Lua function creation on EVAL, basic Lua return type to Redis protocol convertion done.

src/scripting.c

@@ -0,0 +1,100 @@
+#include "redis.h"
+#include "sha1.h"
+
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+
+void scriptingInit(void) {
+    lua_State *lua = lua_open();
+    luaL_openlibs(lua);
+    server.lua = lua;
+}
+
+/* Hash the scripit into a SHA1 digest. We use this as Lua function name.
+ * Digest should point to a 41 bytes buffer: 40 for SHA1 converted into an
+ * hexadecimal number, plus 1 byte for null term. */
+void hashScript(char *digest, char *script, size_t len) {
+    SHA1_CTX ctx;
+    unsigned char hash[20];
+    char *cset = "0123456789abcdef";
+    int j;
+
+    SHA1Init(&ctx);
+    SHA1Update(&ctx,(unsigned char*)script,len);
+    SHA1Final(hash,&ctx);
+
+    for (j = 0; j < 20; j++) {
+        digest[j*2] = cset[((hash[j]&0xF0)>>4)];
+        digest[j*2+1] = cset[(hash[j]&0xF)];
+    }
+    digest[40] = '\0';
+}
+
+void luaReplyToRedisReply(redisClient *c, lua_State *lua) {
+    int t = lua_type(lua,1);
+
+    switch(t) {
+    case LUA_TSTRING:
+        addReplyBulkCBuffer(c,(char*)lua_tostring(lua,1),lua_strlen(lua,1));
+        break;
+    case LUA_TBOOLEAN:
+        addReply(c,lua_toboolean(lua,1) ? shared.cone : shared.czero);
+        break;
+    case LUA_TNUMBER:
+        addReplyLongLong(c,(long long)lua_tonumber(lua,1));
+        break;
+    default:
+        addReply(c,shared.nullbulk);
+    }
+    lua_pop(lua,1);
+}
+
+void evalCommand(redisClient *c) {
+    lua_State *lua = server.lua;
+    char funcname[43];
+
+    /* We obtain the script SHA1, then check if this function is already
+     * defined into the Lua state */
+    funcname[0] = 'f';
+    funcname[1] = '_';
+    hashScript(funcname+2,c->argv[1]->ptr,sdslen(c->argv[1]->ptr));
+    lua_getglobal(lua, funcname);
+    if (lua_isnil(lua,1)) {
+        /* Function not defined... let's define it. */
+        sds funcdef = sdsempty();
+
+        lua_pop(lua,1); /* remove the nil from the stack */
+        funcdef = sdscat(funcdef,"function ");
+        funcdef = sdscatlen(funcdef,funcname,42);
+        funcdef = sdscatlen(funcdef," ()\n",4);
+        funcdef = sdscatlen(funcdef,c->argv[1]->ptr,sdslen(c->argv[1]->ptr));
+        funcdef = sdscatlen(funcdef,"\nend\n",5);
+        printf("Defining:\n%s\n",funcdef);
+
+        if (luaL_loadbuffer(lua,funcdef,sdslen(funcdef),"func definition")) {
+            addReplyErrorFormat(c,"Error compiling script (new function): %s\n",
+                lua_tostring(lua,-1));
+            lua_pop(lua,1);
+            return;
+        }
+        if (lua_pcall(lua,0,0,0)) {
+            addReplyErrorFormat(c,"Error running script (new function): %s\n",
+                lua_tostring(lua,-1));
+            lua_pop(lua,1);
+            return;
+        }
+        lua_getglobal(lua, funcname);
+    }
+    
+    /* At this point whatever this script was never seen before or if it was
+     * already defined, we can call it. We have zero arguments and expect
+     * a single return value. */
+    if (lua_pcall(lua,0,1,0)) {
+        addReplyErrorFormat(c,"Error running script (call to %s): %s\n",
+            funcname, lua_tostring(lua,-1));
+        lua_pop(lua,1);
+        return;
+    }
+    luaReplyToRedisReply(c,lua);
+}