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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 18:07:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 18:07:14 +0000
commita175314c3e5827eb193872241446f2f8f5c9d33c (patch)
treecd3d60ca99ae00829c52a6ca79150a5b6e62528b /sql/sql_hset.h
parentInitial commit. (diff)
downloadmariadb-10.5-upstream.tar.xz
mariadb-10.5-upstream.zip
Adding upstream version 1:10.5.12.upstream/1%10.5.12upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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1 files changed, 117 insertions, 0 deletions
diff --git a/sql/sql_hset.h b/sql/sql_hset.h
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+#ifndef SQL_HSET_INCLUDED
+#define SQL_HSET_INCLUDED
+/* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
+
+#include "hash.h"
+
+
+/**
+ A type-safe wrapper around mysys HASH.
+*/
+
+template <typename T>
+class Hash_set
+{
+public:
+ enum { START_SIZE= 8 };
+ /**
+ Constructs an empty hash. Does not allocate memory, it is done upon
+ the first insert. Thus does not cause or return errors.
+ */
+ Hash_set(PSI_memory_key psi_key, uchar *(*K)(const T *, size_t *, my_bool),
+ CHARSET_INFO *cs= &my_charset_bin)
+ {
+ my_hash_clear(&m_hash);
+ m_hash.get_key= (my_hash_get_key)K;
+ m_hash.charset= cs;
+ m_hash.array.m_psi_key= psi_key;
+ }
+ Hash_set(PSI_memory_key psi_key, CHARSET_INFO *charset, ulong default_array_elements,
+ size_t key_offset, size_t key_length, my_hash_get_key get_key,
+ void (*free_element)(void*), uint flags)
+ {
+ my_hash_init(psi_key, &m_hash, charset, default_array_elements, key_offset,
+ key_length, get_key, free_element, flags);
+ }
+ /**
+ Destroy the hash by freeing the buckets table. Does
+ not call destructors for the elements.
+ */
+ ~Hash_set()
+ {
+ my_hash_free(&m_hash);
+ }
+ /**
+ Insert a single value into a hash. Does not tell whether
+ the value was inserted -- if an identical value existed,
+ it is not replaced.
+
+ @retval TRUE Out of memory.
+ @retval FALSE OK. The value either was inserted or existed
+ in the hash.
+ */
+ bool insert(T *value)
+ {
+ my_hash_init_opt(m_hash.array.m_psi_key, &m_hash, m_hash.charset,
+ START_SIZE, 0, 0, m_hash.get_key, 0, HASH_UNIQUE);
+ return my_hash_insert(&m_hash, reinterpret_cast<const uchar*>(value));
+ }
+ bool remove(T *value)
+ {
+ return my_hash_delete(&m_hash, reinterpret_cast<uchar*>(value));
+ }
+ T *find(const void *key, size_t klen) const
+ {
+ return (T*)my_hash_search(&m_hash, reinterpret_cast<const uchar *>(key), klen);
+ }
+ /** Is this hash set empty? */
+ bool is_empty() const { return m_hash.records == 0; }
+ /** Returns the number of unique elements. */
+ size_t size() const { return static_cast<size_t>(m_hash.records); }
+ /** Erases all elements from the container */
+ void clear() { my_hash_reset(&m_hash); }
+ const T* at(size_t i) const
+ {
+ return reinterpret_cast<T*>(my_hash_element(const_cast<HASH*>(&m_hash), i));
+ }
+ /** An iterator over hash elements. Is not insert-stable. */
+ class Iterator
+ {
+ public:
+ Iterator(Hash_set &hash_set)
+ : m_hash(&hash_set.m_hash),
+ m_idx(0)
+ {}
+ /**
+ Return the current element and reposition the iterator to the next
+ element.
+ */
+ inline T *operator++(int)
+ {
+ if (m_idx < m_hash->records)
+ return reinterpret_cast<T*>(my_hash_element(m_hash, m_idx++));
+ return NULL;
+ }
+ void rewind() { m_idx= 0; }
+ private:
+ HASH *m_hash;
+ uint m_idx;
+ };
+private:
+ HASH m_hash;
+};
+
+#endif // SQL_HSET_INCLUDED