add new files for gna patch #1541

(Browse SVN revision 17565)

If somebody has a savegame which gave errors / resulted in bugs since march 2010 it should be tested against the new savefile format (using the script sg-test.bin; file #9459). I did include all the changes but perhaps I did missed something important.

same information:

• generator 2 should be used (else freeciv vrashes)
• a game with size 100 and aifill 100 is working
• saving a game needs > 5min and results in a big(!) savefile (130MB uncompressed)
• most of the time is needed to compress the data
• size 40 and aifill 40: 170kB (22MB uncompressed)

updated patch; this fixes a lot of trouble with the new savegame format. It is required if you want to use > 32 players or bigger maps.

patch comment:

(file #9448)

About loading / saving different versions of savegames:

• keep one function to load the current version
• small functions between releases for savegame changes (2.2.0 -> 2.2.1; 2.2.0 => 2.3.0) which change the secfile data (add / modify / remove data)
• compile option to deactivate this code path

pseud code (based on this patch):
void sg_load_player_version202000(struct loaddata *loading); { ... #ifdef FC_COMPAT_SAVEGAME sg_load_player_compat(struct loaddata *loading); #endif sg_load_player(loading); ... } #ifdef FC_COMPAT_SAVEGAME void sg_load_player_compat(struct loaddata *loading) { /* get savegame version and load corresponding function, i.e */ sg_load_player_version201000(loading); } void sg_load_player_version201000(struct loaddata *loading) { /* modify secfile; all changes between versions */ int data = secfile_secfile_lookup_int_default(loading->file, default_value, "old.secfile.position"); secfile_delete("old.secfile.position"); secfile_insert_int(loading->file, data, "new.secfile.definition"); } #endif void sg_load_player(struct loaddata *loading) { /* loads the 2.3.0 development version of the savegame */ }

This could use the internal definitions if the game is resetted before the main (current) loading routine is started.

> One the one hand there is no structure, one the other hand
> loading a damaged savegame will kill the server.

I doubt this is realizable without designing real game and map objects.

Did you already read things I wrote some times ago at http://freeciv.wikia.com/wiki/User:Pepeto/Some_ideas_for_2.3

The current savegame.c file has some disadvantages. One the one hand there is no structure, one the other hand loading a damaged savegame will kill the server. This patch series adds a savegame2.c file to freeciv. This file is a rewrite of the old savegame file. Comments to additional movements of code or renaming of variables within the save file are wellcome.

The file attached to this ticket contants all data. Important is the bash script 'sg-test.bin'. It can be used to test the compability between the old and new savegames. If you rename a savegame as 'sg-testme.sav.bz2', this file will

• load 'sg-testme.sav.bz2' and save it in the old format (sg-test01-old.sav.bz2)
• load 'sg-test01-old.sav.bz2' and save it in the new format (sg-test02-new.sav.bz2)
• load 'sg-test02-new.sav.bz2' and save it in the old format (sg-test03-old.sav.bz2)
• load 'sg-test01-old.sav.bz2' and save it in the old format (sg-test04-old.sav.bz2)
• create diffs between 1-3, 1-4 and 3-4

The main differences are:

• no map for dead players are saved in the new format
• differences within the event log
• (sometimes) differences in the update time for tiles, this can also be found in the diff 1-4 (only old format)