3.4 Psr\Http\Message\StreamInterface

<?php
namespace Psr\Http\Message;

/**
 * Describes a data stream.
 *
 * Typically, an instance will wrap a PHP stream; this interface provides
 * a wrapper around the most common operations, including serialization of
 * the entire stream to a string.
 */
interface StreamInterface
{
    /**
     * Reads all data from the stream into a string, from the beginning to end.
     *
     * This method MUST attempt to seek to the beginning of the stream before
     * reading data and read the stream until the end is reached.
     *
     * Warning: This could attempt to load a large amount of data into memory.
     *
     * This method MUST NOT raise an exception in order to conform with PHP's
     * string casting operations.
     *
     * @see http://php.net/manual/en/language.oop5.magic.php#object.tostring
     * @return string
     */
    public function __toString();

    /**
     * Closes the stream and any underlying resources.
     *
     * @return void
     */
    public function close();

    /**
     * Separates any underlying resources from the stream.
     *
     * After the stream has been detached, the stream is in an unusable state.
     *
     * @return resource|null Underlying PHP stream, if any
     */
    public function detach();

    /**
     * Get the size of the stream if known.
     *
     * @return int|null Returns the size in bytes if known, or null if unknown.
     */
    public function getSize();

    /**
     * Returns the current position of the file read/write pointer
     *
     * @return int Position of the file pointer
     * @throws \RuntimeException on error.
     */
    public function tell();

    /**
     * Returns true if the stream is at the end of the stream.
     *
     * @return bool
     */
    public function eof();

    /**
     * Returns whether or not the stream is seekable.
     *
     * @return bool
     */
    public function isSeekable();

    /**
     * Seek to a position in the stream.
     *
     * @see http://www.php.net/manual/en/function.fseek.php
     * @param int $offset Stream offset
     * @param int $whence Specifies how the cursor position will be calculated
     *     based on the seek offset. Valid values are identical to the built-in
     *     PHP $whence values for `fseek()`.  SEEK_SET: Set position equal to
     *     offset bytes SEEK_CUR: Set position to current location plus offset
     *     SEEK_END: Set position to end-of-stream plus offset.
     * @throws \RuntimeException on failure.
     */
    public function seek($offset, $whence = SEEK_SET);

    /**
     * Seek to the beginning of the stream.
     *
     * If the stream is not seekable, this method will raise an exception;
     * otherwise, it will perform a seek(0).
     *
     * @see seek()
     * @see http://www.php.net/manual/en/function.fseek.php
     * @throws \RuntimeException on failure.
     */
    public function rewind();

    /**
     * Returns whether or not the stream is writable.
     *
     * @return bool
     */
    public function isWritable();

    /**
     * Write data to the stream.
     *
     * @param string $string The string that is to be written.
     * @return int Returns the number of bytes written to the stream.
     * @throws \RuntimeException on failure.
     */
    public function write($string);

    /**
     * Returns whether or not the stream is readable.
     *
     * @return bool
     */
    public function isReadable();

    /**
     * Read data from the stream.
     *
     * @param int $length Read up to $length bytes from the object and return
     *     them. Fewer than $length bytes may be returned if underlying stream
     *     call returns fewer bytes.
     * @return string Returns the data read from the stream, or an empty string
     *     if no bytes are available.
     * @throws \RuntimeException if an error occurs.
     */
    public function read($length);

    /**
     * Returns the remaining contents in a string
     *
     * @return string
     * @throws \RuntimeException if unable to read.
     * @throws \RuntimeException if error occurs while reading.
     */
    public function getContents();

    /**
     * Get stream metadata as an associative array or retrieve a specific key.
     *
     * The keys returned are identical to the keys returned from PHP's
     * stream_get_meta_data() function.
     *
     * @see http://php.net/manual/en/function.stream-get-meta-data.php
     * @param string $key Specific metadata to retrieve.
     * @return array|mixed|null Returns an associative array if no key is
     *     provided. Returns a specific key value if a key is provided and the
     *     value is found, or null if the key is not found.
     */
    public function getMetadata($key = null);
}

3.5 Psr\Http\Message\UriInterface

<?php
namespace Psr\Http\Message;

/**
 * URI 数据对象。
 *
 * 此接口按照 RFC 3986 来构建 HTTP URI，提供了一些通用的操作，你可以自由的对此接口
 * 进行扩展。你可以使用此 URI 接口来做 HTTP 相关的操作，也可以使用此接口做任何 URI 
 * 相关的操作。
 *
 * 此接口的实例化对象被视为无法修改的，所有能修改状态的方法，都 **必须** 有一套机制，在内部保
 * 持好原有的内容，然后把修改状态后的，新的实例返回。
 *
 * @see http://tools.ietf.org/html/rfc3986 (URI 通用标准规范)
 */
interface UriInterface
{
    /**
     * 从 URI 中取出 scheme。
     *
     * 如果不存在 Scheme，此方法 **必须** 返回空字符串。
     *
     * 返回的数据 **必须** 是小写字母，遵照  RFC 3986 规范 3.1 章节。
     *
     * 最后部分的 ":" 字串不属于 Scheme，**一定不可** 作为返回数据的一部分。
     *
     * @see https://tools.ietf.org/html/rfc3986#section-3.1
     * @return string URI scheme 的值
     */
    public function getScheme();

    /**
     * 返回 URI 授权信息。
     *
     * 如果没有 URI 信息的话，**必须** 返回一个空数组。
     *
     * URI 的授权信息语法是：
     *
     * <pre>
     * [user-info@]host[:port]
     * </pre>
     *
     * 如果端口部分没有设置，或者端口不是标准端口，**一定不可** 包含在返回值内。
     *
     * @see https://tools.ietf.org/html/rfc3986#section-3.2
     * @return string URI 授权信息，格式为："[user-info@]host[:port]" 
     */
    public function getAuthority();

    /**
     * 从 URI 中获取用户信息。
     *
     * 如果不存在用户信息，此方法 **必须** 返回一个空字符串。
     *
     * 用户信息后面跟着的 "@" 字符，不是用户信息里面的一部分，**一定不可** 在返回值里
     * 出现。
     *
     * @return string URI 的用户信息，格式："username[:password]" 
     */
    public function getUserInfo();

    /**
     * 从 URI 信息中获取 HOST 值。
     *
     * 如果 URI 中没有此值，**必须** 返回空字符串。
     *
     * 返回的数据 **必须** 是小写字母，遵照  RFC 3986 规范 3.2.2 章节。
     *
     * @see http://tools.ietf.org/html/rfc3986#section-3.2.2
     * @return string URI 信息中的 HOST 值。
     */
    public function getHost();

    /**
     * 从 URI 信息中获取端口信息。
     *
     * 如果端口信息是与当前 Scheme 的标准端口不匹配的话，就使用整数值的格式返回，如果是一
     * 样的话，**必须** 返回 `null` 值。
     * 
     * 如果存在端口信息，都是不存在 scheme 信息的话，**必须** 返回 `null` 值。
     * 
     * 如果不存在端口数据，但是 scheme 数据存在的话，**可以** 返回 scheme 对应的
     * 标准端口，但是 **应该** 返回 `null`。
     * 
     * @return null|int 从 URI 信息中的端口信息。
     */
    public function getPort();

    /**
     * 从 URI 信息中获取路径。
     *
     *  The path can either be empty or absolute (starting with a slash) or
     * rootless (not starting with a slash). Implementations MUST support all
     * three syntaxes.
     *
     * Normally, the empty path "" and absolute path "/" are considered equal as
     * defined in RFC 7230 Section 2.7.3. But this method MUST NOT automatically
     * do this normalization because in contexts with a trimmed base path, e.g.
     * the front controller, this difference becomes significant. It's the task
     * of the user to handle both "" and "/".
     *
     * The value returned MUST be percent-encoded, but MUST NOT double-encode
     * any characters. To determine what characters to encode, please refer to
     * RFC 3986, Sections 2 and 3.3.
     *
     * As an example, if the value should include a slash ("/") not intended as
     * delimiter between path segments, that value MUST be passed in encoded
     * form (e.g., "%2F") to the instance.
     *
     * @see https://tools.ietf.org/html/rfc3986#section-2
     * @see https://tools.ietf.org/html/rfc3986#section-3.3
     * @return string The URI path.
     */
    public function getPath();

    /**
     * Retrieve the query string of the URI.
     *
     * If no query string is present, this method MUST return an empty string.
     *
     * The leading "?" character is not part of the query and MUST NOT be
     * added.
     *
     * The value returned MUST be percent-encoded, but MUST NOT double-encode
     * any characters. To determine what characters to encode, please refer to
     * RFC 3986, Sections 2 and 3.4.
     *
     * As an example, if a value in a key/value pair of the query string should
     * include an ampersand ("&") not intended as a delimiter between values,
     * that value MUST be passed in encoded form (e.g., "%26") to the instance.
     *
     * @see https://tools.ietf.org/html/rfc3986#section-2
     * @see https://tools.ietf.org/html/rfc3986#section-3.4
     * @return string The URI query string.
     */
    public function getQuery();

    /**
     * Retrieve the fragment component of the URI.
     *
     * If no fragment is present, this method MUST return an empty string.
     *
     * The leading "#" character is not part of the fragment and MUST NOT be
     * added.
     *
     * The value returned MUST be percent-encoded, but MUST NOT double-encode
     * any characters. To determine what characters to encode, please refer to
     * RFC 3986, Sections 2 and 3.5.
     *
     * @see https://tools.ietf.org/html/rfc3986#section-2
     * @see https://tools.ietf.org/html/rfc3986#section-3.5
     * @return string The URI fragment.
     */
    public function getFragment();

    /**
     * Return an instance with the specified scheme.
     *
     * This method MUST retain the state of the current instance, and return
     * an instance that contains the specified scheme.
     *
     * Implementations MUST support the schemes "http" and "https" case
     * insensitively, and MAY accommodate other schemes if required.
     *
     * An empty scheme is equivalent to removing the scheme.
     *
     * @param string $scheme The scheme to use with the new instance.
     * @return self A new instance with the specified scheme.
     * @throws \InvalidArgumentException for invalid schemes.
     * @throws \InvalidArgumentException for unsupported schemes.
     */
    public function withScheme($scheme);

    /**
     * Return an instance with the specified user information.
     *
     * This method MUST retain the state of the current instance, and return
     * an instance that contains the specified user information.
     *
     * Password is optional, but the user information MUST include the
     * user; an empty string for the user is equivalent to removing user
     * information.
     *
     * @param string $user The user name to use for authority.
     * @param null|string $password The password associated with $user.
     * @return self A new instance with the specified user information.
     */
    public function withUserInfo($user, $password = null);

    /**
     * Return an instance with the specified host.
     *
     * This method MUST retain the state of the current instance, and return
     * an instance that contains the specified host.
     *
     * An empty host value is equivalent to removing the host.
     *
     * @param string $host The hostname to use with the new instance.
     * @return self A new instance with the specified host.
     * @throws \InvalidArgumentException for invalid hostnames.
     */
    public function withHost($host);

    /**
     * Return an instance with the specified port.
     *
     * This method MUST retain the state of the current instance, and return
     * an instance that contains the specified port.
     *
     * Implementations MUST raise an exception for ports outside the
     * established TCP and UDP port ranges.
     *
     * A null value provided for the port is equivalent to removing the port
     * information.
     *
     * @param null|int $port The port to use with the new instance; a null value
     *     removes the port information.
     * @return self A new instance with the specified port.
     * @throws \InvalidArgumentException for invalid ports.
     */
    public function withPort($port);

    /**
     * Return an instance with the specified path.
     *
     * This method MUST retain the state of the current instance, and return
     * an instance that contains the specified path.
     *
     * The path can either be empty or absolute (starting with a slash) or
     * rootless (not starting with a slash). Implementations MUST support all
     * three syntaxes.
     *
     * If an HTTP path is intended to be host-relative rather than path-relative
     * then it must begin with a slash ("/"). HTTP paths not starting with a slash
     * are assumed to be relative to some base path known to the application or
     * consumer.
     *
     * Users can provide both encoded and decoded path characters.
     * Implementations ensure the correct encoding as outlined in getPath().
     *
     * @param string $path The path to use with the new instance.
     * @return self A new instance with the specified path.
     * @throws \InvalidArgumentException for invalid paths.
     */
    public function withPath($path);

    /**
     * Return an instance with the specified query string.
     *
     * This method MUST retain the state of the current instance, and return
     * an instance that contains the specified query string.
     *
     * Users can provide both encoded and decoded query characters.
     * Implementations ensure the correct encoding as outlined in getQuery().
     *
     * An empty query string value is equivalent to removing the query string.
     *
     * @param string $query The query string to use with the new instance.
     * @return self A new instance with the specified query string.
     * @throws \InvalidArgumentException for invalid query strings.
     */
    public function withQuery($query);

    /**
     * Return an instance with the specified URI fragment.
     *
     * This method MUST retain the state of the current instance, and return
     * an instance that contains the specified URI fragment.
     *
     * Users can provide both encoded and decoded fragment characters.
     * Implementations ensure the correct encoding as outlined in getFragment().
     *
     * An empty fragment value is equivalent to removing the fragment.
     *
     * @param string $fragment The fragment to use with the new instance.
     * @return self A new instance with the specified fragment.
     */
    public function withFragment($fragment);

    /**
     * Return the string representation as a URI reference.
     *
     * Depending on which components of the URI are present, the resulting
     * string is either a full URI or relative reference according to RFC 3986,
     * Section 4.1. The method concatenates the various components of the URI,
     * using the appropriate delimiters:
     *
     * - If a scheme is present, it MUST be suffixed by ":".
     * - If an authority is present, it MUST be prefixed by "//".
     * - The path can be concatenated without delimiters. But there are two
     *   cases where the path has to be adjusted to make the URI reference
     *   valid as PHP does not allow to throw an exception in __toString():
     *     - If the path is rootless and an authority is present, the path MUST
     *       be prefixed by "/".
     *     - If the path is starting with more than one "/" and no authority is
     *       present, the starting slashes MUST be reduced to one.
     * - If a query is present, it MUST be prefixed by "?".
     * - If a fragment is present, it MUST be prefixed by "#".
     *
     * @see http://tools.ietf.org/html/rfc3986#section-4.1
     * @return string
     */
    public function __toString();
}

3.6 Psr\Http\Message\UploadedFileInterface

<?php
namespace Psr\Http\Message;

/**
 * 通过 HTTP 请求上传的一个文件内容。
 *
 * 此接口的实例是被视为无法修改的，所有能修改状态的方法，都 **必须** 有一套机制，在内部保
 * 持好原有的内容，然后把修改状态后的，新的实例返回。
 */
interface UploadedFileInterface
{
    /**
     * 获取上传文件的数据流。
     *
     * 此方法必须返回一个 `StreamInterface` 实例，此方法的目的在于允许 PHP 对获取到的数
     * 据流直接操作，如 stream_copy_to_stream() 。
     *
     * 如果在调用此方法之前调用了 `moveTo()` 方法，此方法 **必须** 抛出异常。
     *
     * @return StreamInterface 上传文件的数据流
     * @throws \RuntimeException 没有数据流的情形下。
     * @throws \RuntimeException 无法创建数据流。
     */
    public function getStream();

    /**
     * 把上传的文件移动到新目录。
     *
     * 此方法保证能同时在 `SAPI` 和 `non-SAPI` 环境下使用。实现类库 **必须** 判断
     * 当前处在什么环境下，并且使用合适的方法来处理，如 move_uploaded_file(), rename()
     * 或者数据流操作。
     *
     * $targetPath 可以是相对路径，也可以是绝对路径，使用 rename() 解析起来应该是一样的。
     *
     * 当这一次完成后，原来的文件 **必须** 会被移除。
     * 
     * 如果此方法被调用多次，一次以后的其他调用，都要抛出异常。
     *
     * 如果在 SAPI 环境下的话，$_FILES 内有值，当使用  moveTo(), is_uploaded_file()
     * 和 move_uploaded_file() 方法来移动文件时 **应该** 确保权限和上传状态的准确性。
     * 
     * 如果你希望操作数据流的话，请使用 `getStream()` 方法，因为在 SAPI 场景下，无法
     * 保证书写入数据流目标。
     * 
     * @see http://php.net/is_uploaded_file
     * @see http://php.net/move_uploaded_file
     * @param string $targetPath 目标文件路径。
     * @throws \InvalidArgumentException 参数有问题时抛出异常。
     * @throws \RuntimeException 发生任何错误，都抛出此异常。
     * @throws \RuntimeException 多次运行，也抛出此异常。
     */
    public function moveTo($targetPath);

    /**
     * 获取文件大小。
     *
     * 实现类库 **应该** 优先使用 $_FILES 里的 `size` 数值。
     * 
     * @return int|null 以 bytes 为单位，或者 null 未知的情况下。
     */
    public function getSize();

    /**
     * 获取上传文件时出现的错误。
     *
     * 返回值 **必须** 是 PHP 的 UPLOAD_ERR_XXX 常量。
     *
     * 如果文件上传成功，此方法 **必须** 返回 UPLOAD_ERR_OK。
     *
     * 实现类库 **必须** 返回 $_FILES 数组中的 `error` 值。
     * 
     * @see http://php.net/manual/en/features.file-upload.errors.php
     * @return int PHP 的 UPLOAD_ERR_XXX 常量。
     */
    public function getError();

    /**
     * 获取客户端上传的文件的名称。
     * 
     * 永远不要信任此方法返回的数据，客户端有可能发送了一个恶意的文件名来攻击你的程序。
     * 
     * 实现类库 **应该** 返回存储在 $_FILES 数组中 `name` 的值。
     *
     * @return string|null 用户上传的名字，或者 null 如果没有此值。
     */
    public function getClientFilename();

    /**
     * 客户端提交的文件类型。
     * 
     * 永远不要信任此方法返回的数据，客户端有可能发送了一个恶意的文件类型名称来攻击你的程序。
     *
     * 实现类库 **应该** 返回存储在 $_FILES 数组中 `type` 的值。
     *
     * @return string|null 用户上传的类型，或者 null 如果没有此值。
     */
    public function getClientMediaType();
}