Repo created

libs/coding/reader_streambuf.cpp

@@ -0,0 +1,59 @@
+#include "coding/reader_streambuf.hpp"
+#include "coding/file_writer.hpp"
+#include "coding/reader.hpp"
+
+#include <algorithm>
+
+ReaderStreamBuf::ReaderStreamBuf(std::unique_ptr<Reader> && p) : m_p(std::move(p)), m_pos(0), m_size(m_p->Size()) {}
+
+// Define destructor in .cpp due to using unique_ptr with incomplete type.
+ReaderStreamBuf::~ReaderStreamBuf() = default;
+
+std::streamsize ReaderStreamBuf::xsgetn(char_type * s, std::streamsize n)
+{
+  std::streamsize const count = std::min(n, static_cast<std::streamsize>(m_size - m_pos));
+  if (count > 0)
+  {
+    m_p->Read(m_pos, s, count);
+    m_pos += count;
+  }
+  return count;
+}
+
+ReaderStreamBuf::int_type ReaderStreamBuf::underflow()
+{
+  std::streamsize s = xsgetn(m_buf, sizeof(m_buf));
+  if (s > 0)
+  {
+    setg(m_buf, m_buf, m_buf + s);
+    return traits_type::to_int_type(m_buf[0]);
+  }
+  else
+  {
+    return traits_type::eof();
+  }
+}
+
+std::streamsize WriterStreamBuf::xsputn(char_type const * s, std::streamsize n)
+{
+  m_writer.Write(s, n);
+  return n;
+}
+
+WriterStreamBuf::int_type WriterStreamBuf::overflow(int_type c)
+{
+  if (!traits_type::eq_int_type(c, traits_type::eof()))
+  {
+    char_type const t = traits_type::to_char_type(c);
+    xsputn(&t, 1);
+  }
+  return !traits_type::eof();
+}
+
+int WriterStreamBuf::sync()
+{
+  FileWriter * p = dynamic_cast<FileWriter *>(&m_writer);
+  if (p)
+    p->Flush();
+  return 0;
+}