1 files changed, 434 insertions, 0 deletions
diff --git a/src/core/buffer.cpp b/src/core/buffer.cpp
new file mode 100644
index 0000000..ad471d7
--- /dev/null
+++ b/src/core/buffer.cpp
@@ -0,0 +1,434 @@
+#include "buffer.h"
+
+#include <algorithm>
+#include <cassert>
+#include <cstring>
+#include <iomanip>
+#include <sstream>
+
+namespace saw {
+error buffer::push(const uint8_t &value) {
+	size_t write_remain = write_composite_length();
+	if (write_remain > 0) {
+		write() = value;
+		write_advance(1);
+	} else {
+		return make_error<err::buffer_exhausted>();
+	}
+	return no_error();
+}
+
+error buffer::push(const uint8_t &buffer, size_t size) {
+	error error = write_require_length(size);
+	if (error.failed()) {
+		return error;
+	}
+	const uint8_t *buffer_ptr = &buffer;
+	while (size > 0) {
+		size_t segment = std::min(write_segment_length(), size);
+		memcpy(&write(), buffer_ptr, segment);
+		write_advance(segment);
+		size -= segment;
+		buffer_ptr += segment;
+	}
+	return no_error();
+}
+
+error buffer::pop(uint8_t &value) {
+	if (read_composite_length() > 0) {
+		value = read();
+		read_advance(1);
+	} else {
+		return make_error<err::buffer_exhausted>();
+	}
+	return no_error();
+}
+
+error buffer::pop(uint8_t &buffer, size_t size) {
+	if (read_composite_length() >= size) {
+		uint8_t *buffer_ptr = &buffer;
+		while (size > 0) {
+			size_t segment = std::min(read_segment_length(), size);
+			memcpy(buffer_ptr, &read(), segment);
+			read_advance(segment);
+			size -= segment;
+			buffer_ptr += segment;
+		}
+	} else {
+		return make_error<err::buffer_exhausted>();
+	}
+	return no_error();
+}
+
+std::string buffer::to_string() const {
+	std::ostringstream oss;
+	for (size_t i = 0; i < read_composite_length(); ++i) {
+		oss << read(i);
+	}
+	return oss.str();
+}
+
+std::string buffer::to_hex() const {
+	std::ostringstream oss;
+	oss << std::hex << std::setfill('0');
+	for (size_t i = 0; i < read_composite_length(); ++i) {
+		oss << std::setw(2) << (uint16_t)read(i);
+		if ((i + 1) < read_composite_length()) {
+			oss << ((i % 4 == 3) ? '\n' : ' ');
+		}
+	}
+	return oss.str();
+}
+
+buffer_view::buffer_view(buffer &buffer)
+	: buffer_{buffer}, read_offset_{0}, write_offset_{0} {}
+
+size_t buffer_view::read_position() const {
+	return read_offset_ + buffer_.read_position();
+}
+
+size_t buffer_view::read_composite_length() const {
+	assert(read_offset_ <= buffer_.read_composite_length());
+	if (read_offset_ > buffer_.read_composite_length()) {
+		return 0;
+	}
+
+	return buffer_.read_composite_length() - read_offset_;
+}
+
+size_t buffer_view::read_segment_length(size_t offset) const {
+	size_t off = offset + read_offset_;
+	assert(off <= buffer_.read_composite_length());
+	if (off > buffer_.read_composite_length()) {
+		return 0;
+	}
+
+	return buffer_.read_segment_length(off);
+}
+
+void buffer_view::read_advance(size_t bytes) {
+	size_t offset = bytes + read_offset_;
+	assert(offset <= buffer_.read_composite_length());
+	if (offset > buffer_.read_composite_length()) {
+		read_offset_ += buffer_.read_composite_length();
+		return;
+	}
+
+	read_offset_ += bytes;
+}
+
+uint8_t &buffer_view::read(size_t i) {
+	size_t pos = i + read_offset_;
+
+	assert(pos < buffer_.read_composite_length());
+
+	return buffer_.read(pos);
+}
+
+const uint8_t &buffer_view::read(size_t i) const {
+	size_t pos = i + read_offset_;
+
+	assert(pos < buffer_.read_composite_length());
+
+	return buffer_.read(pos);
+}
+
+size_t buffer_view::write_position() const {
+	return write_offset_ + buffer_.write_position();
+}
+
+size_t buffer_view::write_composite_length() const {
+	assert(write_offset_ <= buffer_.write_composite_length());
+	if (write_offset_ > buffer_.write_composite_length()) {
+		return 0;
+	}
+
+	return buffer_.write_composite_length() - write_offset_;
+}
+
+size_t buffer_view::write_segment_length(size_t offset) const {
+	size_t off = offset + write_offset_;
+	assert(off <= buffer_.write_composite_length());
+	if (off > buffer_.write_composite_length()) {
+		return 0;
+	}
+
+	return buffer_.write_segment_length(off);
+}
+
+void buffer_view::write_advance(size_t bytes) {
+	size_t offset = bytes + write_offset_;
+	assert(offset <= buffer_.write_composite_length());
+	if (offset > buffer_.write_composite_length()) {
+		write_offset_ += buffer_.write_composite_length();
+		return;
+	}
+
+	write_offset_ += bytes;
+}
+
+uint8_t &buffer_view::write(size_t i) {
+	size_t pos = i + write_offset_;
+
+	assert(pos < buffer_.write_composite_length());
+
+	return buffer_.write(pos);
+}
+
+const uint8_t &buffer_view::write(size_t i) const {
+	size_t pos = i + write_offset_;
+
+	assert(pos < buffer_.write_composite_length());
+
+	return buffer_.write(pos);
+}
+
+error buffer_view::write_require_length(size_t bytes) {
+	return buffer_.write_require_length(bytes + write_offset_);
+}
+
+size_t buffer_view::read_offset() const { return read_offset_; }
+
+size_t buffer_view::write_offset() const { return write_offset_; }
+
+ring_buffer::ring_buffer() : read_position_{0}, write_position_{0} {
+	buffer_.resize(RING_BUFFER_MAX_SIZE);
+}
+
+ring_buffer::ring_buffer(size_t size) : read_position_{0}, write_position_{0} {
+	buffer_.resize(size);
+}
+
+size_t ring_buffer::read_position() const { return read_position_; }
+
+/*
+ * If write is ahead of read it is a simple distance, but if read ist ahead of
+ * write then there are two segments
+ *
+ */
+size_t ring_buffer::read_composite_length() const {
+	return write_position() < read_position()
+			   ? buffer_.size() - (read_position() - write_position())
+			   : (write_reached_read_ ? buffer_.size()
+									  : write_position() - read_position());
+}
+
+/*
+ * If write is ahead then it's the simple distance again. If read is ahead it's
+ * until the end of the buffer/segment
+ */
+size_t ring_buffer::read_segment_length(size_t offset) const {
+	size_t read_composite = read_composite_length();
+	assert(offset <= read_composite);
+	offset = std::min(offset, read_composite);
+	size_t remaining = read_composite - offset;
+
+	size_t read_offset = read_position() + offset;
+	read_offset = read_offset >= buffer_.size() ? read_offset - buffer_.size()
+												: read_offset;
+
+	// case 1 write is located before read and reached read
+	// then offset can be used normally
+	// case 2 write is located at read, but read reached write
+	// then it is set to zero by readCompositeLength()
+	// case 3 write is located after read
+	// since std::min you can use simple subtraction
+	if (write_position() < read_offset) {
+		return buffer_.size() - read_offset;
+	}
+
+	if (write_position() == read_offset) {
+		if (remaining > 0) {
+			return buffer_.size() - read_offset;
+		} else {
+			return 0;
+		}
+	}
+
+	return write_position() - read_offset;
+}
+
+void ring_buffer::read_advance(size_t bytes) {
+	size_t read_composite = read_composite_length();
+
+	assert(bytes <= read_composite);
+	bytes = std::min(bytes, read_composite);
+	size_t advanced = read_position_ + bytes;
+	read_position_ = advanced >= buffer_.size() ? advanced - buffer_.size()
+												: advanced;
+	write_reached_read_ = bytes > 0 ? false : write_reached_read_;
+}
+
+uint8_t &ring_buffer::read(size_t i) {
+	assert(i < read_composite_length());
+	size_t pos = read_position_ + i;
+	pos = pos >= buffer_.size() ? pos - buffer_.size() : pos;
+	return buffer_[pos];
+}
+
+const uint8_t &ring_buffer::read(size_t i) const {
+	assert(i < read_composite_length());
+	size_t pos = read_position_ + i;
+	pos = pos >= buffer_.size() ? pos - buffer_.size() : pos;
+	return buffer_[pos];
+}
+
+size_t ring_buffer::write_position() const { return write_position_; }
+
+size_t ring_buffer::write_composite_length() const {
+	return read_position() > write_position()
+			   ? (read_position() - write_position())
+			   : (write_reached_read_
+					  ? 0
+					  : buffer_.size() - (write_position() - read_position()));
+}
+
+size_t ring_buffer::write_segment_length(size_t offset) const {
+	size_t write_composite = write_composite_length();
+	assert(offset <= write_composite);
+	offset = std::min(offset, write_composite);
+
+	size_t write_offset = write_position() + offset;
+	write_offset = write_offset >= buffer_.size()
+					   ? write_offset - buffer_.size()
+					   : write_offset;
+
+	if (read_position_ > write_offset) {
+		return read_position_ - write_offset;
+	}
+
+	if (write_reached_read_) {
+		return 0;
+	}
+
+	return buffer_.size() - write_offset;
+}
+
+void ring_buffer::write_advance(size_t bytes) {
+	assert(bytes <= write_composite_length());
+	size_t advanced = write_position_ + bytes;
+	write_position_ = advanced >= buffer_.size() ? advanced - buffer_.size()
+												 : advanced;
+
+	write_reached_read_ =
+		(write_position_ == read_position_ && bytes > 0 ? true : false);
+}
+
+uint8_t &ring_buffer::write(size_t i) {
+	assert(i < write_composite_length());
+	size_t pos = write_position_ + i;
+	pos = pos >= buffer_.size() ? pos - buffer_.size() : pos;
+	return buffer_[pos];
+}
+
+const uint8_t &ring_buffer::write(size_t i) const {
+	assert(i < write_composite_length());
+	size_t pos = write_position_ + i;
+	pos = pos >= buffer_.size() ? pos - buffer_.size() : pos;
+	return buffer_[pos];
+}
+/*
+	Error RingBuffer::increaseSize(size_t size){
+		size_t old_size = buffer.size();
+		size_t new_size = old_size + size;
+		buffer.resize(new_size);
+		if(readPosition() > writePosition() || (readPosition() ==
+   writePosition() && write_reached_read)){ size_t remaining = old_size -
+   writePosition(); size_t real_remaining = 0; while(remaining > 0){ size_t
+   segment = std::min(remaining, size); memcpy(&buffer[new_size-segment],
+   &buffer[old_size-segment], segment); remaining -= segment; size -= segment;
+				old_size -= segment;
+				new_size -= segment;
+			}
+		}
+
+		return noError();
+	}
+*/
+error ring_buffer::write_require_length(size_t bytes) {
+	size_t write_remain = write_composite_length();
+	if (bytes > write_remain) {
+		return make_error<err::buffer_exhausted>();
+	}
+	return no_error();
+}
+
+array_buffer::array_buffer(size_t size)
+	: read_position_{0}, write_position_{0} {
+	buffer_.resize(size);
+}
+
+size_t array_buffer::read_position() const { return read_position_; }
+
+size_t array_buffer::read_composite_length() const {
+	return write_position_ - read_position_;
+}
+
+size_t array_buffer::read_segment_length(size_t offset) const {
+	size_t read_composite = read_composite_length();
+	assert(offset <= read_composite);
+
+	offset = std::min(read_composite, offset);
+	size_t read_offset = read_position_ + offset;
+
+	return write_position_ - read_offset;
+}
+
+void array_buffer::read_advance(size_t bytes) {
+	assert(bytes <= read_composite_length());
+	read_position_ += bytes;
+}
+
+uint8_t &array_buffer::read(size_t i) {
+	assert(i < read_composite_length());
+
+	return buffer_[i + read_position_];
+}
+
+const uint8_t &array_buffer::read(size_t i) const {
+	assert(i + read_position_ < buffer_.size());
+
+	return buffer_[i + read_position_];
+}
+
+size_t array_buffer::write_position() const { return write_position_; }
+
+size_t array_buffer::write_composite_length() const {
+	assert(write_position_ <= buffer_.size());
+	return buffer_.size() - write_position_;
+}
+
+size_t array_buffer::write_segment_length(size_t offset) const {
+	assert(write_position_ <= buffer_.size());
+	size_t write_composite = write_composite_length();
+
+	assert(offset <= write_composite);
+	offset = std::min(write_composite, offset);
+	size_t write_offset = write_position_ + offset;
+
+	return buffer_.size() - write_offset;
+}
+
+void array_buffer::write_advance(size_t bytes) {
+	assert(bytes <= write_composite_length());
+	write_position_ += bytes;
+}
+
+uint8_t &array_buffer::write(size_t i) {
+	assert(i < write_composite_length());
+	return buffer_[i + write_position_];
+}
+
+const uint8_t &array_buffer::write(size_t i) const {
+	assert(i < write_composite_length());
+	return buffer_[i + write_position_];
+}
+error array_buffer::write_require_length(size_t bytes) {
+	size_t write_remain = write_composite_length();
+	if (bytes > write_remain) {
+		return make_error<err::buffer_exhausted>();
+	}
+	return no_error();
+}
+
+} // namespace saw