#include <string.h>
#include "Buffer.h"
#include "General.h"
#include "config.h"

Buffer::Buffer() : Handle(-1), buffer(NULL), realsiz(0), bufsiz(0), ptr(0) { }

Buffer::~Buffer() {
    free(buffer);
}

ssize_t Buffer::write(const void *buf, size_t count) {
    if (count + realsiz > bufsiz) {
	int numblocks = (count + realsiz) / realloc_threshold;
	int remains = (count + realsiz) % realloc_threshold;
	buffer = (char *) realloc(buffer, bufsiz = ((numblocks + (remains ? 1 : 0)) * realloc_threshold));
    }
    memcpy(buffer + realsiz, buf, count);
    realsiz += count;
    
    return count;
}

ssize_t Buffer::read(void *buf, size_t count) {
    count = MIN(count, realsiz - ptr);
    
    if (!count) {
	return 0;
    }

    memcpy(buf, buffer + ptr, count);
    ptr += count;
    
    if (ptr >= realloc_threshold) {
	int numblocks = (bufsiz / realloc_threshold) - (ptr / realloc_threshold);
	memmove(buffer, buffer + numblocks * realloc_threshold, numblocks * realloc_threshold);
	buffer = (char *) realloc(buffer, bufsiz = (numblocks * realloc_threshold));
	ptr -= numblocks * realloc_threshold;
	realsiz -= numblocks * realloc_threshold;
    }
    
    return count;
}

bool Buffer::CanRead() {
    return true;
}

bool Buffer::CanWrite() {
    return true;
}

String Buffer::GetName() {
    return "Buffer";
}