* introduce --empty and --autoupgrade, and document them

man/mu.1

@@ -36,8 +36,7 @@ information in a database
 .TP
 \fBfind\fR
 for finding messages in your database, using certain search parameters (see
-below for details). You can use \fBquery\fR and \fBsearch\fR as synonyms for
-\fBfind\fR.
+below for details).
 
 .TP
 \fBmkdir\fR
@@ -141,6 +140,24 @@ re-index all mails, even ones that are already in the database.
 \fB\-u\fR, \fB\-\-nocleanup\fR
 disables the database cleanup that \fBmu\fR does by default after indexing.
 
+.TP
+\fB\-y\fR, \fB\-\-empty\fR
+clear all messages from the database before
+indexing. This is effectively the same as removing the database. The
+difference with \fB\-\-reindex\fR is that \fB\-\-empty\fR guarantees that
+after the indexing has finished, there are no 'old' messages in the database
+anymore, which is not true with \fB\-\-reindex\fR when indexing only a part of
+messages (using \fB\-\-maildir\fR). For this reason, it's necessary to run
+\fBmu index \-\-empty\fR when there is an upgrade in the database
+format. \fBmu index\fR will warn you about this.
+
+.TP
+\fB\-u\fR, \fB\-\-autoupgrade\fR
+automatically use \fB\-y\fR, \fB\-\-empty\fR when \fBmu\fR notices that the
+database version is not up-to-date. This option is for use in cron scripts
+etc., so they won't require any user interaction, even when mu introduces a
+new database vesion.
+
 .TP
 
 .B NOTE:

src/mu-cmd.c

@@ -44,16 +44,13 @@ cmd_from_string (const char* cmd)
 		return MU_CMD_INDEX;
 
 	/* support some synonyms... */
-	if ((strcmp (cmd, "query") == 0) ||
-	    (strcmp (cmd, "find")  == 0) ||
-	    (strcmp (cmd, "search") == 0))
+	if (strcmp (cmd, "find")  == 0) 
 		return MU_CMD_FIND;
 
 	if (strcmp (cmd, "cleanup") == 0)
 		return MU_CMD_CLEANUP;
 	
-	if ((strcmp (cmd, "mkmdir") == 0) ||
-	    (strcmp (cmd, "mkdir") == 0)) 
+	if (strcmp (cmd, "mkdir") == 0) 
 		return MU_CMD_MKDIR;
 	
 	/* if ((strcmp (cmd, "help") == 0) || */
@@ -63,26 +60,12 @@ cmd_from_string (const char* cmd)
 	return MU_CMD_UNKNOWN;
 }
 
-static gboolean
-database_needs_reindex (MuConfigOptions *opts)
+static void
+update_warning (void)
 {
-	gchar *version;
-	gboolean reindex;
-	
-	version = mu_util_xapian_db_version (opts->xpath);		
-	if (!version || strcmp (version, MU_XAPIAN_DB_VERSION) != 0) {
-		g_warning ("expected database version %s, "
-			   "but current version is %s",
-			   MU_XAPIAN_DB_VERSION,
-			   version ? version : "<none>");
-		g_message ("please run `mu index --reindex' for your full "
-			   "maildir");
-		reindex = TRUE;
-	} else
-		reindex = FALSE;
-
-	g_free (version);
-	return reindex;
+	g_warning ("the database needs to be updated to version %s",
+		   MU_XAPIAN_DB_VERSION);
+	g_message ("please run 'mu index --empty' (see the manpage)");
 }
 
 
@@ -338,9 +321,11 @@ cmd_find (MuConfigOptions *opts)
 		
 	if (!query_params_valid (opts))
 		return FALSE;
-
-	if (database_needs_reindex(opts))
+	
+	if (mu_util_xapian_db_version_up_to_date (opts->xpath)) {
+		update_warning ();
 		return FALSE;
+	}
 	
 	/* first param is 'query', search params are after that */
 	params = (const gchar**)&opts->params[1];
@@ -408,6 +393,31 @@ index_msg_cb  (MuIndexStats* stats, void *user_data)
 }
 
 
+static gboolean
+database_version_check_and_update (MuConfigOptions *opts)
+{
+	/* we empty the database before doing anything */
+	if (opts->empty) {
+		opts->reindex = TRUE;
+		g_message ("Emptying database %s", opts->xpath);
+		return mu_util_xapian_clear_database (opts->xpath);
+	}
+		
+	if (mu_util_xapian_db_version_up_to_date (opts->xpath))
+		return TRUE; /* ok, nothing to do */
+	
+	/* ok, database is not up to date */
+	if (opts->autoupgrade) {
+		opts->reindex = TRUE;
+		g_message ("Auto-upgrade: clearing old database first");
+		return mu_util_xapian_clear_database (opts->xpath);
+	}
+
+	update_warning ();
+	return FALSE;
+}
+
+
 static gboolean
 cmd_index (MuConfigOptions *opts)
 {
@@ -415,10 +425,10 @@ cmd_index (MuConfigOptions *opts)
 
 	if (!check_index_params (opts))
 		return FALSE;
-
-	if (!opts->reindex && database_needs_reindex(opts))
-		return FALSE;
 	
+	if (!database_version_check_and_update(opts))
+		return FALSE;
+		
 	mu_msg_gmime_init ();
 	{
 		MuIndex *midx;

src/mu-config.c

@@ -65,6 +65,10 @@ config_options_group_index (MuConfigOptions *opts)
 		 "top of the maildir", NULL},
 		{"reindex", 'r', 0, G_OPTION_ARG_NONE, &opts->reindex,
 		 "index already indexed messages too", NULL},
+		{"empty", 'y', 0, G_OPTION_ARG_NONE, &opts->empty,
+		 "empty the database before indexing"},
+		{"autoupgrade", 'u', 0, G_OPTION_ARG_NONE, &opts->autoupgrade,
+		 "automatically upgrade the database with new mu versions"},
 		{"nocleanup", 'u', 0, G_OPTION_ARG_NONE, &opts->nocleanup,
 		 "don't clean up the database after indexing", NULL},
 		{ NULL, 0, 0, 0, NULL, NULL, NULL }

src/mu-config.h

@@ -45,6 +45,9 @@ struct _MuConfigOptions {
 	char	        *maildir;	/* where the mails are */
 	gboolean         nocleanup;	/* don't cleanup deleted mails from db */
 	gboolean         reindex;	/* re-index existing mails */
+	gboolean         empty;         /* empty the database before indexing */
+	gboolean         autoupgrade;   /* automatically upgrade db
+					 * when needed */
 	
 	/* options for querying */
 	gboolean         xquery;        /* give the Xapian query instead of

src/mu-store-xapian.cc

@@ -73,6 +73,7 @@ mu_store_xapian_new  (const char* xpath)
 }
 
 
+
 char*
 mu_store_xapian_version (MuStoreXapian *store)
 {

src/mu-util-xapian.cc

@@ -20,14 +20,25 @@
 #include "config.h"
 #include <xapian.h>
 
+
 #include <cstring>
+#include <errno.h>
+
 #include "mu-util.h"
 #include "mu-util-xapian.h"
 
 char*
 mu_util_xapian_db_version (const gchar *xpath)
 {
+	g_return_val_if_fail (xpath, NULL);
+	
 	try {
+		if (!access(xpath, F_OK) == 0) {
+			g_warning ("cannot access %s: %s",
+				   xpath, strerror(errno));
+			return NULL;
+		}
+		
 		Xapian::Database db (xpath);
 		const std::string version
 			(db.get_metadata (MU_XAPIAN_VERSION_KEY));
@@ -45,6 +56,8 @@ mu_util_xapian_db_version_up_to_date (const gchar *xpath)
 {
 	gchar *version;
 	gboolean uptodate;
+
+	g_return_val_if_fail (xpath, FALSE);
 	
 	version = mu_util_xapian_db_version (xpath);
 	if (!version)
@@ -57,5 +70,20 @@ mu_util_xapian_db_version_up_to_date (const gchar *xpath)
 }
 
 
-
+gboolean
+mu_util_xapian_clear_database (const gchar *xpath)
+{
+	g_return_val_if_fail (xpath, FALSE);
+	
+	try {
+		Xapian::WritableDatabase db
+			(xpath, Xapian::DB_CREATE_OR_OVERWRITE);
+		db.flush ();
+		
+		return TRUE;
+		
+	} MU_XAPIAN_CATCH_BLOCK;
+	
+	return FALSE;
+}
 

src/mu-util-xapian.h

@@ -47,6 +47,20 @@ char* mu_util_xapian_db_version (const gchar *xpath);
  */
 gboolean mu_util_xapian_db_version_up_to_date (const gchar *xpath);
 
+
+
+/** 
+ * clear the database, ie., remove all of the contents. This is a
+ * destructive operation, but the database can be restored be doing a
+ * full scan of the maildirs.
+ * 
+ * @param xpath path to the database
+ * 
+ * @return TRUE if the clearing succeeded, FALSE otherwise.
+ */
+gboolean mu_util_xapian_clear_database (const gchar *xpath);
+
+
 G_END_DECLS
 
 #endif /*__MU_UTIL_XAPIAN_H__*/