summaryrefslogtreecommitdiffstats
path: root/src/include/nodes/extensible.h
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
commit46651ce6fe013220ed397add242004d764fc0153 (patch)
tree6e5299f990f88e60174a1d3ae6e48eedd2688b2b /src/include/nodes/extensible.h
parentInitial commit. (diff)
downloadpostgresql-14-46651ce6fe013220ed397add242004d764fc0153.tar.xz
postgresql-14-46651ce6fe013220ed397add242004d764fc0153.zip
Adding upstream version 14.5.upstream/14.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/include/nodes/extensible.h')
-rw-r--r--src/include/nodes/extensible.h160
1 files changed, 160 insertions, 0 deletions
diff --git a/src/include/nodes/extensible.h b/src/include/nodes/extensible.h
new file mode 100644
index 0000000..9e425e5
--- /dev/null
+++ b/src/include/nodes/extensible.h
@@ -0,0 +1,160 @@
+/*-------------------------------------------------------------------------
+ *
+ * extensible.h
+ * Definitions for extensible nodes and custom scans
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/nodes/extensible.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef EXTENSIBLE_H
+#define EXTENSIBLE_H
+
+#include "access/parallel.h"
+#include "commands/explain.h"
+#include "nodes/execnodes.h"
+#include "nodes/pathnodes.h"
+#include "nodes/plannodes.h"
+
+/* maximum length of an extensible node identifier */
+#define EXTNODENAME_MAX_LEN 64
+
+/*
+ * An extensible node is a new type of node defined by an extension. The
+ * type is always T_ExtensibleNode, while the extnodename identifies the
+ * specific type of node. extnodename can be looked up to find the
+ * ExtensibleNodeMethods for this node type.
+ */
+typedef struct ExtensibleNode
+{
+ NodeTag type;
+ const char *extnodename; /* identifier of ExtensibleNodeMethods */
+} ExtensibleNode;
+
+/*
+ * node_size is the size of an extensible node of this type in bytes.
+ *
+ * nodeCopy is a function which performs a deep copy from oldnode to newnode.
+ * It does not need to copy type or extnodename, which are copied by the
+ * core system.
+ *
+ * nodeEqual is a function which performs a deep equality comparison between
+ * a and b and returns true or false accordingly. It does not need to compare
+ * type or extnodename, which are compared by the core system.
+ *
+ * nodeOut is a serialization function for the node type. It should use the
+ * output conventions typical for outfuncs.c. It does not need to output
+ * type or extnodename; the core system handles those.
+ *
+ * nodeRead is a deserialization function for the node type. It does not need
+ * to read type or extnodename; the core system handles those. It should fetch
+ * the next token using pg_strtok() from the current input stream, and then
+ * reconstruct the private fields according to the manner in readfuncs.c.
+ *
+ * All callbacks are mandatory.
+ */
+typedef struct ExtensibleNodeMethods
+{
+ const char *extnodename;
+ Size node_size;
+ void (*nodeCopy) (struct ExtensibleNode *newnode,
+ const struct ExtensibleNode *oldnode);
+ bool (*nodeEqual) (const struct ExtensibleNode *a,
+ const struct ExtensibleNode *b);
+ void (*nodeOut) (struct StringInfoData *str,
+ const struct ExtensibleNode *node);
+ void (*nodeRead) (struct ExtensibleNode *node);
+} ExtensibleNodeMethods;
+
+extern void RegisterExtensibleNodeMethods(const ExtensibleNodeMethods *method);
+extern const ExtensibleNodeMethods *GetExtensibleNodeMethods(const char *name,
+ bool missing_ok);
+
+/*
+ * Flags for custom paths, indicating what capabilities the resulting scan
+ * will have.
+ */
+#define CUSTOMPATH_SUPPORT_BACKWARD_SCAN 0x0001
+#define CUSTOMPATH_SUPPORT_MARK_RESTORE 0x0002
+
+/*
+ * Custom path methods. Mostly, we just need to know how to convert a
+ * CustomPath to a plan.
+ */
+typedef struct CustomPathMethods
+{
+ const char *CustomName;
+
+ /* Convert Path to a Plan */
+ struct Plan *(*PlanCustomPath) (PlannerInfo *root,
+ RelOptInfo *rel,
+ struct CustomPath *best_path,
+ List *tlist,
+ List *clauses,
+ List *custom_plans);
+ struct List *(*ReparameterizeCustomPathByChild) (PlannerInfo *root,
+ List *custom_private,
+ RelOptInfo *child_rel);
+} CustomPathMethods;
+
+/*
+ * Custom scan. Here again, there's not much to do: we need to be able to
+ * generate a ScanState corresponding to the scan.
+ */
+typedef struct CustomScanMethods
+{
+ const char *CustomName;
+
+ /* Create execution state (CustomScanState) from a CustomScan plan node */
+ Node *(*CreateCustomScanState) (CustomScan *cscan);
+} CustomScanMethods;
+
+/*
+ * Execution-time methods for a CustomScanState. This is more complex than
+ * what we need for a custom path or scan.
+ */
+typedef struct CustomExecMethods
+{
+ const char *CustomName;
+
+ /* Required executor methods */
+ void (*BeginCustomScan) (CustomScanState *node,
+ EState *estate,
+ int eflags);
+ TupleTableSlot *(*ExecCustomScan) (CustomScanState *node);
+ void (*EndCustomScan) (CustomScanState *node);
+ void (*ReScanCustomScan) (CustomScanState *node);
+
+ /* Optional methods: needed if mark/restore is supported */
+ void (*MarkPosCustomScan) (CustomScanState *node);
+ void (*RestrPosCustomScan) (CustomScanState *node);
+
+ /* Optional methods: needed if parallel execution is supported */
+ Size (*EstimateDSMCustomScan) (CustomScanState *node,
+ ParallelContext *pcxt);
+ void (*InitializeDSMCustomScan) (CustomScanState *node,
+ ParallelContext *pcxt,
+ void *coordinate);
+ void (*ReInitializeDSMCustomScan) (CustomScanState *node,
+ ParallelContext *pcxt,
+ void *coordinate);
+ void (*InitializeWorkerCustomScan) (CustomScanState *node,
+ shm_toc *toc,
+ void *coordinate);
+ void (*ShutdownCustomScan) (CustomScanState *node);
+
+ /* Optional: print additional information in EXPLAIN */
+ void (*ExplainCustomScan) (CustomScanState *node,
+ List *ancestors,
+ ExplainState *es);
+} CustomExecMethods;
+
+extern void RegisterCustomScanMethods(const CustomScanMethods *methods);
+extern const CustomScanMethods *GetCustomScanMethods(const char *CustomName,
+ bool missing_ok);
+
+#endif /* EXTENSIBLE_H */