[kutil] Update map iteration

Add an iterator type to kutil::map, and allow for each loops. Also
unify the compare() signature expected by sorting containers, and fixes
to adding and sorting in kutil::vector.

src/kernel/frame_allocator.cpp

@@ -8,11 +8,11 @@ using memory::page_offset;
 using frame_block_node = kutil::list_node<frame_block>;
 
 int
-frame_block::compare(const frame_block *rhs) const
+frame_block::compare(const frame_block &rhs) const
 {
-	if (address < rhs->address)
+	if (address < rhs.address)
 		return -1;
-	else if (address > rhs->address)
+	else if (address > rhs.address)
 		return 1;
 	return 0;
 }

src/kernel/frame_allocator.h

@@ -46,6 +46,6 @@ struct frame_block
 	/// Compare two blocks by address.
 	/// \arg rhs   The right-hand comparator
 	/// \returns   <0 if this is sorts earlier, >0 if this sorts later, 0 for equal
-	int compare(const frame_block *rhs) const;
+	int compare(const frame_block &rhs) const;
 };
 

src/libraries/kutil/include/kutil/linked_list.h

@@ -321,7 +321,7 @@ public:
 		if (!item) return;
 
 		item_type *cur = m_head;
-		while (cur && item->compare(cur) > 0)
+		while (cur && item->compare(*cur) > 0)
 			cur = cur->m_next;
 
 		insert_before(cur, item);

src/libraries/kutil/include/kutil/map.h

@@ -70,6 +70,21 @@ public:
 	static constexpr size_t min_capacity = 8;
 	static constexpr size_t max_load = 90;
 
+	class iterator
+	{
+	public:
+		iterator(node *n) : m_node(n) {}
+		inline node & operator*() { return *m_node; }
+		inline node * operator->() { return m_node; }
+		inline const node & operator*() const { return *m_node; }
+		inline iterator & operator++() { incr(); return *this; }
+		inline iterator operator++(int) { node *old = m_node; incr(); return iterator(old); }
+		inline bool operator!=(const iterator &o) { return m_node != o.m_node; }
+	private:
+		void incr() { do { m_node++; } while ( m_node && m_node->hash() == 0 ); }
+		node *m_node;
+	};
+
 	/// Default constructor. Creates an empty map with the given capacity.
 	base_map(size_t capacity = 0) :
 		m_count(0),
@@ -86,6 +101,18 @@ public:
 		kfree(m_nodes);
 	}
 
+	iterator begin() {
+		return iterator(m_nodes);
+	}
+
+	const iterator begin() const {
+		return iterator(m_nodes);
+	}
+
+	const iterator end() const {
+		return iterator(m_nodes + m_capacity);
+	}
+
 	void insert(K k, V v) {
 		if (++m_count > threshold()) grow();
 		insert_node(hash(k), std::move(k), std::move(v));

src/libraries/kutil/include/kutil/vector.h

@@ -125,19 +125,21 @@ public:
 	}
 
 	/// Insert an item into the list in a sorted position. Depends on T
-	/// having a method `int compare(const T *other)`.
-	void sorted_insert(const T& item)
+	/// having a method `int compare(const T &other)`.
+	/// \returns index of the new item
+	size_t sorted_insert(const T& item)
 	{
 		size_t start = 0;
 		size_t end = m_size;
 		while (end > start) {
 			size_t m = start + (end - start) / 2;
-			int c = item.compare(&m_elements[m]);
+			int c = item.compare(m_elements[m]);
 			if (c < 0) end = m;
 			else start = m + 1;
 		}
 
 		insert(start, item);
+		return start;
 	}
 
 	/// Remove an item from the end of the array.
@@ -156,16 +158,30 @@ public:
 		remove_at(0);
 	}
 
-	/// Remove the item at the given index from the array, not
-	/// order-preserving.
-	void remove_at(size_t i)
+	/// Remove an item from the array.
+	void remove(const T &item)
 	{
-		if (i >= count()) return;
+		kassert(m_size, "Called remove() on an empty array");
+		for (size_t i = 0; i < m_size; ++i) {
+			if (m_elements[i] == item) {
+				remove_at(i);
+				break;
+			}
+		}
+	}
 
-		m_elements[i].~T();
-		for (; i < m_size - 1; ++i)
-			m_elements[i] = m_elements[i+1];
-		m_size -= 1;
+	/// Remove n items starting at the given index from the array,
+	/// order-preserving.
+	void remove_at(size_t i, size_t n = 1)
+	{
+		for (size_t j = i; j < i + n; ++j) {
+			if (j >= m_size) return;
+			m_elements[j].~T();
+		}
+
+		for (; i < m_size - n; ++i)
+			m_elements[i] = m_elements[i+n];
+		m_size -= n;
 	}
 
 	/// Remove the first occurance of an item from the array, not

src/tests/container_helpers.h

@@ -6,8 +6,8 @@ struct unsortableT {
 
 struct sortableT {
 	int value;
-	int compare(const sortableT *other) const {
-		return value - other->value;
+	int compare(const sortableT &other) const {
+		return value - other.value;
 	}
 };