语法: data = ngx.req.get_body_data()
环境: rewrite_by_lua*, access_by_lua*, content_by_lua*
取回内存中的请求体数据。本函数返回 Lua 字符串而不是包含解析过参数的 Lua table。如果想要返回 Lua table，请使用 ngx.req.get_post_args 函数。
当以下情况时，此函数返回 nil，
- 请求体尚未被读取，
- 请求体已经被存入磁盘上的临时文件，
- 或请求体大小是 0。
如果请求体尚未被读取，请先调用 ngx.req.read_body (或打开 lua_need_request_body 选项强制本模块读取请求体。此方法不推荐）。
如果请求体已经被存入临时文件，请使用 ngx.req.get_body_file 函数代替。
如需要强制在内存中保存请求体，请设置 client_body_buffer_size 和 client_max_body_size 为同样大小。
请注意，调用此函数比使用 ngx.var.request_body 或 ngx.var.echo_request_body 更有效率，因为本函数能够节省一次内存分配与数据复制。
这个函数在 `v0.3.1rc17`` 版本中首次引入。
更多用法请参考 ngx.req.get_body_file。
English Source
syntax: data = ngx.req.get_body_data()
context: rewrite_by_lua*, access_by_lua*, content_by_lua*
Retrieves in-memory request body data. It returns a Lua string rather than a Lua table holding all the parsed query arguments. Use the ngx.req.get_post_args function instead if a Lua table is required.
This function returns nil if
- the request body has not been read,
- the request body has been read into disk temporary files,
- or the request body has zero size.
If the request body has not been read yet, call ngx.req.read_body first (or turned on lua_need_request_body to force this module to read the request body. This is not recommended however).
If the request body has been read into disk files, try calling the ngx.req.get_body_file function instead.
To force in-memory request bodies, try setting client_body_buffer_size to the same size value in client_max_body_size.
Note that calling this function instead of using ngx.var.request_body or ngx.var.echo_request_body is more efficient because it can save one dynamic memory allocation and one data copy.
This function was first introduced in the v0.3.1rc17 release.
See also ngx.req.get_body_file.