GLib.HashTable

Fields

None

Methods

class add (hash_table, key)
class contains (hash_table, key)
class destroy (hash_table)
class insert (hash_table, key, value)
class lookup (hash_table, key)
class lookup_extended (hash_table, lookup_key)
class remove (hash_table, key)
class remove_all (hash_table)
class replace (hash_table, key, value)
class size (hash_table)
class steal (hash_table, key)
class steal_all (hash_table)
class steal_extended (hash_table, lookup_key)
class unref (hash_table)

Details

class GLib.HashTable

The GLib.HashTable struct is an opaque data structure to represent a Hash Table. It should only be accessed via the following functions.

classmethod add(hash_table, key)[source]
Parameters:
Returns:

True if the key did not exist yet
Return type:

bool

This is a convenience function for using a GLib.HashTable as a set. It is equivalent to calling GLib.HashTable.replace() with key as both the key and the value.

In particular, this means that if key already exists in the hash table, then the old copy of key in the hash table is freed and key replaces it in the table.

When a hash table only ever contains keys that have themselves as the corresponding value it is able to be stored more efficiently. See the discussion in the section description.

Starting from GLib 2.40, this function returns a boolean value to indicate whether the newly added value was already in the hash table or not.

New in version 2.32.

classmethod contains(hash_table, key)[source]
Parameters:
Returns:

True if key is in hash_table, False otherwise.
Return type:

bool

Checks if key is in hash_table.

New in version 2.32.

classmethod destroy(hash_table)[source]
Parameters:hash_table ({object: object}) – a GLib.HashTable

Destroys all keys and values in the GLib.HashTable and decrements its reference count by 1. If keys and/or values are dynamically allocated, you should either free them first or create the GLib.HashTable with destroy notifiers using g_hash_table_new_full(). In the latter case the destroy functions you supplied will be called on all keys and values during the destruction phase.

classmethod insert(hash_table, key, value)[source]
Parameters:
Returns:

True if the key did not exist yet
Return type:

bool

Inserts a new key and value into a GLib.HashTable.

If the key already exists in the GLib.HashTable its current value is replaced with the new value. If you supplied a value_destroy_func when creating the GLib.HashTable, the old value is freed using that function. If you supplied a key_destroy_func when creating the GLib.HashTable, the passed key is freed using that function.

Starting from GLib 2.40, this function returns a boolean value to indicate whether the newly added value was already in the hash table or not.

classmethod lookup(hash_table, key)[source]
Parameters:
Returns:

the associated value, or None if the key is not found
Return type:

object or None

Looks up a key in a GLib.HashTable. Note that this function cannot distinguish between a key that is not present and one which is present and has the value None. If you need this distinction, use GLib.HashTable.lookup_extended().

classmethod lookup_extended(hash_table, lookup_key)[source]
Parameters:
Returns:

True if the key was found in the GLib.HashTable

orig_key:return location for the original key
value:return location for the value associated with the key

Return type:

(bool, orig_key: object, value: object)

Looks up a key in the GLib.HashTable, returning the original key and the associated value and a bool which is True if the key was found. This is useful if you need to free the memory allocated for the original key, for example before calling GLib.HashTable.remove().

You can actually pass None for lookup_key to test whether the None key exists, provided the hash and equal functions of hash_table are None-safe.

classmethod remove(hash_table, key)[source]
Parameters:
Returns:

True if the key was found and removed from the GLib.HashTable
Return type:

bool

Removes a key and its associated value from a GLib.HashTable.

If the GLib.HashTable was created using g_hash_table_new_full(), the key and value are freed using the supplied destroy functions, otherwise you have to make sure that any dynamically allocated values are freed yourself.

classmethod remove_all(hash_table)[source]
Parameters:hash_table ({object: object}) – a GLib.HashTable

Removes all keys and their associated values from a GLib.HashTable.

If the GLib.HashTable was created using g_hash_table_new_full(), the keys and values are freed using the supplied destroy functions, otherwise you have to make sure that any dynamically allocated values are freed yourself.

New in version 2.12.

classmethod replace(hash_table, key, value)[source]
Parameters:
Returns:

True if the key did not exist yet
Return type:

bool

Inserts a new key and value into a GLib.HashTable similar to GLib.HashTable.insert(). The difference is that if the key already exists in the GLib.HashTable, it gets replaced by the new key. If you supplied a value_destroy_func when creating the GLib.HashTable, the old value is freed using that function. If you supplied a key_destroy_func when creating the GLib.HashTable, the old key is freed using that function.

Starting from GLib 2.40, this function returns a boolean value to indicate whether the newly added value was already in the hash table or not.

classmethod size(hash_table)[source]
Parameters:hash_table ({object: object}) – a GLib.HashTable
Returns:the number of key/value pairs in the GLib.HashTable.
Return type:int

Returns the number of elements contained in the GLib.HashTable.

classmethod steal(hash_table, key)[source]
Parameters:
Returns:

True if the key was found and removed from the GLib.HashTable
Return type:

bool

Removes a key and its associated value from a GLib.HashTable without calling the key and value destroy functions.

classmethod steal_all(hash_table)[source]
Parameters:hash_table ({object: object}) – a GLib.HashTable

Removes all keys and their associated values from a GLib.HashTable without calling the key and value destroy functions.

New in version 2.12.

classmethod steal_extended(hash_table, lookup_key)[source]
Parameters:
Returns:

True if the key was found in the GLib.HashTable

stolen_key:return location for the original key
stolen_value:return location for the value associated with the key

Return type:

(bool, stolen_key: object, stolen_value: object)

Looks up a key in the GLib.HashTable, stealing the original key and the associated value and returning True if the key was found. If the key was not found, False is returned.

If found, the stolen key and value are removed from the hash table without calling the key and value destroy functions, and ownership is transferred to the caller of this method; as with GLib.HashTable.steal().

You can pass None for lookup_key, provided the hash and equal functions of hash_table are None-safe.

New in version 2.58.

classmethod unref(hash_table)[source]
Parameters:hash_table ({object: object}) – a valid GLib.HashTable

Atomically decrements the reference count of hash_table by one. If the reference count drops to 0, all keys and values will be destroyed, and all memory allocated by the hash table is released. This function is MT-safe and may be called from any thread.

New in version 2.10.