From: Michael D. Lowis <mike@mdlowis.com>
Date: Sun, 29 Mar 2015 23:02:09 +0000 (-0400)
Subject: Started implementing splaytrees
X-Git-Url: https://git.mdlowis.com/?a=commitdiff_plain;h=84dc2a0af47fff920fdb90936263969b450ebe2b;p=archive%2Fatc.git

Started implementing splaytrees
---

diff --git a/source/runtime/splaytree.c b/source/runtime/splaytree.c
index 34d5a05..37d9c5d 100644
--- a/source/runtime/splaytree.c
+++ b/source/runtime/splaytree.c
@@ -5,20 +5,61 @@
 #include "splaytree.h"
 #include <stdlib.h>
 
+static node_t* create_tree(uintptr_t val) {
+    node_t* node = (node_t*)malloc(sizeof(node_t));
+    node->value  = val;
+    node->parent = NULL;
+    node->left   = NULL;
+    node->right  = NULL;
+    return node;
+}
+
+static void destroy_tree(node_t* node) {
+    if (NULL != node) {
+        destroy_tree(node->left);
+        destroy_tree(node->right);
+    }
+}
+
 splaytree_t* splaytree_create(comp_fn_t cfn)
 {
-    (void)cfn;
-    return NULL;
+    splaytree_t* splaytree = (splaytree_t*)malloc(sizeof(splaytree_t));
+    splaytree->compare = cfn;
+    splaytree->root    = NULL;
+    return splaytree;
 }
 
 void splaytree_destroy(splaytree_t* tree)
 {
-    (void)tree;
+    destroy_tree(tree->root);
+    free(tree);
 }
 
-void splaytree_insert(splaytree_t* tree)
+void splaytree_insert(splaytree_t* tree, uintptr_t value)
 {
-    (void)tree;
+    if (tree->root == NULL) {
+        tree->root = create_tree(value);
+    } else {
+        node_t* curr = tree->root;
+        while (1) {
+            int cmp = tree->compare(value, curr->value);
+            if (0 == cmp) {
+                break;
+            } else if (cmp < 1) {
+                if (NULL == curr->left) {
+                    curr->left = create_tree(value);
+                } else {
+                    curr = curr->left;
+                }
+            } else if (cmp > 1) {
+                if (NULL == curr->right) {
+                    curr->right = create_tree(value);
+                } else {
+                    curr = curr->right;
+                }
+            }
+        }
+    }
 }
 
 uintptr_t splaytree_lookup(splaytree_t* tree, uintptr_t value)
diff --git a/source/runtime/splaytree.h b/source/runtime/splaytree.h
index dd18a21..2689ab0 100644
--- a/source/runtime/splaytree.h
+++ b/source/runtime/splaytree.h
@@ -14,7 +14,7 @@ typedef struct node_t {
     struct node_t* right;
 } node_t;
 
-typedef int (*comp_fn_t)(uintptr_t a, uintptr_t b);
+typedef int (*comp_fn_t)(uintptr_t key, uintptr_t cval);
 
 typedef struct splaytree_t {
     comp_fn_t compare;
@@ -25,7 +25,7 @@ splaytree_t* splaytree_create(comp_fn_t cfn);
 
 void splaytree_destroy(splaytree_t* tree);
 
-void splaytree_insert(splaytree_t* tree);
+void splaytree_insert(splaytree_t* tree, uintptr_t value);
 
 uintptr_t splaytree_lookup(splaytree_t* tree, uintptr_t value);
 
diff --git a/tests/test_splaytree.c b/tests/test_splaytree.c
index 396c42a..157e070 100644
--- a/tests/test_splaytree.c
+++ b/tests/test_splaytree.c
@@ -2,7 +2,15 @@
 #include "splaytree.h"
 
 TEST_SUITE(SplayTree) {
-    TEST(Verify_foo) {
-        CHECK(0);
+    /* Verify: splaytree_create
+     *************************************************************************/
+    TEST(Verify_Create_allocates_and_initializes_an_empty_tree) {
+        splaytree_t* tree = splaytree_create((comp_fn_t)0x1234);
+        CHECK(tree->compare == (comp_fn_t)0x1234);
+        CHECK(tree->root    == NULL);
+        splaytree_destroy(tree);
     }
+
+    /* Verify: splaytree_create
+     *************************************************************************/
 }