// huffware script: data cow, by fred huffhines. // // a data cow is a script that manages a list of text items. it allows an object // to offload the memory burden of managing a list of items, since LSL is very tight // on memory, even when compiled to mono. // // this script is licensed by the GPL v3 which is documented at: http://www.gnu.org/licenses/gpl.html // do not use it in objects without fully realizing you are implicitly accepting that license. // // global variables. list the_list; // the main list that we manage here. we support adding to it, retrieving it // and modifying it via our API. list the_names; // the short names for each item in our list. we are basically supporting a // symbol table data structure here. // link message API for the data cow library. ////////////// // do not redefine these constants. integer DATA_COW_HUFFWARE_ID = 10017; // the unique id within the huffware system for the jaunt script to // accept commands on. this is used in llMessageLinked as the num parameter. string HUFFWARE_PARM_SEPARATOR = "{~~~}"; // this pattern is an uncommon thing to see in text, so we use it to separate // our commands in link messages. ///string HUFFWARE_ITEM_SEPARATOR = "{|||}"; // used to separate lists of items from each other when stored inside a parameter. // this allows lists to be passed as single string parameters if needed. integer REPLY_DISTANCE = 100008; // offset added to service's huffware id in reply IDs. ////////////// // string RESET_LIST_COMMAND = "reset_L"; // flushes out the currently held list. does not send a reply. string ADD_ITEM_COMMAND = "add_I"; // adds items to the list. this is a list of pairs of name/value, where the name is // how the item will be looked up from the list, and the value is the contents to be stored. // this command has no reply. string REMOVE_ITEM_COMMAND = "rm_I"; // accepts a list of names for items. all the mentioned ones will be removed from the list. // this command also has no reply. string GET_COW_LENGTH = "get_Lc"; // returns a single integer which is the length of the cow's list currently. string GET_ITEM_COMMAND = "get_I"; // retrieves the item's contents for a given name. first parm is the name. if there // are other parameters, then they are taken as other items to return also. // the return data will be pairs of for each of the names in the request // that is not empty. note that you can use an integer index by prefacing it with a // '#' sign. for example, asking for item "#32" will return index 32 in the list of items. string TAGGED_GET_ITEM_COMMAND = "get_T"; // like get item, except the first parameter is an identifier that the caller wants to // use to tag this request. the other parameters are still taken as names. the response // will contain the tag as the first item, then the pairs that were found. ////////////// // sets up the data cow for business. initialize() { // flush all contents. the_list = []; the_names = []; } // find a named item in our list, if it exists. integer lookup_item(string name) { integer indy; if (llGetSubString(name, 0, 0) == "#") { // our special sign for just using an index. indy = (integer)llGetSubString(name, 1, -1); if ( (indy >= 0) && (indy < llGetListLength(the_names)) ) return indy; } else { for (indy = 0; indy < llGetListLength(the_names); indy++) { if (name == llList2String(the_names, indy)) return indy; // we know where it is now. } } return -1; // never found it. } // places a named item in our list. if there's an existing item with // that name, then it's replaced. integer global_mem_complained = FALSE; add_item(string name, string content) { if (llGetFreeMemory() < 2000) { if (!global_mem_complained) { global_mem_complained = TRUE; llOwnerSay("out of memory at " + name); } return; } integer current = lookup_item(name); if (current < 0) { //llOwnerSay("new item: " + name); // this is a new item. the_names += name; the_list += content; } else { //llOwnerSay("reusing slot " + (string)current + " for " + name); // this is an old item to be replaced. the_list = chop_list(the_list, 0, current - 1) + [ content ] + chop_list(the_list, current + 1, llGetListLength(the_list) - 1); } //log_it("mem=" + (string)llGetFreeMemory()); } // deletes an existing item if possible. TRUE is returned on success. integer remove_item(string name) { integer indy = lookup_item(name); if (indy < 0) return FALSE; // not present. // found our sad whackee. we know the name and content should be // stored at the exact same index in the two lists. the_names = chop_list(the_names, 0, indy - 1) + chop_list(the_names, indy + 1, llGetListLength(the_names) - 1); the_list = chop_list(the_list, 0, indy - 1) + chop_list(the_list, indy + 1, llGetListLength(the_list) - 1); return TRUE; // all done here. } // supports our link message API by answering requests from clients. handle_link_message(integer sender, integer num, string msg, key id) { if (num != DATA_COW_HUFFWARE_ID) return; // not for us. //log_it("hlm--mem free=" + (string)llGetFreeMemory()); //log_it("rcvd: " + msg + " " + (string)num + " " + (string)id); if (msg == RESET_LIST_COMMAND) { initialize(); } else if (msg == ADD_ITEM_COMMAND) { list parms = llParseString2List(id, [HUFFWARE_PARM_SEPARATOR], []); integer indy; for (indy = 0; indy < llGetListLength(parms); indy += 2) { add_item(llList2String(parms, indy), llList2String(parms, indy + 1)); } } else if (msg == REMOVE_ITEM_COMMAND) { list parms = llParseString2List(id, [HUFFWARE_PARM_SEPARATOR], []); integer indy; for (indy = 0; indy < llGetListLength(parms); indy++) { remove_item(llList2String(parms, indy)); } } else if (msg == GET_COW_LENGTH) { list parms = llParseString2List(id, [HUFFWARE_PARM_SEPARATOR], []); string tag = llList2String(parms, 0); list to_reply; if (tag != "") to_reply = [ tag ]; to_reply += [ llGetListLength(the_list) ]; send_reply(LINK_THIS, to_reply, msg); } else if ( (msg == GET_ITEM_COMMAND) || (msg == TAGGED_GET_ITEM_COMMAND) ) { list parms = llParseString2List(id, [HUFFWARE_PARM_SEPARATOR], []); integer indy; string tag; if (msg == TAGGED_GET_ITEM_COMMAND) { // extract the tag, if they want that type of command handling. tag = llList2String(parms, 0); parms = llDeleteSubList(parms, 0, 0); } list to_reply; // make sure we return the tag if they gave us one. if (tag != "") to_reply = [ tag ]; for (indy = 0; indy < llGetListLength(parms); indy++) { // iterate through the parameters and reply about any that we find. integer found_posn = lookup_item(llList2String(parms, indy)); if (found_posn >= 0) { // this item did exist. to_reply += [ llList2String(the_names, found_posn), llList2String(the_list, found_posn) ]; } } send_reply(LINK_THIS, to_reply, msg); } } ////////////// // from hufflets... // //integer debug_num = 0; // a debugging output method. can be disabled entirely in one place. //log_it(string to_say) //{ // debug_num++; // // tell this to the owner. // llOwnerSay(llGetScriptName() + "[" + (string)debug_num + "] " + to_say); // // say this on open chat, but use an unusual channel. //// llSay(108, llGetScriptName() + "[" + (string)debug_num + "] " + to_say); //} // returns the portion of the list between start and end, but only if they are // valid compared with the list length. an attempt to use negative start or // end values also returns a blank list. list chop_list(list to_chop, integer start, integer end) { integer last_len = llGetListLength(to_chop) - 1; if ( (start < 0) || (end < 0) || (start > last_len) || (end > last_len) ) return []; return llList2List(to_chop, start, end); } // a simple version of a reply for a command that has been executed. the parameters // might contain an outcome or result of the operation that was requested. send_reply(integer destination, list parms, string command) { llMessageLinked(destination, DATA_COW_HUFFWARE_ID + REPLY_DISTANCE, command, llDumpList2String(parms, HUFFWARE_PARM_SEPARATOR)); } // // end hufflets ////////////// default { state_entry() { if (llSubStringIndex(llGetObjectName(), "huffotronic") < 0) state real_default; } on_rez(integer parm) { state rerun; } } state rerun { state_entry() { state default; } } state real_default { state_entry() { initialize(); } link_message(integer sender, integer num, string msg, key id) { handle_link_message(sender, num, msg, id); } }