ngx.shared.DICT --------------- **语法:** *dict = ngx.shared.DICT* **语法:** *dict = ngx.shared\[name_var\]* **环境:** *init_by_lua*\**, init_worker_by_lua*\**, set_by_lua*\**, rewrite_by_lua*\**, access_by_lua*\**, content_by_lua*\**, header_filter_by_lua*\**, body_filter_by_lua*\**, log_by_lua*\**, ngx.timer.*\* 获取基于共享内存名为 `DICT` 的 Lua 字典对象，它是一个共享内存区块，通过 [lua_shared_dict](#lua_shared_dict) 指令定义。 所有共享内存区块均被当前 nginx 服务器实例的所有 nginx worker 进程共享。 获取的 `dict` 对象有如下方法： * [get](#ngxshareddictget) * [get_stale](#ngxshareddictget_stale) * [set](#ngxshareddictset) * [safe_set](#ngxshareddictsafe_set) * [add](#ngxshareddictadd) * [safe_add](#ngxshareddictsafe_add) * [replace](#ngxshareddictreplace) * [delete](#ngxshareddictdelete) * [incr](#ngxshareddictincr) * [flush_all](#ngxshareddictflush_all) * [flush_expired](#ngxshareddictflush_expired) * [get_keys](#ngxshareddictget_keys) 例如： ```nginx http { lua_shared_dict dogs 10m; server { location /set { content_by_lua ' local dogs = ngx.shared.dogs dogs:set("Jim", 8) ngx.say("STORED") '; } location /get { content_by_lua ' local dogs = ngx.shared.dogs ngx.say(dogs:get("Jim")) '; } } } ``` 测试结果如下： ```bash $ curl localhost/set STORED $ curl localhost/get 8 $ curl localhost/get 8 ``` 当访问 `/get` 时，无论有多少 Nginx worker 进程，将一直输出数字 `8`，因为 `dogs` 字典存储在共享内存中，对 *所有* worker 进程可见。 当服务器配置重新加载时共享内存字典内容不会丢失 (不管是通过送 `HUP` 信号给 Nginx 进程或使用命令行 `-s reload` 属性)。 但是，当 Nginx 服务器退出时，字典存储内容将丢失。 这个功能最早出现在 `v0.3.1rc22` 版本中。 > English Source **syntax:** *dict = ngx.shared.DICT* **syntax:** *dict = ngx.shared\[name_var\]* **context:** *init_by_lua*\**, init_worker_by_lua*\**, set_by_lua*\**, rewrite_by_lua*\**, access_by_lua*\**, content_by_lua*\**, header_filter_by_lua*\**, body_filter_by_lua*\**, log_by_lua*\**, ngx.timer.*\* Fetching the shm-based Lua dictionary object for the shared memory zone named `DICT` defined by the [lua_shared_dict](#lua_shared_dict) directive. Shared memory zones are always shared by all the nginx worker processes in the current nginx server instance. The resulting object `dict` has the following methods: * [get](#ngxshareddictget) * [get_stale](#ngxshareddictget_stale) * [set](#ngxshareddictset) * [safe_set](#ngxshareddictsafe_set) * [add](#ngxshareddictadd) * [safe_add](#ngxshareddictsafe_add) * [replace](#ngxshareddictreplace) * [delete](#ngxshareddictdelete) * [incr](#ngxshareddictincr) * [flush_all](#ngxshareddictflush_all) * [flush_expired](#ngxshareddictflush_expired) * [get_keys](#ngxshareddictget_keys) Here is an example: ```nginx http { lua_shared_dict dogs 10m; server { location /set { content_by_lua ' local dogs = ngx.shared.dogs dogs:set("Jim", 8) ngx.say("STORED") '; } location /get { content_by_lua ' local dogs = ngx.shared.dogs ngx.say(dogs:get("Jim")) '; } } } ``` Let us test it: ```bash $ curl localhost/set STORED $ curl localhost/get 8 $ curl localhost/get 8 ``` The number `8` will be consistently output when accessing `/get` regardless of how many Nginx workers there are because the `dogs` dictionary resides in the shared memory and visible to *all* of the worker processes. The shared dictionary will retain its contents through a server config reload (either by sending the `HUP` signal to the Nginx process or by using the `-s reload` command-line option). The contents in the dictionary storage will be lost, however, when the Nginx server quits. This feature was first introduced in the `v0.3.1rc22` release. [返回目录](#nginx-api-for-lua)