request.write(chunk[, encoding][, callback])

发送一个请求主体的数据块。 通过多次调用此方法,可以将请求主体发送到服务器。 在这种情况下,建议在创建请求时使用 ['Transfer-Encoding', 'chunked'] 请求头行。

encoding 参数是可选的,仅当 chunk 是字符串时才适用。 默认为 'utf8'

callback 参数是可选的,当刷新此数据块时调用,但仅当数据块非空时才会调用。

如果将整个数据成功刷新到内核缓冲区,则返回 true。 如果全部或部分数据在用户内存中排队,则返回 false。 当缓冲区再次空闲时,则触发 'drain' 事件。

当使用空字符串或 buffer 调用 write 函数时,则什么也不做且等待更多输入。

Sends a chunk of the body. By calling this method many times, a request body can be sent to a server. In that case, it is suggested to use the ['Transfer-Encoding', 'chunked'] header line when creating the request.

The encoding argument is optional and only applies when chunk is a string. Defaults to 'utf8'.

The callback argument is optional and will be called when this chunk of data is flushed, but only if the chunk is non-empty.

Returns true if the entire data was flushed successfully to the kernel buffer. Returns false if all or part of the data was queued in user memory. 'drain' will be emitted when the buffer is free again.

When write function is called with empty string or buffer, it does nothing and waits for more input.