Util: Add socket helper classes

src/common/binary_span_reader_writer.cpp

@@ -0,0 +1,110 @@
+// SPDX-FileCopyrightText: 2024 Connor McLaughlin <stenzek@gmail.com>
+// SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
+
+#include "binary_span_reader_writer.h"
+#include "small_string.h"
+
+BinarySpanReader::BinarySpanReader() = default;
+
+BinarySpanReader::BinarySpanReader(std::span<const u8> buf) : m_buf(buf)
+{
+}
+
+bool BinarySpanReader::PeekCString(std::string_view* dst)
+{
+  size_t pos = m_pos;
+  size_t size = 0;
+  while (pos < m_buf.size())
+  {
+    if (m_buf[pos] == 0)
+      break;
+
+    pos++;
+    size++;
+  }
+
+  if (pos == m_buf.size())
+    return false;
+
+  *dst = std::string_view(reinterpret_cast<const char*>(&m_buf[m_pos]), size);
+  return true;
+}
+
+bool BinarySpanReader::ReadCString(std::string* dst)
+{
+  std::string_view sv;
+  if (!PeekCString(&sv))
+    return false;
+
+  dst->assign(sv);
+  m_pos += sv.size() + 1;
+  return true;
+}
+
+bool BinarySpanReader::ReadCString(std::string_view* dst)
+{
+  if (!PeekCString(dst))
+    return false;
+
+  m_pos += dst->size() + 1;
+  return true;
+}
+
+bool BinarySpanReader::ReadCString(SmallStringBase* dst)
+{
+  std::string_view sv;
+  if (!PeekCString(&sv))
+    return false;
+
+  dst->assign(sv);
+  m_pos += sv.size() + 1;
+  return true;
+}
+
+std::string_view BinarySpanReader::ReadCString()
+{
+  std::string_view ret;
+  if (PeekCString(&ret))
+    m_pos += ret.size() + 1;
+  return ret;
+}
+
+bool BinarySpanReader::PeekCString(std::string* dst)
+{
+  std::string_view sv;
+  if (!PeekCString(&sv))
+    return false;
+
+  dst->assign(sv);
+  return true;
+}
+
+bool BinarySpanReader::PeekCString(SmallStringBase* dst)
+{
+  std::string_view sv;
+  if (!PeekCString(&sv))
+    return false;
+
+  dst->assign(sv);
+  m_pos += sv.size() + 1;
+  return true;
+}
+
+BinarySpanWriter::BinarySpanWriter() = default;
+
+BinarySpanWriter::BinarySpanWriter(std::span<u8> buf) : m_buf(buf)
+{
+}
+
+bool BinarySpanWriter::WriteCString(std::string_view val)
+{
+  if ((m_pos + val.size() + 1) > m_buf.size()) [[unlikely]]
+    return false;
+
+  if (!val.empty())
+    std::memcpy(&m_buf[m_pos], val.data(), val.size());
+
+  m_buf[m_pos + val.size()] = 0;
+  m_pos += val.size() + 1;
+  return true;
+}