Problem: lack conversion message_t and multipart_t (zeromq#391)

Solution: add encode/decode methods to multipart_t giving a codec compatible with the CZMQ equivalent.

tests/CMakeLists.txt

@@ -27,6 +27,7 @@ add_executable(
     multipart.cpp
     recv_multipart.cpp
     send_multipart.cpp
+    codec_multipart.cpp
     monitor.cpp
     utilities.cpp
 )

tests/codec_multipart.cpp

@@ -0,0 +1,210 @@
+#include <catch.hpp>
+#include <zmq_addon.hpp>
+
+#ifdef ZMQ_CPP11
+
+TEST_CASE("multipart codec empty", "[codec_multipart]")
+{
+    using namespace zmq;
+
+    multipart_t mmsg;
+    message_t msg = mmsg.encode();
+    CHECK(msg.size() == 0);
+
+    multipart_t mmsg2;
+    mmsg2.decode_append(msg);
+    CHECK(mmsg2.size() == 0);
+
+}
+
+TEST_CASE("multipart codec small", "[codec_multipart]")
+{
+    using namespace zmq;
+
+    multipart_t mmsg;
+    mmsg.addstr("Hello World");
+    message_t msg = mmsg.encode();
+    CHECK(msg.size() == 1 + 11); // small size packing
+
+    mmsg.addstr("Second frame");
+    msg = mmsg.encode();
+    CHECK(msg.size() == 1 + 11 + 1 + 12);
+
+    multipart_t mmsg2;
+    mmsg2.decode_append(msg);
+    CHECK(mmsg2.size() == 2);
+    std::string part0 = mmsg2[0].to_string();
+    CHECK(part0 == "Hello World");
+    CHECK(mmsg2[1].to_string() == "Second frame");
+}
+
+TEST_CASE("multipart codec big", "[codec_multipart]")
+{
+    using namespace zmq;
+
+    message_t big(495);         // large size packing
+    big.data<char>()[0] = 'X';
+
+    multipart_t mmsg;
+    mmsg.pushmem(big.data(), big.size());
+    message_t msg = mmsg.encode();
+    CHECK(msg.size() == 5 + 495);
+    CHECK(msg.data<unsigned char>()[0] == std::numeric_limits<uint8_t>::max());
+    CHECK(msg.data<unsigned char>()[5] == 'X');
+
+    CHECK(mmsg.size() == 1);
+    mmsg.decode_append(msg);
+    CHECK(mmsg.size() == 2);
+    CHECK(mmsg[0].data<char>()[0] == 'X');
+}
+
+TEST_CASE("multipart codec decode bad data overflow", "[codec_multipart]")
+{
+    using namespace zmq;
+
+    char bad_data[3] = {5, 'h', 'i'};
+    message_t wrong_size(bad_data, 3);
+    CHECK(wrong_size.size() == 3);
+    CHECK(wrong_size.data<char>()[0] == 5);
+
+    CHECK_THROWS_AS(
+        multipart_t::decode(wrong_size),
+        std::out_of_range);
+}
+
+TEST_CASE("multipart codec decode bad data extra data", "[codec_multipart]")
+{
+    using namespace zmq;
+
+    char bad_data[3] = {1, 'h', 'i'};
+    message_t wrong_size(bad_data, 3);
+    CHECK(wrong_size.size() == 3);
+    CHECK(wrong_size.data<char>()[0] == 1);
+
+    CHECK_THROWS_AS(
+        multipart_t::decode(wrong_size),
+        std::out_of_range);
+}
+
+
+// After exercising it, this test is disabled over concern of running
+// on hosts which lack enough free memory to allow the absurdly large
+// message part to be allocated.
+#if 0
+TEST_CASE("multipart codec encode too big", "[codec_multipart]")
+{
+    using namespace zmq;
+
+    const size_t too_big_size = 1L + std::numeric_limits<uint32_t>::max();
+    CHECK(too_big_size > std::numeric_limits<uint32_t>::max());
+    char* too_big_data = new char[too_big_size];
+    multipart_t mmsg(too_big_data, too_big_size);
+    delete [] too_big_data;
+
+    CHECK(mmsg.size() == 1);
+    CHECK(mmsg[0].size() > std::numeric_limits<uint32_t>::max());
+
+    CHECK_THROWS_AS(
+        mmsg.encode(),
+        std::range_error);
+}
+#endif
+
+TEST_CASE("multipart codec free function with vector of message_t", "[codec_multipart]")
+{
+    using namespace zmq;
+    std::vector<message_t> parts;
+    parts.emplace_back("Hello", 5);
+    parts.emplace_back("World",5);
+    auto msg = encode(parts);
+    CHECK(msg.size() == 1 + 5 + 1 + 5 );
+    CHECK(msg.data<unsigned char>()[0] == 5);
+    CHECK(msg.data<unsigned char>()[1] == 'H');
+    CHECK(msg.data<unsigned char>()[6] == 5);
+    CHECK(msg.data<unsigned char>()[7] == 'W');
+
+    std::vector<message_t> parts2;
+    decode(msg, std::back_inserter(parts2));
+    CHECK(parts.size() == 2);
+    CHECK(parts[0].size() == 5);
+    CHECK(parts[1].size() == 5);
+}
+
+TEST_CASE("multipart codec free function with vector of const_buffer", "[codec_multipart]")
+{
+    using namespace zmq;
+    std::vector<const_buffer> parts;
+    parts.emplace_back("Hello", 5);
+    parts.emplace_back("World",5);
+    auto msg = encode(parts);
+    CHECK(msg.size() == 1 + 5 + 1 + 5 );
+    CHECK(msg.data<unsigned char>()[0] == 5);
+    CHECK(msg.data<unsigned char>()[1] == 'H');
+    CHECK(msg.data<unsigned char>()[6] == 5);
+    CHECK(msg.data<unsigned char>()[7] == 'W');
+
+    std::vector<message_t> parts2;
+    decode(msg, std::back_inserter(parts2));
+    CHECK(parts.size() == 2);
+    CHECK(parts[0].size() == 5);
+    CHECK(parts[1].size() == 5);
+}
+
+TEST_CASE("multipart codec free function with vector of mutable_buffer", "[codec_multipart]")
+{
+    using namespace zmq;
+    std::vector<mutable_buffer> parts;
+    char hello[6] = "Hello";
+    parts.emplace_back(hello, 5);
+    char world[6] = "World";
+    parts.emplace_back(world,5);
+    auto msg = encode(parts);
+    CHECK(msg.size() == 1 + 5 + 1 + 5 );
+    CHECK(msg.data<unsigned char>()[0] == 5);
+    CHECK(msg.data<unsigned char>()[1] == 'H');
+    CHECK(msg.data<unsigned char>()[6] == 5);
+    CHECK(msg.data<unsigned char>()[7] == 'W');
+
+    std::vector<message_t> parts2;
+    decode(msg, std::back_inserter(parts2));
+    CHECK(parts.size() == 2);
+    CHECK(parts[0].size() == 5);
+    CHECK(parts[1].size() == 5);
+}
+
+TEST_CASE("multipart codec free function with multipart_t", "[codec_multipart]")
+{
+    using namespace zmq;
+    multipart_t mmsg;
+    mmsg.addstr("Hello");
+    mmsg.addstr("World");
+    auto msg = encode(mmsg);
+    CHECK(msg.size() == 1 + 5 + 1 + 5);
+    CHECK(msg.data<unsigned char>()[0] == 5);
+    CHECK(msg.data<unsigned char>()[1] == 'H');
+    CHECK(msg.data<unsigned char>()[6] == 5);
+    CHECK(msg.data<unsigned char>()[7] == 'W');
+
+    multipart_t mmsg2;
+    decode(msg, std::back_inserter(mmsg2));
+    CHECK(mmsg2.size() == 2);
+    CHECK(mmsg2[0].size() == 5);
+    CHECK(mmsg2[1].size() == 5);
+}
+
+TEST_CASE("multipart codec static method decode to multipart_t", "[codec_multipart]")
+{
+    using namespace zmq;
+    multipart_t mmsg;
+    mmsg.addstr("Hello");
+    mmsg.addstr("World");
+    auto msg = encode(mmsg);
+
+    auto mmsg2 = multipart_t::decode(msg);
+    CHECK(mmsg2.size() == 2);
+    CHECK(mmsg2[0].size() == 5);
+    CHECK(mmsg2[1].size() == 5);
+}
+
+
+#endif

zmq.hpp

@@ -26,6 +26,12 @@
 #ifndef __ZMQ_HPP_INCLUDED__
 #define __ZMQ_HPP_INCLUDED__
 
+#ifdef _WIN32
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif
+#endif
+
 // macros defined if has a specific standard or greater
 #if (defined(__cplusplus) && __cplusplus >= 201103L)                                \
   || (defined(_MSC_VER) && _MSC_VER >= 1900)