Added read() and write() functions to Partition::

These functions make it possible to read or write bytes on a partition
without worrying of sectors.

2 files changed, 45 insertions, 0 deletions

diff --git a/Source/Kernel/VFS/Partition.class.cpp b/Source/Kernel/VFS/Partition.class.cpp
index 0c7832b..1032dee 100644
--- a/Source/Kernel/VFS/Partition.class.cpp
+++ b/Source/Kernel/VFS/Partition.class.cpp
@@ -17,6 +17,47 @@ bool Partition::writeBlocks(u64int startblock, u32int count, u8int *data) {
 	return m_device->writeBlocks(startblock - m_startblock, count, data);
 }
 
+bool Partition::read(u64int start, u32int length, u8int *data) {
+	u32int blksz = m_device->blockSize();
+	u64int startBlock = start / blksz;
+	u32int offset = start % blksz;
+	u32int blocks = (length + offset) / blksz;
+	if ((length + offset) % blksz != 0) blocks++;
+
+	u8int* buff = new u8int [blocks * blksz];	//THIS MAY FAIL :D
+	if (buff == 0) return false;
+
+	if (!readBlocks(startBlock, blocks, buff)) return false;
+	memcpy(data, buff + offset, length);
+
+	delete [] buff;
+	return true;
+}
+
+bool Partition::write(u64int start, u32int length, u8int *data) {
+	u32int blksz = m_device->blockSize();
+	u64int startBlock = start / blksz;
+	u32int offset = start % blksz;
+	u32int blocks = (length + offset) / blksz;
+	if ((length + offset) % blksz != 0) blocks++;
+	u64int lastBlock = startBlock + (u64int)blocks - 1;
+
+	u8int* buff = new u8int [blocks * blksz];
+	if (buff == 0) return false;
+
+	if (offset != 0) {
+		if (!readBlocks(startBlock, 1, buff)) return false;
+	}
+	if (lastBlock != startBlock and (length + offset) % blksz != 0) {
+		if (!readBlocks(lastBlock, 1, buff + ((blocks - 1) * blksize))) return false;
+	}
+	memcpy(buff + offset, data, length);
+	if (!writeBlocks(startBlock, blocks, buff)) return false;
+
+	delete[] buff;
+	return true;
+}
+
 //Accessors
 BlockDevice* Partition::getDevice() { return m_device; }
 u64int Partition::getStartBlock() { return m_startblock; }
diff --git a/Source/Kernel/VFS/Partition.class.h b/Source/Kernel/VFS/Partition.class.h
index e9087bf..8df1c4f 100644
--- a/Source/Kernel/VFS/Partition.class.h
+++ b/Source/Kernel/VFS/Partition.class.h
@@ -15,6 +15,10 @@ class Partition {
 	bool readBlocks(u64int startblock, u32int count, u8int *data);
 	bool writeBlocks(u64int startblock, u32int count, u8int *data);
 
+	//These two just use the readBlocks && writeBlocks defined above
+	bool read(u64int start, u32int length, u8int *data);
+	bool write(u64int start, u32int length, u8int *data);
+
 	//Accessors :
 	BlockDevice* getDevice();
 	u64int getStartBlock();