EBackend.CacheKeys¶

Subclasses:: None

Methods¶

Inherited:: GObject.Object (37)
Structs:: GObject.ObjectClass (5)

class	`new` (cache, table_name, key_column_name, value_column_name)
	`count_keys_sync` (cancellable)
	`foreach_sync` (func, user_data, cancellable)
	`get_cache` ()
	`get_key_column_name` ()
	`get_ref_count_sync` (key, cancellable)
	`get_sync` (key, cancellable)
	`get_table_name` ()
	`get_value_column_name` ()
	`init_table_sync` (cancellable)
	`put_sync` (key, value, inc_ref_counts, cancellable)
	`remove_all_sync` (cancellable)
	`remove_sync` (key, dec_ref_counts, cancellable)

Virtual Methods¶

Inherited:: GObject.Object (7)

do_changed ()

Properties¶

Name	Type	Flags
`cache`	`EBackend.Cache`	r/w/co/en
`key-column-name`	`str`	r/w/co/en
`table-name`	`str`	r/w/co/en
`value-column-name`	`str`	r/w/co/en

Signals¶

Inherited:: GObject.Object (1)

Name	Short Description
`changed`	A signal emitted when the stored keys changed, aka when a new key is added or when an existing key is removed.

Fields¶

Inherited:: GObject.Object (1)

Name	Type	Access	Description
parent	`GObject.Object`	r

Class Details¶

class EBackend.CacheKeys(**kwargs)¶

Bases:: GObject.Object
Abstract:: No
Structure:: EBackend.CacheKeysClass

Contains only private data that should be read and manipulated using the functions below.

New in version 3.48.

classmethod new(cache, table_name, key_column_name, value_column_name)¶

Parameters:

cache (EBackend.Cache) – an EBackend.Cache
table_name (str) – a table name to operate with
key_column_name (str) – column name for the keys
value_column_name (str) – column name for the values

Returns:

a new EBackend.CacheKeys

Return type:

EBackend.CacheKeys

Creates a new EBackend.CacheKeys, which will operate with table_name, using column key_column_name to store keys and value_column_name to store values.

The created EBackend.CacheKeys doesn’t hold a reference to the cache, the caller is supposed to make sure the cache won’t be freed before the EBackend.CacheKeys is freed. This is to avoid circular dependency between the cache and the EBackend.CacheKeys, when the EBackend.CacheKey is created by the cache itself (which is the expected use case).

New in version 3.48.

count_keys_sync(cancellable)¶

Parameters:

cancellable (Gio.Cancellable or None) – optional Gio.Cancellable object, or None

Raises:

GLib.Error

Returns:

Whether succeeded.

out_n_stored:: return location to set count of stored keys

Return type:

(bool, out_n_stored: int)

Counts how many keys the self stores and set it to the out_n_stored.

New in version 3.48.

foreach_sync(func, user_data, cancellable)¶

Parameters:

func (EBackend.CacheKeysForeachFunc) – an EBackend.CacheKeysForeachFunc, which is called for each stored key
user_data (object or None) – user data for the func
cancellable (Gio.Cancellable or None) – optional Gio.Cancellable object, or None

Raises:

GLib.Error

Returns:

Whether succeeded.

Return type:

bool

Calls func for each stored key in the self, providing information about its value and reference count.

New in version 3.48.

get_cache()¶

Returns:: an EBackend.Cache
Return type:: EBackend.Cache

Gets an EBackend.Cache, with which the self had been created.

New in version 3.48.

get_key_column_name()¶

Returns:: a key column name
Return type:: str

Gets a key column name, with which the self had been created.

New in version 3.48.

get_ref_count_sync(key, cancellable)¶

Parameters:

key (str) – a key to get reference count for
cancellable (Gio.Cancellable or None) – optional Gio.Cancellable object, or None

Raises:

GLib.Error

Returns:

Whether succeeded.

out_ref_count:: return location for the stored reference count for the key

Return type:

(bool, out_ref_count: int)

Gets currently stored reference count for the key. Note the reference count can be 0, which means the key is stored forever.

New in version 3.48.

get_sync(key, cancellable)¶

Parameters:

key (str) – a key to get
cancellable (Gio.Cancellable or None) – optional Gio.Cancellable object, or None

Raises:

GLib.Error

Returns:

Whether succeeded.

out_value:: return location for the stored value for the key

Return type:

(bool, out_value: str)

Gets a stored value with given key, which had been previously put into the self with EBackend.CacheKeys.put_sync().

The returned string should be freed with GLib.free() when no longer needed.

New in version 3.48.

get_table_name()¶

Returns:: a table name
Return type:: str

Gets a table name, with which the self had been created.

New in version 3.48.

get_value_column_name()¶

Returns:: a value column name
Return type:: str

Get a value column name, with which the self had been created.

New in version 3.48.

init_table_sync(cancellable)¶

Parameters:: cancellable (Gio.Cancellable or None) – optional Gio.Cancellable object, or None
Raises:: GLib.Error
Returns:: Whether succeeded.
Return type:: bool

Initializes table in the corresponding EBackend.Cache.

New in version 3.48.

put_sync(key, value, inc_ref_counts, cancellable)¶

Parameters:

key (str) – a key identifier to put
value (str) – a value to put with the key
inc_ref_counts (int) – how many refs to add, or 0 to have it stored forever
cancellable (Gio.Cancellable or None) – optional Gio.Cancellable object, or None

Raises:

GLib.Error

Returns:

Whether succeeded.

Return type:

bool

Puts the key and value into the self. The function adds a new or replaces an existing key, if any such already exists in the self.

New in version 3.48.

remove_all_sync(cancellable)¶

Parameters:: cancellable (Gio.Cancellable or None) – optional Gio.Cancellable object, or None
Raises:: GLib.Error
Returns:: Whether succeeded.
Return type:: bool

Removes all stored keys from the self.

New in version 3.48.

remove_sync(key, dec_ref_counts, cancellable)¶

Parameters:

key (str) – a key to remove/dereference
dec_ref_counts (int) – reference counts to drop, 0 to remove it regardless of the current reference count
cancellable (Gio.Cancellable or None) – optional Gio.Cancellable object, or None

Raises:

GLib.Error

Returns:

Whether succeeded.

Return type:

bool

Dereferences use count of the key by dec_ref_counts and removes it from the cache when the reference count reaches zero. Special case is with dec_ref_counts is zero, in which case the key is removed regardless of the current reference count.

It’s not an error when the key doesn’t exist in the cache.

New in version 3.48.

do_changed() virtual¶

Signal Details¶

EBackend.CacheKeys.signals.changed(cache_keys)¶

Signal Name:: changed
Flags:: RUN_LAST
Parameters:: cache_keys (EBackend.CacheKeys) – The object which received the signal

A signal emitted when the stored keys changed, aka when a new key is added or when an existing key is removed. It’s not emitted when only a reference count changes for a key.

New in version 3.48.

Property Details¶

EBackend.CacheKeys.props.cache¶

Name:: cache
Type:: EBackend.Cache
Default Value:: None
Flags:: READABLE, WRITABLE, CONSTRUCT_ONLY, EXPLICIT_NOTIFY

The EBackend.Cache being used for this keys table.

New in version 3.48.

EBackend.CacheKeys.props.key_column_name¶

Name:: key-column-name
Type:: str
Default Value:: None
Flags:: READABLE, WRITABLE, CONSTRUCT_ONLY, EXPLICIT_NOTIFY

The column name for the keys.

New in version 3.48.

EBackend.CacheKeys.props.table_name¶

Name:: table-name
Type:: str
Default Value:: None
Flags:: READABLE, WRITABLE, CONSTRUCT_ONLY, EXPLICIT_NOTIFY

The table name of this keys table.

New in version 3.48.

EBackend.CacheKeys.props.value_column_name¶

Name:: value-column-name
Type:: str
Default Value:: None
Flags:: READABLE, WRITABLE, CONSTRUCT_ONLY, EXPLICIT_NOTIFY

The column name for the values.

New in version 3.48.