sqlite - add test extension - half.c

storage/sqlite/ext/half.c

@@ -0,0 +1,30 @@
+/* Add your header comment here */
+
+#include <sqlite3ext.h>
+SQLITE_EXTENSION_INIT1
+
+/*
+** The half() SQL function returns half of its input value.
+*/
+static void halfFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  sqlite3_result_double(context, 0.5*sqlite3_value_double(argv[0]));
+}
+
+/* SQLite invokes this routine once when it loads the extension.
+** Create new functions, collating sequences, and virtual table
+** modules here.  This is usually the only exported symbol in
+** the shared library.
+*/
+int sqlite3_extension_init(
+  sqlite3 *db,
+  char **pzErrMsg,
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi)
+  sqlite3_create_function(db, "half", 1, SQLITE_ANY, 0, halfFunc, 0, 0);
+  return 0;
+}