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ProcessMemoryByteReader::offsetExists()   A

Complexity

Conditions 1
Paths 1

Size

Total Lines 3
Code Lines 1

Duplication

Lines 0
Ratio 0 %

Importance

Changes 0
Metric Value
cc 1
eloc 1
nc 1
nop 1
dl 0
loc 3
rs 10
c 0
b 0
f 0
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<?php
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/**
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 * This file is part of the sj-i/php-profiler package.
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 *
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 * (c) sji <[email protected]>
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 *
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 * For the full copyright and license information, please view the LICENSE
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 * file that was distributed with this source code.
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 */
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declare(strict_types=1);
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namespace PhpProfiler\Lib\ByteStream;
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use OutOfBoundsException;
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use PhpProfiler\Lib\Process\MemoryMap\ProcessModuleMemoryMapInterface;
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use PhpProfiler\Lib\Process\MemoryReader\MemoryReaderInterface;
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final class ProcessMemoryByteReader implements ByteReaderInterface
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{
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    use ByteReaderDisableWriteAccessTrait;
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    private const PAGE_SIZE = 8192;
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    private MemoryReaderInterface $memory_reader;
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    private int $pid;
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    private ProcessModuleMemoryMapInterface $memory_map;
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    /** @var CDataByteReader[] */
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    private array $pages = [];
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    /**
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     * ProcessMemoryByteReader constructor.
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     * @param MemoryReaderInterface $memory_reader
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     * @param int $pid
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     * @param ProcessModuleMemoryMapInterface $memory_map
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     */
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    public function __construct(
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        MemoryReaderInterface $memory_reader,
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        int $pid,
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        ProcessModuleMemoryMapInterface $memory_map
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    ) {
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        $this->memory_reader = $memory_reader;
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        $this->pid = $pid;
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        $this->memory_map = $memory_map;
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    }
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    public function offsetExists($offset): bool
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    {
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        return $this->memory_map->isInRange($offset);
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    }
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    public function offsetGet($offset): int
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    {
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        if (!isset($this[$offset])) {
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            throw new OutOfBoundsException();
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        }
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        $base_address = $this->memory_map->getBaseAddress();
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        $page = (int)($offset / self::PAGE_SIZE);
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        $page_block = $this->locatePage($page, $base_address);
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        $diff = 0;
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        if ($page * self::PAGE_SIZE < $base_address) {
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            $diff = $base_address - $page * self::PAGE_SIZE;
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        }
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        return $page_block[($offset % self::PAGE_SIZE) - $diff];
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    }
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    private function locatePage(int $page, int $base_address): CDataByteReader
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    {
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        if (!isset($this->pages[$page])) {
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            $this->pages[$page] = new CDataByteReader(
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                $this->memory_reader->read(
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                    $this->pid,
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                    max($base_address, $page * self::PAGE_SIZE),
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                    self::PAGE_SIZE
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                )
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            );
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        }
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        return $this->pages[$page];
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    }
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    public function createSliceAsString(int $offset, int $size): string
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    {
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        $result = '';
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        for ($i = $offset; $i < ($offset + $size); $i++) {
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            $result .= chr($this[$i]);
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        }
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        return $result;
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    }
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}
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