Add basic schema versioning support

apropos-utils.c

@@ -142,10 +142,23 @@ static int
 create_db(sqlite3 *db)
 {
 	const char *sqlstr = NULL;
+	char *schemasql;
 	char *errmsg = NULL;
 
 /*------------------------ Create the tables------------------------------*/
 
+	schemasql = sqlite3_mprintf("PRAGMA user_version = %d",
+	    APROPOS_SCHEMA_VERSION);
+	sqlite3_exec(db, schemasql, NULL, NULL, &errmsg);
+	if (errmsg != NULL) {
+		warnx("%s", errmsg);
+		free(errmsg);
+		sqlite3_close(db);
+		sqlite3_shutdown();
+		return -1;
+	}
+	sqlite3_free(schemasql);
+
 	sqlstr = "CREATE VIRTUAL TABLE mandb USING fts4(section, name, "
 			    "name_desc, desc, lib, return_vals, env, files, "
 			    "exit_status, diagnostics, errors, md5_hash UNIQUE, machine, "
@@ -263,20 +276,22 @@ sqlite3 *
 init_db(int db_flag)
 {
 	sqlite3 *db = NULL;
+	sqlite3_stmt *stmt;
 	struct stat sb;
 	int rc;
 	int create_db_flag = 0;
 
-	/* Check if the databse exists or not */
+	/* Check if the database exists or not */
 	if (!(stat(DBPATH, &sb) == 0 && S_ISREG(sb.st_mode))) {
 		/* Database does not exist, check if DB_CREATE was specified, and set
 		 * flag to create the database schema
 		 */
-		if (db_flag == (MANDB_CREATE))
-			create_db_flag = 1;
-		else
-		/* db does not exist and DB_CREATE was also not specified, return NULL */
+		if (db_flag != (MANDB_CREATE)) {
+			warnx("Missing apropos database. "
+			      "Please run makemandb to create it.");
 			return NULL;
+		}
+		create_db_flag = 1;
 	}
 
 	/* Now initialize the database connection */
@@ -288,32 +303,50 @@ init_db(int db_flag)
 		sqlite3_shutdown();
 		return NULL;
 	}
-
+
+	if (create_db_flag && create_db(db) < 0) {
+		warnx("%s", "Unable to create database schema");
+		goto error;
+	}
+
+	rc = sqlite3_prepare_v2(db, "PRAGMA user_version", -1, &stmt, NULL);
+	if (rc != SQLITE_OK) {
+		warnx("Unable to query schema version");
+		goto error;
+	}
+	if (sqlite3_step(stmt) != SQLITE_ROW) {
+		sqlite3_finalize(stmt);
+		warnx("Unable to query schema version");
+		goto error;
+	}
+	if (sqlite3_column_int(stmt, 0) != APROPOS_SCHEMA_VERSION) {
+		sqlite3_finalize(stmt);
+		warnx("Incorrect schema version found. "
+		      "Please run makemandb -f.");
+		goto error;
+	}
+	sqlite3_finalize(stmt);
+
 	sqlite3_extended_result_codes(db, 1);
 
 	/* Register the zip and unzip functions for FTS compression */
 	rc = sqlite3_create_function(db, "zip", 1, SQLITE_ANY, NULL, zip, NULL, NULL);
 	if (rc != SQLITE_OK) {
-		sqlite3_close(db);
-		sqlite3_shutdown();
-		errx(EXIT_FAILURE, "Unable to register function: compress");
+		warnx("Unable to register function: compress");
+		goto error;
 	}
 
 	rc = sqlite3_create_function(db, "unzip", 1, SQLITE_ANY, NULL, 
                                  unzip, NULL, NULL);
 	if (rc != SQLITE_OK) {
-		sqlite3_close(db);
-		sqlite3_shutdown();
-		errx(EXIT_FAILURE, "Unable to register function: uncompress");
-	}
-
-	if (create_db_flag && create_db(db) < 0) {
-		warnx("%s", "Unable to create database schema");
-		sqlite3_close(db);
-		sqlite3_shutdown();
-		return NULL;
+		warnx("Unable to register function: uncompress");
+		goto error;
 	}
 	return db;
+error:
+	sqlite3_close(db);
+	sqlite3_shutdown();
+	return NULL;
 }
 
 /*
@@ -719,4 +752,3 @@ int run_query_pager(sqlite3 *db, query_args *args)
 	args->callback_data = (void *) &orig_data;
 	return run_query(db, snippet_args, args);
 }
-

apropos-utils.h

@@ -44,6 +44,8 @@
 #define MANDB_WRITE SQLITE_OPEN_READWRITE
 #define MANDB_CREATE SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
 
+#define APROPOS_SCHEMA_VERSION 20120130
+
 /*
  * Used to identify the section of a man(7) page.
  * This is similar to the enum mdoc_sec defined in mdoc.h from mdocml project.

apropos.c

@@ -137,10 +137,8 @@ main(int argc, char *argv[])
 	 }
 
 	if ((db = init_db(MANDB_READONLY)) == NULL)
-		errx(EXIT_FAILURE, "The database does not exist. Please run makemandb "
-			"first and then try again");
+		exit(EXIT_FAILURE);
 
-
 	/* If user wants to page the output, then set some settings */
 	if (aflags.pager) {
 		/* Open a pipe to the pager */

makemandb.c

@@ -51,7 +51,7 @@ typedef struct secbuff {
 typedef struct makemandb_flags {
 	int optimize;
 	int limit;	// limit the indexing to only NAME section
-	int f;		// force removal of old database
+	int recreate;	// Database was created from scratch
 } makemandb_flags;
 
 typedef struct mandb_rec {
@@ -299,7 +299,7 @@ main(int argc, char *argv[])
 		switch (ch) {
 		case 'f':
 			remove(DBPATH);
-			mflags.f = 1;
+			mflags.recreate = 1;
 			break;
 		case 'l':
 			mflags.limit = 1;
@@ -320,7 +320,7 @@ main(int argc, char *argv[])
 	mp = mparse_alloc(MPARSE_AUTO, MANDOCLEVEL_FATAL, NULL, NULL);
 
 	if ((db = init_db(MANDB_CREATE)) == NULL)
-		errx(EXIT_FAILURE, "Could not initialize the database");
+		exit(EXIT_FAILURE);
 
 	sqlite3_exec(db, "PRAGMA synchronous = 0", NULL, NULL, 	&errmsg);
 	if (errmsg != NULL) {
@@ -657,7 +657,7 @@ update_db(sqlite3 *db, struct mparse *mp, mandb_rec *rec)
 		" due to errors = %d\n",
 		total_count, new_count, link_count, err_count);
 
-	if (!mflags.f) {
+	if (!mflags.recreate) {
 		printf("Deleting stale index entries\n");
 		sqlstr = "DELETE FROM mandb WHERE rowid IN"
 			 " (SELECT id FROM mandb_meta "