File Iterator

Ссылка GitHub

Установка

php composer.phar require --prefer-dist jumper423/file-iterator

или

"jumper423/yfile-iterator": "*"

в файле composer.json.

Использование

$fileIterator = new \jumper423\FileIterator(__DIR__ . '/file');
$fileIterator->rewind();
$fileIterator->next();
$fileIterator->next();
$fileIterator->seek(3);
$fileIterator->next();
echo $fileIterator->current();
$fileIterator->next();
echo $fileIterator->current();
$fileIterator->seek(9);
$fileIterator->next();
$fileIterator->next();
if ($fileIterator->valid()) {
    ...
}

Покрыт тестами

vendor/bin/phpunit 

Ссылка GitHub

<?php

namespace jumper423;

class File
{
    private static $instances = [];

    public static function getInstance(string $path)
    {
        if (!array_key_exists($path, self::$instances)) {
            self::$instances[$path] = new self($path);
        }
        return self::$instances[$path];
    }

    private $handle;
    private $strings = [];
    private $count;

    public function __construct(string $path)
    {
        $this->count = 0;
        $this->handle = fopen($path, "r");
        $this->definitionStrings();
    }

    private function definitionStrings()
    {
        while (fgets($this->handle) !== false) {
            $this->strings[] = ftell($this->handle);
            ++$this->count;
        }
    }

    public function getCount(){
        return $this->count;
    }

    public function getString(int $index) {
        if ($index >= $this->getCount()) {
            throw new \Exception('Not');
        }
        if ($index === 0){
            fseek($this->handle, 0);
        } else {
            fseek($this->handle, $this->strings[$index - 1]);
        }
        return rtrim(fgets($this->handle), "\r\n");
    }
}

<?php

namespace jumper423;

class FileIterator implements \SeekableIterator
{
    private $position;

    /**
     * @var File
     */
    private $file;

    public function __construct($path)
    {
        $this->file = File::getInstance($path);
    }

    public function seek($position)
    {
        if ($position < 0 || $position >= $this->file->getCount()) {
            throw new \OutOfBoundsException("invalid seek position ($position)");
        }
        $this->position = $position;
    }

    public function rewind()
    {
        $this->position = 0;
    }

    public function current()
    {
        return $this->file->getString($this->position);
    }

    public function key()
    {
        return $this->position;
    }

    public function next()
    {
        ++$this->position;
    }

    public function valid()
    {
        return $this->position < $this->file->getCount();
    }
}