X-Git-Url: https://git.saurik.com/apple/security.git/blobdiff_plain/72a12576750f52947eb043106ba5c12c0d07decf..b1ab9ed8d0e0f1c3b66d7daa8fd5564444c56195:/libsecurity_filedb/lib/ReadWriteSection.cpp?ds=inline

diff --git a/libsecurity_filedb/lib/ReadWriteSection.cpp b/libsecurity_filedb/lib/ReadWriteSection.cpp
new file mode 100644
index 00000000..be2a5e75
--- /dev/null
+++ b/libsecurity_filedb/lib/ReadWriteSection.cpp
@@ -0,0 +1,53 @@
+#include "ReadWriteSection.h"
+
+uint32 WriteSection::put(uint32 inOffset, uint32 inValue)
+{
+	uint32 aLength = CheckUInt32Add(inOffset, sizeof(inValue));
+	if (aLength > mCapacity)
+		grow(aLength);
+
+	if (mAddress == NULL)
+		CssmError::throwMe(CSSMERR_DL_DATABASE_CORRUPT);
+
+	*reinterpret_cast<uint32 *>(mAddress + inOffset) = htonl(inValue);
+	return aLength;
+}
+
+
+
+uint32 WriteSection::put(uint32 inOffset, uint32 inLength, const uint8 *inData)
+{
+	// if we are being asked to put 0 bytes, just return
+	if (inLength == 0 || inData == NULL)
+	{
+		return inOffset;
+	}
+	
+	uint32 aLength = CheckUInt32Add(inOffset, inLength);
+	
+	// Round up to nearest multiple of 4 bytes, to pad with zeros
+	uint32 aNewOffset = align(aLength);
+	if (aNewOffset > mCapacity)
+		grow(aNewOffset);
+
+	if (mAddress == NULL)
+		CssmError::throwMe(CSSMERR_DL_DATABASE_CORRUPT);
+
+	memcpy(mAddress + inOffset, inData, inLength);
+
+	for (uint32 anOffset = aLength; anOffset < aNewOffset; anOffset++)
+		mAddress[anOffset] = 0;
+
+	return aNewOffset;
+}
+
+
+
+void WriteSection::grow(size_t inNewCapacity)
+{
+	size_t n = CheckUInt32Multiply(mCapacity, 2);
+	size_t aNewCapacity = max(n, inNewCapacity);
+	mAddress = reinterpret_cast<uint8 *>(mAllocator.realloc(mAddress, aNewCapacity));
+	memset(mAddress + mCapacity, 0, aNewCapacity - mCapacity);
+	mCapacity = aNewCapacity;
+}