README

提供PSR7 Stream和StreamFactory接口的实现

用法

• 创建Psr7 Stream

// ...
use Drewlabs\Psr7Stream\Stream;

// ...

// Creates PHP built-in streams such as php://memory and php://temp
$stream = Stream::new('', 'wb+');

• 流工厂

• 从PHP资源创建Psr7 Stream

// ...
use Drewlabs\Psr7Stream\StreamFactory;

// ...

// Create a PSR7 stream factory instance
$factory = new StreamFactory();

// Creates stream from resources
$stream = $factory->createStreamFromResource(fopen(__DIR__ . '/../../examples/test.txt', 'rb'));

• 从文件路径创建Psr7 Stream

// ...
use Drewlabs\Psr7Stream\StreamFactory;

// ...

// Create a PSR7 stream factory instance
$factory = new StreamFactory();

// Creates stream from path
$stream = $factory->createStreamFromFile(__DIR__ . '/../../examples/test.txt');

+v1.2x

从v1.2.x版本开始，添加了堆叠流实现和懒流实现。

• 堆叠流

堆叠流是对流接口的抽象，使用连续内存（数组）创建了一个StreamInterface实例的堆栈，并为整个组提供相同的流接口API。对于像close()、detach()、read()、getSize()等操作，每个项目将按插入的顺序进行访问。

创建堆叠流

use Drewlabs\Psr7Stream\StreamFactory as Factory;

$stream = Factory::stack();

// TO initialize the instance at contruction time
// The stream instance is initialized with 2 chunks
$stream = Factory::stack(Stream::new(''), Stream::new(__DIR__ . '/vendor/autoload.php'))

注意 堆叠流提供了两个额外的用于添加和删除元素的方法。

向堆栈中添加新的流

use Drewlabs\Psr7Stream\StreamFactory as Factory;

$stream = Factory::stack();

// Add a new stream instance
$stream->push(Stream::new('/path/to/resource'));

移除最后插入的堆栈

use Drewlabs\Psr7Stream\StreamFactory as Factory;

$stream = Factory::stack();

// Pop the last stream from the stack and return it
$s = $stream->pop();

警告 使用pop()方法时请小心，因为它会将流内部的指针重置，以避免数据损坏。

• 懒流

懒流是一个简单的流对象的抽象，只有在开发者准备好进行操作（如read()、write()等）时才会解析流。它提供了一个懒创建的PSR7 StreamInterface实例实现。

可以通过传递一个可调用来构造方法创建懒流

use Drewlabs\Psr7Stream\StreamFactory as Factory;
use Drewlabs\Psr7Stream\Stream;
use Drewlabs\Psr7Stream\LazyStream;
//

$stream_source = 'Hello world...';

$stream = Factory::lazy(function() use (&$stream_source) {
    return Stream::new($stream_source);
});

// Or using constructor

$stream = new LazyStream(function() use (&$stream_source) {
    return Stream::new($stream_source);
});

或使用CreatesStream接口的实例，它提供了一个面向对象的方式来创建新的流

use Drewlabs\Psr7Stream\CreatesStream;
use Drewlabs\Psr7Stream\Stream;

// CreateTextStream.php
class CreateTextStream implements CreatesStream
{
    /**
     * 
     * @var string
     * */
    private $source;

    public function __construct($source)
    {
        $this->source = $source;
    }

    public function createStream()
    {
        return Stream::new($this->source);
    }
}

// main.php
$stream = new LazyStream(new CreateTextStream('/path/to/resource'));

// Or using factory function
$stream = Factory::lazy(new CreateTextStream('/path/to/resource'));