1 files changed, 53 insertions, 0 deletions
diff --git a/log.cpp b/log.cpp
index 7698e4f..dae56c7 100644
--- a/log.cpp
+++ b/log.cpp
@@ -2,3 +2,56 @@
 
 log_stream log_cout;
 
+log_stream::log_stream(): m_active(false), m_buffer(), m_log_lines() {}
+
+void log_stream::log_lines(int n) {
+  m_log_lines = n;
+}
+
+std::string log_stream::get_log() {
+  return m_buffer.str();
+}
+
+// log to buffer
+void log_stream::activate()
+{
+  m_active = true;
+}
+
+// log to plain console
+void log_stream::deactivate()
+{
+  m_active = false;
+}
+
+log_stream& log_stream::operator<<(
+  std::basic_ostream<char>& (*func)
+      (std::basic_ostream<char>&) ) {
+  if (m_active) {
+    m_buffer << *func;
+    trim_buffer();
+  }
+  else
+  {
+    std::cout << *func;
+  }
+  return *this;
+}
+
+void log_stream::trim_buffer()
+{
+  std::string s = m_buffer.str();
+  size_t pos = s.npos;
+  for (int i = 0; i <= m_log_lines; ++i) {
+    pos = s.rfind("\n", pos);
+    if (pos == s.npos) {
+      // too few lines
+      return;
+    }
+    if (pos > 0) {
+      --pos;
+    }
+  }
+
+  m_buffer.str(s.substr((pos <= (s.size() - 2)) ? pos + 2 : pos));
+}