Second Life viewer sources 1.13.2.12

1 files changed, 521 insertions, 0 deletions

diff --git a/linden/indra/llcommon/llskiplist.h b/linden/indra/llcommon/llskiplist.h
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+++ b/linden/indra/llcommon/llskiplist.h
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+/** 
+ * @file llskiplist.h
+ * @brief skip list implementation
+ *
+ * Copyright (c) 2001-2007, Linden Research, Inc.
+ * 
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlife.com/developers/opensource/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at http://secondlife.com/developers/opensource/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ */
+#ifndef LL_LLSKIPLIST_H
+#define LL_LLSKIPLIST_H
+
+#include "llerror.h"
+//#include "vmath.h"
+
+// NOTA BENE: Insert first needs to be < NOT <=
+
+template <class DATA_TYPE, S32 BINARY_DEPTH = 10>
+class LLSkipList
+{
+public:
+        typedef BOOL (*compare)(const DATA_TYPE& first, const DATA_TYPE& second);
+        typedef compare insert_func;
+        typedef compare equals_func;
+
+        void init();
+
+        // basic constructor
+        LLSkipList();
+
+        // basic constructor including sorter
+        LLSkipList(insert_func insert_first, equals_func equals);
+        ~LLSkipList();
+
+        inline void setInsertFirst(insert_func insert_first);
+        inline void setEquals(equals_func equals);
+
+        inline BOOL addData(const DATA_TYPE& data);
+        inline BOOL checkData(const DATA_TYPE& data);
+
+        // returns number of items in the list
+        inline S32 getLength() const; // NOT a constant time operation, traverses entire list!
+
+        inline BOOL moveData(const DATA_TYPE& data, LLSkipList *newlist);
+
+        inline BOOL removeData(const DATA_TYPE& data);
+
+        // remove all nodes from the list but do not delete data
+        inline void removeAllNodes();
+
+        // place mCurrentp on first node
+        inline void resetList();
+
+        // return the data currently pointed to, set mCurentOperatingp to that node and bump mCurrentp
+        inline DATA_TYPE getCurrentData();
+
+        // same as getCurrentData() but a more intuitive name for the operation
+        inline DATA_TYPE getNextData();
+
+        // remove the Node at mCurentOperatingp
+        // leave mCurrentp and mCurentOperatingp on the next entry
+        inline void removeCurrentData();
+
+        // reset the list and return the data currently pointed to, set mCurentOperatingp to that node and bump mCurrentp
+        inline DATA_TYPE getFirstData();
+
+        class LLSkipNode
+        {
+        public:
+                LLSkipNode()
+                :       mData(0)
+                {
+                        S32 i;
+                        for (i = 0; i < BINARY_DEPTH; i++)
+                        {
+                                mForward[i] = NULL;
+                        }
+                }
+
+                LLSkipNode(DATA_TYPE data)
+                        : mData(data)
+                {
+                        S32 i;
+                        for (i = 0; i < BINARY_DEPTH; i++)
+                        {
+                                mForward[i] = NULL;
+                        }
+                }
+
+                ~LLSkipNode()
+                {
+                }
+
+                DATA_TYPE                                       mData;
+                LLSkipNode                                      *mForward[BINARY_DEPTH];
+
+        private:
+                // Disallow copying of LLSkipNodes by not implementing these methods.
+                LLSkipNode(const LLSkipNode &);
+                LLSkipNode &operator=(const LLSkipNode &);
+        };
+
+        static BOOL defaultEquals(const DATA_TYPE& first, const DATA_TYPE& second)
+        {
+                return first == second;
+        }
+
+private:
+        LLSkipNode                                      mHead;
+        LLSkipNode                                      *mUpdate[BINARY_DEPTH];
+        LLSkipNode                                      *mCurrentp;
+        LLSkipNode                                      *mCurrentOperatingp;
+        S32                                                     mLevel;
+        insert_func mInsertFirst;
+        equals_func mEquals;
+
+private:
+        // Disallow copying of LLSkipNodes by not implementing these methods.
+        LLSkipList(const LLSkipList &);
+        LLSkipList &operator=(const LLSkipList &);
+};
+
+
+///////////////////////
+//
+// Implementation
+//
+
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline void LLSkipList<DATA_TYPE, BINARY_DEPTH>::init()
+{
+        if (BINARY_DEPTH < 2)
+        {
+                llerrs << "Trying to create skip list with too little depth, "
+                        "must be 2 or greater" << llendl;
+        }
+        S32 i;
+        for (i = 0; i < BINARY_DEPTH; i++)
+        {
+                mHead.mForward[i] = NULL;
+                mUpdate[i] = NULL;
+        }
+        mLevel = 1;
+        mCurrentp = *(mHead.mForward);
+        mCurrentOperatingp = *(mHead.mForward);
+}
+
+
+// basic constructor
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline LLSkipList<DATA_TYPE, BINARY_DEPTH>::LLSkipList()
+:       mInsertFirst(NULL), 
+        mEquals(defaultEquals)
+{
+        init();
+}
+
+// basic constructor including sorter
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline LLSkipList<DATA_TYPE, BINARY_DEPTH>::LLSkipList(insert_func insert,
+                                                                                                           equals_func equals)
+:       mInsertFirst(insert), 
+        mEquals(equals)
+{
+        init();
+}
+
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline LLSkipList<DATA_TYPE, BINARY_DEPTH>::~LLSkipList()
+{
+        removeAllNodes();
+}
+
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline void LLSkipList<DATA_TYPE, BINARY_DEPTH>::setInsertFirst(insert_func insert_first)
+{
+        mInsertFirst = insert_first;
+}
+
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline void LLSkipList<DATA_TYPE, BINARY_DEPTH>::setEquals(equals_func equals)
+{
+        mEquals = equals;
+}
+
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline BOOL LLSkipList<DATA_TYPE, BINARY_DEPTH>::addData(const DATA_TYPE& data)
+{
+        S32                     level;
+        LLSkipNode      *current = &mHead;
+        LLSkipNode      *temp;
+        // find the pointer one in front of the one we want
+        if (mInsertFirst)
+        {
+                for (level = mLevel - 1; level >= 0; level--)
+                {
+                        temp = *(current->mForward + level);
+                        while (  (temp)
+                                   &&(mInsertFirst(temp->mData, data)))
+                        {
+                                current = temp;
+                                temp = *(current->mForward + level);
+                        }
+                        *(mUpdate + level) = current;
+                }
+        }
+        else
+        {
+                for (level = mLevel - 1; level >= 0; level--)
+                {
+                        temp = *(current->mForward + level);
+                        while (  (temp)
+                                   &&(temp->mData < data))
+                        {
+                                current = temp;
+                                temp = *(current->mForward + level);
+                        }
+                        *(mUpdate + level) = current;
+                }
+        }
+        // we're now just in front of where we want to be . . . take one step forward
+        current = *current->mForward;
+
+        // now add the new node
+        S32 newlevel;
+        for (newlevel = 1; newlevel <= mLevel && newlevel < BINARY_DEPTH; newlevel++)
+        {
+                if (frand(1.f) < 0.5f)
+                        break;
+        }
+
+        LLSkipNode *snode = new LLSkipNode(data);
+
+        if (newlevel > mLevel)
+        {
+                mHead.mForward[mLevel] = NULL;
+                mUpdate[mLevel] = &mHead;
+                mLevel = newlevel;
+        }
+
+        for (level = 0; level < newlevel; level++)
+        {
+                snode->mForward[level] = mUpdate[level]->mForward[level];
+                mUpdate[level]->mForward[level] = snode;
+        }
+        return TRUE;
+}
+
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline BOOL LLSkipList<DATA_TYPE, BINARY_DEPTH>::checkData(const DATA_TYPE& data)
+{
+        S32                     level;
+        LLSkipNode      *current = &mHead;
+        LLSkipNode      *temp;
+        // find the pointer one in front of the one we want
+        if (mInsertFirst)
+        {
+                for (level = mLevel - 1; level >= 0; level--)
+                {
+                        temp = *(current->mForward + level);
+                        while (  (temp)
+                                   &&(mInsertFirst(temp->mData, data)))
+                        {
+                                current = temp;
+                                temp = *(current->mForward + level);
+                        }
+                        *(mUpdate + level) = current;
+                }
+        }
+        else
+        {
+                for (level = mLevel - 1; level >= 0; level--)
+                {
+                        temp = *(current->mForward + level);
+                        while (  (temp)
+                                   &&(temp->mData < data))
+                        {
+                                current = temp;
+                                temp = *(current->mForward + level);
+                        }
+                        *(mUpdate + level) = current;
+                }
+        }
+        // we're now just in front of where we want to be . . . take one step forward
+        current = *current->mForward;
+
+
+        if (current)
+        {
+                return mEquals(current->mData, data);
+        }
+
+        return FALSE;
+}
+
+// returns number of items in the list
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline S32 LLSkipList<DATA_TYPE, BINARY_DEPTH>::getLength() const
+{
+        U32     length = 0;
+        for (LLSkipNode* temp = *(mHead.mForward); temp != NULL; temp = temp->mForward[0])
+        {
+                length++;
+        }
+        return length;
+}
+
+
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline BOOL LLSkipList<DATA_TYPE, BINARY_DEPTH>::moveData(const DATA_TYPE& data, LLSkipList *newlist)
+{
+        BOOL removed = removeData(data);
+        BOOL added = newlist->addData(data);
+        return removed && added;
+}
+
+
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline BOOL LLSkipList<DATA_TYPE, BINARY_DEPTH>::removeData(const DATA_TYPE& data)
+{
+        S32                     level;
+        LLSkipNode      *current = &mHead;
+        LLSkipNode      *temp;
+        // find the pointer one in front of the one we want
+        if (mInsertFirst)
+        {
+                for (level = mLevel - 1; level >= 0; level--)
+                {
+                        temp = *(current->mForward + level);
+                        while (  (temp)
+                                   &&(mInsertFirst(temp->mData, data)))
+                        {
+                                current = temp;
+                                temp = *(current->mForward + level);
+                        }
+                        *(mUpdate + level) = current;
+                }
+        }
+        else
+        {
+                for (level = mLevel - 1; level >= 0; level--)
+                {
+                        temp = *(current->mForward + level);
+                        while (  (temp)
+                                   &&(temp->mData < data))
+                        {
+                                current = temp;
+                                temp = *(current->mForward + level);
+                        }
+                        *(mUpdate + level) = current;
+                }
+        }
+        // we're now just in front of where we want to be . . . take one step forward
+        current = *current->mForward;
+
+
+        if (!current)
+        {
+                // empty list or beyond the end!
+                return FALSE;
+        }
+
+        // is this the one we want?
+        if (!mEquals(current->mData, data))
+        {
+                // nope!
+                return FALSE;
+        }
+        else
+        {
+                // do we need to fix current or currentop?
+                if (current == mCurrentp)
+                {
+                        mCurrentp = current->mForward[0];
+                }
+
+                if (current == mCurrentOperatingp)
+                {
+                        mCurrentOperatingp = current->mForward[0];
+                }
+                // yes it is!  change pointers as required
+                for (level = 0; level < mLevel; level++)
+                {
+                        if (mUpdate[level]->mForward[level] != current)
+                        {
+                                // cool, we've fixed all the pointers!
+                                break;
+                        }
+                        mUpdate[level]->mForward[level] = current->mForward[level];
+                }
+
+                // clean up cuurent
+                delete current;
+
+                // clean up mHead
+                while (  (mLevel > 1)
+                           &&(!mHead.mForward[mLevel - 1]))
+                {
+                        mLevel--;
+                }
+        }
+        return TRUE;
+}
+
+// remove all nodes from the list but do not delete data
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline void LLSkipList<DATA_TYPE, BINARY_DEPTH>::removeAllNodes()
+{
+        LLSkipNode *temp;
+        // reset mCurrentp
+        mCurrentp = *(mHead.mForward);
+
+        while (mCurrentp)
+        {
+                temp = mCurrentp->mForward[0];
+                delete mCurrentp;
+                mCurrentp = temp;
+        }
+
+        S32 i;
+        for (i = 0; i < BINARY_DEPTH; i++)
+        {
+                mHead.mForward[i] = NULL;
+                mUpdate[i] = NULL;
+        }
+
+        mCurrentp = *(mHead.mForward);
+        mCurrentOperatingp = *(mHead.mForward);
+}
+
+// place mCurrentp on first node
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline void LLSkipList<DATA_TYPE, BINARY_DEPTH>::resetList()
+{
+        mCurrentp = *(mHead.mForward);
+        mCurrentOperatingp = *(mHead.mForward);
+}
+
+// return the data currently pointed to, set mCurentOperatingp to that node and bump mCurrentp
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline DATA_TYPE LLSkipList<DATA_TYPE, BINARY_DEPTH>::getCurrentData()
+{
+        if (mCurrentp)
+        {
+                mCurrentOperatingp = mCurrentp;
+                mCurrentp = mCurrentp->mForward[0];
+                return mCurrentOperatingp->mData;
+        }
+        else
+        {
+                //return NULL;          // causes compile warning
+                return (DATA_TYPE)0;                    // equivalent, but no warning
+        }
+}
+
+// same as getCurrentData() but a more intuitive name for the operation
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline DATA_TYPE LLSkipList<DATA_TYPE, BINARY_DEPTH>::getNextData()
+{
+        if (mCurrentp)
+        {
+                mCurrentOperatingp = mCurrentp;
+                mCurrentp = mCurrentp->mForward[0];
+                return mCurrentOperatingp->mData;
+        }
+        else
+        {
+                //return NULL;          // causes compile warning
+                return (DATA_TYPE)0;                    // equivalent, but no warning
+        }
+}
+
+// remove the Node at mCurentOperatingp
+// leave mCurrentp and mCurentOperatingp on the next entry
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline void LLSkipList<DATA_TYPE, BINARY_DEPTH>::removeCurrentData()
+{
+        if (mCurrentOperatingp)
+        {
+                removeData(mCurrentOperatingp->mData);
+        }
+}
+
+// reset the list and return the data currently pointed to, set mCurentOperatingp to that node and bump mCurrentp
+template <class DATA_TYPE, S32 BINARY_DEPTH>
+inline DATA_TYPE LLSkipList<DATA_TYPE, BINARY_DEPTH>::getFirstData()
+{
+        mCurrentp = *(mHead.mForward);
+        mCurrentOperatingp = *(mHead.mForward);
+        if (mCurrentp)
+        {
+                mCurrentOperatingp = mCurrentp;
+                mCurrentp = mCurrentp->mForward[0];
+                return mCurrentOperatingp->mData;
+        }
+        else
+        {
+                //return NULL;          // causes compile warning
+                return (DATA_TYPE)0;                    // equivalent, but no warning
+        }
+}
+
+
+#endif