From 2fa4a0c9b9875e69824d141c5055ba0394743314 Mon Sep 17 00:00:00 2001 From: Rodrigo Moya Date: Mon, 12 Feb 2001 20:50:20 +0000 Subject: added DB3 transactions support 2001-02-11 Rodrigo Moya * pcs/cal-backend-db.c: added DB3 transactions support svn path=/trunk/; revision=8184 --- calendar/pcs/cal-backend-db.c | 174 +++++++++++++++++++++++++++++++++++------- 1 file changed, 145 insertions(+), 29 deletions(-) (limited to 'calendar/pcs') diff --git a/calendar/pcs/cal-backend-db.c b/calendar/pcs/cal-backend-db.c index 0165164e5e..70f7ac784f 100644 --- a/calendar/pcs/cal-backend-db.c +++ b/calendar/pcs/cal-backend-db.c @@ -28,8 +28,11 @@ # error "You need libdb3 to compile the DB backend" #endif +#define ENVIRONMENT_DIRECTORY "%s/evolution/local/Calendar/db.environment" + /* structure to identify an open cursor */ typedef struct { + gint ref; DBC* dbc; DB* parent_db; /* TODO: convert into a hash table */ @@ -43,6 +46,7 @@ struct _CalBackendDBPrivate { GnomeVFSURI *uri; /* Berkeley DB's library handles */ + DB_ENV *environment; DB *objects_db; DB *history_db; @@ -86,9 +90,13 @@ static gboolean cal_backend_db_update_object (CalBackend *backend, static gboolean cal_backend_db_remove_object (CalBackend *backend, const char *uid); static void close_cursor (CalBackendDB *cbdb, CalBackendDBCursor *cursor); -static CalBackendDBCursor* open_cursor (CalBackendDB *cbdb, DB *db); -static CalBackendDBCursor* find_cursor_by_db (CalBackendDB *cbdb, DB *db); -static DBT* find_record_by_id (CalBackendDBCursor *cursor, const gchar *id); +static CalBackendDBCursor *open_cursor (CalBackendDB *cbdb, DB *db); +static CalBackendDBCursor *find_cursor_by_db (CalBackendDB *cbdb, DB *db); +static DBT *find_record_by_id (CalBackendDBCursor *cursor, const gchar *id); + +static DB_TXN *begin_transaction (CalBackendDB *cbdb); +static void commit_transaction (DB_TXN *tid); +static void rollback_transaction (DB_TXN *tid); static CalBackendClass *parent_class; @@ -216,6 +224,10 @@ close_cursor (CalBackendDB *cbdb, CalBackendDBCursor *cursor) g_return_if_fail(cursor != NULL); + cursor->ref--; + if (cursor->ref > 0) + return; + /* free all keys and data */ while ((node = g_list_first(cursor->keys))) { dbt = (DBT *) node->data; @@ -247,8 +259,10 @@ open_cursor (CalBackendDB *cbdb, DB *db) /* search for the cursor in our list of cursors */ cursor = find_cursor_by_db(cbdb, db); - if (cursor) + if (cursor) { + cursor->ref++; return cursor; + } /* create the cursor */ cursor = g_new0(CalBackendDBCursor, 1); @@ -265,8 +279,7 @@ open_cursor (CalBackendDB *cbdb, DB *db) cursor->data = g_list_append(cursor->data, g_memdup(&data, sizeof(data))); } if (ret == DB_NOTFOUND) { - cbdb->priv->cursors = g_list_prepend(cbdb->priv->cursors, - (gpointer) cursor); + cbdb->priv->cursors = g_list_prepend(cbdb->priv->cursors, (gpointer) cursor); return cursor; } @@ -309,7 +322,7 @@ find_record_by_id (CalBackendDBCursor *cursor, const gchar *id) for (node = g_list_first(cursor->keys); node != NULL; node = g_list_next(node)) { DBT* key = (DBT *) node->data; if (key) { - if (!strcmp(key->data, id)) { + if (!strcmp((gchar *) key->data, id)) { GList* tmp = g_list_nth(cursor->data, pos); if (tmp) return (DBT *) node->data; @@ -321,6 +334,47 @@ find_record_by_id (CalBackendDBCursor *cursor, const gchar *id) return NULL; /* not found */ } +static DB_TXN * +begin_transaction (CalBackendDB *cbdb) +{ + DB_TXN *tid; + gint ret; + + g_return_val_if_fail(IS_CAL_BACKEND_DB(cbdb), NULL); + g_return_val_if_fail(cbdb->priv != NULL, NULL); + + if ((ret = txn_begin(cbdb->priv->environment, NULL, &tid, 0)) != 0) { + /* TODO: error logging */ + return NULL; + } + + return tid; +} + +static void +commit_transaction (DB_TXN *tid) +{ + gint ret; + + g_return_if_fail(tid != NULL); + + if ((ret = txn_begin(tid, 0)) != 0) { + /* TODO: error logging? */ + } +} + +static void +rollback_transaction (DB_TXN *tid) +{ + gint ret; + + g_return_if_fail(tid != NULL); + + if ((ret = txn_abort(tid)) != 0) { + /* TODO: error logging? */ + } +} + /* * Calendar backend methods */ @@ -400,6 +454,7 @@ static gboolean open_database_file (CalBackendDB *cbdb, const gchar *str_uri, gboolean only_if_exists) { gint ret; + struct stat sb; g_return_val_if_fail(IS_CAL_BACKEND_DB(cbdb), FALSE); g_return_val_if_fail(cbdb->priv != NULL, FALSE); @@ -407,13 +462,50 @@ open_database_file (CalBackendDB *cbdb, const gchar *str_uri, gboolean only_if_e g_return_val_if_fail(cbdb->priv->history_db != NULL, FALSE); g_return_val_if_fail(str_uri != NULL, FALSE); + /* initialize DB environment (for transactions) */ + if (stat(ENVIRONMENT_DIRECTORY, &sb) != 0) { + gchar *dir; + + /* if the directory exists, we're done, since DB will fail if it's the + * wrong one. If it does not exist, create the environment */ + dir = g_strdup_printf(ENVIRONMENT_DIRECTORY, g_get_home_dir()); + if (mkdir(dir, I_RWXU) != 0) { + g_free((gpointer) dir); + return FALSE; + } + + g_free((gpointer) dir); + + /* create the environment handle */ + if ((ret = db_env_create(&cbdb->priv->environment, 0)) != 0) { + return FALSE; + } + + cbdb->priv->environment->set_errorpfx(cbdb->priv->environment, "cal-backend-db"); + + /* open the transactional environment */ + if ((ret = cbdb->priv->environment->open(cbdb->priv->environment, + ENVIRONMENT_DIRECTORY, + DB_CREATE | DB_INIT_LOCK | DB_INIT_LOG | + DB_INIT_MPOOL | DB_INIT_TXN | + DB_RECOVER | DB_THREAD, + S_IRUSR | S_IWUSR)) != 0) { + return FALSE; + } + } + /* open/create objects database into given file */ + if ((ret = db_create(&cbdb->priv->objects_db, cbdb->priv->environment, 0)) != 0 + || (ret = db_create(&cbdb->priv->history_db, cbdb->priv->environment, 0)) != 0) { + return FALSE; + } + if (only_if_exists) { ret = cbdb->priv->objects_db->open(cbdb->priv->objects_db, str_uri, "calendar_objects", DB_HASH, - 0, + DB_THREAD, 0644); } else { @@ -421,7 +513,7 @@ open_database_file (CalBackendDB *cbdb, const gchar *str_uri, gboolean only_if_e str_uri, "calendar_objects", DB_HASH, - DB_CREATE, + DB_CREATE | DB_THREAD, 0644); } if (ret == 0) { @@ -466,11 +558,6 @@ cal_backend_db_open (CalBackend *backend, GnomeVFSURI *uri, gboolean only_if_exi | GNOME_VFS_URI_HIDE_TOPLEVEL_METHOD)); /* open database file */ - if ((ret = db_create(&cbdb->priv->objects_db, NULL, 0)) != 0 - || (ret = db_create(&cbdb->priv->history_db, NULL, 0)) != 0) { - g_free((gpointer) str_uri); - return CAL_BACKEND_OPEN_ERROR; - } if (!open_database_file(cbdb, (const gchar *) str_uri, only_if_exists)) { g_free((gpointer) str_uri); return CAL_BACKEND_OPEN_ERROR; @@ -524,6 +611,7 @@ cal_backend_db_get_n_objects (CalBackend *backend, CalObjType type) icalcomponent_free(icalcomp); } } + close_cursor(cbdb, cursor); } return total_count; @@ -549,8 +637,13 @@ cal_backend_db_get_object (CalBackend *backend, const char *uid) DBT *data; data = find_record_by_id(cursor, uid); - if (data) - return (char *) data->data; + if (data) { + gchar *str = g_strdup((char *) data->data); + close_cursor(cbdb, cursor); + return str; + } + + close_cursor(cbdb, cursor); } return NULL; @@ -573,6 +666,7 @@ cal_backend_db_get_type_by_uid (CalBackend *backend, const char *uid) cursor = open_cursor(cbdb, cbdb->priv->objects_db); if (cursor) { DBT *data = find_record_by_id(cursor, uid); + if (data) { icalcomponent icalcomp = icalparser_parse_string((char *) data->data); if (icalcomp) { @@ -593,9 +687,11 @@ cal_backend_db_get_type_by_uid (CalBackend *backend, const char *uid) } icalcomponent_free(icalcomp); + close_cursor(cbdb, cursor); return type; } } + close_cursor(cbdb, cursor); } return CAL_COMPONENT_NO_TYPE; @@ -663,6 +759,7 @@ cal_backend_db_get_uids (CalBackend *backend, CalObjType type) for (node = g_list_first(cursor->data); node != NULL; node = g_list_next(node)) { list = add_uid_if_match(list, cursor, node, type); } + close_cursor(cbdb, cursor); } return list; @@ -788,6 +885,8 @@ cal_backend_db_get_objects_in_range (CalBackend *backend, /* build the list to be returned from the hash table */ g_hash_table_foreach(uid_hash, add_uid_to_list, &list); g_hash_table_destroy(uid_hash); + + close_cursor(cbdb, cursor); } return list; @@ -836,6 +935,8 @@ cal_backend_db_get_alarms_in_range (CalBackend *backend, time_t start, time_t en seq->_buffer = CORBA_sequence_GNOME_Evolution_Calendar_CalComponentAlarms_allocbuf(number_of_alarms); /* TODO: populate CORBA sequence */ + + close_cursor(cbdb, cursor); } g_list_free(alarm_list); @@ -872,6 +973,8 @@ cal_backend_db_get_alarms_for_object (CalBackend *backend, corba_alarms = GNOME_Evolution_Calendar_CalComponentAlarms__alloc(); /* TODO: populate the CORBA alarms */ + + close_cursor(cbdb, cursor); } return corba_alarms; @@ -900,6 +1003,7 @@ cal_backend_db_update_object (CalBackend *backend, const char *uid, const char * DBT key; DBT new_data; int ret; + DB_TXN *tid; /* try to change the value in the cursor */ memset(&key, 0, sizeof(key)); @@ -910,25 +1014,32 @@ cal_backend_db_update_object (CalBackend *backend, const char *uid, const char * new_data.data = (void *) calobj; new_data.size = strlen(calobj); // + 1 - /* move the cursor to the given key */ - if ((ret = cursor->dbc->c_get(cursor->dbc, &key, NULL, DB_FIRST)) != 0) { + /* start transaction */ + tid = begin_transaction(cbdb); + if (!tid) { + close_cursor(cbdb, cursor); return FALSE; } - /* TODO: start transaction */ - - if ((ret = cursor->dbc->c_put(cursor->dbc, &key, &new_data, DB_CURRENT)) != 0) { - /* TODO: rollback transaction */ + if ((ret = cursor->parent_db->put(cursor->parent_db, + tid, + &key, + &new_data, + 0)) != 0) { + rollback_transaction(tid); + close_cursor(cbdb, cursor); return FALSE; } /* TODO: update history database */ - /* TODO: commit transaction */ + commit_transaction(tid); + close_cursor(cbdb, cursor); memcpy(data, &new_data, sizeof(new_data)); return TRUE; } + close_cursor(cbdb, cursor); } return FALSE; @@ -954,25 +1065,28 @@ cal_backend_db_remove_object (CalBackend *backend, const char *uid) GList *l; int ret; DBT key; + DB_TXN *tid; memset(&key, 0, sizeof(key); key.data = (void *) uid; key.size = strlen(uid); // + 1 - if ((ret = cursor->dbc->c_get(cursor->dbc, &key, NULL, DB_FIRST)) != 0) { + /* start transaction */ + tid = begin_transaction(cbdb); + if (!tid) { + close_cursor(cbdb, cursor); return FALSE; } - /* TODO: begin transaction */ - /* remove record from cursor */ - if ((ret = cursor->dbc->c_del(cursor->dbc, 0)) != 0) { - /* TODO: rollback transaction */ + if ((ret = cursor->parent_db->del(cursor->parent_db, tid, key, 0)) != 0) { + rollback_transaction(tid); + close_cursor(cbdb, cursor); return FALSE; } /* TODO: update history database */ - /* TODO: commit transaction */ + commit_transaction(tid); /* remove record from in-memory lists */ l = g_list_nth(cursor->keys, @@ -986,9 +1100,11 @@ cal_backend_db_remove_object (CalBackend *backend, const char *uid) cursor->data = g_list_remove(cursor->data, (gpointer) data); g_free((gpointer) data); } + close_cursor(cbdb, cursor); return TRUE; } + close_cursor(cbdb, cursor); } return FALSE; -- cgit v1.2.3