83 lines
1.4 KiB
PHP
83 lines
1.4 KiB
PHP
<?php
|
|
|
|
namespace Machine\Memory;
|
|
|
|
use Countable;
|
|
use InvalidArgumentException;
|
|
use Program\Block;
|
|
use RuntimeException;
|
|
|
|
class MemoryController implements Countable
|
|
{
|
|
private ProgramMemory $memory;
|
|
public ?int $N = null;
|
|
/** @var Block[]|null */
|
|
private ?array $blockBuffer;
|
|
private int $index;
|
|
|
|
|
|
public function __construct(ProgramMemory $memory)
|
|
{
|
|
$this->memory = $memory;
|
|
$this->blockBuffer = null;
|
|
}
|
|
|
|
|
|
public function loadProgram(int $N): void
|
|
{
|
|
$program = $this->memory->read($N);
|
|
if (!$program) {
|
|
throw new InvalidArgumentException("Program N{$N} not found");
|
|
}
|
|
$this->N = $N;
|
|
$this->blockBuffer = $program->getIterator()->getArrayCopy();
|
|
$this->index = 0;
|
|
}
|
|
|
|
|
|
public function reset(): void
|
|
{
|
|
$this->N = null;
|
|
$this->blockBuffer = null;
|
|
$this->index = 0;
|
|
}
|
|
|
|
|
|
public function count()
|
|
{
|
|
return count($this->blockBuffer) - $this->index;
|
|
}
|
|
|
|
|
|
public function previous(): ?Block
|
|
{
|
|
$this->guardNoProgramLoaded();
|
|
$block = $this->blockBuffer[$this->index--];
|
|
|
|
return $block ? clone $block : null;
|
|
}
|
|
|
|
|
|
public function next(): ?Block
|
|
{
|
|
$this->guardNoProgramLoaded();
|
|
$block = $this->blockBuffer[$this->index++];
|
|
|
|
return $block ? clone $block : null;
|
|
}
|
|
|
|
|
|
public function ready(): bool
|
|
{
|
|
return $this->count() > 0;
|
|
}
|
|
|
|
|
|
private function guardNoProgramLoaded(): void
|
|
{
|
|
if (is_null($this->blockBuffer)) {
|
|
throw new RuntimeException('No program loaded in memory');
|
|
}
|
|
}
|
|
}
|