Bunch of changes including mpdf library for creating pdf of invoices. It now attaches a PDF invoice when marked sent. Don't mark invoice_status sent if it partial or paid, removed green text from balance under clients only use red if the client has a balance and some other cleanups were done

vendor/setasign/fpdi/src/PdfParser/CrossReference/AbstractReader.php

@@ -0,0 +1,96 @@
+<?php
+/**
+ * This file is part of FPDI
+ *
+ * @package   setasign\Fpdi
+ * @copyright Copyright (c) 2019 Setasign - Jan Slabon (https://www.setasign.com)
+ * @license   http://opensource.org/licenses/mit-license The MIT License
+ */
+
+namespace setasign\Fpdi\PdfParser\CrossReference;
+
+use setasign\Fpdi\PdfParser\PdfParser;
+use setasign\Fpdi\PdfParser\Type\PdfDictionary;
+use setasign\Fpdi\PdfParser\Type\PdfToken;
+use setasign\Fpdi\PdfParser\Type\PdfTypeException;
+
+/**
+ * Abstract class for cross-reference reader classes.
+ *
+ * @package setasign\Fpdi\PdfParser\CrossReference
+ */
+abstract class AbstractReader
+{
+    /**
+     * @var PdfParser
+     */
+    protected $parser;
+
+    /**
+     * @var PdfDictionary
+     */
+    protected $trailer;
+
+    /**
+     * AbstractReader constructor.
+     *
+     * @param PdfParser $parser
+     * @throws CrossReferenceException
+     * @throws PdfTypeException
+     */
+    public function __construct(PdfParser $parser)
+    {
+        $this->parser = $parser;
+        $this->readTrailer();
+    }
+
+    /**
+     * Get the trailer dictionary.
+     *
+     * @return PdfDictionary
+     */
+    public function getTrailer()
+    {
+        return $this->trailer;
+    }
+
+    /**
+     * Read the trailer dictionary.
+     *
+     * @throws CrossReferenceException
+     * @throws PdfTypeException
+     */
+    protected function readTrailer()
+    {
+        try {
+            $trailerKeyword = $this->parser->readValue(null, PdfToken::class);
+            if ($trailerKeyword->value !== 'trailer') {
+                throw new CrossReferenceException(
+                    \sprintf(
+                        'Unexpected end of cross reference. "trailer"-keyword expected, got: %s.',
+                        $trailerKeyword->value
+                    ),
+                    CrossReferenceException::UNEXPECTED_END
+                );
+            }
+        } catch (PdfTypeException $e) {
+            throw new CrossReferenceException(
+                'Unexpected end of cross reference. "trailer"-keyword expected, got an invalid object type.',
+                CrossReferenceException::UNEXPECTED_END,
+                $e
+            );
+        }
+
+        try {
+            $trailer = $this->parser->readValue(null, PdfDictionary::class);
+        } catch (PdfTypeException $e) {
+            throw new CrossReferenceException(
+                'Unexpected end of cross reference. Trailer not found.',
+                CrossReferenceException::UNEXPECTED_END,
+                $e
+            );
+        }
+
+        $this->trailer = $trailer;
+    }
+}

vendor/setasign/fpdi/src/PdfParser/CrossReference/CrossReference.php

@@ -0,0 +1,320 @@
+<?php
+/**
+ * This file is part of FPDI
+ *
+ * @package   setasign\Fpdi
+ * @copyright Copyright (c) 2019 Setasign - Jan Slabon (https://www.setasign.com)
+ * @license   http://opensource.org/licenses/mit-license The MIT License
+ */
+
+namespace setasign\Fpdi\PdfParser\CrossReference;
+
+use setasign\Fpdi\PdfParser\PdfParser;
+use setasign\Fpdi\PdfParser\Type\PdfDictionary;
+use setasign\Fpdi\PdfParser\Type\PdfIndirectObject;
+use setasign\Fpdi\PdfParser\Type\PdfNumeric;
+use setasign\Fpdi\PdfParser\Type\PdfStream;
+use setasign\Fpdi\PdfParser\Type\PdfToken;
+use setasign\Fpdi\PdfParser\Type\PdfTypeException;
+
+/**
+ * Class CrossReference
+ *
+ * This class processes the standard cross reference of a PDF document.
+ *
+ * @package setasign\Fpdi\PdfParser\CrossReference
+ */
+class CrossReference
+{
+    /**
+     * The byte length in which the "startxref" keyword should be searched.
+     *
+     * @var int
+     */
+    static public $trailerSearchLength = 5500;
+
+    /**
+     * @var int
+     */
+    protected $fileHeaderOffset = 0;
+
+    /**
+     * @var PdfParser
+     */
+    protected $parser;
+
+    /**
+     * @var ReaderInterface[]
+     */
+    protected $readers = [];
+
+    /**
+     * CrossReference constructor.
+     *
+     * @param PdfParser $parser
+     * @throws CrossReferenceException
+     * @throws PdfTypeException
+     */
+    public function __construct(PdfParser $parser, $fileHeaderOffset = 0)
+    {
+        $this->parser = $parser;
+        $this->fileHeaderOffset = $fileHeaderOffset;
+
+        $offset = $this->findStartXref();
+        $reader = null;
+        /** @noinspection TypeUnsafeComparisonInspection */
+        while ($offset != false) { // By doing an unsafe comparsion we ignore faulty references to byte offset 0
+            try {
+                $reader = $this->readXref($offset + $this->fileHeaderOffset);
+            } catch (CrossReferenceException $e) {
+                // sometimes the file header offset is part of the byte offsets, so let's retry by resetting it to zero.
+                if ($e->getCode() === CrossReferenceException::INVALID_DATA && $this->fileHeaderOffset !== 0) {
+                    $this->fileHeaderOffset = 0;
+                    $reader = $this->readXref($offset + $this->fileHeaderOffset);
+                } else {
+                    throw $e;
+                }
+            }
+
+            $trailer = $reader->getTrailer();
+            $this->checkForEncryption($trailer);
+            $this->readers[] = $reader;
+
+            if (isset($trailer->value['Prev'])) {
+                $offset = $trailer->value['Prev']->value;
+            } else {
+                $offset = false;
+            }
+        }
+
+        // fix faulty sub-section header
+        if ($reader instanceof FixedReader) {
+            /**
+             * @var FixedReader $reader
+             */
+            $reader->fixFaultySubSectionShift();
+        }
+
+        if ($reader === null) {
+            throw new CrossReferenceException('No cross-reference found.', CrossReferenceException::NO_XREF_FOUND);
+        }
+    }
+
+    /**
+     * Get the size of the cross reference.
+     *
+     * @return integer
+     */
+    public function getSize()
+    {
+        return $this->getTrailer()->value['Size']->value;
+    }
+
+    /**
+     * Get the trailer dictionary.
+     *
+     * @return PdfDictionary
+     */
+    public function getTrailer()
+    {
+        return $this->readers[0]->getTrailer();
+    }
+
+    /**
+     * Get the cross reference readser instances.
+     *
+     * @return ReaderInterface[]
+     */
+    public function getReaders()
+    {
+        return $this->readers;
+    }
+
+    /**
+     * Get the offset by an object number.
+     *
+     * @param int $objectNumber
+     * @return integer|bool
+     */
+    public function getOffsetFor($objectNumber)
+    {
+        foreach ($this->getReaders() as $reader) {
+            $offset = $reader->getOffsetFor($objectNumber);
+            if ($offset !== false) {
+                return $offset;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Get an indirect object by its object number.
+     *
+     * @param int $objectNumber
+     * @return PdfIndirectObject
+     * @throws CrossReferenceException
+     */
+    public function getIndirectObject($objectNumber)
+    {
+        $offset = $this->getOffsetFor($objectNumber);
+        if ($offset === false) {
+            throw new CrossReferenceException(
+                \sprintf('Object (id:%s) not found.', $objectNumber),
+                CrossReferenceException::OBJECT_NOT_FOUND
+            );
+        }
+
+        $parser = $this->parser;
+
+        $parser->getTokenizer()->clearStack();
+        $parser->getStreamReader()->reset($offset + $this->fileHeaderOffset);
+
+        try {
+            /** @var PdfIndirectObject $object */
+            $object = $parser->readValue(null, PdfIndirectObject::class);
+        } catch (PdfTypeException $e) {
+            throw new CrossReferenceException(
+                \sprintf('Object (id:%s) not found at location (%s).', $objectNumber, $offset),
+                CrossReferenceException::OBJECT_NOT_FOUND,
+                $e
+            );
+        }
+
+        if ($object->objectNumber !== $objectNumber) {
+            throw new CrossReferenceException(
+                \sprintf('Wrong object found, got %s while %s was expected.', $object->objectNumber, $objectNumber),
+                CrossReferenceException::OBJECT_NOT_FOUND
+            );
+        }
+
+        return $object;
+    }
+
+    /**
+     * Read the cross-reference table at a given offset.
+     *
+     * Internally the method will try to evaluate the best reader for this cross-reference.
+     *
+     * @param int $offset
+     * @return ReaderInterface
+     * @throws CrossReferenceException
+     * @throws PdfTypeException
+     */
+    protected function readXref($offset)
+    {
+        $this->parser->getStreamReader()->reset($offset);
+        $this->parser->getTokenizer()->clearStack();
+        $initValue = $this->parser->readValue();
+        
+        return $this->initReaderInstance($initValue);
+    }
+
+    /**
+     * Get a cross-reference reader instance.
+     *
+     * @param PdfToken|PdfIndirectObject $initValue
+     * @return ReaderInterface|bool
+     * @throws CrossReferenceException
+     * @throws PdfTypeException
+     */
+    protected function initReaderInstance($initValue)
+    {
+        $position = $this->parser->getStreamReader()->getPosition()
+            + $this->parser->getStreamReader()->getOffset() + $this->fileHeaderOffset;
+
+        if ($initValue instanceof PdfToken && $initValue->value === 'xref') {
+            try {
+                return new FixedReader($this->parser);
+            } catch (CrossReferenceException $e) {
+                $this->parser->getStreamReader()->reset($position);
+                $this->parser->getTokenizer()->clearStack();
+
+                return new LineReader($this->parser);
+            }
+        }
+
+        if ($initValue instanceof PdfIndirectObject) {
+            // check for encryption
+            $stream = PdfStream::ensure($initValue->value);
+
+            $type = PdfDictionary::get($stream->value, 'Type');
+            if ($type->value !== 'XRef') {
+                throw new CrossReferenceException(
+                    'The xref position points to an incorrect object type.',
+                    CrossReferenceException::INVALID_DATA
+                );
+            }
+
+            $this->checkForEncryption($stream->value);
+
+            throw new CrossReferenceException(
+                'This PDF document probably uses a compression technique which is not supported by the ' .
+                'free parser shipped with FPDI. (See https://www.setasign.com/fpdi-pdf-parser for more details)',
+                CrossReferenceException::COMPRESSED_XREF
+            );
+        }
+
+        throw new CrossReferenceException(
+            'The xref position points to an incorrect object type.',
+            CrossReferenceException::INVALID_DATA
+        );
+    }
+
+    /**
+     * Check for encryption.
+     *
+     * @param PdfDictionary $dictionary
+     * @throws CrossReferenceException
+     */
+    protected function checkForEncryption(PdfDictionary $dictionary)
+    {
+        if (isset($dictionary->value['Encrypt'])) {
+            throw new CrossReferenceException(
+                'This PDF document is encrypted and cannot be processed with FPDI.',
+                CrossReferenceException::ENCRYPTED
+            );
+        }
+    }
+
+    /**
+     * Find the start position for the first cross-reference.
+     *
+     * @return int The byte-offset position of the first cross-reference.
+     * @throws CrossReferenceException
+     */
+    protected function findStartXref()
+    {
+        $reader = $this->parser->getStreamReader();
+        $reader->reset(-self::$trailerSearchLength, self::$trailerSearchLength);
+
+        $buffer = $reader->getBuffer(false);
+        $pos = \strrpos($buffer, 'startxref');
+        $addOffset = 9;
+        if ($pos === false) {
+            // Some corrupted documents uses startref, instead of startxref
+            $pos = \strrpos($buffer, 'startref');
+            if ($pos === false) {
+                throw new CrossReferenceException(
+                    'Unable to find pointer to xref table',
+                    CrossReferenceException::NO_STARTXREF_FOUND
+                );
+            }
+            $addOffset = 8;
+        }
+
+        $reader->setOffset($pos + $addOffset);
+
+        try {
+            $value = $this->parser->readValue(null, PdfNumeric::class);
+        } catch (PdfTypeException $e) {
+            throw new CrossReferenceException(
+                'Invalid data after startxref keyword.',
+                CrossReferenceException::INVALID_DATA,
+                $e
+            );
+        }
+
+        return $value->value;
+    }
+}

vendor/setasign/fpdi/src/PdfParser/CrossReference/CrossReferenceException.php

@@ -0,0 +1,80 @@
+<?php
+/**
+ * This file is part of FPDI
+ *
+ * @package   setasign\Fpdi
+ * @copyright Copyright (c) 2019 Setasign - Jan Slabon (https://www.setasign.com)
+ * @license   http://opensource.org/licenses/mit-license The MIT License
+ */
+
+namespace setasign\Fpdi\PdfParser\CrossReference;
+
+use setasign\Fpdi\PdfParser\PdfParserException;
+
+/**
+ * Exception used by the CrossReference and Reader classes.
+ *
+ * @package setasign\Fpdi\PdfParser\CrossReference
+ */
+class CrossReferenceException extends PdfParserException
+{
+    /**
+     * @var int
+     */
+    const INVALID_DATA = 0x0101;
+
+    /**
+     * @var int
+     */
+    const XREF_MISSING = 0x0102;
+
+    /**
+     * @var int
+     */
+    const ENTRIES_TOO_LARGE = 0x0103;
+
+    /**
+     * @var int
+     */
+    const ENTRIES_TOO_SHORT = 0x0104;
+
+    /**
+     * @var int
+     */
+    const NO_ENTRIES = 0x0105;
+
+    /**
+     * @var int
+     */
+    const NO_TRAILER_FOUND = 0x0106;
+
+    /**
+     * @var int
+     */
+    const NO_STARTXREF_FOUND = 0x0107;
+
+    /**
+     * @var int
+     */
+    const NO_XREF_FOUND = 0x0108;
+
+    /**
+     * @var int
+     */
+    const UNEXPECTED_END = 0x0109;
+
+    /**
+     * @var int
+     */
+    const OBJECT_NOT_FOUND = 0x010A;
+
+    /**
+     * @var int
+     */
+    const COMPRESSED_XREF = 0x010B;
+
+    /**
+     * @var int
+     */
+    const ENCRYPTED = 0x010C;
+}

vendor/setasign/fpdi/src/PdfParser/CrossReference/FixedReader.php

@@ -0,0 +1,196 @@
+<?php
+/**
+ * This file is part of FPDI
+ *
+ * @package   setasign\Fpdi
+ * @copyright Copyright (c) 2019 Setasign - Jan Slabon (https://www.setasign.com)
+ * @license   http://opensource.org/licenses/mit-license The MIT License
+ */
+
+namespace setasign\Fpdi\PdfParser\CrossReference;
+
+use setasign\Fpdi\PdfParser\PdfParser;
+use setasign\Fpdi\PdfParser\StreamReader;
+
+/**
+ * Class FixedReader
+ *
+ * This reader allows a very less overhead parsing of single entries of the cross-reference, because the main entries
+ * are only read when needed and not in a single run.
+ *
+ * @package setasign\Fpdi\PdfParser\CrossReference
+ */
+class FixedReader extends AbstractReader implements ReaderInterface
+{
+    /**
+     * @var StreamReader
+     */
+    protected $reader;
+
+    /**
+     * Data of subsections.
+     *
+     * @var array
+     */
+    protected $subSections;
+
+    /**
+     * FixedReader constructor.
+     *
+     * @param PdfParser $parser
+     * @throws CrossReferenceException
+     */
+    public function __construct(PdfParser $parser)
+    {
+        $this->reader = $parser->getStreamReader();
+        $this->read();
+        parent::__construct($parser);
+    }
+
+    /**
+     * Get all subsection data.
+     *
+     * @return array
+     */
+    public function getSubSections()
+    {
+        return $this->subSections;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getOffsetFor($objectNumber)
+    {
+        foreach ($this->subSections as $offset => list($startObject, $objectCount)) {
+            if ($objectNumber >= $startObject && $objectNumber < ($startObject + $objectCount)) {
+                $position = $offset + 20 * ($objectNumber - $startObject);
+                $this->reader->ensure($position, 20);
+                $line = $this->reader->readBytes(20);
+                if ($line[17] === 'f') {
+                    return false;
+                }
+
+                return (int) \substr($line, 0, 10);
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Read the cross-reference.
+     *
+     * This reader will only read the subsections in this method. The offsets were resolved individually by this
+     * information.
+     *
+     * @throws CrossReferenceException
+     */
+    protected function read()
+    {
+        $subSections = [];
+
+        $startObject = $entryCount = $lastLineStart = null;
+        $validityChecked = false;
+        while (($line = $this->reader->readLine(20)) !== false) {
+            if (\strpos($line, 'trailer') !== false) {
+                $this->reader->reset($lastLineStart);
+                break;
+            }
+
+            // jump over if line content doesn't match the expected string
+            if (\sscanf($line, '%d %d', $startObject, $entryCount) !== 2) {
+                continue;
+            }
+
+            $oldPosition = $this->reader->getPosition();
+            $position = $oldPosition + $this->reader->getOffset();
+
+            if (!$validityChecked && $entryCount > 0) {
+                $nextLine = $this->reader->readBytes(21);
+                /* Check the next line for maximum of 20 bytes and not longer
+                 * By catching 21 bytes and trimming the length should be still 21.
+                 */
+                if (\strlen(\trim($nextLine)) !== 21) {
+                    throw new CrossReferenceException(
+                        'Cross-reference entries are larger than 20 bytes.',
+                        CrossReferenceException::ENTRIES_TOO_LARGE
+                    );
+                }
+
+                /* Check for less than 20 bytes: cut the line to 20 bytes and trim; have to result in exactly 18 bytes.
+                 * If it would have less bytes the substring would get the first bytes of the next line which would
+                 * evaluate to a 20 bytes long string after trimming.
+                 */
+                if (\strlen(\trim(\substr($nextLine, 0, 20))) !== 18) {
+                    throw new CrossReferenceException(
+                        'Cross-reference entries are less than 20 bytes.',
+                        CrossReferenceException::ENTRIES_TOO_SHORT
+                    );
+                }
+
+                $validityChecked = true;
+            }
+
+            $subSections[$position] = [$startObject, $entryCount];
+
+            $lastLineStart = $position + $entryCount * 20;
+            $this->reader->reset($lastLineStart);
+        }
+
+        // reset after the last correct parsed line
+        $this->reader->reset($lastLineStart);
+
+        if (\count($subSections) === 0) {
+            throw new CrossReferenceException(
+                'No entries found in cross-reference.',
+                CrossReferenceException::NO_ENTRIES
+            );
+        }
+
+        $this->subSections = $subSections;
+    }
+
+    /**
+     * Fixes an invalid object number shift.
+     *
+     * This method can be used to repair documents with an invalid subsection header:
+     *
+     * <code>
+     * xref
+     * 1 7
+     * 0000000000 65535 f
+     * 0000000009 00000 n
+     * 0000412075 00000 n
+     * 0000412172 00000 n
+     * 0000412359 00000 n
+     * 0000412417 00000 n
+     * 0000412468 00000 n
+     * </code>
+     *
+     * It shall only be called on the first table.
+     *
+     * @return bool
+     */
+    public function fixFaultySubSectionShift()
+    {
+        $subSections = $this->getSubSections();
+        if (\count($subSections) > 1) {
+            return false;
+        }
+
+        $subSection = \current($subSections);
+        if ($subSection[0] != 1) {
+            return false;
+        }
+
+        if ($this->getOffsetFor(1) === false) {
+            foreach ($subSections as $offset => list($startObject, $objectCount)) {
+                $this->subSections[$offset] = [$startObject - 1, $objectCount];
+            }
+            return true;
+        }
+
+        return false;
+    }
+}

vendor/setasign/fpdi/src/PdfParser/CrossReference/LineReader.php

@@ -0,0 +1,173 @@
+<?php
+/**
+ * This file is part of FPDI
+ *
+ * @package   setasign\Fpdi
+ * @copyright Copyright (c) 2019 Setasign - Jan Slabon (https://www.setasign.com)
+ * @license   http://opensource.org/licenses/mit-license The MIT License
+ */
+
+namespace setasign\Fpdi\PdfParser\CrossReference;
+
+use setasign\Fpdi\PdfParser\PdfParser;
+use setasign\Fpdi\PdfParser\StreamReader;
+
+/**
+ * Class LineReader
+ *
+ * This reader class read all cross-reference entries in a single run.
+ * It supports reading cross-references with e.g. invalid data (e.g. entries with a length < or > 20 bytes).
+ *
+ * @package setasign\Fpdi\PdfParser\CrossReference
+ */
+class LineReader extends AbstractReader implements ReaderInterface
+{
+    /**
+     * The object offsets.
+     *
+     * @var array
+     */
+    protected $offsets;
+
+    /**
+     * LineReader constructor.
+     *
+     * @param PdfParser $parser
+     * @throws CrossReferenceException
+     */
+    public function __construct(PdfParser $parser)
+    {
+        $this->read($this->extract($parser->getStreamReader()));
+        parent::__construct($parser);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getOffsetFor($objectNumber)
+    {
+        if (isset($this->offsets[$objectNumber])) {
+            return $this->offsets[$objectNumber][0];
+        }
+
+        return false;
+    }
+
+    /**
+     * Get all found offsets.
+     *
+     * @return array
+     */
+    public function getOffsets()
+    {
+        return $this->offsets;
+    }
+
+    /**
+     * Extracts the cross reference data from the stream reader.
+     *
+     * @param StreamReader $reader
+     * @return string
+     * @throws CrossReferenceException
+     */
+    protected function extract(StreamReader $reader)
+    {
+        $cycles = -1;
+        $bytesPerCycle = 100;
+
+        $reader->reset(null, $bytesPerCycle);
+
+        while (
+            ($trailerPos = \strpos($reader->getBuffer(false), 'trailer', \max($bytesPerCycle * $cycles++, 0))) === false
+        ) {
+            if ($reader->increaseLength($bytesPerCycle) === false) {
+                break;
+            }
+        }
+
+        if ($trailerPos === false) {
+            throw new CrossReferenceException(
+                'Unexpected end of cross reference. "trailer"-keyword not found.',
+                CrossReferenceException::NO_TRAILER_FOUND
+            );
+        }
+
+        $xrefContent = \substr($reader->getBuffer(false), 0, $trailerPos);
+        $reader->reset($reader->getPosition() + $trailerPos);
+
+        return $xrefContent;
+    }
+
+    /**
+     * Read the cross-reference entries.
+     *
+     * @param string $xrefContent
+     * @throws CrossReferenceException
+     */
+    protected function read($xrefContent)
+    {
+        // get eol markers in the first 100 bytes
+        \preg_match_all("/(\r\n|\n|\r)/", \substr($xrefContent, 0, 100), $m);
+
+        if (\count($m[0]) === 0) {
+            throw new CrossReferenceException(
+                'No data found in cross-reference.',
+                CrossReferenceException::INVALID_DATA
+            );
+        }
+
+        // count(array_count_values()) is faster then count(array_unique())
+        // @see https://github.com/symfony/symfony/pull/23731
+        // can be reverted for php7.2
+        $differentLineEndings = \count(\array_count_values($m[0]));
+        if ($differentLineEndings > 1) {
+            $lines = \preg_split("/(\r\n|\n|\r)/", $xrefContent, -1, PREG_SPLIT_NO_EMPTY);
+        } else {
+            $lines = \explode($m[0][0], $xrefContent);
+        }
+
+        unset($differentLineEndings, $m);
+        $linesCount = \count($lines);
+        $start = null;
+        $entryCount = 0;
+
+        $offsets = [];
+
+        /** @noinspection ForeachInvariantsInspection */
+        for ($i = 0; $i < $linesCount; $i++) {
+            $line = \trim($lines[$i]);
+            if ($line) {
+                $pieces = \explode(' ', $line);
+
+                $c = \count($pieces);
+                switch ($c) {
+                    case 2:
+                        $start = (int) $pieces[0];
+                        $entryCount += (int) $pieces[1];
+                        break;
+
+                    /** @noinspection PhpMissingBreakStatementInspection */
+                    case 3:
+                        switch ($pieces[2]) {
+                            case 'n':
+                                $offsets[$start] = [(int) $pieces[0], (int) $pieces[1]];
+                                $start++;
+                                break 2;
+                            case 'f':
+                                $start++;
+                                break 2;
+                        }
+                        // fall through if pieces doesn't match
+
+                    default:
+                        throw new CrossReferenceException(
+                            \sprintf('Unexpected data in xref table (%s)', \implode(' ', $pieces)),
+                            CrossReferenceException::INVALID_DATA
+                        );
+                }
+            }
+        }
+
+        $this->offsets = $offsets;
+    }
+}

vendor/setasign/fpdi/src/PdfParser/CrossReference/ReaderInterface.php

@@ -0,0 +1,35 @@
+<?php
+/**
+ * This file is part of FPDI
+ *
+ * @package   setasign\Fpdi
+ * @copyright Copyright (c) 2019 Setasign - Jan Slabon (https://www.setasign.com)
+ * @license   http://opensource.org/licenses/mit-license The MIT License
+ */
+
+namespace setasign\Fpdi\PdfParser\CrossReference;
+
+use setasign\Fpdi\PdfParser\Type\PdfDictionary;
+
+/**
+ * ReaderInterface for cross-reference readers.
+ *
+ * @package setasign\Fpdi\PdfParser\CrossReference
+ */
+interface ReaderInterface
+{
+    /**
+     * Get an offset by an object number.
+     *
+     * @param int $objectNumber
+     * @return int|bool False if the offset was not found.
+     */
+    public function getOffsetFor($objectNumber);
+
+    /**
+     * Get the trailer related to this cross reference.
+     *
+     * @return PdfDictionary
+     */
+    public function getTrailer();
+}