/* Make a db.h that will be link-time compatible with Sleepycat's Berkeley DB. */

#include <db.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>


void print_dbtype(void) {
    /* DBTYPE is mentioned by db_open.html */
    printf("typedef enum {\n");
    printf(" DB_BTREE=%d\n", DB_BTREE);
    printf("} DBTYPE;\n");
}


//#define DECL_LIMIT 100
struct fieldinfo {
    char *decl;
    unsigned int off;
    unsigned int size;
};

#include "sample_offsets_32.h"
#include "sample_offsets_64.h"

void print_struct (const char *structname, int need_internal, struct fieldinfo *fields32, struct fieldinfo *fields64, unsigned int N) {
    unsigned int i;
    unsigned int current_32 = 0;
    unsigned int current_64 = 0;
    int dummy_counter=0;
    int did_toku_internal=0;
//    int total32 = fields32[N-1].size;
//    int total64 = fields32[N-1].size;
    printf("struct __toku_%s {\n", structname);
    for (i=0; i<N-1; i++) {
	unsigned int this_32 = fields32[i].off;
	unsigned int this_64 = fields64[i].off;
	assert(strcmp(fields32[i].decl, fields64[i].decl)==0);
	//fprintf(stderr, "this32=%d current32=%d this64=%d current64=%d\n", this_32, current_32, this_64, current_64);
	if (this_32 > current_32 || this_64 > current_64) {
	    unsigned int diff32 = this_32-current_32;
	    unsigned int diff64 = this_64-current_64;
	    assert(this_32 > current_32 && this_64 > current_64);
	    if (diff32!=diff64) {
		unsigned int diff = diff64-diff32;
		unsigned int n_dummys = diff/4;
		if (need_internal && !did_toku_internal) {
		    printf("  struct __toku_%s_internal *i;\n", structname);
		    n_dummys--;
		    did_toku_internal=1;
		}
		if (n_dummys>0) printf("  void* dummy%d[%d];\n", dummy_counter++, n_dummys);
		diff64-=diff*2;
		diff32-=diff;
		
	    }
	    assert(diff32==diff64);
	    if (diff32>0) {
		printf("  char dummy%d[%d];\n", dummy_counter++, diff32);
	    }
	    current_32 = this_32;
	    current_64 = this_64;
	}
	if (this_32<current_32 || this_64<current_64) {
	    printf("Whoops\n");
	}
	printf("  %s; /* 32-bit offset=%d size=%d, 64=bit offset=%d size=%d */\n", fields32[i].decl, fields32[i].off, fields32[i].size, fields64[i].off, fields64[i].size);
	current_32 += fields32[i].size;
	current_64 += fields64[i].size;
    }
    assert(did_toku_internal || !need_internal);
    printf("};\n");
}

int main (int argc __attribute__((__unused__)), char *argv[] __attribute__((__unused__))) {
    printf("#ifndef _DB_H\n");
    printf("#define _DB_H\n");
    printf("/* This code generated by make_db_h.   Copyright (c) 2007 Tokutek */\n");
    printf("#if defined(__cplusplus)\nextern \"C\" {\n#endif\n");
    printf("typedef struct __toku_db DB;\n");
    print_dbtype();

    assert(sizeof(db_fields32)==sizeof(db_fields64));
    print_struct("db", 1, db_fields32, db_fields64, sizeof(db_fields32)/sizeof(db_fields32[0]));

    assert(sizeof(dbt_fields32)==sizeof(dbt_fields64));
    print_struct("dbt", 0, dbt_fields32, dbt_fields64, sizeof(dbt_fields32)/sizeof(dbt_fields32[0]));

    assert(sizeof(db_txn_fields32)==sizeof(db_txn_fields64));
    print_struct("db_txn", 1, db_txn_fields32, db_txn_fields64, sizeof(db_txn_fields32)/sizeof(db_txn_fields32[0]));

    assert(sizeof(dbc_fields32)==sizeof(dbc_fields64));
    print_struct("dbc", 1, dbc_fields32, dbc_fields64, sizeof(dbc_fields32)/sizeof(dbc_fields32[0]));

    printf("#if defined(__cplusplus)\n}\n#endif\n");
    printf("#endif\n");
    return 0;
}