
	fclose(tempfp);
	buf = 0.0;
	length = 0;
}

// 返回第i個復數的引用，先將當前buf中的內容寫入臨時文件
COMPLEX& diskcbuffer::retrieve(size_t i)
{
	long off;
	off = n*sizeof(COMPLEX);
	fseek(tempfp, off, SEEK_SET);
	fwrite(&buf, sizeof(COMPLEX), 1, tempfp);
	off = i*sizeof(COMPLEX);
	fseek(tempfp, off, SEEK_SET);
	fread(&buf, sizeof(COMPLEX), 1, tempfp);
	n = i;
	return buf;
}

// 克隆一個內容完全相同的磁盤緩存區
cbuffer* diskcbuffer::clone()
{
	cbuffer* b;
	b = new diskcbuffer(length);
	if(length > 0)
		for(size_t i=0; i<length; i++)
			(b->retrieve(i)) = (*this)[i];
	return b;
}