Cantil

Code/Documentation

Scalable publish-subscribe implementation.

Note, this project is under active development.

1. Features

• User-defined message interface.
• Red-black tree for the channels dictionary.
• Memory pools for messages and queues.
• Logger with trace levels and exceptions.
• Common data structures: list, queue, dictionary.
• Single-thread implementation.
• Multi-thread implementation.

2. Portability

• Platforms: ubuntu, macos, windows.
• OSAL: operating system abstraction layer.
• C99 support: gcc -std=c99 -pedantic ....

3. Build

Output file
libcantil.a

# default build
cd /path/to/cantil
make
 
# customized build
cd /my/empty/dir
/path/to/cantil/tools/configure.sh /path/to/config.yaml
make

4. Message broker

4.1. Define the message interface

static size_t size(void)
{
        return sizeof(char[8]);
}
 
static void init(CnLoad* load, va_list vlist)
{
        const char* format = va_arg(vlist, char*);
 
        vsnprintf(load, 8, format, vlist);
}
 
static void deinit(CnLoad* load)
{
        (void)load;
}
 
const struct CnLoadVt SAMPLE_LOAD_API[] = {
        {.size = size, .ctor = init, .dtor = deinit}};

4.2. Initialize the message broker

CnBroker* broker = broker_create(SAMPLE_LOAD_API);

4.3. Exchange messages

TEST(subscriber, should_receive_enqueued_message)
{
        CnBroker* broker = broker_create(SAMPLE_LOAD_API);
        CnSubscriber* sber = subscriber_create(broker);
        CnChannel* ch = NULL;
 
        subscribe(sber, "test");
        publish(broker_search(broker, "test"), "%X", 0xF00D);
        TEST_ASSERT_NULL(channel_gettopic(ch));
        TEST_ASSERT_EQUAL_STRING("F00D", subscriber_await(sber, &ch));
        TEST_ASSERT_EQUAL_STRING("test", channel_gettopic(ch));
        broker_destroy(broker);
}