util.cache (and tests): Call on_evict after insertion of the new key, so inside on_ev...

diff --git a/tests/test_util_cache.lua b/tests/test_util_cache.lua
index a174eea757383d5d521074ce86d540197716c528..72cb5a856ed486cf437e05c588edad228fd2bdfb 100644 (file)
--- a/tests/test_util_cache.lua
+++ b/tests/test_util_cache.lua
@@ -170,5 +170,60 @@ function new(new)
        end
        assert_equal(i, 4);
        
+       local evicted_key, evicted_value;
+       local c = new(3, function (_key, _value)
+               evicted_key, evicted_value = _key, _value;
+       end);
+       local function set(k, v, should_evict_key, should_evict_value)
+               evicted_key, evicted_value = nil, nil;
+               c:set(k, v);
+               assert_equal(evicted_key, should_evict_key);
+               assert_equal(evicted_value, should_evict_value);
+       end
+       set("a", 1)
+       set("a", 1)
+       set("a", 1)
+       set("a", 1)
+       set("a", 1)
+
+       set("b", 2)
+       set("c", 3)
+       set("b", 2)
+       set("d", 4, "a", 1)
+       set("e", 5, "c", 3)
+       
+
+       local evicted_key, evicted_value;
+       local c3 = new(1, function (_key, _value, c3)
+               evicted_key, evicted_value = _key, _value;
+               if _key == "a" then
+                       -- Put it back in...
+                       -- Check that the newest key/value was set before on_evict was called
+                       assert_equal(c3:get("b"), 2);
+                       -- Sanity check for what we're evicting
+                       assert_equal(_key, "a");
+                       assert_equal(_value, 1);
+                       -- Re-insert the evicted key (causes this evict function to run again with "b",2)
+                       c3:set(_key, _value)
+                       assert_equal(c3:get(_key), _value)
+               end
+       end);
+       local function set(k, v, should_evict_key, should_evict_value)
+               evicted_key, evicted_value = nil, nil;
+               c3:set(k, v);
+               assert_equal(evicted_key, should_evict_key);
+               assert_equal(evicted_value, should_evict_value);
+       end
+       set("a", 1)
+       set("a", 1)
+       set("a", 1)
+       set("a", 1)
+       set("a", 1)
 
+       -- The evict handler re-inserts "a"->1, so "b" gets evicted:
+       set("b", 2, "b", 2)
+       -- Check the final state is what we expect
+       assert_equal(c3:get("a"), 1);
+       assert_equal(c3:get("b"), nil);
+       assert_equal(c3:count(), 1);
 end

diff --git a/util/cache.lua b/util/cache.lua
index 72b74351a37733e2374abb6b0a5b602043ff3f71..d3639b3f7aebc791bfdf8b57d395af810b03e25e 100644 (file)
--- a/util/cache.lua
+++ b/util/cache.lua
@@ -51,19 +51,20 @@ function cache_methods:set(k, v)
                return true;
        end
        -- Check whether we need to remove oldest k/v
+       local on_evict, evicted_key, evicted_value;
        if self._count == self.size then
                local tail = self._tail;
-               local on_evict = self._on_evict;
-               if on_evict then
-                       on_evict(tail.key, tail.value);
-               end
+               on_evict, evicted_key, evicted_value = self._on_evict, tail.key, tail.value;
                _remove(self, tail);
-               self._data[tail.key] = nil;
+               self._data[evicted_key] = nil;
        end
 
        m = { key = k, value = v, prev = nil, next = nil };
        self._data[k] = m;
        _insert(self, m);
+       if on_evict and evicted_key then
+               on_evict(evicted_key, evicted_value, self);
+       end
        return true;
 end