Reader class for reading a manifest. More...

#include <c2pa.hpp>

Public Member Functions
	Reader (IContextProvider &context, const std::string &format, std::istream &stream)
	Create a Reader from a context and stream.

	Reader (IContextProvider &context, const std::filesystem::path &source_path)
	Create a Reader from a context and file path.

	Reader (std::shared_ptr< IContextProvider > context, const std::string &format, std::istream &stream)
	Create a Reader from a shared context and stream.

	Reader (std::shared_ptr< IContextProvider > context, const std::filesystem::path &source_path)
	Create a Reader from a shared context and file path.

	Reader (const std::string &format, std::istream &stream)
	Create a Reader from a stream (will use global settings if any loaded).

	Reader (const std::filesystem::path &source_path)
	Create a Reader from a file path (will use global settings if any loaded).

	Reader (const Reader &)=delete

Reader &	operator= (const Reader &)=delete

	Reader (Reader &&other) noexcept

Reader &	operator= (Reader &&other) noexcept

	~Reader ()

bool	is_embedded () const
	Check if the reader was created from an embedded manifest.

std::optional< std::string >	remote_url () const
	Returns the remote url of the manifest if this `Reader` obtained the manifest remotely.

std::string	json () const
	Get the manifest as a JSON string.

int64_t	get_resource (const std::string &uri, const std::filesystem::path &path)
	Get a resource from the reader and write it to a file.

int64_t	get_resource (const std::string &uri, std::ostream &stream)
	Get a resource from the reader and write it to an output stream.

C2paReader *	get_api_internal_raw_reader () const
	Get the raw C2paReader pointer.

Static Public Member Functions
static std::optional< Reader >	from_asset (IContextProvider &context, const std::filesystem::path &source_path)
	Try to open a Reader from a context and file path when the asset may lack C2PA data.

static std::optional< Reader >	from_asset (IContextProvider &context, const std::string &format, std::istream &stream)
	Try to create a Reader from a context and stream when the asset may lack C2PA data.

static std::optional< Reader >	from_asset (std::shared_ptr< IContextProvider > context, const std::filesystem::path &source_path)
	Try to open a Reader from a shared context and file path when the asset may lack C2PA data.

static std::optional< Reader >	from_asset (std::shared_ptr< IContextProvider > context, const std::string &format, std::istream &stream)
	Try to create a Reader from a shared context and stream when the asset may lack C2PA data.

static std::vector< std::string >	supported_mime_types ()
	Get a list of mime types that the SDK can read manifests from.

Detailed Description

Reader class for reading a manifest.

This class is used to read and validate a manifest from a stream or file. Resources are managed using RAII; member order ensures cpp_stream (which holds a C stream pointing at the ifstream) is destroyed before owned_stream.

Constructor & Destructor Documentation

◆ Reader() [1/8]

c2pa::Reader::Reader	(	IContextProvider &	context,
		const std::string &	format,
		std::istream &	stream
	)

Create a Reader from a context and stream.

Parameters

context	Context provider; used at construction to configure settings.
format	The mime format of the stream.
stream	The input stream to read from.

Exceptions

C2paException if context.is_valid() returns false, or for other errors encountered by the C2PA library.

Deprecated:: Use Reader(std::shared_ptr<IContextProvider>, format, stream) instead. The reference overload does not extend the lifetime of the context, which can be problematic when progress callbacks fire after the context is destroyed.

◆ Reader() [2/8]

c2pa::Reader::Reader	(	IContextProvider &	context,
		const std::filesystem::path &	source_path
	)

Create a Reader from a context and file path.

Parameters

context	Context provider; used at construction only to configure settings.
source_path	The path to the file to read.

Exceptions

C2paException if context.is_valid() returns false, or for other errors encountered by the C2PA library.

Note: Prefer using the streaming APIs if possible.

Deprecated:: Use Reader(std::shared_ptr<IContextProvider>, source_path) instead. The reference overload does not extend the lifetime of the context, which can be problematic when progress callbacks fire after the context is destroyed.

◆ Reader() [3/8]

c2pa::Reader::Reader	(	std::shared_ptr< IContextProvider >	context,
		const std::string &	format,
		std::istream &	stream
	)

Create a Reader from a shared context and stream.

The Reader retains a shared reference to the context, keeping it alive for the lifetime of the Reader.

Parameters

context	Shared context provider.
format	The mime format of the stream.
stream	The input stream to read from.

Exceptions

C2paException if context is null or context->is_valid() returns false.

◆ Reader() [4/8]

c2pa::Reader::Reader	(	std::shared_ptr< IContextProvider >	context,
		const std::filesystem::path &	source_path
	)

Create a Reader from a shared context and file path.

The Reader retains a shared reference to the context, keeping it alive for the lifetime of the Reader.

Parameters

context	Shared context provider.
source_path	The path to the file to read.

Exceptions

C2paException if context is null or context->is_valid() returns false.

◆ Reader() [5/8]

c2pa::Reader::Reader	(	const std::string &	format,
		std::istream &	stream
	)

Create a Reader from a stream (will use global settings if any loaded).

The validation_status field in the JSON contains validation results.

Parameters

format	The mime format of the stream.
stream	The input stream to read from.

Exceptions

C2paException for errors encountered by the C2PA library.

Deprecated:: Use Reader(IContextProvider& context, format, stream) instead.

◆ Reader() [6/8]

c2pa::Reader::Reader ( const std::filesystem::path & source_path )

Create a Reader from a file path (will use global settings if any loaded).

Parameters

source_path The path to the file to read.

Exceptions

C2paException for errors encountered by the C2PA library.

Deprecated:: Use Reader(IContextProvider& context, source_path) instead.

Note: Prefer using the streaming APIs if possible.

◆ Reader() [7/8]

c2pa::Reader::Reader ( const Reader & )

delete

◆ Reader() [8/8]

c2pa::Reader::Reader ( Reader && other )

inlinenoexcept

            : c2pa_reader(std::exchange(other.c2pa_reader, nullptr)),
              owned_stream(std::move(other.owned_stream)),
              cpp_stream(std::move(other.cpp_stream)),
              context_ref(std::move(other.context_ref)) {
        }

◆ ~Reader()

c2pa::Reader::~Reader ( )

Member Function Documentation

◆ from_asset() [1/4]

static std::optional< Reader > c2pa::Reader::from_asset	(	IContextProvider &	context,
		const std::filesystem::path &	source_path
	)

static

Try to open a Reader from a context and file path when the asset may lack C2PA data.

Returns: A Reader if JUMBF (c2pa/manifest) data is present; std::nullopt if none.

Exceptions

C2paException	for errors other than a missing manifest (e.g. invalid asset).
std::system_error	if the file cannot be opened.

Deprecated:: Use from_asset(std::shared_ptr<IContextProvider>, source_path) instead. The reference overload does not extend the lifetime of the context, which can cause a use-after-free crash when progress callbacks fire after the context is destroyed.

◆ from_asset() [2/4]

static std::optional< Reader > c2pa::Reader::from_asset	(	IContextProvider &	context,
		const std::string &	format,
		std::istream &	stream
	)

static

Try to create a Reader from a context and stream when the asset may lack C2PA data.

Returns: A Reader if JUMBF (c2pa/manifest) data is present; std::nullopt if none.

Exceptions

C2paException for errors other than a missing manifest.

Deprecated:: Use from_asset(std::shared_ptr<IContextProvider>, format, stream) instead. The reference overload does not extend the lifetime of the context, which can cause a use-after-free crash when progress callbacks fire after the context is destroyed.

◆ from_asset() [3/4]

static std::optional< Reader > c2pa::Reader::from_asset	(	std::shared_ptr< IContextProvider >	context,
		const std::filesystem::path &	source_path
	)

static

Try to open a Reader from a shared context and file path when the asset may lack C2PA data.

The Reader retains a shared reference to the context if C2PA data is found.

Returns: A Reader if JUMBF (c2pa/manifest) data is present; std::nullopt if none.

Exceptions

C2paException for errors other than a missing manifest.

◆ from_asset() [4/4]

static std::optional< Reader > c2pa::Reader::from_asset	(	std::shared_ptr< IContextProvider >	context,
		const std::string &	format,
		std::istream &	stream
	)

static

Try to create a Reader from a shared context and stream when the asset may lack C2PA data.

The Reader retains a shared reference to the context if C2PA data is found.

Returns: A Reader if JUMBF (c2pa/manifest) data is present; std::nullopt if none.

Exceptions

C2paException for errors other than a missing manifest.

◆ get_api_internal_raw_reader()

C2paReader * c2pa::Reader::get_api_internal_raw_reader ( ) const

inline

Get the raw C2paReader pointer.

Returns: The raw C2paReader pointer.

Note: This is intended for internal API use and compatibility with C APIs.

944{ return c2pa_reader; }

◆ get_resource() [1/2]

int64_t c2pa::Reader::get_resource	(	const std::string &	uri,
		const std::filesystem::path &	path
	)

Get a resource from the reader and write it to a file.

Parameters

uri	The URI of the resource.
path	The file path to write the resource to.

Returns: The number of bytes written.

Exceptions

C2paException for errors encountered by the C2PA library.

Note: Prefer using the streaming APIs if possible.

◆ get_resource() [2/2]

int64_t c2pa::Reader::get_resource	(	const std::string &	uri,
		std::ostream &	stream
	)

Get a resource from the reader and write it to an output stream.

Parameters

uri	The URI of the resource.
stream	The output stream to write the resource to.

Returns: The number of bytes written.

Exceptions

C2paException for errors encountered by the C2PA library.

◆ is_embedded()

bool c2pa::Reader::is_embedded ( ) const

inline

Check if the reader was created from an embedded manifest.

Returns: true if the manifest was embedded in the asset, false if external.

Exceptions

C2paException for errors encountered by the C2PA library.

                                                      {
            return c2pa_reader_is_embedded(c2pa_reader);
        }

◆ json()

std::string c2pa::Reader::json ( ) const

Get the manifest as a JSON string.

Returns: The manifest as a JSON string.

Exceptions

C2paException for errors encountered by the C2PA library.

◆ operator=() [1/2]

Reader & c2pa::Reader::operator= ( const Reader & )

delete

◆ operator=() [2/2]

Reader & c2pa::Reader::operator= ( Reader && other )

inlinenoexcept

                                                   {
            if (this != &other) {
                c2pa_free(c2pa_reader);
                c2pa_reader = std::exchange(other.c2pa_reader, nullptr);
                owned_stream = std::move(other.owned_stream);
                cpp_stream = std::move(other.cpp_stream);
                context_ref = std::move(other.context_ref);
            }
            return *this;
        }

◆ remote_url()

std::optional< std::string > c2pa::Reader::remote_url ( ) const

Returns the remote url of the manifest if this Reader obtained the manifest remotely.

Returns: Optional string containing the remote URL, or std::nullopt if manifest was embedded.

Exceptions

C2paException for errors encountered by the C2PA library.

◆ supported_mime_types()

static std::vector< std::string > c2pa::Reader::supported_mime_types ( )

static

Get a list of mime types that the SDK can read manifests from.

Returns: Vector of supported MIME type strings.

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

c2pa.hpp

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Reader() [1/8]

◆ Reader() [2/8]

◆ Reader() [3/8]

◆ Reader() [4/8]

◆ Reader() [5/8]

◆ Reader() [6/8]

◆ Reader() [7/8]

◆ Reader() [8/8]

◆ ~Reader()

Member Function Documentation

◆ from_asset() [1/4]

◆ from_asset() [2/4]

◆ from_asset() [3/4]

◆ from_asset() [4/4]

◆ get_api_internal_raw_reader()

◆ get_resource() [1/2]

◆ get_resource() [2/2]

◆ is_embedded()

◆ json()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ remote_url()

◆ supported_mime_types()