int GetBookMoves(int moveNr, char *book, entry_t entries[])
{ // retrieve all entries for given position from book in 'entries', return number.
- FILE *f;
+ static FILE *f = NULL;
+ static char curBook[MSG_SIZ];
entry_t entry;
int offset;
uint64 key;
if(book == NULL || moveNr >= 2*appData.bookDepth) return -1;
// if(gameInfo.variant != VariantNormal) return -1; // Zobrist scheme only works for normal Chess, so far
- f=fopen(book,"rb");
+ if(!f || strcmp(book, curBook)){ // keep book file open until book changed
+ strncpy(curBook, book, MSG_SIZ);
+ if(f) fclose(f);
+ f = fopen(book,"rb");
+ }
if(!f){
DisplayError("Polyglot book not valid", 0);
appData.usePolyglotBook = FALSE;
offset=find_key(f, key, &entry);
if(entry.key != key) {
- fclose(f);
return FALSE;
}
entries[0] = entry;
if(count == MOVE_BUF) break;
entries[count++] = entry;
}
- fclose(f);
return count;
}
for(i=0; i<count; i++){
total_weight += entries[i].weight;
}
+ if(total_weight == 0) return NULL; // force book miss rather than playing moves with weight 0.
j = (random() & 0xFFF) * total_weight >> 12; // create random < total_weight
total_weight = 0;
for(i=0; i<count; i++){