Implemented better error handling in the SQLite3 framework

The core sqlite_query() function will now always return a pointer to a
dbresult structure.  This structure now contains a query status and
the error message from the sqlite3 backend if something went wrong.

This means that error checking from now on should use the
sqlite_query_status() macro and not to check if sqlite_query() returns
NULL.

Another fundamental change is that sqlite_free_results() must always be
called on the dbresult structure now, to free the memory used by either
data from the query or the error message.

Signed-off-by: David Sommerseth <dazo@users.sourceforge.net>

1 files changed, 33 insertions, 0 deletions

diff --git a/database/sqlite/sqlite.h b/database/sqlite/sqlite.h
index ba4cac5..5a7c5fd 100644
--- a/database/sqlite/sqlite.h
+++ b/database/sqlite/sqlite.h
@@ -81,6 +81,24 @@ typedef struct __sqlite_tuples {
 
 
 /**
+ *  Defines dbresult status types
+ */
+typedef enum _QueryStatus { dbEMPTY,   /**< No SQL query has been performed */
+                            dbSUCCESS, /**< SQL query was successful */
+                            dbERROR,   /**< SQL query failed */
+                            dbINVALID  /**< Invalid dbresult (NULL value) */
+} QueryStatus;
+
+/**
+ *  Defines error severities
+ */
+typedef enum _ErrorSeverity { sevWARNING,   /**< Query returns some data, but with errors in completeing it */
+                              sevERROR,     /**< Query could not complete, but may try again */
+                              sevCRITICAL, /**< Query failed and there is no point of trying again */
+                              sevPANIC      /**< Query failed and eurephia should shutdown */
+} ErrorSeverity;
+
+/**
  * The main definition of the dbresult strucutre.  This structure keeps the
  * complete information about both fields and values of all records from a query.
  *
@@ -91,6 +109,9 @@ typedef struct __sqlite_tuples {
  * as possible.
  */
 typedef struct __sqlite_dbresult {
+        QueryStatus status;           /**< Indicates if the query was successful or not */
+        char *query;                  /**< Copy of the parsed SQL query */
+
         // Query results
         _sqlite_tuples *tuples;       /**< Pointer to the chains which contains field values */
         _sqlite_header *headerrec;    /**< Pointer to the chains with info about the field/columns */
@@ -102,6 +123,10 @@ typedef struct __sqlite_dbresult {
         // "Search" pointers
         _sqlite_tuples *srch_tuples;    /**< "Cache" of the last record being looked up */
         _sqlite_header *srch_headerrec; /**< "Cache" of the last header record being looked up */
+
+        // Error handling
+        ErrorSeverity errSeverity;      /**< Severity of the error  */
+        char *errMsg;                   /**< If status == dbERROR, a error message can be found here */
 } dbresult;
 
 
@@ -110,6 +135,7 @@ typedef struct __sqlite_dbresult {
  */
 typedef enum _SQLqueryType { SQL_SELECT, SQL_INSERT, SQL_UPDATE, SQL_DELETE } SQLqueryType;
 
+
 /**
  * Free up a dbresult structure.  This is the public interface for the
  * internal function _sqlite_free_results()
@@ -118,9 +144,16 @@ typedef enum _SQLqueryType { SQL_SELECT, SQL_INSERT, SQL_UPDATE, SQL_DELETE } SQ
  */
 #define sqlite_free_results(r) { _sqlite_free_results(r); r = NULL; }
 void _sqlite_free_results(dbresult *);
+
+void sqlite_log_error(eurephiaCTX *ctx, dbresult *dbres );
+#ifdef HAVE_LIBXML2
+xmlNode *sqlite_log_error_xml(eurephiaCTX *ctx, dbresult *dbres );
+#endif
+
 dbresult *sqlite_query(eurephiaCTX *ctx, const char *, ...);
 dbresult *sqlite_query_mapped(eurephiaCTX *ctx, SQLqueryType type, const char *sqlstub,
                               eDBfieldMap *valMap, eDBfieldMap *whereMap, const char *sortkeys);
+#define sqlite_query_status(res) (QueryStatus) (res != NULL ? res->status : dbINVALID)
 char *sqlite_get_value(dbresult *res, int, int);
 #ifdef HAVE_LIBXML2
 xmlNodePtr sqlite_xml_value(xmlNodePtr node, xmlFieldType xmltyp, char *name, dbresult *res, int row, int col);