PhosphorLayer::JsonSurfaceStore Class Reference

File-backed ISurfaceStore — one JSON document on disk. More...

#include <phosphor-layer/include/PhosphorLayer/defaults/JsonSurfaceStore.h>

Inheritance diagram for PhosphorLayer::JsonSurfaceStore:

Public Member Functions
	JsonSurfaceStore (QString filePath)
	~JsonSurfaceStore () override
bool	save (const QString &key, const QJsonObject &data) override
	Persist data under key.
QJsonObject	load (const QString &key) const override
	Load the JSON object previously stored under key.
bool	has (const QString &key) const override
	True if key exists in the store.
void	remove (const QString &key) override
	Remove the entry for key (no-op if absent).
QString	filePath () const
	File path this store reads from / writes to.
Public Member Functions inherited from PhosphorLayer::ISurfaceStore
	ISurfaceStore ()=default
virtual	~ISurfaceStore ()=default

Detailed Description

File-backed ISurfaceStore — one JSON document on disk.

The entire store is serialised as a single JSON object keyed by key-name. Loads happen lazily on first access; saves use QSaveFile for atomicity (write-to-temp + rename). Suitable for modest amounts of state (hundreds of keys); for heavier workloads wrap KConfig or a database.

The file path is consumer-chosen. Typical usage:

JsonSurfaceStore store(QStandardPaths::writableLocation(
                           QStandardPaths::AppDataLocation)
                       + "/surface-state.json");

Note

Thread safety. This store is NOT thread-safe — save() and load() share a single in-memory QJsonObject without locks. All calls must originate from the same thread (typically the GUI thread). Consumers that need cross-thread access must serialise calls externally, or wrap the store in their own mutex. Every save() also rewrites the full file; batching on the caller side is recommended if many keys are mutated together.

Constructor & Destructor Documentation

JsonSurfaceStore()

PhosphorLayer::JsonSurfaceStore::JsonSurfaceStore ( QString  filePath )

explicit

~JsonSurfaceStore()

PhosphorLayer::JsonSurfaceStore::~JsonSurfaceStore ( )

override

Member Function Documentation

filePath()

QString PhosphorLayer::JsonSurfaceStore::filePath

(

)

const

File path this store reads from / writes to.

has()

bool PhosphorLayer::JsonSurfaceStore::has ( const QString &  key ) const

overridevirtual

True if key exists in the store.

Implements PhosphorLayer::ISurfaceStore.

load()

QJsonObject PhosphorLayer::JsonSurfaceStore::load ( const QString &  key ) const

overridevirtual

Load the JSON object previously stored under key.

Returns an empty object if the key does not exist or the stored data cannot be parsed.

Implements PhosphorLayer::ISurfaceStore.

remove()

void PhosphorLayer::JsonSurfaceStore::remove ( const QString &  key )

overridevirtual

Remove the entry for key (no-op if absent).

Implements PhosphorLayer::ISurfaceStore.

save()

bool PhosphorLayer::JsonSurfaceStore::save ( const QString &  key, const QJsonObject &  data  )

overridevirtual

Persist data under key.

Overwrites any existing entry. Returns false on I/O failure (the implementation logs the reason).

Implements PhosphorLayer::ISurfaceStore.

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

• phosphor-layer/include/PhosphorLayer/defaults/JsonSurfaceStore.h