find_nodes_in_area: Extend maximal count to U32_MAX (#5277)

Extend documentation, limit area volume
Remove u16 count limitation

* Prevent integer overflow, replace minp/maxp with pos1/pos2

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 2bbf18310cd4d8f0c2f54c9b0ef18f31ccb09338..e893d6461da50f16504c50ab2b4c5951b0a76f55 100644 (file)
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -2462,12 +2462,13 @@ and `minetest.auth_reload` call the authetification handler.
     * `nodenames`: e.g. `{"ignore", "group:tree"}` or `"default:dirt"`
     * `search_center` is an optional boolean (default: `false`)
       If true `pos` is also checked for the nodes
-* `minetest.find_nodes_in_area(minp, maxp, nodenames)`: returns a list of positions
-    * returns as second value a table with the count of the individual nodes found
+* `minetest.find_nodes_in_area(pos1, pos2, nodenames)`: returns a list of positions
     * `nodenames`: e.g. `{"ignore", "group:tree"}` or `"default:dirt"`
-* `minetest.find_nodes_in_area_under_air(minp, maxp, nodenames)`: returns a list of positions
-    * returned positions are nodes with a node air above
+    * First return value: Table with all node positions
+    * Second return value: Table with the count of each node with the node name as index
+* `minetest.find_nodes_in_area_under_air(pos1, pos2, nodenames)`: returns a list of positions
     * `nodenames`: e.g. `{"ignore", "group:tree"}` or `"default:dirt"`
+    * Return value: Table with all node positions with a node air above
 * `minetest.get_perlin(noiseparams)`
 * `minetest.get_perlin(seeddiff, octaves, persistence, scale)`
     * Return world-specific perlin noise (`int(worldseed)+seeddiff`)

diff --git a/src/script/lua_api/l_env.cpp b/src/script/lua_api/l_env.cpp
index b8b6bc5bae7658eb7dadc8f05f198a66f5290e74..e7284b0354f352219e0a258945a54c5df1ce918b 100644 (file)
--- a/src/script/lua_api/l_env.cpp
+++ b/src/script/lua_api/l_env.cpp
@@ -651,38 +651,51 @@ int ModApiEnvMod::l_find_nodes_in_area(lua_State *L)
        INodeDefManager *ndef = getServer(L)->ndef();
        v3s16 minp = read_v3s16(L, 1);
        v3s16 maxp = read_v3s16(L, 2);
+       sortBoxVerticies(minp, maxp);
+
+       v3s16 cube = maxp - minp + 1;
+
+       /* Limit for too large areas, assume default values
+        * and give tolerances of 1 node on each side
+        * (chunksize * MAP_BLOCKSIZE + 2)^3 = 551368
+       */
+       if ((u64)cube.X * (u64)cube.Y * (u64)cube.Z > 551368) {
+               luaL_error(L, "find_nodes_in_area(): area volume"
+                               " exceeds allowed value of 551368");
+               return 0;
+       }
+
        std::set<content_t> filter;
-       if(lua_istable(L, 3)) {
-               int table = 3;
+       if (lua_istable(L, 3)) {
                lua_pushnil(L);
-               while(lua_next(L, table) != 0) {
+               while (lua_next(L, 3) != 0) {
                        // key at index -2 and value at index -1
                        luaL_checktype(L, -1, LUA_TSTRING);
                        ndef->getIds(lua_tostring(L, -1), filter);
                        // removes value, keeps key for next iteration
                        lua_pop(L, 1);
                }
-       } else if(lua_isstring(L, 3)) {
+       } else if (lua_isstring(L, 3)) {
                ndef->getIds(lua_tostring(L, 3), filter);
        }
 
-       std::map<content_t, u16> individual_count;
+       std::unordered_map<content_t, u32> individual_count;
 
        lua_newtable(L);
        u64 i = 0;
        for (s16 x = minp.X; x <= maxp.X; x++)
-               for (s16 y = minp.Y; y <= maxp.Y; y++)
-                       for (s16 z = minp.Z; z <= maxp.Z; z++) {
-                               v3s16 p(x, y, z);
-                               content_t c = env->getMap().getNodeNoEx(p).getContent();
-                               if (filter.count(c) != 0) {
-                                       push_v3s16(L, p);
-                                       lua_rawseti(L, -2, ++i);
-                                       individual_count[c]++;
-                               }
+       for (s16 y = minp.Y; y <= maxp.Y; y++)
+       for (s16 z = minp.Z; z <= maxp.Z; z++) {
+               v3s16 p(x, y, z);
+               content_t c = env->getMap().getNodeNoEx(p).getContent();
+               if (filter.count(c) != 0) {
+                       push_v3s16(L, p);
+                       lua_rawseti(L, -2, ++i);
+                       individual_count[c]++;
+               }
        }
        lua_newtable(L);
-       for (std::set<content_t>::iterator it = filter.begin();
+       for (std::set<content_t>::const_iterator it = filter.begin();
                        it != filter.end(); ++it) {
                lua_pushnumber(L, individual_count[*it]);
                lua_setfield(L, -2, ndef->get(*it).name.c_str());
@@ -706,12 +719,25 @@ int ModApiEnvMod::l_find_nodes_in_area_under_air(lua_State *L)
        INodeDefManager *ndef = getServer(L)->ndef();
        v3s16 minp = read_v3s16(L, 1);
        v3s16 maxp = read_v3s16(L, 2);
+       sortBoxVerticies(minp, maxp);
+
+       v3s16 cube = maxp - minp + 1;
+
+       /* Limit for too large areas, assume default values
+        * and give tolerances of 1 node on each side
+        * (chunksize * MAP_BLOCKSIZE + 2)^3 = 551368
+       */
+       if ((u64)cube.X * (u64)cube.Y * (u64)cube.Z > 551368) {
+               luaL_error(L, "find_nodes_in_area_under_air(): area volume"
+                               " exceeds allowed value of 551368");
+               return 0;
+       }
+
        std::set<content_t> filter;
 
        if (lua_istable(L, 3)) {
-               int table = 3;
                lua_pushnil(L);
-               while(lua_next(L, table) != 0) {
+               while (lua_next(L, 3) != 0) {
                        // key at index -2 and value at index -1
                        luaL_checktype(L, -1, LUA_TSTRING);
                        ndef->getIds(lua_tostring(L, -1), filter);
@@ -732,7 +758,7 @@ int ModApiEnvMod::l_find_nodes_in_area_under_air(lua_State *L)
                for (; y <= maxp.Y; y++) {
                        v3s16 psurf(x, y + 1, z);
                        content_t csurf = env->getMap().getNodeNoEx(psurf).getContent();
-                       if(c != CONTENT_AIR && csurf == CONTENT_AIR &&
+                       if (c != CONTENT_AIR && csurf == CONTENT_AIR &&
                                        filter.count(c) != 0) {
                                push_v3s16(L, v3s16(x, y, z));
                                lua_rawseti(L, -2, ++i);