engine::State Class Reference

#include <state.hpp>

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Detailed Description

Abstraction denoting the state of a currently ongoing render/calculation process, as it is tied to the supporting facilities of the backend.

An State (subclass) instance is the sole connection for the render node to invoke services of the backend needed to carry out the calculations.

See also:

engine::RenderInvocation top-level entrance point

nodeinvocation.hpp impl. used from within the nodes

Definition at line 55 of file state.hpp.

Public Member Functions
virtual BuffHandle	allocateBuffer (BufferDescriptor const &)=0
	allocate a new writable buffer with type and size according to the BufferDescriptor.
virtual BuffHandle	fetch (FrameID const &)=0
	try to fetch an existing buffer containing the denoted frame from a cache or similar backing system (e.g.
virtual FrameID const &	genFrameID (NodeID const &, uint chanNo)=0
	generate (or calculate) an ID denoting a media data frame appearing at the given position in the render network, for the time point this rendering process is currently calculating data for.
virtual BuffTableStorage &	getBuffTableStorage ()=0
	necessary for creating a local BuffTableChunk
virtual void	is_calculated (BuffHandle const &)=0
	declare the data contained in the Buffer to be ready.
virtual void	releaseBuffer (BuffHandle &)=0
	resign control of the buffer denoted by the handle
Protected Member Functions
virtual State &	getCurrentImplementation ()=0
	resolves to the State object currently "in charge".
Friends
class	engine::StateAdapter

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Member Function Documentation

virtual BuffHandle engine::State::allocateBuffer

(

BufferDescriptor const &

)

[pure virtual]

allocate a new writable buffer with type and size according to the BufferDescriptor.

The actual provider of this buffer depends on the State implementation; it could be a temporary, located in the cache, used for feeding calculated frames over a network, etc.

Returns:

a BuffHandle encapsulating the information necessary to get at the actual buffer address and for releasing the buffer.

Implemented in engine::AllocBufferFromParent, and engine::AllocBufferFromCache.

Referenced by engine::AllocBufferFromCache::allocateBuffer(), and engine::AllocBufferFromParent::allocateBuffer().

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virtual BuffHandle engine::State::fetch

(

FrameID const &

)

[pure virtual]

try to fetch an existing buffer containing the denoted frame from a cache or similar backing system (e.g.

network peer).

Returns:

either a handle to a readonly buffer, or a null handle

Note:

the client is responsible for not modifying the provided data

Implemented in engine::StateAdapter.

Referenced by engine::StateAdapter::fetch().

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virtual FrameID const& engine::State::genFrameID	(	NodeID const &	,
		uint	chanNo
	)			[pure virtual]

generate (or calculate) an ID denoting a media data frame appearing at the given position in the render network, for the time point this rendering process is currently calculating data for.

Parameters:

	NodeID	the unique identification of a specific node
	chanNo	the number of the output channel of this node

Returns:

a complete FrameID which unambiguously denotes this specific frame and can be used for caching

Implemented in engine::Invocation.

Referenced by engine::Invocation::genFrameID().

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virtual BuffTableStorage& engine::State::getBuffTableStorage

(

)

[pure virtual]

necessary for creating a local BuffTableChunk

Implemented in engine::StateAdapter.

Referenced by engine::StateAdapter::getBuffTableStorage().

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virtual State& engine::State::getCurrentImplementation

(

)

[protected, pure virtual]

resolves to the State object currently "in charge".

Intended as a performance shortcut to avoid calling up through a chain of virtual functions when deep down in chained ProcNode::pull() calls. This allows derived classes to proxy the state interface.

Implemented in engine::StateAdapter.

virtual void engine::State::is_calculated

(

BuffHandle const &

)

[pure virtual]

declare the data contained in the Buffer to be ready.

The caller is required to restrain itself from modifying the data afterwards, as this buffer now can be used (readonly) by other calculation processes in parallel.

Implemented in engine::StateAdapter.

Referenced by engine::StateAdapter::is_calculated().

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virtual void engine::State::releaseBuffer

(

BuffHandle &

)

[pure virtual]

resign control of the buffer denoted by the handle

Implemented in engine::StateAdapter.

Referenced by engine::StateAdapter::releaseBuffer().

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

• proc/state.hpp