From 603a1a9dccfd540ad47b700997355b050e2bb37a Mon Sep 17 00:00:00 2001
From: Nathan Giddings <nathang567@gmail.com>
Date: Tue, 6 Apr 2021 14:44:45 -0500
Subject: [PATCH] Turned Scheduler into more generic heap

---
 src/heap.cpp      | 78 +++++++++++++++++++++++++++++++++++++++++++++++
 src/heap.hpp      | 38 +++++++++++++++++++++++
 src/scheduler.cpp | 68 -----------------------------------------
 src/scheduler.hpp | 37 ----------------------
 4 files changed, 116 insertions(+), 105 deletions(-)
 create mode 100644 src/heap.cpp
 create mode 100644 src/heap.hpp
 delete mode 100644 src/scheduler.cpp
 delete mode 100644 src/scheduler.hpp

diff --git a/src/heap.cpp b/src/heap.cpp
new file mode 100644
index 0000000..6ad056c
--- /dev/null
+++ b/src/heap.cpp
@@ -0,0 +1,78 @@
+#include "heap.hpp"
+
+template<class T>
+kernelns::Heap<T>::Heap()
+{
+    
+}
+
+template<class T>
+kernelns::Heap<T>::Heap(T** array, size_t maxSize)
+{
+    m_array = array;
+    m_size = 0;
+    m_limit = maxSize;
+}
+
+template<class T>
+T* kernelns::Heap<T>::extractMin()
+{
+    if(m_size == 0)
+        return nullptr;
+    m_size--;
+    T* p = m_array[0];
+    m_array[0] = m_array[m_size];
+    heapify(0);
+    return p;
+}
+
+template<class T>
+void kernelns::Heap<T>::insert(T* n)
+{
+    if(m_size == m_limit) // TODO: have insert return status code
+        return;
+    size_t i = m_size;
+    m_size++;
+    while(i > 0 && *m_array[(i - 1) / 2] > *n)
+    {
+        m_array[i] = m_array[(i - 1) / 2];
+        i = (i - 1) / 2;
+    }
+    m_array[i] = n;
+}
+
+template<class T>
+void kernelns::Heap<T>::remove(T* n)
+{
+    for(size_t i = 0; i < m_size; i++)
+    {
+        if(m_array[i] == n)
+        {
+            m_size--;
+            m_array[i] = m_array[m_size];
+            heapify(i);
+            break;
+        }
+    }
+}
+
+template<class T>
+void kernelns::Heap<T>::heapify(size_t i)
+{
+    if(i * 2 + 1 >= m_size)
+		return;
+    if (*m_array[i * 2 + 1] <= *m_array[i] && *m_array[i * 2 + 1] <= *m_array[i * 2 + 2])
+    {
+        T buffer = m_array[i];
+        m_array[i] = m_array[i * 2 + 1];
+        m_array[i * 2 + 1] = buffer;
+        heapify(i * 2 + 1);
+    }
+    else if (*m_array[i * 2 + 2] <= *m_array[i] && *m_array[i * 2 + 2] <= *m_array[i * 2 + 1])
+    {
+        T buffer = m_array[i];
+        m_array[i] = m_array[i * 2 + 2];
+        m_array[i * 2 + 2] = buffer;
+        heapify(i * 2 + 2);
+    }
+}
\ No newline at end of file
diff --git a/src/heap.hpp b/src/heap.hpp
new file mode 100644
index 0000000..93af712
--- /dev/null
+++ b/src/heap.hpp
@@ -0,0 +1,38 @@
+#ifndef SCHEDULER_H
+#define SCHEDULER_H
+
+#include <stddef.h>
+
+#include "process.hpp"
+
+namespace kernelns
+{
+
+template<class T>
+class Heap
+{
+public:
+
+    Heap();
+
+    Heap(T** array, size_t maxSize);
+
+    T* extractMin();
+
+    void insert(T* n);
+
+    void remove(T* n);
+
+private:
+
+    void heapify(size_t index);
+
+    T** m_array;
+
+    size_t m_size, m_limit;
+
+};
+
+};
+
+#endif
\ No newline at end of file
diff --git a/src/scheduler.cpp b/src/scheduler.cpp
deleted file mode 100644
index 57089a1..0000000
--- a/src/scheduler.cpp
+++ /dev/null
@@ -1,68 +0,0 @@
-#include "scheduler.hpp"
-
-kernelns::ProcessQueue::ProcessQueue()
-{
-    
-}
-
-kernelns::ProcessQueue::ProcessQueue(Process** array)
-{
-    m_array = array;
-    m_size = 0;
-}
-
-kernelns::Process* kernelns::ProcessQueue::extractMin()
-{
-    if(m_size == 0)
-        return NULL;
-    m_size--;
-    Process* p = m_array[0];
-    m_array[0] = m_array[m_size];
-    heapify(0);
-    return p;
-}
-
-void kernelns::ProcessQueue::insert(Process* n)
-{
-    size_t i = m_size;
-    m_size++;
-    for(; i > 0 && m_array[(i - 1) / 2]->priority > n->priority; i = (i - 1) / 2)
-	{
-		m_array[i] = m_array[(i - 1) / 2];
-	}
-    m_array[i] = n;
-}
-
-void kernelns::ProcessQueue::remove(Process* n)
-{
-    for(size_t i = 0; i < m_size; i++)
-    {
-        if(m_array[i] == n)
-        {
-            m_size--;
-            m_array[i] = m_array[m_size];
-            heapify(i);
-            break;
-        }
-    }
-}
-
-void kernelns::ProcessQueue::heapify(size_t i)
-{
-    if(i * 2 + 1 >= m_size)
-			return;
-    if (m_array[i]->priority >= m_array[i * 2 + 1]->priority && m_array[i * 2 + 1]->priority <= m_array[i * 2 + 2]->priority)
-    {
-        Process* buffer = m_array[i];
-        m_array[i] = m_array[i * 2 + 1];
-        m_array[i * 2 + 1] = buffer;
-        heapify(i * 2 + 1);
-    }
-    else if (m_array[i]->priority >= m_array[i * 2 + 2]->priority && m_array[i * 2 + 2]->priority <= m_array[i * 2 + 1]->priority)
-    {
-        Process* buffer = m_array[i];
-        m_array[i] = m_array[i * 2 + 2];
-        m_array[i * 2 + 2] = buffer;
-        heapify(i * 2 + 2);
-    }
-}
\ No newline at end of file
diff --git a/src/scheduler.hpp b/src/scheduler.hpp
deleted file mode 100644
index c58ee32..0000000
--- a/src/scheduler.hpp
+++ /dev/null
@@ -1,37 +0,0 @@
-#ifndef SCHEDULER_H
-#define SCHEDULER_H
-
-#include <stddef.h>
-
-#include "process.hpp"
-
-namespace kernelns
-{
-
-class ProcessQueue
-{
-public:
-
-    ProcessQueue();
-
-    ProcessQueue(Process** array);
-
-    Process* extractMin();
-
-    void insert(Process* n);
-
-    void remove(Process* n);
-
-private:
-
-    void heapify(size_t index);
-
-    Process** m_array;
-
-    size_t m_size;
-
-};
-
-};
-
-#endif
\ No newline at end of file