Add BPTree.

src/defines.h

@@ -17,4 +17,15 @@
 #define N_START 4
 #define N_P_START 1
 
+// Uncomment the line below if you are compiling on Windows.
+// #define WINDOWS
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#ifdef WINDOWS
+#define bool char
+#define false 0
+#define true 1
+#endif
+
 #endif //PRRT_DEFINES_H

src/util/CMakeLists.txt

-add_library(UTIL ../defines.h common.c common.h list.c list.h dbg.h)
\ No newline at end of file
+add_library(UTIL ../defines.h common.c common.h list.c list.h dbg.h bptree.c bptree.h)
\ No newline at end of file

src/util/bptree.h

+/*
+ *
+ *  bpt:  B+ Tree Implementation
+ *  Copyright (C) 2010  Amittai Aviram  http://www.amittai.com
+ *
+ *  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, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  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, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ *  Author:  Amittai Aviram
+ *    http://www.amittai.com
+ *    amittai.aviram@gmail.edu or afa13@columbia.edu
+ *    Senior Software Engineer
+ *    MathWorks, Inc.
+ *    3 Apple Hill Drive
+ *    Natick, MA 01760
+ *  Original Date:  26 June 2010
+ *  Last modified: 15 April 2014
+ *
+ *  This implementation demonstrates the B+ tree data structure
+ *  for educational purposes, includin insertion, deletion, search, and display
+ *  of the search path, the leaves, or the whole tree.
+ *
+ *  Must be compiled with a C99-compliant C compiler such as the latest GCC.
+ *
+ *  Usage:  bpt [order]
+ *  where order is an optional argument
+ *  (integer MIN_ORDER <= order <= MAX_ORDER)
+ *  defined as the maximal number of pointers in any node.
+ *
+ */
+
+#ifndef PRRT_BPTREE_H
+#define PRRT_BPTREE_H
+
+#include <src/defines.h>
+#include "list.h"
+
+/* Type representing a node in the B+ tree. This type is general enough to serve for both the leaf and the internal
+ * node. The heart of the node is the array of keys and the array of corresponding  pointers. The relation between
+ * keys and pointers differs between leaves and internal nodes. In a leaf, the index of each key equals the index of
+ * its corresponding pointer, with a maximum of order - 1 key-pointer pairs. The last pointer points to the leaf to the
+ * right (or NULL in the case of the rightmost leaf). In an internal node, the first pointer refers to lower nodes with
+ * keys less than the smallest key in the keys array. Then, with indices i starting at 0, the pointer at i + 1 points
+ * to the subtree with keys greater than or equal to the key in this node at index i. The num_keys field is used to keep
+ * track of the number of valid keys. In an internal node, the number of valid pointers is always num_keys + 1.
+ * In a leaf, the number of valid pointers to data is always num_keys. The last leaf pointer points to the next leaf.
+ */
+typedef struct BPTreeNode {
+    void ** pointers;
+    int * keys;
+    struct BPTreeNode * parent;
+    bool is_leaf;
+    int num_keys;
+    struct BPTreeNode * next; // Used for queue.
+} BPTreeNode;
+
+// Operations
+BPTreeNode *BPTree_insert(BPTreeNode *root, int key, void *value);
+BPTreeNode *BPTree_delete(BPTreeNode *root, int key);
+BPTreeNode *BPTree_destroy(BPTreeNode *root);
+void *BPTree_get(BPTreeNode *root, int key);
+void BPTree_get_range(BPTreeNode *root, List *list, int key_start, int key_end);
+
+// Helpers
+void BPTree_print(BPTreeNode *root);
+int BPTree_height(BPTreeNode *root);
+
+#endif //PRRT_BPTREE_H

tests/CMakeLists.txt

 add_subdirectory(lib/gtest-1.7.0)
 include_directories(SYSTEM ${gtest_SOURCE_DIR}/include ${gtest_SOURCE_DIR})
 
-add_executable(prrtTests forward_packet_table_tests.cpp)
+add_executable(prrtTests forward_packet_table_tests.cpp bptree_tests.cpp)
 target_link_libraries(prrtTests LINK_PUBLIC PRRT UTIL gtest gtest_main)
\ No newline at end of file

tests/bptree_tests.cpp

+#include <gtest/gtest.h>
+
+extern "C" {
+    #include "src/util/bptree.h"
+}
+
+class BPlusTreeTest : public ::testing::Test {
+protected:
+    virtual void SetUp() {
+        root = NULL;
+        void* p = malloc(sizeof(int));
+        root = BPTree_insert(root, 1, p);
+    }
+
+    virtual void TearDown() {
+        root = BPTree_destroy(root);
+    }
+
+    BPTreeNode* root;
+
+};
+
+TEST_F(BPlusTreeTest, InsertDelete) {
+    void* p = malloc(sizeof(int));
+    ASSERT_EQ(BPTree_height(root), 0);
+    root = BPTree_insert(root, 2, p);
+    ASSERT_EQ(BPTree_height(root), 0);
+    root = BPTree_insert(root, 3, p);
+    ASSERT_EQ(BPTree_height(root), 0);
+    root = BPTree_insert(root, 4, p);
+    ASSERT_EQ(BPTree_height(root), 1);
+    root = BPTree_delete(root, 3);
+    ASSERT_EQ(BPTree_height(root), 0);
+}
+
+TEST_F(BPlusTreeTest, InsertAndFind) {
+    void* p = malloc(sizeof(int));
+    void* p2 = malloc(sizeof(int));
+    root = BPTree_insert(root, 2, p);
+    root = BPTree_insert(root, 3, p2);
+    root = BPTree_insert(root, 4, p);
+
+    ASSERT_EQ(BPTree_get(root, 3), p2);
+    ASSERT_NE(BPTree_get(root, 3), p);
+}
+
+TEST_F(BPlusTreeTest, FindRange) {
+    int n = 10;
+    void* p[10];
+    root = BPTree_delete(root, 1);
+    for (int i = 0; i < n; i++) {
+        void *pVoid = malloc(sizeof(int));
+        p[i] = pVoid;
+        root = BPTree_insert(root, i, pVoid);
+    }
+
+    List* list = List_create();
+    BPTree_get_range(root, list, 2, 3);
+    ASSERT_EQ(List_count(list), 2);
+    ASSERT_EQ(List_shift(list), p[2]);
+    ASSERT_EQ(List_shift(list), p[3]);
+    ASSERT_EQ(List_count(list), 0);
+    List_destroy(list);
+    list = List_create();
+    BPTree_get_range(root, list, 1, 3);
+    ASSERT_EQ(List_count(list), 3);
+    BPTree_print(root);
+}