1 files changed, 89 insertions, 0 deletions
diff --git a/Source/Kernel/VFS/BlockCache.class.cpp b/Source/Kernel/VFS/BlockCache.class.cpp
new file mode 100644
index 0000000..d505a99
--- /dev/null
+++ b/Source/Kernel/VFS/BlockCache.class.cpp
@@ -0,0 +1,89 @@
+#include <DeviceManager/Time.ns.h>
+
+template <typename T>
+BlockCache<T>::BlockCache(T* dev) {
+	m_dev = dev;
+	m_count = 0;
+}
+
+template <typename T>
+BlockCache<T>::~BlockCache() {
+	sync();
+	m_count = 0;
+	delete m_cache;
+	delete m_cacheInfo;
+}
+
+template <typename T>
+void BlockCache<T>::sync() {
+	for (u32int i = 0; i < m_count; i++) {
+		if (m_cacheInfo[i].dirty) m_dev->writeBlocks(m_cacheInfo[i].id, 1, m_cache + (i * m_dev->blockSize()));
+	}	
+}
+
+template <typename T>
+void BlockCache<T>::init(u32int count) {
+	m_count = count;
+	m_cacheInfo = new cached_block_t[count];
+	for (u32int i = 0; i < m_count; i++) {
+		m_cacheInfo[i].id = 0;
+		m_cacheInfo[i].lastuse = 0;
+		m_cacheInfo[i].dirty = false;
+	}
+	m_cache = (u8int*)Mem::alloc(m_count * m_dev->blockSize());
+}
+
+template <typename T>
+bool BlockCache<T>::setCache(u64int block, u8int* data, bool dirty) {
+	u32int best = 0;
+	for (u32int i = 0; i < m_count; i++) {
+		if (m_cacheInfo[i].id == block) {
+			best = i;
+			break;
+		}
+		if (m_cacheInfo[i].lastuse < m_cacheInfo[best].lastuse) best = i;
+	}
+	if (best >= m_count) return false;
+	if (m_cacheInfo[best].dirty && (m_cacheInfo[best].id != block or !dirty))
+	   m_dev->writeBlocks(m_cacheInfo[best].id, 1, m_cache + (best * m_dev->blockSize()));
+	m_cacheInfo[best].id = block;
+	m_cacheInfo[best].lastuse = Time::uptime();
+	m_cacheInfo[best].dirty = dirty;
+	memcpy(m_cache + (best * m_dev->blockSize()), data, m_dev->blockSize());
+	return true;
+}
+
+template <typename T>
+bool BlockCache<T>::getCache(u64int block, u8int* data) {
+	for (u32int i = 0; i < m_count; i++) {
+		if (m_cacheInfo[i].id == block && m_cacheInfo[i].lastuse != 0) {
+			m_cacheInfo[i].lastuse = Time::uptime();
+			memcpy(data, m_cache + (i * m_dev->blockSize()), m_dev->blockSize());
+			return true;
+		}
+	}
+	return false;
+}
+
+template <typename T>
+bool BlockCache<T>::readBlocks(u64int startblock, u32int count, u8int* data) {
+	if (count == 1) {
+		if (getCache(startblock, data)) return true;
+		if (!m_dev->readBlocks(startblock, count, data)) return false;
+		setCache(startblock, data);
+		return true;
+	} else {
+		return m_dev->readBlocks(startblock, count, data);
+	}
+}
+
+template <typename T>
+bool BlockCache<T>::writeBlocks(u64int startblock, u32int count, u8int* data) {
+	if (m_dev->readOnly()) return false;
+	if (count == 1) {
+		if (!setCache(startblock, data, true)) return m_dev->writeBlocks(startblock, count, data);
+		return true;
+	} else {
+		return m_dev->writeBlocks(startblock, count, data);
+	}
+}