Code Style

C Code Style

In ZTAS we use a variantion of the BSD KNF style, also known as Kernel Normal Form, with the following differences:

• 4 spaces indentation
• pointer types have the * close to the type instead of the variable
• wrapped lines are aligned with the inner-most parenthesis

Some examples follow:

While and For Loops

while (!queue_empty(connection->requests)) {
    message_t* m = queue_deq(connection->requests);
    connection->cbs.done(connection, m->data, connection->args);
    free(m);
}

for (i = 0; i < MAX_INFLIGHT; ++i) {
    message_t* r = (message_t*) malloc(sizeof(message_t));
    r->data = NULL;
    r->size = 0;
    queue_enq(connection->free_req, (void*) r);
}

If-else Conditionals

The opening bracket of a function on the same line; space between binary operators and assignment operators; no space between variables and parenthesis; one space between if and condition; else on the same line as the closing bracket of if.

int flag = 1;
if (-1 == setsockopt(connection->sock, IPPROTO_TCP, TCP_NODELAY,
                     (char*)&flag, sizeof(flag))) {
    printf("Couldn't setsockopt(TCP_NODELAY)\n");
    exit(EXIT_FAILURE);
}

if (sent != m->size && sent < 0) {
    ev_io_stop(connection->loop, &connection->send_w);
    return;
} else {
    connection->backoff /= 2;
    if (connection->backoff < MIN_BACKOFF)
        connection->backoff = MIN_BACKOFF;
}

Functions

The return type of the function on a single line; The opening bracket of a function on a single line as well.

void
connection_stop(connection_t* connection)
{
    connection_teardown(connection);
    // stop async watchers
    ev_async_stop(connection->loop, &connection->async_w);
    ev_timer_stop(connection->loop, &connection->wait_w);
}

Function Prototypes

The return type of the function on the same line. If function is static, use static modifier only on the prototype.

static void connection_async_cb(struct ev_loop* loop, struct ev_async* watcher,
                                int revents);

Type Definitions

typedef struct {
    void*    data;
    uint64_t size;
} message_t;

Python Code Style

• Mandatory 4 spaces for indentation

• Mandatory adding the following line to files that do not end with .py:

  # -*- python -*-