View Code - 20260723

« Back to History

Delimiter.php | 20260723_000646.php Initial Domain Snapshot

<?php

namespace PhpOffice\PhpSpreadsheet\Reader\Csv;

class Delimiter
{
    protected const POTENTIAL_DELIMITERS = [',', ';', "\t", '|', ':', ' ', '~'];

/** @var resource */
    protected $fileHandle;

protected string $escapeCharacter;

protected string $enclosure;

/** @var array<string, int[]> */
    protected array $counts = [];

protected int $numberLines = 0;

protected ?string $delimiter = null;

/**
     * @param resource $fileHandle
     */
    public function __construct($fileHandle, string $escapeCharacter, string $enclosure)
    {
        $this->fileHandle = $fileHandle;
        $this->escapeCharacter = $escapeCharacter;
        $this->enclosure = $enclosure;

$this->countPotentialDelimiters();
    }

public function getDefaultDelimiter(): string
    {
        return self::POTENTIAL_DELIMITERS[0];
    }

public function linesCounted(): int
    {
        return $this->numberLines;
    }

protected function countPotentialDelimiters(): void
    {
        $this->counts = array_fill_keys(self::POTENTIAL_DELIMITERS, []);
        $delimiterKeys = array_flip(self::POTENTIAL_DELIMITERS);

// Count how many times each of the potential delimiters appears in each line
        $this->numberLines = 0;
        while (($line = $this->getNextLine()) !== false && (++$this->numberLines < 1000)) {
            $this->countDelimiterValues($line, $delimiterKeys);
        }
    }

/** @param array<string, int> $delimiterKeys */
    protected function countDelimiterValues(string $line, array $delimiterKeys): void
    {
        $splitString = mb_str_split($line, 1, 'UTF-8');
        $distribution = array_count_values($splitString);
        $countLine = array_intersect_key($distribution, $delimiterKeys);

foreach (self::POTENTIAL_DELIMITERS as $delimiter) {
            $this->counts[$delimiter][] = $countLine[$delimiter] ?? 0;
        }
    }

public function infer(): ?string
    {
        // Calculate the mean square deviations for each delimiter
        //     (ignoring delimiters that haven't been found consistently)
        $meanSquareDeviations = [];
        $middleIdx = (int) floor(($this->numberLines - 1) / 2);

foreach (self::POTENTIAL_DELIMITERS as $delimiter) {
            $series = $this->counts[$delimiter];
            sort($series);

$median = ($this->numberLines % 2)
                ? $series[$middleIdx]
                : ($series[$middleIdx] + $series[$middleIdx + 1]) / 2;

if ($median === 0) {
                continue;
            }

$meanSquareDeviations[$delimiter] = array_reduce(
                $series,
                fn ($sum, $value): int|float => $sum + ($value - $median) ** 2
            ) / count($series);
        }

// ... and pick the delimiter with the smallest mean square deviation
        //         (in case of ties, the order in potentialDelimiters is respected)
        $min = INF;
        foreach (self::POTENTIAL_DELIMITERS as $delimiter) {
            if (!isset($meanSquareDeviations[$delimiter])) {
                continue;
            }

if ($meanSquareDeviations[$delimiter] < $min) {
                $min = $meanSquareDeviations[$delimiter];
                $this->delimiter = $delimiter;
            }
        }

return $this->delimiter;
    }

/**
     * Get the next full line from the file.
     *
     * @return false|string
     */
    public function getNextLine()
    {
        $line = '';
        $enclosure = ($this->escapeCharacter === '' ? ''
                : ('(?<!' . preg_quote($this->escapeCharacter, '/') . ')'))
            . preg_quote($this->enclosure, '/');

do {
            // Get the next line in the file
            $newLine = fgets($this->fileHandle);

// Return false if there is no next line
            if ($newLine === false) {
                return false;
            }

// Add the new line to the line passed in
            $line = $line . $newLine;

// Drop everything that is enclosed to avoid counting false positives in enclosures
            $line = (string) preg_replace('/(' . $enclosure . '.*' . $enclosure . ')/Us', '', $line);

// See if we have any enclosures left in the line
            // if we still have an enclosure then we need to read the next line as well
        } while (preg_match('/(' . $enclosure . ')/', $line) > 0);

return ($line !== '') ? $line : false;
    }
}