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<?php
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/**
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 * This file is part of FPDI
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 *
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 * @package   setasign\Fpdi
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 * @copyright Copyright (c) 2023 Setasign GmbH & Co. KG (https://www.setasign.com)
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 * @license   http://opensource.org/licenses/mit-license The MIT License
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 */
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namespace setasign\Fpdi\PdfParser;
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/**
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 * A tokenizer class.
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 */
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class Tokenizer
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{
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    /**
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     * @var StreamReader
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     */
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    protected $streamReader;
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    /**
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     * A token stack.
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     *
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     * @var string[]
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     */
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    protected $stack = [];
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    /**
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     * Tokenizer constructor.
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     *
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     * @param StreamReader $streamReader
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     */
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    public function __construct(StreamReader $streamReader)
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    {
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        $this->streamReader = $streamReader;
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    }
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    /**
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     * Get the stream reader instance.
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     *
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     * @return StreamReader
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     */
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    public function getStreamReader()
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    {
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        return $this->streamReader;
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    }
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    /**
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     * Clear the token stack.
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     */
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    public function clearStack()
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    {
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        $this->stack = [];
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    }
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    /**
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     * Push a token onto the stack.
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     *
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     * @param string $token
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     */
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    public function pushStack($token)
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    {
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        $this->stack[] = $token;
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    }
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    /**
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     * Get next token.
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     *
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     * @return bool|string
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     */
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    public function getNextToken()
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    {
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        $token = \array_pop($this->stack);
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        if ($token !== null) {
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            return $token;
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        }
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        if (($byte = $this->streamReader->readByte()) === false) {
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            return false;
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        }
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        if (\in_array($byte, ["\x20", "\x0A", "\x0D", "\x0C", "\x09", "\x00"], true)) {
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            if ($this->leapWhiteSpaces() === false) {
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                return false;
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            }
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            $byte = $this->streamReader->readByte();
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        }
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        switch ($byte) {
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            case '/':
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            case '[':
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            case ']':
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            case '(':
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            case ')':
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            case '{':
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            case '}':
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            case '<':
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            case '>':
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                return $byte;
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            case '%':
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                $this->streamReader->readLine();
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                return $this->getNextToken();
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        }
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        /* This way is faster than checking single bytes.
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         */
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        $bufferOffset = $this->streamReader->getOffset();
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        do {
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            $lastBuffer = $this->streamReader->getBuffer(false);
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            $pos = \strcspn(
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                $lastBuffer,
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                "\x00\x09\x0A\x0C\x0D\x20()<>[]{}/%",
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                $bufferOffset
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            );
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        } while (
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            // Break the loop if a delimiter or white space char is matched
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            // in the current buffer or increase the buffers length
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            $lastBuffer !== false &&
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            (
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                $bufferOffset + $pos === \strlen($lastBuffer) &&
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                $this->streamReader->increaseLength()
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            )
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        );
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        $result = \substr($lastBuffer, $bufferOffset - 1, $pos + 1);
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        $this->streamReader->setOffset($bufferOffset + $pos);
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        return $result;
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    }
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    /**
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     * Leap white spaces.
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     *
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     * @return boolean
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     */
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    public function leapWhiteSpaces()
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    {
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        do {
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            if (!$this->streamReader->ensureContent()) {
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                return false;
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            }
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            $buffer = $this->streamReader->getBuffer(false);
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            $matches = \strspn($buffer, "\x20\x0A\x0C\x0D\x09\x00", $this->streamReader->getOffset());
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            if ($matches > 0) {
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                $this->streamReader->addOffset($matches);
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            }
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        } while ($this->streamReader->getOffset() >= $this->streamReader->getBufferLength());
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        return true;
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    }
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}