From 8c626a9d96cf2106822648d5b38d11a352a822cf Mon Sep 17 00:00:00 2001
From: "chengjie.zhou" <chengjie.zhou@ly.com>
Date: Wed, 3 Jun 2020 17:27:42 +0800
Subject: [PATCH 1/6] add evict call back func in lrucache

---
 lib/resty/lrucache.lua              |  6 +++++-
 lib/resty/lrucache/pureffi.lua      |  6 +++++-
 t/009-evict-call-back.t             | 31 +++++++++++++++++++++++++++++
 t/100-pureffi/009-evict-call-back.t | 31 +++++++++++++++++++++++++++++
 4 files changed, 72 insertions(+), 2 deletions(-)
 create mode 100644 t/009-evict-call-back.t
 create mode 100644 t/100-pureffi/009-evict-call-back.t

diff --git a/lib/resty/lrucache.lua b/lib/resty/lrucache.lua
index 147842a..2eed0bc 100644
--- a/lib/resty/lrucache.lua
+++ b/lib/resty/lrucache.lua
@@ -151,7 +151,7 @@ local function ptr2num(ptr)
 end
 
 
-function _M.new(size)
+function _M.new(size, evict_cb)
     if size < 1 then
         return nil, "size too small"
     end
@@ -164,6 +164,7 @@ function _M.new(size)
         node2key = {},
         num_items = 0,
         max_items = size,
+        evict_cb = evict_cb,
     }
     return setmetatable(self, mt)
 end
@@ -241,6 +242,9 @@ function _M.set(self, key, value, ttl, flags)
             -- print(key, ": evicting oldkey: ", oldkey, ", oldnode: ",
             --         tostring(node))
             if oldkey then
+                if self.evict_cb then
+                    self.evict_cb(oldkey, hasht[oldkey])
+                end
                 hasht[oldkey] = nil
                 key2node[oldkey] = nil
             end
diff --git a/lib/resty/lrucache/pureffi.lua b/lib/resty/lrucache/pureffi.lua
index fc1103e..5beacca 100644
--- a/lib/resty/lrucache/pureffi.lua
+++ b/lib/resty/lrucache/pureffi.lua
@@ -318,7 +318,7 @@ local mt = { __index = _M }
 -- load-factor is specified, it will be clamped to the range of [0.1, 1](i.e.
 -- if load-factor is greater than 1, it will be saturated to 1, likewise,
 -- if load-factor is smaller than 0.1, it will be clamped to 0.1).
-function _M.new(size, load_factor)
+function _M.new(size, load_factor, evict_cb)
     if size < 1 then
         return nil, "size too small"
     end
@@ -350,6 +350,7 @@ function _M.new(size, load_factor)
         val_v = new_tab(size, 0),
         bucket_v = ffi_new(int_array_t, bucket_sz),
         num_items = 0,
+        evict_cb = evict_cb,
     }
     -- "note_v" is an array of all the nodes used in the LRU queue. Exprpession
     -- node_v[i] evaluates to the element of ID "i".
@@ -526,6 +527,9 @@ function _M.set(self, key, value, ttl, flags)
             -- evict the least recently used key
             -- assert(not queue_is_empty(self.cache_queue))
             node = queue_last(self.cache_queue)
+            if self.evict_cb then
+                self.evict_cb(self.key_v[node.id], self.val_v[node.id])
+            end
             remove_key(self, self.key_v[node.id])
         else
             -- take a free queue node
diff --git a/t/009-evict-call-back.t b/t/009-evict-call-back.t
new file mode 100644
index 0000000..2a82bb0
--- /dev/null
+++ b/t/009-evict-call-back.t
@@ -0,0 +1,31 @@
+# vim:set ft= ts=4 sw=4 et fdm=marker:
+use lib '.';
+use t::TestLRUCache;
+
+repeat_each(2);
+
+plan tests => repeat_each() * (blocks() * 3);
+
+no_long_string();
+run_tests();
+
+__DATA__
+
+=== TEST 1: evict with call back
+--- config
+    location = /t {
+        content_by_lua '
+            local function evict_cb(k,v)
+                ngx.say(k, v)
+            end
+            local lrucache = require "resty.lrucache"
+            local c = lrucache.new(1, evict_cb)
+
+            collectgarbage()
+
+            c:set("dog", 12)
+            c:set("cat", 14)
+        ';
+    }
+--- response_body
+dog12
diff --git a/t/100-pureffi/009-evict-call-back.t b/t/100-pureffi/009-evict-call-back.t
new file mode 100644
index 0000000..6813593
--- /dev/null
+++ b/t/100-pureffi/009-evict-call-back.t
@@ -0,0 +1,31 @@
+# vim:set ft= ts=4 sw=4 et fdm=marker:
+use lib '.';
+use t::TestLRUCache;
+
+repeat_each(2);
+
+plan tests => repeat_each() * (blocks() * 3);
+
+no_long_string();
+run_tests();
+
+__DATA__
+
+=== TEST 1: evict with call back
+--- config
+    location = /t {
+        content_by_lua '
+            local function evict_cb(k,v)
+                ngx.say(k, v)
+            end
+            local lrucache = require "resty.lrucache.pureffi"
+            local c = lrucache.new(1, nil, evict_cb)
+
+            collectgarbage()
+
+            c:set("dog", 12)
+            c:set("cat", 14)
+        ';
+    }
+--- response_body
+dog12

From 9e42cfd68d7df15471fa63ee7ba88ebd976940c4 Mon Sep 17 00:00:00 2001
From: "chengjie.zhou" <chengjie.zhou@ly.com>
Date: Tue, 9 Jun 2020 01:27:40 +0800
Subject: [PATCH 2/6] add usage; use content_by_lua_block; use pcall wrap call
 evict func; add call evict_cb at get with ttl item

---
 README.markdown                     | 67 ++++++++++++++++++-----------
 lib/resty/lrucache.lua              |  5 ++-
 lib/resty/lrucache/pureffi.lua      |  5 ++-
 t/009-evict-call-back.t             | 26 ++++++++++-
 t/100-pureffi/009-evict-call-back.t | 26 ++++++++++-
 5 files changed, 99 insertions(+), 30 deletions(-)

diff --git a/README.markdown b/README.markdown
index c4da2f8..f7ca19b 100644
--- a/README.markdown
+++ b/README.markdown
@@ -6,28 +6,29 @@ lua-resty-lrucache - Lua-land LRU cache based on the LuaJIT FFI.
 Table of Contents
 =================
 
-* [Name](#name)
-* [Status](#status)
-* [Synopsis](#synopsis)
-* [Description](#description)
-* [Methods](#methods)
-    * [new](#new)
-    * [set](#set)
-    * [get](#get)
-    * [delete](#delete)
-    * [count](#count)
-    * [capacity](#capacity)
-    * [get_keys](#get_keys)
-    * [flush_all](#flush_all)
-* [Prerequisites](#prerequisites)
-* [Installation](#installation)
-* [Community](#community)
-    * [English Mailing List](#english-mailing-list)
-    * [Chinese Mailing List](#chinese-mailing-list)
-* [Bugs and Patches](#bugs-and-patches)
-* [Author](#author)
-* [Copyright and License](#copyright-and-license)
-* [See Also](#see-also)
+1. [Name](#name)
+2. [Table of Contents](#table-of-contents)
+3. [Status](#status)
+4. [Synopsis](#synopsis)
+5. [Description](#description)
+6. [Methods](#methods)
+   1. [new](#new)
+   2. [set](#set)
+   3. [get](#get)
+   4. [delete](#delete)
+   5. [count](#count)
+   6. [capacity](#capacity)
+   7. [get_keys](#get_keys)
+   8. [flush_all](#flush_all)
+7. [Prerequisites](#prerequisites)
+8. [Installation](#installation)
+9. [Community](#community)
+   1. [English Mailing List](#english-mailing-list)
+   2. [Chinese Mailing List](#chinese-mailing-list)
+10. [Bugs and Patches](#bugs-and-patches)
+11. [Author](#author)
+12. [Copyright and License](#copyright-and-license)
+13. [See Also](#see-also)
 
 Status
 ======
@@ -45,9 +46,14 @@ local _M = {}
 -- alternatively: local lrucache = require "resty.lrucache.pureffi"
 local lrucache = require "resty.lrucache"
 
+local function call_back(key, value)
+    ngx.log(ngx.ERR, "evict:", key, ":", value)
+end
+
 -- we need to initialize the cache on the lua module level so that
 -- it can be shared by all the requests served by each nginx worker process:
-local c, err = lrucache.new(200)  -- allow up to 200 items in the cache
+local c, err = lrucache.new(2, call_back)  -- allow up to 2 items in the cache
+-- local c, err = lrucache.new(2, nil, call_back)  -- for `resty.lrucache.pureffi`
 if not c then
     error("failed to create the cache: " .. (err or "unknown"))
 end
@@ -61,6 +67,12 @@ function _M.go()
     c:set("dog", { age = 10 }, 0.1)  -- expire in 0.1 sec
     c:delete("dog")
 
+    c:set("dog", 32)
+    c:set("parrto", 12) -- in log "evict:cat:56"
+    c:set("cat", 56, 0.1)  -- in log "evict:dog:32"
+    ngx.sleep(1)
+    ngx.say("cat:", c:get("cat")) -- in log "evict:cat:56"
+
     c:flush_all()  -- flush all the cached data
 end
 
@@ -151,7 +163,9 @@ local lrucache = require "resty.lrucache.pureffi"
 
 new
 ---
-`syntax: cache, err = lrucache.new(max_items [, load_factor])`
+`syntax: cache, err = lrucache.new(max_items [, evict_cb])`
+
+`syntax: cache, err = lrucache.new(max_items [, load_factor, evict_cb])`
 
 Creates a new cache instance. Upon failure, returns `nil` and a string
 describing the error.
@@ -167,6 +181,11 @@ saturated to 1; likewise, if load-factor is smaller than `0.1`, it will be
 clamped to `0.1`). This argument is only meaningful for
 `resty.lrucache.pureffi`.
 
+The `evict_cb` argument specifies the item's destory call back. When use `set`
+add new item or `get`(item with ttl), may trigger remove old item, with this
+call back you can do some clean up job. The `evict_cb` will receive two param:
+key and value.
+
 [Back to TOC](#table-of-contents)
 
 set
diff --git a/lib/resty/lrucache.lua b/lib/resty/lrucache.lua
index 2eed0bc..71782fd 100644
--- a/lib/resty/lrucache.lua
+++ b/lib/resty/lrucache.lua
@@ -196,6 +196,9 @@ function _M.get(self, key)
 
     if node.expire >= 0 and node.expire < ngx_now() then
         -- print("expired: ", node.expire, " > ", ngx_now())
+        if self.evict_cb then
+            pcall(self.evict_cb, key, val)
+        end
         return nil, val, node.user_flags
     end
 
@@ -243,7 +246,7 @@ function _M.set(self, key, value, ttl, flags)
             --         tostring(node))
             if oldkey then
                 if self.evict_cb then
-                    self.evict_cb(oldkey, hasht[oldkey])
+                    pcall(self.evict_cb, oldkey, hasht[oldkey])
                 end
                 hasht[oldkey] = nil
                 key2node[oldkey] = nil
diff --git a/lib/resty/lrucache/pureffi.lua b/lib/resty/lrucache/pureffi.lua
index 5beacca..857e722 100644
--- a/lib/resty/lrucache/pureffi.lua
+++ b/lib/resty/lrucache/pureffi.lua
@@ -490,6 +490,9 @@ function _M.get(self, key)
     local expire = node.expire
     if expire >= 0 and expire < ngx_now() then
         -- print("expired: ", node.expire, " > ", ngx_now())
+        if self.evict_cb then
+            pcall(self.evict_cb, key, self.val_v[node_id])
+        end
         return nil, self.val_v[node_id], node.user_flags
     end
 
@@ -528,7 +531,7 @@ function _M.set(self, key, value, ttl, flags)
             -- assert(not queue_is_empty(self.cache_queue))
             node = queue_last(self.cache_queue)
             if self.evict_cb then
-                self.evict_cb(self.key_v[node.id], self.val_v[node.id])
+                pcall(self.evict_cb, self.key_v[node.id], self.val_v[node.id])
             end
             remove_key(self, self.key_v[node.id])
         else
diff --git a/t/009-evict-call-back.t b/t/009-evict-call-back.t
index 2a82bb0..fabfa57 100644
--- a/t/009-evict-call-back.t
+++ b/t/009-evict-call-back.t
@@ -14,7 +14,7 @@ __DATA__
 === TEST 1: evict with call back
 --- config
     location = /t {
-        content_by_lua '
+        content_by_lua_block {
             local function evict_cb(k,v)
                 ngx.say(k, v)
             end
@@ -25,7 +25,29 @@ __DATA__
 
             c:set("dog", 12)
             c:set("cat", 14)
-        ';
+        }
+    }
+--- response_body
+dog12
+
+
+
+=== TEST 2: evict with call back, ttl
+--- config
+    location = /t {
+        content_by_lua_block {
+            local function evict_cb(k,v)
+                ngx.say(k, v)
+            end
+            local lrucache = require "resty.lrucache"
+            local c = lrucache.new(1, evict_cb)
+
+            collectgarbage()
+
+            c:set("dog", 12, 0.1)
+            ngx.sleep(1)
+            c:get("dog")
+        }
     }
 --- response_body
 dog12
diff --git a/t/100-pureffi/009-evict-call-back.t b/t/100-pureffi/009-evict-call-back.t
index 6813593..252969d 100644
--- a/t/100-pureffi/009-evict-call-back.t
+++ b/t/100-pureffi/009-evict-call-back.t
@@ -14,7 +14,7 @@ __DATA__
 === TEST 1: evict with call back
 --- config
     location = /t {
-        content_by_lua '
+        content_by_lua_block {
             local function evict_cb(k,v)
                 ngx.say(k, v)
             end
@@ -25,7 +25,29 @@ __DATA__
 
             c:set("dog", 12)
             c:set("cat", 14)
-        ';
+        }
+    }
+--- response_body
+dog12
+
+
+
+=== TEST 2: evict with call back, ttl
+--- config
+    location = /t {
+        content_by_lua_block {
+            local function evict_cb(k,v)
+                ngx.say(k, v)
+            end
+            local lrucache = require "resty.lrucache.pureffi"
+            local c = lrucache.new(1, nil, evict_cb)
+
+            collectgarbage()
+
+            c:set("dog", 12, 1)
+            ngx.sleep(1)
+            c:get("dog")
+        }
     }
 --- response_body
 dog12

From 74cb21e9ab752925e8369328be1051952856a46e Mon Sep 17 00:00:00 2001
From: "chengjie.zhou" <chengjie.zhou@ly.com>
Date: Tue, 23 Jun 2020 11:30:08 +0800
Subject: [PATCH 3/6] revert toc filed

---
 README.markdown | 45 ++++++++++++++++++++++-----------------------
 1 file changed, 22 insertions(+), 23 deletions(-)

diff --git a/README.markdown b/README.markdown
index f7ca19b..a520a3b 100644
--- a/README.markdown
+++ b/README.markdown
@@ -6,29 +6,28 @@ lua-resty-lrucache - Lua-land LRU cache based on the LuaJIT FFI.
 Table of Contents
 =================
 
-1. [Name](#name)
-2. [Table of Contents](#table-of-contents)
-3. [Status](#status)
-4. [Synopsis](#synopsis)
-5. [Description](#description)
-6. [Methods](#methods)
-   1. [new](#new)
-   2. [set](#set)
-   3. [get](#get)
-   4. [delete](#delete)
-   5. [count](#count)
-   6. [capacity](#capacity)
-   7. [get_keys](#get_keys)
-   8. [flush_all](#flush_all)
-7. [Prerequisites](#prerequisites)
-8. [Installation](#installation)
-9. [Community](#community)
-   1. [English Mailing List](#english-mailing-list)
-   2. [Chinese Mailing List](#chinese-mailing-list)
-10. [Bugs and Patches](#bugs-and-patches)
-11. [Author](#author)
-12. [Copyright and License](#copyright-and-license)
-13. [See Also](#see-also)
+* [Name](#name)
+* [Status](#status)
+* [Synopsis](#synopsis)
+* [Description](#description)
+* [Methods](#methods)
+    * [new](#new)
+    * [set](#set)
+    * [get](#get)
+    * [delete](#delete)
+    * [count](#count)
+    * [capacity](#capacity)
+    * [get_keys](#get_keys)
+    * [flush_all](#flush_all)
+* [Prerequisites](#prerequisites)
+* [Installation](#installation)
+* [Community](#community)
+    * [English Mailing List](#english-mailing-list)
+    * [Chinese Mailing List](#chinese-mailing-list)
+* [Bugs and Patches](#bugs-and-patches)
+* [Author](#author)
+* [Copyright and License](#copyright-and-license)
+* [See Also](#see-also)
 
 Status
 ======

From 16bf4313c0f107159788d83953d58e7b21323730 Mon Sep 17 00:00:00 2001
From: "chengjie.zhou" <chengjie.zhou@ly.com>
Date: Tue, 30 Jun 2020 19:57:42 +0800
Subject: [PATCH 4/6] add pcall error check

---
 lib/resty/lrucache.lua         | 10 ++++++++--
 lib/resty/lrucache/pureffi.lua | 10 ++++++++--
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/lib/resty/lrucache.lua b/lib/resty/lrucache.lua
index 71782fd..c17085a 100644
--- a/lib/resty/lrucache.lua
+++ b/lib/resty/lrucache.lua
@@ -197,7 +197,10 @@ function _M.get(self, key)
     if node.expire >= 0 and node.expire < ngx_now() then
         -- print("expired: ", node.expire, " > ", ngx_now())
         if self.evict_cb then
-            pcall(self.evict_cb, key, val)
+            local ok, err = pcall(self.evict_cb, key, val)
+            if not ok then
+                ngx.log(ngx.ERR, "evict expire key:", key, " fail:", err)
+            end
         end
         return nil, val, node.user_flags
     end
@@ -246,7 +249,10 @@ function _M.set(self, key, value, ttl, flags)
             --         tostring(node))
             if oldkey then
                 if self.evict_cb then
-                    pcall(self.evict_cb, oldkey, hasht[oldkey])
+                    local ok, err = pcall(self.evict_cb, oldkey, hasht[oldkey])
+                    if not ok then
+                        ngx.log(ngx.ERR, "evict old key:", oldkey, " fail:", err)
+                    end
                 end
                 hasht[oldkey] = nil
                 key2node[oldkey] = nil
diff --git a/lib/resty/lrucache/pureffi.lua b/lib/resty/lrucache/pureffi.lua
index 857e722..f14f062 100644
--- a/lib/resty/lrucache/pureffi.lua
+++ b/lib/resty/lrucache/pureffi.lua
@@ -491,7 +491,10 @@ function _M.get(self, key)
     if expire >= 0 and expire < ngx_now() then
         -- print("expired: ", node.expire, " > ", ngx_now())
         if self.evict_cb then
-            pcall(self.evict_cb, key, self.val_v[node_id])
+            local ok, err = pcall(self.evict_cb, key, self.val_v[node_id])
+            if not ok then
+                ngx.log(ngx.ERR, "evict expire key:", key, " fail:", err)
+            end
         end
         return nil, self.val_v[node_id], node.user_flags
     end
@@ -531,7 +534,10 @@ function _M.set(self, key, value, ttl, flags)
             -- assert(not queue_is_empty(self.cache_queue))
             node = queue_last(self.cache_queue)
             if self.evict_cb then
-                pcall(self.evict_cb, self.key_v[node.id], self.val_v[node.id])
+                local ok, err = pcall(self.evict_cb, self.key_v[node.id], self.val_v[node.id])
+                if not ok then
+                    ngx.log(ngx.ERR, "evict old key:", self.key_v[node.id], " fail:", err)
+                end
             end
             remove_key(self, self.key_v[node.id])
         else

From 35f40f9578ba71bf761343b62c6645be74b50f7d Mon Sep 17 00:00:00 2001
From: "chengjie.zhou" <chengjie.zhou@ly.com>
Date: Sun, 5 Jul 2020 10:48:40 +0800
Subject: [PATCH 5/6] add evict_cb type check

---
 lib/resty/lrucache.lua         | 4 ++++
 lib/resty/lrucache/pureffi.lua | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/lib/resty/lrucache.lua b/lib/resty/lrucache.lua
index c17085a..5677cce 100644
--- a/lib/resty/lrucache.lua
+++ b/lib/resty/lrucache.lua
@@ -156,6 +156,10 @@ function _M.new(size, evict_cb)
         return nil, "size too small"
     end
 
+    if type(evict_cb) ~= "function" then
+        return nil, "evict_cb type error"
+    end
+
     local self = {
         hasht = {},
         free_queue = queue_init(size),
diff --git a/lib/resty/lrucache/pureffi.lua b/lib/resty/lrucache/pureffi.lua
index f14f062..f7307fa 100644
--- a/lib/resty/lrucache/pureffi.lua
+++ b/lib/resty/lrucache/pureffi.lua
@@ -323,6 +323,10 @@ function _M.new(size, load_factor, evict_cb)
         return nil, "size too small"
     end
 
+    if type(evict_cb) ~= "function" then
+        return nil, "evict_cb type error"
+    end
+
     -- Determine bucket size, which must be power of two.
     local load_f = load_factor
     if not load_factor then

From e2b6d6e9a123ad7208587268235ef0922e53bc44 Mon Sep 17 00:00:00 2001
From: "chengjie.zhou" <chengjie.zhou@ly.com>
Date: Sun, 5 Jul 2020 11:00:57 +0800
Subject: [PATCH 6/6] evict_cb exist then do type check

---
 lib/resty/lrucache.lua         | 2 +-
 lib/resty/lrucache/pureffi.lua | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/resty/lrucache.lua b/lib/resty/lrucache.lua
index 5677cce..7bc46d4 100644
--- a/lib/resty/lrucache.lua
+++ b/lib/resty/lrucache.lua
@@ -156,7 +156,7 @@ function _M.new(size, evict_cb)
         return nil, "size too small"
     end
 
-    if type(evict_cb) ~= "function" then
+    if evict_cb and type(evict_cb) ~= "function" then
         return nil, "evict_cb type error"
     end
 
diff --git a/lib/resty/lrucache/pureffi.lua b/lib/resty/lrucache/pureffi.lua
index f7307fa..070fbb7 100644
--- a/lib/resty/lrucache/pureffi.lua
+++ b/lib/resty/lrucache/pureffi.lua
@@ -323,7 +323,7 @@ function _M.new(size, load_factor, evict_cb)
         return nil, "size too small"
     end
 
-    if type(evict_cb) ~= "function" then
+    if evict_cb and type(evict_cb) ~= "function" then
         return nil, "evict_cb type error"
     end