X-Git-Url: https://develop.uap-core.de/gitweb/uwplayer.git/blobdiff_plain/83d9f3aaf8206aa081ead0ff630a1c33ed670d71..848befbcc166fff6fdde6a635cf7a31f9f9185e0:/ucx/cx/map.h

diff --git a/ucx/cx/map.h b/ucx/cx/map.h
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+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+/**
+ * \file map.h
+ * \brief Interface for map implementations.
+ * \author Mike Becker
+ * \author Olaf Wintermann
+ * \version 3.0
+ * \copyright 2-Clause BSD License
+ */
+
+#ifndef UCX_MAP_H
+#define UCX_MAP_H
+
+#include "common.h"
+#include "allocator.h"
+#include "iterator.h"
+#include "hash_key.h"
+
+#ifdef    __cplusplus
+extern "C" {
+#endif
+
+#ifndef CX_STORE_POINTERS
+/**
+ * Special constant used for creating collections that are storing pointers.
+ */
+#define CX_STORE_POINTERS 0
+#endif
+
+/** Type for the UCX map. */
+typedef struct cx_map_s CxMap;
+
+/** Type for a map entry. */
+typedef struct cx_map_entry_s CxMapEntry;
+
+/** Type for map class definitions. */
+typedef struct cx_map_class_s cx_map_class;
+
+/** Structure for the UCX map. */
+struct cx_map_s {
+    /** The map class definition. */
+    cx_map_class *cl;
+    /** An allocator that is used for the map elements. */
+    CxAllocator *allocator;
+    /** The number of elements currently stored. */
+    size_t size;
+    /**
+     * The size of an element.
+     */
+    size_t itemsize;
+    /**
+     * True, if this map shall store pointers instead
+     * of copies of objects.
+     */
+    bool store_pointers;
+};
+
+/**
+ * The class definition for arbitrary maps.
+ */
+struct cx_map_class_s {
+    /**
+     * Deallocates the entire memory.
+     */
+    __attribute__((__nonnull__))
+    void (*destructor)(struct cx_map_s *map);
+
+    /**
+     * Removes all elements.
+     */
+    __attribute__((__nonnull__))
+    void (*clear)(struct cx_map_s *map);
+
+    /**
+     * Add or overwrite an element.
+     */
+    __attribute__((__nonnull__))
+    int (*put)(
+            CxMap *map,
+            CxHashKey key,
+            void *value
+    );
+
+    /**
+     * Returns an element.
+     */
+    __attribute__((__nonnull__, __warn_unused_result__))
+    void *(*get)(
+            CxMap const *map,
+            CxHashKey key
+    );
+
+    /**
+     * Removes an element.
+     */
+    __attribute__((__nonnull__))
+    void *(*remove)(
+            CxMap *map,
+            CxHashKey key
+    );
+
+    /**
+     * Iterator over the key/value pairs.
+     */
+    __attribute__((__nonnull__, __warn_unused_result__))
+    CxIterator (*iterator)(CxMap const *map);
+
+    /**
+     * Iterator over the keys.
+     */
+    __attribute__((__nonnull__, __warn_unused_result__))
+    CxIterator (*iterator_keys)(CxMap const *map);
+
+    /**
+     * Iterator over the values.
+     */
+    __attribute__((__nonnull__, __warn_unused_result__))
+    CxIterator (*iterator_values)(CxMap const *map);
+
+    /**
+     * Mutating iterator over the key/value pairs.
+     */
+    __attribute__((__nonnull__, __warn_unused_result__))
+    CxMutIterator (*mut_iterator)(CxMap *map);
+
+    /**
+     * Mutating iterator over the keys.
+     */
+    __attribute__((__nonnull__, __warn_unused_result__))
+    CxMutIterator (*mut_iterator_keys)(CxMap *map);
+
+    /**
+     * Mutating iterator over the values.
+     */
+    __attribute__((__nonnull__, __warn_unused_result__))
+    CxMutIterator (*mut_iterator_values)(CxMap *map);
+};
+
+/**
+ * A map entry.
+ */
+struct cx_map_entry_s {
+    /**
+     * A pointer to the key.
+     */
+    CxHashKey const *key;
+    /**
+     * A pointer to the value.
+     */
+    void *value;
+};
+
+/**
+ * Advises the map to store copies of the objects (default mode of operation).
+ *
+ * Retrieving objects from this map will yield pointers to the copies stored
+ * within this list.
+ *
+ * @param map the map
+ * @see cxMapStorePointers()
+ */
+__attribute__((__nonnull__))
+static inline void cxMapStoreObjects(CxMap *map) {
+    map->store_pointers = false;
+}
+
+/**
+ * Advises the map to only store pointers to the objects.
+ *
+ * Retrieving objects from this list will yield the original pointers stored.
+ *
+ * @note This function forcibly sets the element size to the size of a pointer.
+ * Invoking this function on a non-empty map that already stores copies of
+ * objects is undefined.
+ *
+ * @param map the map
+ * @see cxMapStoreObjects()
+ */
+__attribute__((__nonnull__))
+static inline void cxMapStorePointers(CxMap *map) {
+    map->store_pointers = true;
+    map->itemsize = sizeof(void *);
+}
+
+
+/**
+ * Deallocates the memory of the specified map.
+ *
+ * @param map the map to be destroyed
+ */
+__attribute__((__nonnull__))
+static inline void cxMapDestroy(CxMap *map) {
+    // TODO: likely to add auto-free feature for contents in the future
+    map->cl->destructor(map);
+}
+
+
+/**
+ * Clears a map by removing all elements.
+ *
+ * @param map the map to be cleared
+ */
+__attribute__((__nonnull__))
+static inline void cxMapClear(CxMap *map) {
+    map->cl->clear(map);
+}
+
+/**
+ * Puts a key/value-pair into the map.
+ *
+ * @param map the map
+ * @param key the key
+ * @param value the value
+ * @return 0 on success, non-zero value on failure
+ */
+__attribute__((__nonnull__))
+static inline int cxMapPut(
+        CxMap *map,
+        CxHashKey key,
+        void *value
+) {
+    return map->cl->put(map, key, value);
+}
+
+/**
+ * Retrieves a value by using a key.
+ *
+ * @param map the map
+ * @param key the key
+ * @return the value
+ */
+__attribute__((__nonnull__, __warn_unused_result__))
+static inline void *cxMapGet(
+        CxMap const *map,
+        CxHashKey key
+) {
+    return map->cl->get(map, key);
+}
+
+/**
+ * Removes a key/value-pair from the map by using the key.
+ *
+ * If this map is storing pointers, you should make sure that the map
+ * is not the last location where this pointer is stored.
+ * Otherwise, use cxMapRemoveAndGet() to retrieve the pointer while
+ * removing it from the map.
+ *
+ * @param map the map
+ * @param key the key
+ * @see cxMapRemoveAndGet()
+ */
+__attribute__((__nonnull__))
+static inline void cxMapRemove(
+        CxMap *map,
+        CxHashKey key
+) {
+    (void) map->cl->remove(map, key);
+}
+
+/**
+ * Removes a key/value-pair from the map by using the key.
+ *
+ * This function should only be used when the map is storing pointers,
+ * in order to retrieve the pointer you are about to remove.
+ * In any other case, cxMapRemove() is sufficient.
+ *
+ * @param map the map
+ * @param key the key
+ * @return the stored pointer or \c NULL if either the key is not present
+ * in the map or the map is not storing pointers
+ * @see cxMapStorePointers()
+ */
+__attribute__((__nonnull__, __warn_unused_result__))
+static inline void *cxMapRemoveAndGet(
+        CxMap *map,
+        CxHashKey key
+) {
+    return map->cl->remove(map, key);
+}
+
+// TODO: set-like map operations (union, intersect, difference)
+
+/**
+ * Creates a value iterator for a map.
+ *
+ * \note An iterator iterates over all elements successively. Therefore the order
+ * highly depends on the map implementation and may change arbitrarily when the contents change.
+ *
+ * @param map the map to create the iterator for
+ * @return an iterator for the currently stored values
+ */
+__attribute__((__nonnull__, __warn_unused_result__))
+static inline CxIterator cxMapIteratorValues(CxMap *map) {
+    return map->cl->iterator_values(map);
+}
+
+/**
+ * Creates a key iterator for a map.
+ *
+ * The elements of the iterator are keys of type CxHashKey.
+ *
+ * \note An iterator iterates over all elements successively. Therefore the order
+ * highly depends on the map implementation and may change arbitrarily when the contents change.
+ *
+ * @param map the map to create the iterator for
+ * @return an iterator for the currently stored keys
+ */
+__attribute__((__nonnull__, __warn_unused_result__))
+static inline CxIterator cxMapIteratorKeys(CxMap *map) {
+    return map->cl->iterator_keys(map);
+}
+
+/**
+ * Creates an iterator for a map.
+ *
+ * The elements of the iterator are key/value pairs of type CxMapEntry.
+ *
+ * \note An iterator iterates over all elements successively. Therefore the order
+ * highly depends on the map implementation and may change arbitrarily when the contents change.
+ *
+ * @param map the map to create the iterator for
+ * @return an iterator for the currently stored entries
+ * @see cxMapIteratorKeys()
+ * @see cxMapIteratorValues()
+ */
+__attribute__((__nonnull__, __warn_unused_result__))
+static inline CxIterator cxMapIterator(CxMap *map) {
+    return map->cl->iterator(map);
+}
+
+
+/**
+ * Creates a mutating iterator over the values of a map.
+ *
+ * \note An iterator iterates over all elements successively. Therefore the order
+ * highly depends on the map implementation and may change arbitrarily when the contents change.
+ *
+ * @param map the map to create the iterator for
+ * @return an iterator for the currently stored values
+ */
+__attribute__((__nonnull__, __warn_unused_result__))
+static inline CxMutIterator cxMapMutIteratorValues(CxMap *map) {
+    return map->cl->mut_iterator_values(map);
+}
+
+/**
+ * Creates a mutating iterator over the keys of a map.
+ *
+ * The elements of the iterator are keys of type CxHashKey.
+ *
+ * \note An iterator iterates over all elements successively. Therefore the order
+ * highly depends on the map implementation and may change arbitrarily when the contents change.
+ *
+ * @param map the map to create the iterator for
+ * @return an iterator for the currently stored keys
+ */
+__attribute__((__nonnull__, __warn_unused_result__))
+static inline CxMutIterator cxMapMutIteratorKeys(CxMap *map) {
+    return map->cl->mut_iterator_keys(map);
+}
+
+/**
+ * Creates a mutating iterator for a map.
+ *
+ * The elements of the iterator are key/value pairs of type CxMapEntry.
+ *
+ * \note An iterator iterates over all elements successively. Therefore the order
+ * highly depends on the map implementation and may change arbitrarily when the contents change.
+ *
+ * @param map the map to create the iterator for
+ * @return an iterator for the currently stored entries
+ * @see cxMapMutIteratorKeys()
+ * @see cxMapMutIteratorValues()
+ */
+__attribute__((__nonnull__, __warn_unused_result__))
+static inline CxMutIterator cxMapMutIterator(CxMap *map) {
+    return map->cl->mut_iterator(map);
+}
+
+#ifdef    __cplusplus
+}
+#endif
+
+#endif // UCX_MAP_H
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