can_driver.cpp

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/*
 * Copyright (C) 2014 Pavel Kirienko <pavel.kirienko@gmail.com>
 */

#include <gtest/gtest.h>
#include "can.hpp"
#include <uavcan/driver/can.hpp>

TEST(CanFrame, FrameProperties)
{
    EXPECT_TRUE(makeCanFrame(0, "", EXT).isExtended());
    EXPECT_FALSE(makeCanFrame(0, "", STD).isExtended());
    EXPECT_FALSE(makeCanFrame(0, "", EXT).isRemoteTransmissionRequest());
    EXPECT_FALSE(makeCanFrame(0, "", STD).isRemoteTransmissionRequest());

    uavcan::CanFrame frame = makeCanFrame(123, "", STD);
    frame.id |= uavcan::CanFrame::FlagRTR;
    EXPECT_TRUE(frame.isRemoteTransmissionRequest());
    EXPECT_FALSE(frame.isErrorFrame());
    frame.id |= uavcan::CanFrame::FlagERR;
    EXPECT_TRUE(frame.isErrorFrame());
}

TEST(CanFrame, Arbitration)
{
    using uavcan::CanFrame;

    CanFrame a;
    CanFrame b;

    /*
     * Simple
     */
    a.id = 123;
    b.id = 122;
    ASSERT_TRUE(a.priorityLowerThan(b));
    ASSERT_TRUE(b.priorityHigherThan(a));

    a.id = 123 | CanFrame::FlagEFF;
    b.id = 122 | CanFrame::FlagEFF;
    ASSERT_TRUE(a.priorityLowerThan(b));
    ASSERT_TRUE(b.priorityHigherThan(a));

    a.id = 8;
    b.id = 8;
    ASSERT_FALSE(a.priorityLowerThan(b));
    ASSERT_FALSE(b.priorityHigherThan(a));

    /*
     * EXT vs STD
     */
    a.id = 1000;                      // 1000
    b.id = 2000 | CanFrame::FlagEFF;  // 2000 >> 18, wins
    ASSERT_TRUE(a.priorityLowerThan(b));
    ASSERT_TRUE(b.priorityHigherThan(a));

    a.id = 0x400;
    b.id = 0x10000000 | CanFrame::FlagEFF; // (0x400 << 18), 11 most significant bits are the same --> EFF loses
    ASSERT_TRUE(a.priorityHigherThan(b));
    ASSERT_TRUE(b.priorityLowerThan(a));

    /*
     * RTR vs Data
     */
    a.id = 123 | CanFrame::FlagRTR;      // On the same ID, RTR loses
    b.id = 123;
    ASSERT_TRUE(a.priorityLowerThan(b));
    ASSERT_TRUE(b.priorityHigherThan(a));

    a.id = CanFrame::MaskStdID | CanFrame::FlagRTR;  // RTR is STD, so it wins
    b.id = CanFrame::MaskExtID | CanFrame::FlagEFF;  // Lowest possible priority for data frame
    ASSERT_TRUE(a.priorityHigherThan(b));
    ASSERT_TRUE(b.priorityLowerThan(a));

    a.id = 123 | CanFrame::FlagRTR;      // Both RTR arbitrate as usually
    b.id = 122 | CanFrame::FlagRTR;
    ASSERT_TRUE(a.priorityLowerThan(b));
    ASSERT_TRUE(b.priorityHigherThan(a));
}

TEST(CanFrame, ToString)
{
    uavcan::CanFrame frame = makeCanFrame(123, "\x01\x02\x03\x04" "1234", EXT);
    EXPECT_EQ("0x0000007b   01 02 03 04 31 32 33 34  '....1234'", frame.toString());
    EXPECT_TRUE(frame.toString() == frame.toString(uavcan::CanFrame::StrAligned));

    frame = makeCanFrame(123, "z", EXT);
    EXPECT_EQ("0x0000007b   7a                       'z'", frame.toString(uavcan::CanFrame::StrAligned));
    EXPECT_EQ("0x0000007b   7a  'z'", frame.toString());

    EXPECT_EQ("     0x141   61 62 63 64 aa bb cc dd  'abcd....'",
              makeCanFrame(321, "abcd" "\xaa\xbb\xcc\xdd", STD).toString(uavcan::CanFrame::StrAligned));

    EXPECT_EQ("     0x100                            ''",
              makeCanFrame(256, "", STD).toString(uavcan::CanFrame::StrAligned));

    EXPECT_EQ("0x100    ''",
              makeCanFrame(256, "", STD).toString());

    EXPECT_EQ("0x141   61 62 63 64 aa bb cc dd  'abcd....'",
              makeCanFrame(321, "abcd" "\xaa\xbb\xcc\xdd", STD).toString());
}