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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:19:15 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:19:15 +0000
commit6eb9c5a5657d1fe77b55cc261450f3538d35a94d (patch)
tree657d8194422a5daccecfd42d654b8a245ef7b4c8 /src/include/executor/spi_priv.h
parentInitial commit. (diff)
downloadpostgresql-13-6eb9c5a5657d1fe77b55cc261450f3538d35a94d.tar.xz
postgresql-13-6eb9c5a5657d1fe77b55cc261450f3538d35a94d.zip
Adding upstream version 13.4.upstream/13.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/include/executor/spi_priv.h')
-rw-r--r--src/include/executor/spi_priv.h105
1 files changed, 105 insertions, 0 deletions
diff --git a/src/include/executor/spi_priv.h b/src/include/executor/spi_priv.h
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+/*-------------------------------------------------------------------------
+ *
+ * spi_priv.h
+ * Server Programming Interface private declarations
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/executor/spi_priv.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef SPI_PRIV_H
+#define SPI_PRIV_H
+
+#include "executor/spi.h"
+#include "utils/queryenvironment.h"
+
+
+#define _SPI_PLAN_MAGIC 569278163
+
+typedef struct
+{
+ /* current results */
+ uint64 processed; /* by Executor */
+ SPITupleTable *tuptable; /* tuptable currently being built */
+
+ /* subtransaction in which current Executor call was started */
+ SubTransactionId execSubid;
+
+ /* resources of this execution context */
+ slist_head tuptables; /* list of all live SPITupleTables */
+ MemoryContext procCxt; /* procedure context */
+ MemoryContext execCxt; /* executor context */
+ MemoryContext savedcxt; /* context of SPI_connect's caller */
+ SubTransactionId connectSubid; /* ID of connecting subtransaction */
+ QueryEnvironment *queryEnv; /* query environment setup for SPI level */
+
+ /* transaction management support */
+ bool atomic; /* atomic execution context, does not allow
+ * transactions */
+ bool internal_xact; /* SPI-managed transaction boundary, skip
+ * cleanup */
+
+ /* saved values of API global variables for previous nesting level */
+ uint64 outer_processed;
+ SPITupleTable *outer_tuptable;
+ int outer_result;
+} _SPI_connection;
+
+/*
+ * SPI plans have three states: saved, unsaved, or temporary.
+ *
+ * Ordinarily, the _SPI_plan struct itself as well as the argtypes array
+ * are in a dedicated memory context identified by plancxt (which can be
+ * really small). All the other subsidiary state is in plancache entries
+ * identified by plancache_list (note: the list cells themselves are in
+ * plancxt).
+ *
+ * In an unsaved plan, the plancxt as well as the plancache entries' contexts
+ * are children of the SPI procedure context, so they'll all disappear at
+ * function exit. plancache.c also knows that the plancache entries are
+ * "unsaved", so it doesn't link them into its global list; hence they do
+ * not respond to inval events. This is OK since we are presumably holding
+ * adequate locks to prevent other backends from messing with the tables.
+ *
+ * For a saved plan, the plancxt is made a child of CacheMemoryContext
+ * since it should persist until explicitly destroyed. Likewise, the
+ * plancache entries will be under CacheMemoryContext since we tell
+ * plancache.c to save them. We rely on plancache.c to keep the cache
+ * entries up-to-date as needed in the face of invalidation events.
+ *
+ * There are also "temporary" SPI plans, in which the _SPI_plan struct is
+ * not even palloc'd but just exists in some function's local variable.
+ * The plancache entries are unsaved and exist under the SPI executor context,
+ * while additional data such as argtypes and list cells is loose in the SPI
+ * executor context. Such plans can be identified by having plancxt == NULL.
+ *
+ * We can also have "one-shot" SPI plans (which are typically temporary,
+ * as described above). These are meant to be executed once and discarded,
+ * and various optimizations are made on the assumption of single use.
+ * Note in particular that the CachedPlanSources within such an SPI plan
+ * are not "complete" until execution.
+ *
+ * Note: if the original query string contained only whitespace and comments,
+ * the plancache_list will be NIL and so there is no place to store the
+ * query string. We don't care about that, but we do care about the
+ * argument type array, which is why it's seemingly-redundantly stored.
+ */
+typedef struct _SPI_plan
+{
+ int magic; /* should equal _SPI_PLAN_MAGIC */
+ bool saved; /* saved or unsaved plan? */
+ bool oneshot; /* one-shot plan? */
+ bool no_snapshots; /* allow nonatomic CALL/DO execution */
+ List *plancache_list; /* one CachedPlanSource per parsetree */
+ MemoryContext plancxt; /* Context containing _SPI_plan and data */
+ int cursor_options; /* Cursor options used for planning */
+ int nargs; /* number of plan arguments */
+ Oid *argtypes; /* Argument types (NULL if nargs is 0) */
+ ParserSetupHook parserSetup; /* alternative parameter spec method */
+ void *parserSetupArg;
+} _SPI_plan;
+
+#endif /* SPI_PRIV_H */