a11::nodes::NodeMap Class Reference

A thread-safe registry of AsyncNodes keyed by id. More...

#include <cpp/a11/nodes/node_map.h>

Inheritance diagram for a11::nodes::NodeMap:

Public Member Functions
	~NodeMap ()=default
absl::StatusOr< std::shared_ptr< AsyncNode > >	Get (std::string node_id)
	Return the node for an id, creating it if it does not exist.
absl::StatusOr< std::shared_ptr< AsyncNode > >	GetIfExists (std::string_view node_id) const
	Return the node for an id without creating it.
absl::StatusOr< std::shared_ptr< AsyncNode > >	Discard (std::string_view node_id, const std::shared_ptr< AsyncNode > &expected=nullptr)
	Remove the node for an id.
bool	Contains (std::string_view node_id) const
	Report whether a node with the given id exists.
size_t	Size () const
	Return the number of nodes currently in the map.
std::vector< std::string >	Ids () const
	Return the id of every node the map holds, sorted.

Static Public Member Functions
static absl::StatusOr< std::shared_ptr< NodeMap > >	Create (ChunkStoreFactory factory={})
	Create a node map.

Detailed Description

A thread-safe registry of AsyncNodes keyed by id.

Nodes are created lazily on first access via the map's ChunkStoreFactory. Instances are heap-allocated and shared via Create.

Constructor & Destructor Documentation

~NodeMap()

a11::nodes::NodeMap::~NodeMap ( )

default

Member Function Documentation

Contains()

bool a11::nodes::NodeMap::Contains

(

std::string_view

node_id

)

const

Report whether a node with the given id exists.

Parameters

node_id

The node identifier.

Returns

True if the map holds a node under that id.

Create()

absl::StatusOr< std::shared_ptr< NodeMap > > a11::nodes::NodeMap::Create ( ChunkStoreFactory  factory = {} )

static

Create a node map.

Parameters

factory

Factory invoked to build the backing store for each new node; a default store is used when omitted.

Returns

The new map, or an error status on failure.

Discard()

absl::StatusOr< std::shared_ptr< AsyncNode > > a11::nodes::NodeMap::Discard	(	std::string_view	node_id,
		const std::shared_ptr< AsyncNode > &	expected = nullptr
	)

Remove the node for an id.

Parameters

node_id	The node identifier.
expected	If non-null, only remove when the stored node matches this one (compare-and-remove).

Returns

The removed node, or an error status on failure.

Get()

absl::StatusOr< std::shared_ptr< AsyncNode > > a11::nodes::NodeMap::Get

(

std::string

node_id

)

Return the node for an id, creating it if it does not exist.

Parameters

node_id

The node identifier.

Returns

The node, or an error status on failure.

Return the node for an id, creating it if it does not exist.

Parameters

node_id

The node identifier.

Returns

The node, or an error status on failure.

GetIfExists()

absl::StatusOr< std::shared_ptr< AsyncNode > > a11::nodes::NodeMap::GetIfExists

(

std::string_view

node_id

)

const

Return the node for an id without creating it.

Parameters

node_id

The node identifier.

Returns

The node, or nullptr if it does not exist (or an error status).

Ids()

std::vector< std::string > a11::nodes::NodeMap::Ids

(

)

const

Return the id of every node the map holds, sorted.

A snapshot: nodes are created on demand, so the answer is what was there when it was asked for. Sorted rather than in hash order so a caller comparing two snapshots – a test, a diagnostic dump – sees a stable list.

Returns

The ids.

Size()

size_t a11::nodes::NodeMap::Size

(

)

const

Return the number of nodes currently in the map.

Returns

The node count.

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

• cpp/a11/nodes/node_map.h
• cpp/a11/nodes/node_map.cc