changes from H.G. Muller; version 4.3.15

[xboard.git] / pg_show.c

diff --git a/pg_show.c b/pg_show.c
new file mode 100644 (file)
index 0000000..c377cbb
--- /dev/null
+++ b/pg_show.c
@@ -0,0 +1,194 @@
+/* 
+ * This utility looks up the moves and their scores in a Polyglot book
+ *
+ * Usage:
+ * pg_show <book> <hex key>"
+ *
+ * You can find the hex key of a FEN using pg_key. 
+ *
+ * This code is released in the public domain by Michel Van den Bergh.
+ *
+ */
+
+
+#include <stdio.h>
+#include <string.h>
+
+typedef unsigned char uint8;
+typedef unsigned short uint16;
+typedef unsigned int uint32;
+
+#ifdef _MSC_VER
+  typedef unsigned __int64 uint64;
+#else
+  typedef unsigned long long int uint64;
+#endif
+
+typedef struct {
+    uint64 key;        
+    uint16 move;
+    uint16 weight;
+    uint32 learn;
+} entry_t;
+
+entry_t entry_none = {
+    0, 0, 0, 0
+};
+
+char *promote_pieces=" nbrq";
+
+#define MAX_MOVES 100
+
+int int_from_file(FILE *f, int l, uint64 *r){
+    int i,c;
+    for(i=0;i<l;i++){
+        c=fgetc(f);
+        if(c==EOF){
+            return 1;
+        }
+        (*r)=((*r)<<8)+c;
+    }
+    return 0;
+}
+
+int entry_from_file(FILE *f, entry_t *entry){
+    int ret;
+    uint64 r;
+    ret=int_from_file(f,8,&r);
+    if(ret) return 1;
+    entry->key=r;
+    ret=int_from_file(f,2,&r);
+    if(ret) return 1;
+    entry->move=r;
+    ret=int_from_file(f,2,&r);
+    if(ret) return 1;
+    entry->weight=r;
+    ret=int_from_file(f,4,&r);
+    if(ret) return 1;
+    entry->learn=r;
+    return 0;
+}
+
+int find_key(FILE *f, uint64 key, entry_t *entry){
+    int first, last, middle;
+    entry_t first_entry=entry_none, last_entry,middle_entry;
+    first=-1;
+    if(fseek(f,-16,SEEK_END)){
+        *entry=entry_none;
+        entry->key=key+1; //hack
+        return -1;
+    }
+    last=ftell(f)/16;
+    entry_from_file(f,&last_entry);
+    while(1){
+        if(last-first==1){
+            *entry=last_entry;
+            return last;
+        }
+        middle=(first+last)/2;
+        fseek(f,16*middle,SEEK_SET);
+        entry_from_file(f,&middle_entry);
+        if(key<=middle_entry.key){
+            last=middle;
+            last_entry=middle_entry;
+        }else{
+            first=middle;
+            first_entry=middle_entry;
+        }
+    }
+}
+
+void move_to_string(char move_s[6], uint16 move){
+    int f,fr,ff,t,tr,tf,p;
+    f=(move>>6)&077;
+    fr=(f>>3)&0x7;
+    ff=f&0x7;
+    t=move&077;
+    tr=(t>>3)&0x7;
+    tf=t&0x7;
+    p=(move>>12)&0x7;
+    move_s[0]=ff+'a';
+    move_s[1]=fr+'1';
+    move_s[2]=tf+'a';
+    move_s[3]=tr+'1';
+    if(p){
+        move_s[4]=promote_pieces[p];
+        move_s[5]='\0';
+    }else{
+        move_s[4]='\0';
+    }
+    if(!strcmp(move_s,"e1h1")){
+        strcpy(move_s,"e1g1");
+    }else  if(!strcmp(move_s,"e1a1")){
+        strcpy(move_s,"e1c1");
+    }else  if(!strcmp(move_s,"e8h8")){
+        strcpy(move_s,"e8g8");
+    }else  if(!strcmp(move_s,"e8a8")){
+        strcpy(move_s,"e8c8");
+    }
+}
+
+int main(int argc, char *argv[]){
+    FILE *f;
+    entry_t entry;
+    int offset;
+    char *file_name;
+    uint64 key;
+    entry_t entries[MAX_MOVES];
+    int count=0;
+    int ret, i;
+    char move_s[6];
+    int total_weight;
+    if(argc<=2){
+        printf("Usage: pg_show <book> <hex key>\n");
+        return 1;
+    }
+    file_name=argv[1];
+#ifdef _MSC_VER
+    sscanf(argv[2],"%16I64x",&key);
+#else
+    sscanf(argv[2],"%16llx",&key);
+#endif
+    f=fopen(file_name,"rb");
+    if(!f){
+        perror(file_name);
+        return 1;
+    }
+    offset=find_key(f,key,&entry);
+    if(entry.key!=key){
+#ifdef _MSC_VER
+        printf("%016I64x: No such key\n",key);
+#else
+        printf("%016llx: No such key\n",key);
+#endif        
+        return 1;
+    }
+    entries[0]=entry;
+    count=1;
+    fseek(f,16*(offset+1),SEEK_SET);
+    while(1){
+        ret=entry_from_file(f,&entry);
+        if(ret){
+            break;
+        }
+        if(entry.key!=key){
+            break;
+        }
+        if(count==MAX_MOVES){
+            printf("Too many moves in this position (max=%d)\n",MAX_MOVES);
+            return 1;
+        }
+        entries[count++]=entry;
+    }
+    total_weight=0;
+    for(i=0;i<count;i++){
+        total_weight+=entries[i].weight;
+    }
+    for(i=0;i<count;i++){
+        move_to_string(move_s,entries[i].move);
+        printf("move=%s weight=%5.2f%%\n",
+                move_s,
+               100*((double) entries[i].weight/ (double) total_weight));
+    }
+    return 0;
+}