/* WIDE AREA INFORMATION SERVER SOFTWARE:
   No guarantees or restrictions.  See the readme file for the full standard
   disclaimer.

   Brewster@think.com
*/

/* include file for irfiles.c */

#ifndef IRFILES_H
#define IRFILES_H

#include "cdialect.h"
#include "cutil.h"
#include "hutil.h" /* for word_memory_hashtable */
#include "ustubs.h" /* for time_t */

#ifndef THINK_C
#ifndef M_XENIX
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#endif /* M_XENIX */
#endif /* THINK_C */

/* filename extensions for various components */
#define dictionary_ext			".dct"
#define filename_table_ext		".fn"
#define headline_table_ext		".hl"
#define document_table_ext		".doc"
#define index_ext			".inv"
#define source_ext 			".src"

/* these dictionary definitions are used in irhash,irverify, and irfiles */
#define DICTIONARY_HEADER_SIZE 4
#define DICTIONARY_BLOCK_SIZE 1000L  /* in entries, not bytes */
#define DICTIONARY_ENTRY_HASH_CODE_SIZE 2
/* #define DICTIONARY_ENTRY_COUNT_SIZE 3  moved to inverted file */
/* #define DICTIONARY_ENTRY_INDEX_BLOCK_SIZE 4 not used and too long a symbol*/
#define DICTIONARY_ELEMENT_SIZE 6 /* was 9 */
#define DICTIONARY_SIZE 524288L

#define INDEX_HEADER_SIZE 4
#define INDEX_BLOCK_SIZE_SIZE 2
#define NEXT_INDEX_BLOCK_SIZE 4
#define INDEX_BLOCK_FLAG_SIZE 1
#define INDEX_BLOCK_HEADER_SIZE 7
#define NUMBER_OF_OCCURANCES_SIZE 4
#define INDEX_BLOCK_NOT_FULL_FLAG 101
#define INDEX_BLOCK_FULL_FLAG 69
#define INDEX_BLOCK_DICTIONARY_FLAG 123

#define DOCUMENT_ID_SIZE 4
#define WORD_POSITION_SIZE 0
#define CHARACTER_POSITION_SIZE 3
#define WEIGHT_SIZE 1
#define INDEX_ELEMENT_SIZE 8

typedef struct database {
	char*	database_file;
	FILE*	dictionary_stream;
	FILE*	filename_table_stream;
	FILE*	headline_table_stream;
	FILE*	document_table_stream;
	FILE*	index_stream;
	word_memory_hashtable* the_word_memory_hashtable;
	long	doc_table_allocated_entries;
	long	dictionary_size;  /* in entries */
	long 	number_of_words; /* for building.  number of different words */
	long	index_file_number; /* for building. */
} database;

typedef struct document_table_entry {
	long	filename_id;
	long	headline_id;
	long	start_character;
	long	end_character;
	long 	document_length; /* in characters */
	long	number_of_lines; /* in lines */
	time_t  date;            /* 0 if unknown */
} document_table_entry;

#ifdef __cplusplus
/* declare these as C style functions */
extern "C"
	{
#endif /* def __cplusplus */

database* 	openDatabase _AP((char* name, boolean initialize,boolean for_search));
void		closeDatabase _AP((database* the_db));
void		disposeDatabase _AP((database* the_db));

void initialize_index_files _AP((database* db));

char *read_filename_table_entry _AP((long position, 
				  char* filename,
				  char* type, 
				  time_t* file_write_date,
				  database* db));

long write_filename_table_entry _AP((char* filename, char *type, database* db));
boolean filename_in_database _AP((char *filename, char *type,
				  time_t *write_file_date, database *db));
char *read_headline_table_entry _AP((long position,database* db));
long write_headline_table_entry _AP((char* headline, database* db));


boolean read_document_table_entry 
  _AP((document_table_entry* doc_entry,long number,database* db));

long write_document_table_entry
  _AP((document_table_entry* doc_table_entry, database* db));

long next_document_id _AP((database* db));


void close_dictionary_file _AP((database *db));

long add_word_to_dictionary
	 _AP((char *word, long index_file_block_number, long number_of_occurances,
	 database* db));
long look_up_word_in_dictionary _AP((char *word,database* db));
long init_dict_file_for_writing _AP((database *db));
void init_dict_file_detailed _AP((FILE* dictionary_stream,
				  long number_of_blocks));


boolean register_src_structure _AP((char *filename));
boolean write_src_structure _AP((char *filename, 
				 char *database_name, 
				 char *typename,
				 char **filenames, 
				 long number_of_filename,
				 boolean export_database,
				 long tcp_port));


long allocate_index_block _AP((long how_large, FILE* stream));

unsigned char *read_dictionary_block _AP((unsigned char* block,
					  long position,long length,
					  FILE* stream));
				     				 
void print_dictionary _AP((database* db));
char *dictionary_block_word _AP((long i,unsigned char* block));
long dictionary_block_position _AP((long i,unsigned char* block));
long dictionary_block_word_occurances _AP((long i,unsigned char* block));
void print_dictionary_block _AP((unsigned char* block,long size));

/* database functions */
char* dictionary_filename _AP((char* destination, database* db));
char* filename_table_filename _AP((char* destination, database* db));
char* headline_table_filename _AP((char* destination, database* db));
char* document_table_filename _AP((char* destination, database* db));
char* index_filename _AP((char* destination, database* db));
char* index_filename_with_version _AP((long version, char* destination, 
				  database* db));
char* source_filename _AP((char* destination, database* db));

#ifdef __cplusplus
	}
#endif /* def __cplusplus */

#endif /* IRFILES_H */