diff --git a/include/ircd/buffer/buffer_base.h b/include/ircd/buffer/buffer_base.h
index 150a077e1..416b12db1 100644
--- a/include/ircd/buffer/buffer_base.h
+++ b/include/ircd/buffer/buffer_base.h
@@ -36,6 +36,7 @@ struct ircd::buffer::buffer
 	explicit operator std::string() const;
 	operator string_view() const;
 
+	buffer(const buffer &start, const size_t &size);
 	buffer(const it &start, const it &stop);
 	buffer(const it &start, const size_t &size);
 	buffer();
@@ -61,6 +62,16 @@ ircd::buffer::buffer<it>::buffer(const it &start,
 :std::pair<it, it>{start, stop}
 {}
 
+template<class it>
+inline __attribute__((always_inline))
+ircd::buffer::buffer<it>::buffer(const buffer &start,
+                                 const size_t &size)
+:buffer
+{
+	data(start), std::min(ircd::buffer::size(start), size)
+}
+{}
+
 template<class it>
 inline __attribute__((always_inline, flatten))
 ircd::buffer::buffer<it>::operator string_view()
diff --git a/include/ircd/buffer/const_buffer.h b/include/ircd/buffer/const_buffer.h
index e9e14b811..5dffe1543 100644
--- a/include/ircd/buffer/const_buffer.h
+++ b/include/ircd/buffer/const_buffer.h
@@ -24,6 +24,7 @@ struct ircd::buffer::const_buffer
 	template<size_t SIZE> const_buffer(const char (&buf)[SIZE]);
 	template<size_t SIZE> const_buffer(const std::array<char, SIZE> &buf);
 	const_buffer(const buffer<const char *> &b);
+	const_buffer(const buffer<char *> &b, const size_t &);
 	const_buffer(const buffer<char *> &b);
 	const_buffer(const mutable_buffer &b);
 	const_buffer(const string_view &s);
@@ -42,6 +43,13 @@ ircd::buffer::const_buffer::const_buffer(const buffer<char *> &b)
 :buffer<const char *>{data(b), size(b)}
 {}
 
+inline
+__attribute__((always_inline))
+ircd::buffer::const_buffer::const_buffer(const buffer<char *> &b,
+                                         const size_t &max)
+:buffer<const char *>{{data(b), size(b)}, max}
+{}
+
 inline
 __attribute__((always_inline))
 ircd::buffer::const_buffer::const_buffer(const mutable_buffer &b)