First

2024-07-02 18:12:23 +02:00
commit b344afa9fe
89 changed files with 10568 additions and 0 deletions
@@ -0,0 +1,150 @@
+
+#include "fs/BufferedSource.h"
+#include <algorithm>
+
+namespace fs
+{
+//////////////////////////////////////////////////////////////////////////
+
+template< typename SourceType>
+BufferedSource<SourceType>::BufferedSource(SourceType source, size_t bufferSize)
+	: m_source(std::move(source))
+{
+	if (bufferSize < 8)
+		bufferSize = 8;
+
+	m_buffer.reserve(bufferSize);
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+template< typename SourceType>
+tl::optional<Error> BufferedSource<SourceType>::getLastError() const
+{
+	tl::optional<Error> error = m_optLastError;
+	m_optLastError = tl::nullopt;
+	return error;
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+template< typename SourceType>
+size_t BufferedSource<SourceType>::read(tl::span<uint8_t> data)
+{
+	if (data.empty() || m_endOfSource)
+		return 0;
+
+	auto bufferPtr = data.data();
+	size_t totalSize = 0;
+	size_t pendingSize = data.size();
+
+	while (pendingSize)
+	{
+		if (m_buffer.empty() || m_bufferOffset >= m_buffer.size())
+		{
+			m_buffer.resize_uninitialized(m_buffer.capacity());
+			m_bufferStartOffset = m_source.tell();
+			m_bufferOffset = 0;
+			const size_t readSize = m_source.read(m_buffer);
+			m_buffer.resize_uninitialized(readSize);
+			if (readSize == 0)
+			{
+				m_optLastError = m_source.getLastError();
+				m_endOfSource = !m_optLastError.has_value(); //no error? then EOS
+				return totalSize;
+			}
+		}
+
+		TL_ASSERT(m_buffer.size());
+		TL_ASSERT(m_buffer.size() > m_bufferOffset);
+		const size_t frameSize = tl::min(m_buffer.size() - m_bufferOffset, pendingSize);
+		TL_ASSERT(frameSize);
+
+		memcpy(bufferPtr, m_buffer.data() + m_bufferOffset, frameSize);
+		bufferPtr += frameSize;
+
+		TL_ASSERT(data.size() >= frameSize);
+		pendingSize -= frameSize;
+
+		totalSize += frameSize;
+		TL_ASSERT(totalSize <= data.size());
+
+		m_bufferOffset += frameSize;
+	}
+
+	m_endOfSource = tell() >= getSize();
+
+	return totalSize;
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+template< typename SourceType>
+void BufferedSource<SourceType>::seekBeg(uint64_t offset)
+{
+	offset = tl::min(offset, m_source.getSize());
+	if (offset < m_bufferStartOffset || offset >= m_bufferStartOffset + m_buffer.size())
+	{
+		m_source.seekBeg(offset);
+		m_optLastError = m_source.getLastError();
+		m_buffer.clear();
+		m_bufferOffset = 0;
+		m_bufferStartOffset = m_source.tell();
+	}
+	else
+		m_bufferOffset = offset - m_bufferStartOffset;
+
+	m_endOfSource = tell() >= getSize();
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+template< typename SourceType>
+void BufferedSource<SourceType>::seekRel(int64_t offset)
+{
+	if (!offset)
+		return;
+
+	if (offset != 0)
+	{
+		int64_t newOffset = tell();
+		newOffset += offset;
+		newOffset = tl::max<int64_t>(newOffset, 0);
+		seekBeg(static_cast<uint64_t>(tl::min<int64_t>(newOffset, getSize())));
+	}
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+template< typename SourceType>
+uint64_t BufferedSource<SourceType>::tell() const
+{
+	return m_bufferStartOffset + m_bufferOffset;
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+template< typename SourceType>
+uint64_t BufferedSource<SourceType>::getSize() const
+{
+	return m_source.getSize();
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+template< typename SourceType>
+bool BufferedSource<SourceType>::isEOS() const
+{
+	return m_endOfSource;
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+template< typename SourceType>
+size_t BufferedSource<SourceType>::getPreferredBufferSize() const
+{
+	return m_buffer.size();
+}
+
+}
+