ircd: Add utils for manipulating boost iov's.

include/ircd/bufs.h

@@ -0,0 +1,165 @@
+/*
+ * charybdis5
+ * Copyright (C) 2016 Jason Volk <jason@zemos.net>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice is present in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+#define HAVE_IRCD_BUFS_H
+
+#ifdef __cplusplus
+#include <boost/asio/buffer.hpp>
+
+namespace ircd {
+inline namespace bufs {
+
+using boost::asio::buffer_cast;
+using boost::asio::const_buffer;
+using boost::asio::const_buffers_1;
+using boost::asio::mutable_buffer;
+using boost::asio::mutable_buffers_1;
+
+const mutable_buffer null_buffer
+{
+	nullptr, 0
+};
+
+const std::array<mutable_buffer, 1> null_buffers
+{{
+	null_buffer
+}};
+
+size_t size(const mutable_buffer &buf);
+size_t size(const const_buffer &buf);
+template<class mutable_buffers> size_t size(const mutable_buffers &iov);
+template<class const_buffers> size_t size(const const_buffers &iov);
+
+size_t copy(const const_buffer &src, const mutable_buffer &dst);
+template<class buffers> size_t copy(const buffers &iov, const mutable_buffer &buf);
+template<class mutable_buffers> size_t copy(const mutable_buffer &buf, const mutable_buffers &iov);
+template<class mutable_buffers> size_t copy(const const_buffer &buf, const mutable_buffers &iov);
+
+void fill(const mutable_buffer &buf, const uint8_t &val = 0);
+template<class mutable_buffers> void fill(const mutable_buffers &buf, const uint8_t &val = 0);
+
+
+template<class mutable_buffers>
+void
+fill(const mutable_buffers &bufs,
+     const uint8_t &val)
+{
+	for(auto &buf : bufs)
+		fill(buf, val);
+}
+
+inline void
+fill(const mutable_buffer &buf,
+     const uint8_t &val)
+{
+	memset(buffer_cast<uint8_t *>(buf), val, size(buf));
+}
+
+template<class mutable_buffers>
+size_t
+copy(const const_buffer &buf,
+     const mutable_buffers &iov)
+{
+	size_t ret(0);
+	for(auto &dst : iov)
+	{
+		const auto remain(buffer_size(buf) - ret);
+		const auto cp_sz(std::min(buffer_size(dst), remain));
+		const auto src(buffer_cast<const uint8_t *>(buf) + ret);
+		memcpy(buffer_cast<uint8_t *>(dst), src, cp_sz);
+		ret += cp_sz;
+	}
+
+	return ret;
+}
+
+template<class mutable_buffers>
+size_t
+copy(const mutable_buffer &buf,
+     const mutable_buffers &iov)
+{
+	size_t ret(0);
+	for(auto &dst : iov)
+	{
+		const auto remain(buffer_size(buf) - ret);
+		const auto cp_sz(std::min(buffer_size(dst), remain));
+		const auto src(buffer_cast<const uint8_t *>(buf) + ret);
+		memcpy(buffer_cast<uint8_t *>(dst), src, cp_sz);
+		ret += cp_sz;
+	}
+
+	return ret;
+}
+
+template<class buffers>
+size_t
+copy(const buffers &iov,
+     const mutable_buffer &buf)
+{
+	size_t ret(0);
+	for(const auto &src : iov)
+	{
+		const auto remain(buffer_size(buf) - ret);
+		const auto cp_sz(std::min(buffer_size(src), remain));
+		const auto dst(buffer_cast<uint8_t *>(buf) + ret);
+		memcpy(dst, buffer_cast<const uint8_t *>(src), cp_sz);
+		ret += cp_sz;
+	}
+
+	return ret;
+}
+
+inline size_t
+copy(const const_buffer &src,
+     const mutable_buffer &dst)
+{
+	const auto cp_sz(std::min(buffer_size(src), buffer_size(dst)));
+	memcpy(buffer_cast<uint8_t *>(dst), buffer_cast<const uint8_t *>(src), cp_sz);
+	return cp_sz;
+}
+
+template<class buffers>
+size_t
+size(const buffers &iov)
+{
+	return std::accumulate(begin(iov), end(iov), size_t(0), []
+	(auto ret, const auto &buffer)
+	{
+		return ret += buffer_size(buffer);
+	});
+}
+
+inline size_t
+size(const mutable_buffer &buf)
+{
+	return buffer_size(buf);
+}
+
+inline size_t
+size(const const_buffer &buf)
+{
+	return buffer_size(buf);
+}
+
+}       // namespace bufs
+}       // namespace ircd
+#endif  // __cplusplus