init

2026-04-07 13:35:22 +08:00
commit 0120fa9ce3
1530 changed files with 424864 additions and 0 deletions
--- a/pg_include/foreign/fdwapi.h
+++ b/pg_include/foreign/fdwapi.h
@@ -0,0 +1,100 @@
+/*-------------------------------------------------------------------------
+ *
+ * fdwapi.h
+ *	  API for foreign-data wrappers
+ *
+ * Copyright (c) 2010-2012, PostgreSQL Global Development Group
+ *
+ * src/include/foreign/fdwapi.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FDWAPI_H
+#define FDWAPI_H
+
+#include "nodes/execnodes.h"
+#include "nodes/relation.h"
+
+/* To avoid including explain.h here, reference ExplainState thus: */
+struct ExplainState;
+
+
+/*
+ * Callback function signatures --- see fdwhandler.sgml for more info.
+ */
+
+typedef void (*GetForeignRelSize_function) (PlannerInfo *root,
+														RelOptInfo *baserel,
+														Oid foreigntableid);
+
+typedef void (*GetForeignPaths_function) (PlannerInfo *root,
+													  RelOptInfo *baserel,
+													  Oid foreigntableid);
+
+typedef ForeignScan *(*GetForeignPlan_function) (PlannerInfo *root,
+														 RelOptInfo *baserel,
+														  Oid foreigntableid,
+													  ForeignPath *best_path,
+															 List *tlist,
+														 List *scan_clauses);
+
+typedef void (*ExplainForeignScan_function) (ForeignScanState *node,
+													struct ExplainState *es);
+
+typedef void (*BeginForeignScan_function) (ForeignScanState *node,
+													   int eflags);
+
+typedef TupleTableSlot *(*IterateForeignScan_function) (ForeignScanState *node);
+
+typedef void (*ReScanForeignScan_function) (ForeignScanState *node);
+
+typedef void (*EndForeignScan_function) (ForeignScanState *node);
+
+typedef int (*AcquireSampleRowsFunc) (Relation relation, int elevel,
+											   HeapTuple *rows, int targrows,
+												  double *totalrows,
+												  double *totaldeadrows);
+
+typedef bool (*AnalyzeForeignTable_function) (Relation relation,
+												 AcquireSampleRowsFunc *func,
+													BlockNumber *totalpages);
+
+/*
+ * FdwRoutine is the struct returned by a foreign-data wrapper's handler
+ * function.  It provides pointers to the callback functions needed by the
+ * planner and executor.
+ *
+ * More function pointers are likely to be added in the future.  Therefore
+ * it's recommended that the handler initialize the struct with
+ * makeNode(FdwRoutine) so that all fields are set to NULL.  This will
+ * ensure that no fields are accidentally left undefined.
+ */
+typedef struct FdwRoutine
+{
+	NodeTag		type;
+
+	/*
+	 * These functions are required.
+	 */
+	GetForeignRelSize_function GetForeignRelSize;
+	GetForeignPaths_function GetForeignPaths;
+	GetForeignPlan_function GetForeignPlan;
+	ExplainForeignScan_function ExplainForeignScan;
+	BeginForeignScan_function BeginForeignScan;
+	IterateForeignScan_function IterateForeignScan;
+	ReScanForeignScan_function ReScanForeignScan;
+	EndForeignScan_function EndForeignScan;
+
+	/*
+	 * These functions are optional.  Set the pointer to NULL for any that are
+	 * not provided.
+	 */
+	AnalyzeForeignTable_function AnalyzeForeignTable;
+} FdwRoutine;
+
+
+/* Functions in foreign/foreign.c */
+extern FdwRoutine *GetFdwRoutine(Oid fdwhandler);
+extern FdwRoutine *GetFdwRoutineByRelId(Oid relid);
+
+#endif   /* FDWAPI_H */