alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface Class Reference

#include <HTTPContentFetcherInterface.h>

Inheritance diagram for alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface:

Classes
struct	Header

Public Types
enum	FetchOptions { FetchOptions::CONTENT_TYPE, FetchOptions::ENTIRE_BODY }
	Represents what HTTP content to fetch. More...
enum	State {   State::INITIALIZED, State::FETCHING_HEADER, State::HEADER_DONE, State::FETCHING_BODY,   State::BODY_DONE, State::ERROR }
	The state of payload fetching. More...

Public Member Functions
virtual	~HTTPContentFetcherInterface ()=default
virtual State	getState ()=0
virtual std::string	getUrl () const =0
virtual std::string	getEffectiveUrl () const =0
virtual Header	getHeader (std::atomic< bool > *shouldShutdown)=0
virtual bool	getBody (std::shared_ptr< avsCommon::avs::attachment::AttachmentWriter > writer)=0
virtual void	shutdown ()=0
virtual std::unique_ptr< avsCommon::utils::HTTPContent >	getContent (FetchOptions option, std::unique_ptr< avsCommon::avs::attachment::AttachmentWriter > writer=nullptr, const std::vector< std::string > &customHeaders=std::vector< std::string >())=0

Static Public Member Functions
static std::string	getUserAgent ()
static std::string	stateToString (State state)

Detailed Description

This class allows users to fetch content from remote location using HTTP(S).

Member Enumeration Documentation

FetchOptions

enum alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface::FetchOptions

strong

Represents what HTTP content to fetch.

Enumerator
CONTENT_TYPE	Retrieves the content type part of the HTTP header.
ENTIRE_BODY	Retrieves the entire body of the remote location.

State

enum alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface::State

strong

The state of payload fetching.

Enumerator
INITIALIZED	Initialized but nothing was downloaded yet.
FETCHING_HEADER	Currently fetching the header.
HEADER_DONE	Done fetching the header. Ready to start fetching the body.
FETCHING_BODY	Currently fetching the body.
BODY_DONE	Done fetching the body. At this point the content fetcher can only be used to read the headers.
ERROR	Some error happened at any stage and the content fetcher cannot be used anymore.

Constructor & Destructor Documentation

~HTTPContentFetcherInterface()

virtual alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface::~HTTPContentFetcherInterface ( )

virtualdefault

Destructor.

Member Function Documentation

getBody()

virtual bool alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface::getBody ( std::shared_ptr< avsCommon::avs::attachment::AttachmentWriter >  writer )

pure virtual

Retrieves the body after the header was received. This method is asynchronous and the caller can monitor the download progress using the getState method.

Parameters

writer

The writer to write the payload.

Returns

true if the call is successful.

getContent()

virtual std::unique_ptr<avsCommon::utils::HTTPContent> alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface::getContent ( FetchOptions  option, std::unique_ptr< avsCommon::avs::attachment::AttachmentWriter >  writer = nullptr, const std::vector< std::string > &  customHeaders = std::vector< std::string >()  )

pure virtual

This function retrieves content from a remote location. No thread safety is guaranteed.

Parameters

option	Flag indicating desired content.
writer	An optional writer parameter to be used when writing to an external stream.
customHeaders	An optional list of headers to be attached to the request.

Returns

A new HTTPContent object or nullptr if a failure occurred.

getEffectiveUrl()

virtual std::string alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface::getEffectiveUrl ( ) const

pure virtual

Gets the effective URL associated with this content fetcher.

Note

This is useful in the case of redirects where the first URL used redirects to a different URL to fetch the content.

Returns

The content fetcher's effective URL.

Implemented in alexaClientSDK::playlistParser::test::MockContentFetcher, alexaClientSDK::mediaPlayer::test::MockContentFetcher, and alexaClientSDK::avsCommon::utils::libcurlUtils::LibCurlHttpContentFetcher.

getHeader()

virtual Header alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface::getHeader ( std::atomic< bool > *  shouldShutdown )

pure virtual

Waits until the header was fetched successfully. If any problem happened during header, returns false. After the header was already fetched, this method can be called multiple times and will return immediately.

Parameters

shouldShutdown

A pointer to allow for the caller to asynchronously cancel the wait, if needed. this argument is optional. If it is a null pointer, the function will ignore it.

Returns

The header struct. It is the caller's responsibility to check the struct to see if the header was retrieved successfully.

Implemented in alexaClientSDK::playlistParser::test::MockContentFetcher, alexaClientSDK::mediaPlayer::test::MockContentFetcher, and alexaClientSDK::avsCommon::utils::libcurlUtils::LibCurlHttpContentFetcher.

getState()

virtual State alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface::getState ( )

pure virtual

The current content fetching state. In particular, a caller of getBody, an asynchronous function, can use this method to monitor the download progress.

Returns

The current content fetching state.

Implemented in alexaClientSDK::playlistParser::test::MockContentFetcher, alexaClientSDK::mediaPlayer::test::MockContentFetcher, and alexaClientSDK::avsCommon::utils::libcurlUtils::LibCurlHttpContentFetcher.

getUrl()

virtual std::string alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface::getUrl ( ) const

pure virtual

Gets the URL associated with this content fetcher

Returns

The content fetcher URL

Implemented in alexaClientSDK::playlistParser::test::MockContentFetcher, alexaClientSDK::mediaPlayer::test::MockContentFetcher, and alexaClientSDK::avsCommon::utils::libcurlUtils::LibCurlHttpContentFetcher.

getUserAgent()

std::string alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface::getUserAgent ( )

inlinestatic

Returns a string that represents the User-Agent to be used in HTTP requests.

Returns

User-Agent string to be used in HTTP requests.

shutdown()

virtual void alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface::shutdown ( )

pure virtual

Shuts down the content fetcher.

Implemented in alexaClientSDK::playlistParser::test::MockContentFetcher, alexaClientSDK::mediaPlayer::test::MockContentFetcher, and alexaClientSDK::avsCommon::utils::libcurlUtils::LibCurlHttpContentFetcher.

stateToString()

std::string alexaClientSDK::avsCommon::sdkInterfaces::HTTPContentFetcherInterface::stateToString ( HTTPContentFetcherInterface::State  state )

inlinestatic

Produces the string representation of the state enum values.

Parameters

state

The state enum value.

Returns

Its string representation.

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The documentation for this class was generated from the following file:

• /workplace/avs-device-sdk/AVSCommon/SDKInterfaces/include/AVSCommon/SDKInterfaces/HTTPContentFetcherInterface.h