postgresql/src/include/nodes/miscnodes.h

57 lines
2.2 KiB
C

/*-------------------------------------------------------------------------
*
* miscnodes.h
* Definitions for hard-to-classify node types.
*
* Node types declared here are not part of parse trees, plan trees,
* or execution state trees. We only assign them NodeTag values because
* IsA() tests provide a convenient way to disambiguate what kind of
* structure is being passed through assorted APIs, such as function
* "context" pointers.
*
*
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/nodes/miscnodes.h
*
*-------------------------------------------------------------------------
*/
#ifndef MISCNODES_H
#define MISCNODES_H
#include "nodes/nodes.h"
/*
* ErrorSaveContext -
* function call context node for handling of "soft" errors
*
* A caller wishing to trap soft errors must initialize a struct like this
* with all fields zero/NULL except for the NodeTag. Optionally, set
* details_wanted = true if more than the bare knowledge that a soft error
* occurred is required. The struct is then passed to a SQL-callable function
* via the FunctionCallInfo.context field; or below the level of SQL calls,
* it could be passed to a subroutine directly.
*
* After calling code that might report an error this way, check
* error_occurred to see if an error happened. If so, and if details_wanted
* is true, error_data has been filled with error details (stored in the
* callee's memory context!). FreeErrorData() can be called to release
* error_data, although that step is typically not necessary if the called
* code was run in a short-lived context.
*/
typedef struct ErrorSaveContext
{
NodeTag type;
bool error_occurred; /* set to true if we detect a soft error */
bool details_wanted; /* does caller want more info than that? */
ErrorData *error_data; /* details of error, if so */
} ErrorSaveContext;
/* Often-useful macro for checking if a soft error was reported */
#define SOFT_ERROR_OCCURRED(escontext) \
((escontext) != NULL && IsA(escontext, ErrorSaveContext) && \
((ErrorSaveContext *) (escontext))->error_occurred)
#endif /* MISCNODES_H */