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Diffstat (limited to '')
| -rw-r--r-- | src/tree.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/src/tree.c b/src/tree.c new file mode 100644 index 000000000..0696f4b13 --- /dev/null +++ b/src/tree.c @@ -0,0 +1,260 @@ +#include "tree.h" + +#include <assert.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.h> + +static +TreeNode * +_MakeNode() +{ + TreeNode * ret = malloc(sizeof(TreeNode)); + memset(ret, 0, sizeof(TreeNode)); + return ret; +} + +static +int +_Find(TreeIterator * iter, void * data) +{ + while (1) + { + for (; iter->which < iter->node->dataCount; iter->which++) + { + int comp = iter->tree-> + compareData(data,iter->node->data[iter->which]); + + if (comp == 0) + { + return 1; + } + else if (comp < 0) + { + break; + } + } + + assert(iter->which < CHILDREN_PER_NODE); + + if (iter->node->children[iter->which]) + { + iter->node = iter->node->children[iter->which]; + iter->which = 0; + } + else + { + return 0; + } + } +} + +Tree * +MakeTree(TreeCompareDataFunction compareData, TreeFreeDataFunction freeData) +{ + Tree * ret = malloc(sizeof(Tree)); + ret->compareData = compareData; + ret->freeData = freeData; + ret->rootNode = _MakeNode(); + return ret; +} + +static +TreeNode * +_SplitNode(TreeNode * node) +{ + assert(node->dataCount == DATA_PER_NODE); + + TreeNode * newNode = _MakeNode(); + + unsigned i = DATA_PER_NODE/2; + unsigned j = 0; + for (; i < DATA_PER_NODE; i++, j++) + { + newNode->data[j] = node->data[i]; + newNode->children[j+1] = node->children[i+1]; + if (newNode->children[j+1]) + { + newNode->children[j+1]->parent = newNode; + } + node->data[i] = NULL; + node->children[i+1] = NULL; + } + newNode->dataCount = j; + node->dataCount -= j; + + return newNode; +} + +static +void +_InsertNodeAndData(Tree * tree, + TreeNode * node, + TreeNode * newNode, + void * data) +{ + assert(node->dataCount < DATA_PER_NODE); + assert(!newNode || tree->compareData(data, newNode->data[0]) < 0); + + if (newNode) + { + newNode->parent = node; + } + + int i = 0; + for (; + i < node->dataCount && + tree->compareData(data, node->data[i]) > 0; + i++); + + int j = node->dataCount; + for (; j > i; j--) + { + node->data[j] = node->data[j-1]; + node->children[j+1] = node->children[j]; + } + + assert(!node->children[j] || + tree->compareData(data, node->children[j]->data[0]) > 0); + + node->data[j] = data; + node->children[j+1] = newNode; + node->dataCount++; +} + +static +void * +_AddDataToSplitNodes(Tree * tree, + TreeNode * lessNode, + TreeNode * moreNode, + TreeNode * newNode, + void * data) +{ + assert(newNode == NULL || + tree->compareData(data, newNode->data[0]) < 0); + + void * retData; + + if (tree->compareData(data, moreNode->data[0]) < 0) + { + _InsertNodeAndData(tree, lessNode, newNode, data); + lessNode->dataCount--; + retData = lessNode->data[lessNode->dataCount]; + lessNode->data[lessNode->dataCount] = NULL; + } + else + { + if (newNode) + { + newNode->parent = moreNode; + } + + int i = 0; + for (; + i < moreNode->dataCount && + tree->compareData(data, moreNode->data[i]) > 0; + i++); + + if (i == 0) + { + moreNode->children[0] = newNode; + return data; + } + else + { + retData = moreNode->data[0]; + } + + int j = 0; + for (; j < i; j++) + { + moreNode->data[j] = moreNode->data[j+1]; + moreNode->children[j] = moreNode->children[j+1]; + } + + assert(!moreNode->children[j-1] || + tree->compareData(data, + moreNode->children[j]->data[0]) > 0); + + moreNode->data[j-1] = data; + moreNode->children[j] = newNode; + } + + return retData; +} + +static +void +_InsertAt(TreeIterator * iter, void * data) +{ + TreeNode * node = iter->node; + TreeNode * insertNode = NULL; + + while (node != NULL) + { + // see if there's any NULL data in the current node + if (node->dataCount == DATA_PER_NODE) + { + // no open data slots, split this node! + TreeNode * newNode = _SplitNode(node); + + // insert data in split nodes + data = _AddDataToSplitNodes(iter->tree, + node, + newNode, + insertNode, + data); + + insertNode = newNode; + + if (node->parent == NULL) + { + assert(node == iter->tree->rootNode); + iter->tree->rootNode = _MakeNode(); + node->parent = iter->tree->rootNode; + newNode->parent = iter->tree->rootNode; + iter->tree->rootNode->data[0] = data; + iter->tree->rootNode->children[0] = node; + iter->tree->rootNode->children[1] = newNode; + iter->tree->rootNode->dataCount = 1; + return; + } + + node = node->parent; + } + else + { + // insert the data and newNode + _InsertNodeAndData( iter->tree, + node, + insertNode, + data ); + node = NULL; + } + } + + return; +} + +void SetIteratorToBegin(TreeIterator * iter, Tree * tree) +{ + iter->tree = tree; + iter->node = tree->rootNode; + iter->which = 0; +} + +int +InsertIntoTree(Tree * tree, void * data) +{ + TreeIterator iter; + SetIteratorToBegin(&iter, tree); + + if (_Find(&iter, data)) + { + return 0; + } + + _InsertAt(&iter, data); + + return 1; +} |