# PSR-7 Message Implementation
This repository contains a full [PSR-7](http://www.php-fig.org/psr/psr-7/)
message implementation, several stream decorators, and some helpful
functionality like query string parsing.
[![Build Status](https://travis-ci.org/guzzle/psr7.svg?branch=master)](https://travis-ci.org/guzzle/psr7)
# Stream implementation
This package comes with a number of stream implementations and stream
decorators.
## AppendStream
`GuzzleHttp\Psr7\AppendStream`
Reads from multiple streams, one after the other.
```php
use GuzzleHttp\Psr7;
$a = Psr7\stream_for('abc, ');
$b = Psr7\stream_for('123.');
$composed = new Psr7\AppendStream([$a, $b]);
$composed->addStream(Psr7\stream_for(' Above all listen to me'));
echo $composed; // abc, 123. Above all listen to me.
```
## BufferStream
`GuzzleHttp\Psr7\BufferStream`
Provides a buffer stream that can be written to fill a buffer, and read
from to remove bytes from the buffer.
This stream returns a "hwm" metadata value that tells upstream consumers
what the configured high water mark of the stream is, or the maximum
preferred size of the buffer.
```php
use GuzzleHttp\Psr7;
// When more than 1024 bytes are in the buffer, it will begin returning
// false to writes. This is an indication that writers should slow down.
$buffer = new Psr7\BufferStream(1024);
```
## CachingStream
The CachingStream is used to allow seeking over previously read bytes on
non-seekable streams. This can be useful when transferring a non-seekable
entity body fails due to needing to rewind the stream (for example, resulting
from a redirect). Data that is read from the remote stream will be buffered in
a PHP temp stream so that previously read bytes are cached first in memory,
then on disk.
```php
use GuzzleHttp\Psr7;
$original = Psr7\stream_for(fopen('http://www.google.com', 'r'));
$stream = new Psr7\CachingStream($original);
$stream->read(1024);
echo $stream->tell();
// 1024
$stream->seek(0);
echo $stream->tell();
// 0
```
## DroppingStream
`GuzzleHttp\Psr7\DroppingStream`
Stream decorator that begins dropping data once the size of the underlying
stream becomes too full.
```php
use GuzzleHttp\Psr7;
// Create an empty stream
$stream = Psr7\stream_for();
// Start dropping data when the stream has more than 10 bytes
$dropping = new Psr7\DroppingStream($stream, 10);
$dropping->write('01234567890123456789');
echo $stream; // 0123456789
```
## FnStream
`GuzzleHttp\Psr7\FnStream`
Compose stream implementations based on a hash of functions.
Allows for easy testing and extension of a provided stream without needing
to create a concrete class for a simple extension point.
```php
use GuzzleHttp\Psr7;
$stream = Psr7\stream_for('hi');
$fnStream = Psr7\FnStream::decorate($stream, [
'rewind' => function () use ($stream) {
echo 'About to rewind - ';
$stream->rewind();
echo 'rewound!';
}
]);
$fnStream->rewind();
// Outputs: About to rewind - rewound!
```
## InflateStream
`GuzzleHttp\Psr7\InflateStream`
Uses PHP's zlib.inflate filter to inflate deflate or gzipped content.
This stream decorator skips the first 10 bytes of the given stream to remove
the gzip header, converts the provided stream to a PHP stream resource,
then appends the zlib.inflate filter. The stream is then converted back
to a Guzzle stream resource to be used as a Guzzle stream.
## LazyOpenStream
`GuzzleHttp\Psr7\LazyOpenStream`
Lazily reads or writes to a file that is opened only after an IO operation
take place on the stream.
```php
use GuzzleHttp\Psr7;
$stream = new Psr7\LazyOpenStream('/path/to/file', 'r');
// The file has not yet been opened...
echo $stream->read(10);
// The file is opened and read from only when needed.
```
## LimitStream
`GuzzleHttp\Psr7\LimitStream`
LimitStream can be used to read a subset or slice of an existing stream object.
This can be useful for breaking a large file into smaller pieces to be sent in
chunks (e.g. Amazon S3's multipart upload API).
```php
use GuzzleHttp\Psr7;
$original = Psr7\stream_for(fopen('/tmp/test.txt', 'r+'));
echo $original->getSize();
// >>> 1048576
// Limit the size of the body to 1024 bytes and start reading from byte 2048
$stream = new Psr7\LimitStream($original, 1024, 2048);
echo $stream->getSize();
// >>> 1024
echo $stream->tell();
// >>> 0
```
## MultipartStream
`GuzzleHttp\Psr7\MultipartStream`
Stream that when read returns bytes for a streaming multipart or
multipart/form-data stream.
## NoSeekStream
`GuzzleHttp\Psr7\NoSeekStream`
NoSeekStream wraps a stream and does not allow seeking.
```php
use GuzzleHttp\Psr7;
$original = Psr7\stream_for('foo');
$noSeek = new Psr7\NoSeekStream($original);
echo $noSeek->read(3);
// foo
var_export($noSeek->isSeekable());
// false
$noSeek->seek(0);
var_export($noSeek->read(3));
// NULL
```
## PumpStream
`GuzzleHttp\Psr7\PumpStream`
Provides a read only stream that pumps data from a PHP callable.
When invoking the provided callable, the PumpStream will pass the amount of
data requested to read to the callable. The callable can choose to ignore
this value and return fewer or more bytes than requested. Any extra data
returned by the provided callable is buffered internally until drained using
the read() function of the PumpStream. The provided callable MUST return
false when there is no more data to read.
## Implementing stream decorators
Creating a stream decorator is very easy thanks to the
`GuzzleHttp\Psr7\StreamDecoratorTrait`. This trait provides methods that
implement `Psr\Http\Message\StreamInterface` by proxying to an underlying
stream. Just `use` the `StreamDecoratorTrait` and implement your custom
methods.
For example, let's say we wanted to call a specific function each time the last
byte is read from a stream. This could be implemented by overriding the
`read()` method.
```php
use Psr\Http\Message\StreamInterface;
use GuzzleHttp\Psr7\StreamDecoratorTrait;
class EofCallbackStream implements StreamInterface
{
use StreamDecoratorTrait;
private $callback;
public function __construct(StreamInterface $stream, callable $cb)
{
$this->stream = $stream;
$this->callback = $cb;
}
public function read($length)
{
$result = $this->stream->read($length);
// Invoke the callback when EOF is hit.
if ($this->eof()) {
call_user_func($this->callback);
}
return $result;
}
}
```
This decorator could be added to any existing stream and used like so:
```php
use GuzzleHttp\Psr7;
$original = Psr7\stream_for('foo');
$eofStream = new EofCallbackStream($original, function () {
echo 'EOF!';
});
$eofStream->read(2);
$eofStream->read(1);
// echoes "EOF!"
$eofStream->seek(0);
$eofStream->read(3);
// echoes "EOF!"
```
## PHP StreamWrapper
You can use the `GuzzleHttp\Psr7\StreamWrapper` class if you need to use a
PSR-7 stream as a PHP stream resource.
Use the `GuzzleHttp\Psr7\StreamWrapper::getResource()` method to create a PHP
stream from a PSR-7 stream.
```php
use GuzzleHttp\Psr7\StreamWrapper;
$stream = GuzzleHttp\Psr7\stream_for('hello!');
$resource = StreamWrapper::getResource($stream);
echo fread($resource, 6); // outputs hello!
```
# Function API
There are various functions available under the `GuzzleHttp\Psr7` namespace.
## `function str`
`function str(MessageInterface $message)`
Returns the string representation of an HTTP message.
```php
$request = new GuzzleHttp\Psr7\Request('GET', 'http://example.com');
echo GuzzleHttp\Psr7\str($request);
```
## `function uri_for`
`function uri_for($uri)`
This function accepts a string or `Psr\Http\Message\UriInterface` and returns a
UriInterface for the given value. If the value is already a `UriInterface`, it
is returned as-is.
```php
$uri = GuzzleHttp\Psr7\uri_for('http://example.com');
assert($uri === GuzzleHttp\Psr7\uri_for($uri));
```
## `function stream_for`
`function stream_for($resource = '', array $options =
智慧浩海
- 粉丝: 1w+
- 资源: 5459
最新资源
- 基于RedisSpider分布式爬虫实现高分项目+详细文档+全部资料.zip
- 基于scrapy的大规模定向爬虫高分项目+详细文档+全部资料.zip
- 基于scrapy的爬虫,抓取新华财经文章存入ES做为语料高分项目+详细文档+全部资料.zip
- 基于scrapy框架的爬虫,用以爬取中药材和中西成药的信息高分项目+详细文档+全部资料.zip
- 基于SSM+maven+httpClient+jsoup实现的java爬虫项目,一个完整的小说网站高分项目+详细文档+全部资料.zip
- 基于Scrapy爬虫获取相关旅游信息,并将数据可视化此项目为出游选择目的地提供解决方案高分项目+详细文档+全部资料.zip
- 基于WebMagic的b站视频爬虫高分项目+详细文档+全部资料.zip
- Lecture 9-August 30 (Tutorial).pptx
- 焊接相关国内外标准汇编.pdf
- Lecture 10-August 31.pptx
- Web网页设计期末大作业(完美大作业).zip
- 基于WebMagic封装的垂直爬虫高分项目+详细文档+全部资料.zip
- 基于Winform的一套商家管理工具,用来练习界面布局,自动更新,事件,异步,多线程,网络请求,缓存使用,任务存储,设计模式,爬虫流程,反爬虫机制等高分项目+详细文档+全部资料.zip
- 基于爬虫和文本挖掘技术对知乎上的主题进行分析高分项目+详细文档+全部资料.zip
- 基于豆瓣电影的爬虫实例高分项目+详细文档+全部资料.zip
- 基于若依的爬虫百度云爬虫高分项目+详细文档+全部资料.zip
资源上传下载、课程学习等过程中有任何疑问或建议,欢迎提出宝贵意见哦~我们会及时处理!
点击此处反馈