1/*-------------------------------------------------------------------------
2 *
3 * tablefunc.h
4 * interface for TableFunc executor node
5 *
6 * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
8 *
9 * src/include/executor/tablefunc.h
10 *
11 *-------------------------------------------------------------------------
12 */
13#ifndef _TABLEFUNC_H
14#define _TABLEFUNC_H
15
16/* Forward-declare this to avoid including execnodes.h here */
17struct TableFuncScanState;
18
19/*
20 * TableFuncRoutine holds function pointers used for generating content of
21 * table-producer functions, such as XMLTABLE.
22 *
23 * InitBuilder initialize table builder private objects. The output tuple
24 * descriptor, input functions for the columns, and typioparams are passed
25 * from executor state.
26 *
27 * SetDoc is called to define the input document. The table builder may
28 * apply additional transformations not exposed outside the table builder
29 * context.
30 *
31 * SetNamespace is called to pass namespace declarations from the table
32 * expression. This function may be NULL if namespaces are not supported by
33 * the table builder. Namespaces must be given before setting the row and
34 * column filters. If the name is given as NULL, the entry shall be for the
35 * default namespace.
36 *
37 * SetRowFilter is called do define the row-generating filter, which shall be
38 * used to extract each row from the input document.
39 *
40 * SetColumnFilter is called once for each column, to define the column-
41 * generating filter for the given column.
42 *
43 * FetchRow shall be called repeatedly until it returns that no more rows are
44 * found in the document. On each invocation it shall set state in the table
45 * builder context such that each subsequent GetValue call returns the values
46 * for the indicated column for the row being processed.
47 *
48 * DestroyBuilder shall release all resources associated with a table builder
49 * context. It may be called either because all rows have been consumed, or
50 * because an error occurred while processing the table expression.
51 */
52typedef struct TableFuncRoutine
53{
54 void (*InitOpaque) (struct TableFuncScanState *state, int natts);
55 void (*SetDocument) (struct TableFuncScanState *state, Datum value);
56 void (*SetNamespace) (struct TableFuncScanState *state, const char *name,
57 const char *uri);
58 void (*SetRowFilter) (struct TableFuncScanState *state, const char *path);
59 void (*SetColumnFilter) (struct TableFuncScanState *state,
60 const char *path, int colnum);
61 bool (*FetchRow) (struct TableFuncScanState *state);
62 Datum (*GetValue) (struct TableFuncScanState *state, int colnum,
63 Oid typid, int32 typmod, bool *isnull);
64 void (*DestroyOpaque) (struct TableFuncScanState *state);
65} TableFuncRoutine;
66
67#endif /* _TABLEFUNC_H */
68