epee: better network buffer data structure

avoids pointless allocs and memcpy

2 files changed, 73 insertions, 4 deletions

diff --git a/tests/unit_tests/epee_levin_protocol_handler_async.cpp b/tests/unit_tests/epee_levin_protocol_handler_async.cpp
index 10e62c167..9ea71875b 100644
--- a/tests/unit_tests/epee_levin_protocol_handler_async.cpp
+++ b/tests/unit_tests/epee_levin_protocol_handler_async.cpp
@@ -56,22 +56,22 @@ namespace
     {
     }
 
-    virtual int invoke(int command, const std::string& in_buff, std::string& buff_out, test_levin_connection_context& context)
+    virtual int invoke(int command, const epee::span<const uint8_t> in_buff, std::string& buff_out, test_levin_connection_context& context)
     {
       m_invoke_counter.inc();
       boost::unique_lock<boost::mutex> lock(m_mutex);
       m_last_command = command;
-      m_last_in_buf = in_buff;
+      m_last_in_buf = std::string((const char*)in_buff.data(), in_buff.size());
       buff_out = m_invoke_out_buf;
       return m_return_code;
     }
 
-    virtual int notify(int command, const std::string& in_buff, test_levin_connection_context& context)
+    virtual int notify(int command, const epee::span<const uint8_t> in_buff, test_levin_connection_context& context)
     {
       m_notify_counter.inc();
       boost::unique_lock<boost::mutex> lock(m_mutex);
       m_last_command = command;
-      m_last_in_buf = in_buff;
+      m_last_in_buf = std::string((const char*)in_buff.data(), in_buff.size());
       return m_return_code;
     }
 
diff --git a/tests/unit_tests/epee_utils.cpp b/tests/unit_tests/epee_utils.cpp
index c384ce9a5..75cf2fdd4 100644
--- a/tests/unit_tests/epee_utils.cpp
+++ b/tests/unit_tests/epee_utils.cpp
@@ -46,6 +46,7 @@
 #include "hex.h"
 #include "net/net_utils_base.h"
 #include "net/local_ip.h"
+#include "net/buffer.h"
 #include "p2p/net_peerlist_boost_serialization.h"
 #include "span.h"
 #include "string_tools.h"
@@ -764,3 +765,71 @@ TEST(NetUtils, PrivateRanges)
   ASSERT_EQ(is_local("0.0.30.172"), false);
   ASSERT_EQ(is_local("0.0.30.127"), false);
 }
+
+TEST(net_buffer, basic)
+{
+  epee::net_utils::buffer buf;
+
+  ASSERT_EQ(buf.size(), 0);
+  EXPECT_THROW(buf.span(1), std::runtime_error);
+  buf.append("a", 1);
+  epee::span<const uint8_t> span = buf.span(1);
+  ASSERT_EQ(span.size(), 1);
+  ASSERT_EQ(span.data()[0], 'a');
+  EXPECT_THROW(buf.span(2), std::runtime_error);
+  buf.append("bc", 2);
+  buf.erase(1);
+  EXPECT_THROW(buf.span(3), std::runtime_error);
+  span = buf.span(2);
+  ASSERT_EQ(span.size(), 2);
+  ASSERT_EQ(span.data()[0], 'b');
+  ASSERT_EQ(span.data()[1], 'c');
+  buf.erase(1);
+  EXPECT_THROW(buf.span(2), std::runtime_error);
+  span = buf.span(1);
+  ASSERT_EQ(span.size(), 1);
+  ASSERT_EQ(span.data()[0], 'c');
+  EXPECT_THROW(buf.erase(2), std::runtime_error);
+  buf.erase(1);
+  EXPECT_EQ(buf.size(), 0);
+  EXPECT_THROW(buf.span(1), std::runtime_error);
+}
+
+TEST(net_buffer, existing_capacity)
+{
+  epee::net_utils::buffer buf;
+
+  buf.append("123456789", 9);
+  buf.erase(9);
+  buf.append("abc", 3);
+  buf.append("def", 3);
+  ASSERT_EQ(buf.size(), 6);
+  epee::span<const uint8_t> span = buf.span(6);
+  ASSERT_TRUE(!memcmp(span.data(), "abcdef", 6));
+}
+
+TEST(net_buffer, reallocate)
+{
+  epee::net_utils::buffer buf;
+
+  buf.append(std::string(4000, ' ').c_str(), 4000);
+  buf.append(std::string(8000, '0').c_str(), 8000);
+  ASSERT_EQ(buf.size(), 12000);
+  epee::span<const uint8_t> span = buf.span(12000);
+  ASSERT_TRUE(!memcmp(span.data(), std::string(4000, ' ').c_str(), 4000));
+  ASSERT_TRUE(!memcmp(span.data() + 4000, std::string(8000, '0').c_str(), 8000));
+}
+
+TEST(net_buffer, move)
+{
+  epee::net_utils::buffer buf;
+
+  buf.append(std::string(400, ' ').c_str(), 400);
+  buf.erase(399);
+  buf.append(std::string(4000, '0').c_str(), 4000);
+  ASSERT_EQ(buf.size(), 4001);
+  epee::span<const uint8_t> span = buf.span(4001);
+  ASSERT_TRUE(!memcmp(span.data(), std::string(1, ' ').c_str(), 1));
+  ASSERT_TRUE(!memcmp(span.data() + 1, std::string(4000, '0').c_str(), 4000));
+}
+