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96 строки
3.2 KiB
ReStructuredText
96 строки
3.2 KiB
ReStructuredText
XPCOM Collections
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=================
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``nsTArray`` and ``AutoTArray``
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-------------------------------
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``nsTArray<T>`` is a typesafe array for holding various objects.
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Rust Bindings
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~~~~~~~~~~~~~
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When the ``thin_vec`` crate is built in Gecko, ``thin_vec::ThinVec<T>`` is
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guaranteed to have the same memory layout and allocation strategy as
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``nsTArray``, meaning that the two types may be used interchangably across
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FFI boundaries. The type is **not** safe to pass by-value over FFI
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boundaries, due to Rust and C++ differing in when they run destructors.
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The element type ``T`` must be memory-compatible with both Rust and C++ code
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to use over FFI.
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``nsTHashMap`` and ``nsTHashSet``
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---------------------------------
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These types are the recommended interface for writing new XPCOM hashmaps and
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hashsets in XPCOM code.
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Supported Hash Keys
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~~~~~~~~~~~~~~~~~~~
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The following types are supported as the key parameter to ``nsTHashMap`` and
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``nsTHashSet``.
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========================== ======================
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Type Hash Key
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========================== ======================
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``T*`` ``nsPtrHashKey<T>``
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``T*`` ``nsPtrHashKey<T>``
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``nsCString`` ``nsCStringHashKey``
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``nsString`` ``nsStringHashKey``
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``uint32_t`` ``nsUint32HashKey``
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``uint64_t`` ``nsUint64HashKey``
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``intptr_t`` ``IntPtrHashKey``
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``nsCOMPtr<nsISupports>`` ``nsISupportsHashKey``
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``RefPtr<T>`` ``nsRefPtrHashKey<T>``
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``nsID`` ``nsIDHashKey``
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========================== ======================
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Any key not in this list must inherit from the ``PLDHashEntryHdr`` class to
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implement manual hashing behaviour.
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Class Reference
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~~~~~~~~~~~~~~~
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.. note::
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The ``nsTHashMap`` and ``nsTHashSet`` types are not declared exactly like
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this in code. This is intended largely as a practical reference.
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.. cpp:class:: template<K, V> nsTHashMap<K, V>
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The ``nsTHashMap<K, V>`` class is currently defined as a thin type alias
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around ``nsBaseHashtable``. See the methods defined on that class for
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more detailed documentation.
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https://searchfox.org/mozilla-central/source/xpcom/ds/nsBaseHashtable.h
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.. cpp:function:: uint32_t Count() const
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.. cpp:function:: bool IsEmpty() const
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.. cpp:function:: bool Get(KeyType aKey, V* aData) const
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Get the value, returning a flag indicating the presence of the entry
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in the table.
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.. cpp:function:: V Get(KeyType aKey) const
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Get the value, returning a default-initialized object if the entry is
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not present in the table.
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.. cpp:function:: Maybe<V> MaybeGet(KeyType aKey) const
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Get the value, returning Nothing if the entry is not present in the table.
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.. cpp:function:: V& LookupOrInsert(KeyType aKey, Args&&... aArgs) const
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.. cpp:function:: V& LookupOrInsertWith(KeyType aKey, F&& aFunc) const
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.. cpp:class:: template<K> nsTHashSet<K>
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The ``nsTHashSet<K>`` class is currently defined as a thin type alias
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around ``nsTBaseHashSet``. See the methods defined on that class for
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more detailed documentation.
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https://searchfox.org/mozilla-central/source/xpcom/ds/nsTHashSet.h
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