1 files changed, 62 insertions, 0 deletions
diff --git a/src/common/buffer_seastar.h b/src/common/buffer_seastar.h
new file mode 100644
index 000000000..70a7b9325
--- /dev/null
+++ b/src/common/buffer_seastar.h
@@ -0,0 +1,62 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include <seastar/core/temporary_buffer.hh>
+#include "include/buffer.h"
+#include "common/error_code.h"
+
+namespace details {
+
+template<bool is_const>
+class buffer_iterator_impl {
+public:
+  using pointer = std::conditional_t<is_const, const char*, char *>;
+  buffer_iterator_impl(pointer first, const char* last)
+    : pos(first), end_ptr(last)
+  {}
+  pointer get_pos_add(size_t n) {
+    auto r = pos;
+    pos += n;
+    if (pos > end_ptr) {
+      throw buffer::end_of_buffer{};
+    }
+    return r;
+  }
+  pointer get() const {
+    return pos;
+  }
+protected:
+  pointer pos;
+  const char* end_ptr;
+};
+} // namespace details
+
+class seastar_buffer_iterator : details::buffer_iterator_impl<false> {
+  using parent = details::buffer_iterator_impl<false>;
+  using temporary_buffer = seastar::temporary_buffer<char>;
+public:
+  seastar_buffer_iterator(temporary_buffer& b)
+    : parent(b.get_write(), b.end()), buf(b)
+  {}
+  using parent::pointer;
+  using parent::get_pos_add;
+  using parent::get;
+  ceph::buffer::ptr get_ptr(size_t len);
+
+private:
+  // keep the reference to buf around, so it can be "shared" by get_ptr()
+  temporary_buffer& buf;
+};
+
+class const_seastar_buffer_iterator : details::buffer_iterator_impl<true> {
+  using parent = details::buffer_iterator_impl<true>;
+  using temporary_buffer = seastar::temporary_buffer<char>;
+public:
+  const_seastar_buffer_iterator(temporary_buffer& b)
+    : parent(b.get_write(), b.end())
+  {}
+  using parent::pointer;
+  using parent::get_pos_add;
+  using parent::get;
+  ceph::buffer::ptr get_ptr(size_t len);
+};