void* csync_db_begin(const char *err, const char *fmt, ...)
{
db_stmt_p stmt = NULL;
char *sql;
va_list ap;
int rc, busyc = 0;
char *ppTail;
va_start(ap, fmt);
VASPRINTF(&sql, fmt, ap);
va_end(ap);
in_sql_query++;
csync_db_maybegin();
csync_debug(2, "SQL: %s\n", sql);
while (1) {
rc = db_prepare_stmt(db, sql, &stmt, &ppTail);
if ( rc != DB_BUSY ) break;
if (busyc++ > get_dblock_timeout()) { db = 0; csync_fatal(DEADLOCK_MESSAGE); }
csync_debug(2, "Database is busy, sleeping a sec.\n");
sleep(1);
}
if ( rc != DB_OK && err )
csync_fatal("Database Error: %s [%d]: %s on executing %s\n", err, rc, db_errmsg(db), sql);
free(sql);
return stmt;
}
static void
db_vacuum (void)
{
sqlite3_stmt *stmt;
gint res, page_count, freelist_count;
/* Determine fragmentation ratio using
PRAGMA page_count
PRAGMA freelist_count
as suggested by adriatic in this blog post
http://jeff.ecchi.ca/blog/2011/12/24/investigating-lifereas-startup-performance/#comment-19989
and perform VACUUM only when needed.
*/
db_prepare_stmt (&stmt, "PRAGMA page_count");
sqlite3_reset (stmt);
res = sqlite3_step (stmt);
if (SQLITE_ROW != res)
g_error ("Could not determine page count (error code %d)!", res);
page_count = sqlite3_column_int (stmt, 0);
sqlite3_finalize (stmt);
db_prepare_stmt (&stmt, "PRAGMA freelist_count");
sqlite3_reset (stmt);
res = sqlite3_step (stmt);
if (SQLITE_ROW != res)
g_error ("Could not determine free list count (error code %d)!", res);
freelist_count = sqlite3_column_int (stmt, 0);
sqlite3_finalize (stmt);
float fragmentation = (100 * (float)freelist_count/page_count);
if (fragmentation > VACUUM_ON_FRAGMENTATION_RATIO) {
debug2 (DEBUG_DB, "Performing VACUUM as freelist count/page count ratio %2.2f > %d",
fragmentation, VACUUM_ON_FRAGMENTATION_RATIO);
debug_start_measurement (DEBUG_DB);
db_exec ("VACUUM;");
debug_end_measurement (DEBUG_DB, "VACUUM");
} else {
debug2 (DEBUG_DB, "No VACUUM as freelist count/page count ratio %2.2f <= %d",
fragmentation, VACUUM_ON_FRAGMENTATION_RATIO);
}
}
static sqlite3_stmt *
db_get_statement (const gchar *name)
{
sqlite3_stmt *statement;
gchar *sql;
sql = (gchar *) g_hash_table_lookup (statements, name);
db_prepare_stmt (&statement, sql);
if (!statement)
g_error ("Fatal: unknown prepared statement \"%s\" requested!", name);
sqlite3_reset (statement);
return statement;
}
static gboolean
db_table_exists (const gchar *name)
{
gchar *sql;
sqlite3_stmt *stmt;
gint res;
sql = sqlite3_mprintf ("SELECT COUNT(type) FROM sqlite_master WHERE type = 'table' AND name = '%s';", name);
db_prepare_stmt (&stmt, sql);
sqlite3_reset (stmt);
sqlite3_step (stmt);
res = sqlite3_column_int (stmt, 0);
sqlite3_finalize (stmt);
sqlite3_free (sql);
return (1 == res);
}
static gint
db_get_schema_version (void)
{
guint schemaVersion;
sqlite3_stmt *stmt;
if (!db_table_exists ("info")) {
db_exec ("CREATE TABLE info ( "
" name TEXT, "
" value TEXT, "
" PRIMARY KEY (name) "
");");
db_set_schema_version (-1);
}
db_prepare_stmt (&stmt, "SELECT value FROM info WHERE name = 'schemaVersion'");
sqlite3_step (stmt);
schemaVersion = sqlite3_column_int (stmt, 0);
sqlite3_finalize (stmt);
return schemaVersion;
}
