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authorJames Cook <james@lindenlab.com>2007-01-02 08:33:20 +0000
committerJames Cook <james@lindenlab.com>2007-01-02 08:33:20 +0000
commit420b91db29485df39fd6e724e782c449158811cb (patch)
treeb471a94563af914d3ed3edd3e856d21cb1b69945 /indra/llcommon/llsimplehash.h
Print done when done.
Diffstat (limited to 'indra/llcommon/llsimplehash.h')
-rw-r--r--indra/llcommon/llsimplehash.h137
1 files changed, 137 insertions, 0 deletions
diff --git a/indra/llcommon/llsimplehash.h b/indra/llcommon/llsimplehash.h
new file mode 100644
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+++ b/indra/llcommon/llsimplehash.h
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+/**
+ * @file llsimplehash.h
+ *
+ * Copyright (c) 2003-$CurrentYear$, Linden Research, Inc.
+ * $License$
+ */
+
+#ifndef LL_LLSIMPLEHASH_H
+#define LL_LLSIMPLEHASH_H
+
+#include "llstl.h"
+
+template <typename HASH_KEY_TYPE>
+class LLSimpleHashEntry
+{
+protected:
+ HASH_KEY_TYPE mHashKey;
+ LLSimpleHashEntry<HASH_KEY_TYPE>* mNextEntry;
+public:
+ LLSimpleHashEntry(HASH_KEY_TYPE key) :
+ mHashKey(key),
+ mNextEntry(0)
+ {
+ }
+ virtual ~LLSimpleHashEntry()
+ {
+ }
+ HASH_KEY_TYPE getHashKey() const
+ {
+ return mHashKey;
+ }
+ LLSimpleHashEntry<HASH_KEY_TYPE>* getNextEntry() const
+ {
+ return mNextEntry;
+ }
+ void setNextEntry(LLSimpleHashEntry<HASH_KEY_TYPE>* next)
+ {
+ mNextEntry = next;
+ }
+};
+
+template <typename HASH_KEY_TYPE, int TABLE_SIZE>
+class LLSimpleHash
+{
+public:
+ LLSimpleHash()
+ {
+ llassert(TABLE_SIZE);
+ llassert((TABLE_SIZE ^ (TABLE_SIZE-1)) == (TABLE_SIZE | (TABLE_SIZE-1))); // power of 2
+ memset(mEntryTable, 0, sizeof(mEntryTable));
+ }
+ virtual ~LLSimpleHash()
+ {
+ }
+
+ virtual int getIndex(HASH_KEY_TYPE key)
+ {
+ return key & (TABLE_SIZE-1);
+ }
+
+ bool insert(LLSimpleHashEntry<HASH_KEY_TYPE>* entry)
+ {
+ llassert(entry->getNextEntry() == 0);
+ int index = getIndex(entry->getHashKey());
+ entry->setNextEntry(mEntryTable[index]);
+ mEntryTable[index] = entry;
+ return true;
+ }
+ LLSimpleHashEntry<HASH_KEY_TYPE>* find(HASH_KEY_TYPE key)
+ {
+ int index = getIndex(key);
+ LLSimpleHashEntry<HASH_KEY_TYPE>* res = mEntryTable[index];
+ while(res && (res->getHashKey() != key))
+ {
+ res = res->getNextEntry();
+ }
+ return res;
+ }
+ bool erase(LLSimpleHashEntry<HASH_KEY_TYPE>* entry)
+ {
+ return erase(entry->getHashKey());
+ }
+ bool erase(HASH_KEY_TYPE key)
+ {
+ int index = getIndex(key);
+ LLSimpleHashEntry<HASH_KEY_TYPE>* prev = 0;
+ LLSimpleHashEntry<HASH_KEY_TYPE>* res = mEntryTable[index];
+ while(res && (res->getHashKey() != key))
+ {
+ prev = res;
+ res = res->getNextEntry();
+ }
+ if (res)
+ {
+ LLSimpleHashEntry<HASH_KEY_TYPE>* next = res->getNextEntry();
+ if (prev)
+ {
+ prev->setNextEntry(next);
+ }
+ else
+ {
+ mEntryTable[index] = next;
+ }
+ return true;
+ }
+ else
+ {
+ return false;
+ }
+ }
+ // Removes and returns an arbitrary ("first") element from the table
+ // Used for deleting the entire table.
+ LLSimpleHashEntry<HASH_KEY_TYPE>* pop_element()
+ {
+ for (int i=0; i<TABLE_SIZE; i++)
+ {
+ LLSimpleHashEntry<HASH_KEY_TYPE>* entry = mEntryTable[i];
+ if (entry)
+ {
+ mEntryTable[i] = entry->getNextEntry();
+ return entry;
+ }
+ }
+ return 0;
+ }
+ // debugging
+ LLSimpleHashEntry<HASH_KEY_TYPE>* get_element_at_index(S32 index) const
+ {
+ return mEntryTable[index];
+ }
+
+
+private:
+ LLSimpleHashEntry<HASH_KEY_TYPE>* mEntryTable[TABLE_SIZE];
+};
+
+#endif // LL_LLSIMPLEHASH_H