swoole源码分析之swoole_buffer的append操作

swoole_buffer提供的append操作用于将一个字符串数据追加到缓存区末尾。

int swoole_buffer->append(string $data);

• $data是要写入的数据，支持二进制内容
• 执行成功后，会返回新的长度

下面我们分析下其流程。

static PHP_METHOD(swoole_buffer, append)
{
    swString str;
    bzero(&str, sizeof(str));

    if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s", &str.str, &str.length) == FAILURE)
    {
        RETURN_FALSE;
    }
    if (str.length < 1)
    {
        php_error_docref(NULL TSRMLS_CC, E_WARNING, "string empty.");
        RETURN_FALSE;
    }
    swString *buffer = swoole_get_object(getThis());

    if ((str.length + buffer->length) > buffer->size && (str.length + buffer->length) > SW_STRING_BUFFER_MAXLEN)
    {
        php_error_docref(NULL TSRMLS_CC, E_WARNING, "buffer size can't exceed %d", SW_STRING_BUFFER_MAXLEN);
        RETURN_FALSE;
    }

    size_t size_old = buffer->size;
    if (swString_append(buffer, &str) == SW_OK)
    {
        if (buffer->size > size_old)
        {
            zend_update_property_long(swoole_buffer_class_entry_ptr, getThis(), ZEND_STRL("capacity"), buffer->size TSRMLS_CC);
        }
        zend_update_property_long(swoole_buffer_class_entry_ptr, getThis(), ZEND_STRL("length"),
                buffer->length - buffer->offset TSRMLS_CC);
        RETURN_LONG(buffer->length - buffer->offset);
    }
    else
    {
        RETURN_FALSE;
    }
}

int swString_append(swString *str, swString *append_str)
{
    int new_size = str->length + append_str->length;
    if (new_size > str->size)
    {
        if (swString_extend(str, swoole_size_align(new_size * 2, sysconf(_SC_PAGESIZE))) < 0)
        {
            return SW_ERR;
        }
    }
    memcpy(str->str + str->length, append_str->str, append_str->length);
    str->length += append_str->length;
    return SW_OK;
}