Lua scripts promoted from eval to script load to avoid evict

In ad28d22, we added a Lua eval
scripts eviction. If the script was previously added via EVAL, we
promote it to SCRIPT LOAD, prevent it from being evicted later.

Signed-off-by: Binbin <[email protected]>

src/eval.c

@@ -447,6 +447,13 @@ sds luaCreateFunction(client *c, robj *body, int evalsha) {
     sha1hex(funcname + 2, body->ptr, sdslen(body->ptr));
 
     if ((de = dictFind(lctx.lua_scripts, funcname + 2)) != NULL) {
+        /* If the script was previously added via EVAL, we promote it to
+         * SCRIPT LOAD, prevent it from being evicted later. */
+        luaScript *l = dictGetVal(de);
+        if (evalsha && l->node) {
+            listDelNode(lctx.lua_scripts_lru_list, l->node);
+            l->node = NULL;
+        }
         return dictGetKey(de);
     }
 

tests/unit/scripting.tcl

@@ -1646,6 +1646,19 @@ start_server {tags {"scripting external:skip"}} {
         # cached = num load scripts + 500 eval scripts
         assert_equal $cached [expr $num+500]
     }
+
+    test {Lua scripts promoted from eval to script load} {
+        r script flush
+        r config resetstat
+
+        r eval "return 'hello world'" 0
+        set sha [r script load "return 'hello world'"]
+        for {set j 1} {$j <= 500} {incr j} {
+            r script load "return $j"
+            r eval "return 'str_$j'" 0
+        }
+        assert_equal {hello world} [r evalsha $sha 0]
+    }
 }
 
 } ;# is_eval