Function aofWrite

app/redis-6.2.6/src/aof.c:322–339

This is a wrapper to the write syscall in order to retry on short writes * or if the syscall gets interrupted. It could look strange that we retry * on short writes given that we are writing to a block device: normally if * the first call is short, there is a end-of-space condition, so the next * is likely to fail. However apparently in modern systems this is no longer * true, and in general

 * true, and in general it looks just more resilient to retry the write. If
 * there is an actual error condition we'll get it at the next try. */
ssize_t aofWrite(int fd, const char *buf, size_t len) {
    ssize_t nwritten = 0, totwritten = 0;

    while(len) {
        nwritten = write(fd, buf, len);

        if (nwritten < 0) {
            if (errno == EINTR) continue;
            return totwritten ? totwritten : -1;
        }

        len -= nwritten;
        buf += nwritten;
        totwritten += nwritten;
    }

    return totwritten;
}

/* Write the append only file buffer on disk.
 *