Olympe::AsyncJSONLoader Class Reference

Loads and parses a JSON file on a background thread. More...

#include <AsyncJSONLoader.h>

Collaboration diagram for Olympe::AsyncJSONLoader:

Public Member Functions
	AsyncJSONLoader ()
void	LoadAsync (const std::string &path)
	Starts loading path on a background thread.
AsyncLoadState	GetState () const
	Returns the current state of the loader.
bool	IsReady () const
	Returns true if the result is available (state == Ready).
bool	HasFailed () const
	Returns true if the load failed (state == Failed).
nlohmann::json	GetResult ()
	Returns the parsed JSON if ready; returns an empty object otherwise.
void	Reset ()
	Resets state to Idle and clears the result / error.
const std::string &	GetLastError () const
	Returns the last error message (non-empty when state == Failed).

Static Private Member Functions
static nlohmann::json	LoadFile (const std::string &path)
	Opens, reads, and parses the JSON file; called on the background thread.

Private Attributes
AsyncLoadState	m_State
std::string	m_LastError
nlohmann::json	m_Result
std::future< nlohmann::json >	m_Future

Detailed Description

Loads and parses a JSON file on a background thread.

Typical usage:

AsyncJSONLoader loader;
loader.LoadAsync("data/graph.json");
// ... each frame ...
if (loader.IsReady())
{
    nlohmann::json j = loader.GetResult();
    loader.Reset();
}

Definition at line 59 of file AsyncJSONLoader.h.

Constructor & Destructor Documentation

AsyncJSONLoader()

Olympe::AsyncJSONLoader::AsyncJSONLoader

(

)

Definition at line 21 of file AsyncJSONLoader.cpp.

Member Function Documentation

GetLastError()

const std::string & Olympe::AsyncJSONLoader::GetLastError

(

)

const

Returns the last error message (non-empty when state == Failed).

Definition at line 134 of file AsyncJSONLoader.cpp.

References m_LastError.

GetResult()

nlohmann::json Olympe::AsyncJSONLoader::GetResult

(

)

Returns the parsed JSON if ready; returns an empty object otherwise.

Note

Calling GetResult() does NOT reset the loader. Call Reset() explicitly when you are done with the result.

Definition at line 109 of file AsyncJSONLoader.cpp.

References GetState(), m_Result, and Olympe::Ready.

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GetState()

AsyncLoadState Olympe::AsyncJSONLoader::GetState

(

)

const

Returns the current state of the loader.

Transitions: Idle -> Loading -> Ready | Failed.

Definition at line 50 of file AsyncJSONLoader.cpp.

References Olympe::Failed, GetComponentTypeID_Static(), Olympe::Loading, m_Future, m_Result, m_State, Olympe::Ready, and SYSTEM_LOG.

Referenced by GetResult(), HasFailed(), and IsReady().

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HasFailed()

bool Olympe::AsyncJSONLoader::HasFailed

(

)

const

Returns true if the load failed (state == Failed).

Definition at line 100 of file AsyncJSONLoader.cpp.

References Olympe::Failed, and GetState().

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IsReady()

bool Olympe::AsyncJSONLoader::IsReady

(

)

const

Returns true if the result is available (state == Ready).

Definition at line 95 of file AsyncJSONLoader.cpp.

References GetState(), and Olympe::Ready.

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LoadAsync()

void Olympe::AsyncJSONLoader::LoadAsync

(

const std::string &

path

)

Starts loading path on a background thread.

Any previous result is discarded.

Definition at line 30 of file AsyncJSONLoader.cpp.

References LoadFile(), Olympe::Loading, m_Future, m_LastError, m_Result, and m_State.

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LoadFile()

nlohmann::json Olympe::AsyncJSONLoader::LoadFile ( const std::string &  path )

staticprivate

Opens, reads, and parses the JSON file; called on the background thread.

Returns

Parsed JSON object; throws on error.

Definition at line 143 of file AsyncJSONLoader.cpp.

References GetComponentTypeID_Static().

Referenced by LoadAsync().

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Reset()

void Olympe::AsyncJSONLoader::Reset

(

)

Resets state to Idle and clears the result / error.

Definition at line 120 of file AsyncJSONLoader.cpp.

References Olympe::Idle, m_Future, m_LastError, m_Result, and m_State.

Member Data Documentation

m_Future

std::future<nlohmann::json> Olympe::AsyncJSONLoader::m_Future

mutableprivate

Definition at line 120 of file AsyncJSONLoader.h.

Referenced by GetState(), LoadAsync(), and Reset().

m_LastError

std::string Olympe::AsyncJSONLoader::m_LastError

private

Definition at line 118 of file AsyncJSONLoader.h.

Referenced by GetLastError(), LoadAsync(), and Reset().

m_Result

nlohmann::json Olympe::AsyncJSONLoader::m_Result

private

Definition at line 119 of file AsyncJSONLoader.h.

Referenced by GetResult(), GetState(), LoadAsync(), and Reset().

m_State

AsyncLoadState Olympe::AsyncJSONLoader::m_State

mutableprivate

Definition at line 117 of file AsyncJSONLoader.h.

Referenced by GetState(), LoadAsync(), and Reset().

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

• Source/BlueprintEditor/Optimizations/AsyncJSONLoader.h
• Source/BlueprintEditor/Optimizations/AsyncJSONLoader.cpp