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doc: documented the shdict:ttl() and shdict:expire() API functions. #1157

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doc: documented the shdict:ttl() and shdict:expire() API functions. #1157

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80 changes: 80 additions & 0 deletions README.markdown
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Original file line number Diff line number Diff line change
Expand Up @@ -3191,6 +3191,8 @@ Nginx API for Lua
* [ngx.shared.DICT.lpop](#ngxshareddictlpop)
* [ngx.shared.DICT.rpop](#ngxshareddictrpop)
* [ngx.shared.DICT.llen](#ngxshareddictllen)
* [ngx.shared.DICT.ttl](#ngxshareddictttl)
* [ngx.shared.DICT.expire](#ngxshareddictexpire)
* [ngx.shared.DICT.flush_all](#ngxshareddictflush_all)
* [ngx.shared.DICT.flush_expired](#ngxshareddictflush_expired)
* [ngx.shared.DICT.get_keys](#ngxshareddictget_keys)
Expand Down Expand Up @@ -6198,6 +6200,8 @@ The resulting object `dict` has the following methods:
* [lpop](#ngxshareddictlpop)
* [rpop](#ngxshareddictrpop)
* [llen](#ngxshareddictllen)
* [ttl](#ngxshareddictttl)
* [expire](#ngxshareddictexpire)
* [flush_all](#ngxshareddictflush_all)
* [flush_expired](#ngxshareddictflush_expired)
* [get_keys](#ngxshareddictget_keys)
Expand Down Expand Up @@ -6543,6 +6547,82 @@ See also [ngx.shared.DICT](#ngxshareddict).

[Back to TOC](#nginx-api-for-lua)

ngx.shared.DICT.ttl
-------------------
**syntax:** *ttl, err = ngx.shared.DICT:ttl(key)*

**context:** *init_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.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua**

**requires:** `resty.core.shdict` or `resty.core`
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My initial idea is to introduce this new requires section to make this obvious early in the reading of this method's documentation. There is also a note at the bottom of it with a link to the lua-resty-core library. Open to suggestions!

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@thibaultcha That's fine, though we'll soon make lua-resty-core mandatory and loaded by default in the next ngx_lua release anyway :)

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@agentzh Yeah - I remember :) Alright then!


Retrieves the remaining TTL (time-to-live in seconds) of a key-value pair in the shm-based dictionary [ngx.shared.DICT](#ngxshareddict). Returns the TTL as a number if the operation is successfully completed or `nil` and an error message otherwise.

If the key does not exist (or has already expired), this method will return `nil` and the error string `"not found"`.

The TTL is originally determined by the `exptime` argument of the [set](#ngxshareddictset), [add](#ngxshareddictadd), [replace](#ngxshareddictreplace) (and the likes) methods. It has a time resolution of `0.001` seconds. A value of `0` means that the item will never expire.

Example:

```lua

require "resty.core"

local cats = ngx.shared.cats
local succ, err = cats:set("Marry", "a nice cat", 0.5)

ngx.sleep(0.2)

local ttl, err = cats:ttl("Marry")
ngx.say(ttl) -- 0.3
```

This feature was first introduced in the `v0.10.11` release.

**Note:** This method requires the `resty.core.shdict` or `resty.core` modules from the [lua-resty-core](https://github.com/openresty/lua-resty-core) library.

See also [ngx.shared.DICT](#ngxshareddict).

[Back to TOC](#nginx-api-for-lua)

ngx.shared.DICT.expire
----------------------
**syntax:** *success, err = ngx.shared.DICT:expire(key, exptime)*

**context:** *init_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.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua**

**requires:** `resty.core.shdict` or `resty.core`

Updates the `exptime` (in second) of a key-value pair in the shm-based dictionary [ngx.shared.DICT](#ngxshareddict). Returns a boolean indicating success if the operation completes or `nil` and an error message otherwise.

If the key does not exist, this method will return `nil` and the error string `"not found"`.

The `exptime` argument has a resolution of `0.001` seconds. If `exptime` is `0`, then the item will never expire.

Example:

```lua

require "resty.core"

local cats = ngx.shared.cats
local succ, err = cats:set("Marry", "a nice cat", 0.1)

succ, err = cats:expire("Marry", 0.5)

ngx.sleep(0.2)

local val, err = cats:get("Marry")
ngx.say(val) -- "a nice cat"
```

This feature was first introduced in the `v0.10.11` release.

**Note:** This method requires the `resty.core.shdict` or `resty.core` modules from the [lua-resty-core](https://github.com/openresty/lua-resty-core) library.

See also [ngx.shared.DICT](#ngxshareddict).

[Back to TOC](#nginx-api-for-lua)

ngx.shared.DICT.flush_all
-------------------------
**syntax:** *ngx.shared.DICT:flush_all()*
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70 changes: 70 additions & 0 deletions doc/HttpLuaModule.wiki
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Expand Up @@ -5196,6 +5196,8 @@ The resulting object <code>dict</code> has the following methods:
* [[#ngx.shared.DICT.lpop|lpop]]
* [[#ngx.shared.DICT.rpop|rpop]]
* [[#ngx.shared.DICT.llen|llen]]
* [[#ngx.shared.DICT.ttl|ttl]]
* [[#ngx.shared.DICT.expire|expire]]
* [[#ngx.shared.DICT.flush_all|flush_all]]
* [[#ngx.shared.DICT.flush_expired|flush_expired]]
* [[#ngx.shared.DICT.get_keys|get_keys]]
Expand Down Expand Up @@ -5491,6 +5493,74 @@ This feature was first introduced in the <code>v0.10.6</code> release.

See also [[#ngx.shared.DICT|ngx.shared.DICT]].

== ngx.shared.DICT.ttl ==
'''syntax:''' ''ttl, err = ngx.shared.DICT:ttl(key)''

'''context:''' ''init_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.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua*''

'''requires:''' <code>resty.core.shdict</code> or <code>resty.core</code>

Retrieves the remaining TTL (time-to-live in seconds) of a key-value pair in the shm-based dictionary [[#ngx.shared.DICT|ngx.shared.DICT]]. Returns the TTL as a number if the operation is successfully completed or <code>nil</code> and an error message otherwise.

If the key does not exist (or has already expired), this method will return <code>nil</code> and the error string <code>"not found"</code>.

The TTL is originally determined by the <code>exptime</code> argument of the [[#ngx.shared.DICT.set|set]], [[#ngx.shared.DICT.add|add]], [[#ngx.shared.DICT.replace|replace]] (and the likes) methods. It has a time resolution of <code>0.001</code> seconds. A value of <code>0</code> means that the item will never expire.

Example:

<geshi lang="lua">
require "resty.core"

local cats = ngx.shared.cats
local succ, err = cats:set("Marry", "a nice cat", 0.5)

ngx.sleep(0.2)

local ttl, err = cats:ttl("Marry")
ngx.say(ttl) -- 0.3
</geshi>

This feature was first introduced in the <code>v0.10.11</code> release.

'''Note:''' This method requires the <code>resty.core.shdict</code> or <code>resty.core</code> modules from the [https://github.com/openresty/lua-resty-core lua-resty-core] library.

See also [[#ngx.shared.DICT|ngx.shared.DICT]].

== ngx.shared.DICT.expire ==
'''syntax:''' ''success, err = ngx.shared.DICT:expire(key, exptime)''

'''context:''' ''init_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.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua*''

'''requires:''' <code>resty.core.shdict</code> or <code>resty.core</code>

Updates the <code>exptime</code> (in second) of a key-value pair in the shm-based dictionary [[#ngx.shared.DICT|ngx.shared.DICT]]. Returns a boolean indicating success if the operation completes or <code>nil</code> and an error message otherwise.

If the key does not exist, this method will return <code>nil</code> and the error string <code>"not found"</code>.

The <code>exptime</code> argument has a resolution of <code>0.001</code> seconds. If <code>exptime</code> is <code>0</code>, then the item will never expire.

Example:

<geshi lang="lua">
require "resty.core"

local cats = ngx.shared.cats
local succ, err = cats:set("Marry", "a nice cat", 0.1)

succ, err = cats:expire("Marry", 0.5)

ngx.sleep(0.2)

local val, err = cats:get("Marry")
ngx.say(val) -- "a nice cat"
</geshi>

This feature was first introduced in the <code>v0.10.11</code> release.

'''Note:''' This method requires the <code>resty.core.shdict</code> or <code>resty.core</code> modules from the [https://github.com/openresty/lua-resty-core lua-resty-core] library.

See also [[#ngx.shared.DICT|ngx.shared.DICT]].

== ngx.shared.DICT.flush_all ==
'''syntax:''' ''ngx.shared.DICT:flush_all()''

Expand Down