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-rw-r--r--src/backend/libpq/portalbuf.c511
1 files changed, 511 insertions, 0 deletions
diff --git a/src/backend/libpq/portalbuf.c b/src/backend/libpq/portalbuf.c
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+++ b/src/backend/libpq/portalbuf.c
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+/*-------------------------------------------------------------------------
+ *
+ * portalbuf.c--
+ * portal buffer support routines for src/libpq/portal.c
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * $Header: /cvsroot/pgsql/src/backend/libpq/Attic/portalbuf.c,v 1.1.1.1 1996/07/09 06:21:30 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+/*
+ * INTERFACE ROUTINES
+ * pbuf_alloc - allocate memory for libpq routines
+ * pbuf_free - free memory for libpq routines
+ * pbuf_addPortal - Allocate a new portal buffer
+ * pbuf_addGroup - Add a new tuple group to the portal
+ * pbuf_addTypes - Allocate n type blocks
+ * pbuf_addTuples - Allocate a tuple block
+ * pbuf_addTuple - Allocate a tuple of n fields (attributes)
+ * pbuf_addValues - Allocate n bytes for a value
+ * pbuf_addEntry - Allocate a portal entry
+ * pbuf_freeEntry - Free a portal entry in the portal table
+ * pbuf_freeTypes - Free up the space used by a portal
+ * pbuf_freeTuples - free space used by tuple block
+ * pbuf_freeGroup - free space used by group, types and tuples
+ * pbuf_freePortal - free space used by portal and portal's group
+ * pbuf_getIndex - Return the index of the portal entry
+ * pbuf_setup - Set up a portal for dumping data
+ * pbuf_close - Close a portal, remove it from the portal table
+ * pbuf_findGroup - Return group given the group_index
+ * pbuf_findFnumber - Return field index of a given field within a group
+ * pbuf_findFname - Find the field name given the field index
+ * pbuf_checkFnumber - signal an error if field number is out of bounds
+ *
+ * NOTES
+ * These functions may be used by both frontend routines which
+ * communicate with a backend or by user-defined functions which
+ * are compiled or dynamically loaded into a backend.
+ *
+ * the portals[] array should be organized as a hash table for
+ * quick portal-by-name lookup.
+ *
+ * Do not confuse "PortalEntry" (or "PortalBuffer") with "Portal"
+ * see utils/mmgr/portalmem.c for why. -cim 2/22/91
+ *
+ */
+#include <sys/types.h>
+#include "c.h"
+
+#include "libpq/libpq.h" /* where the declarations go */
+#include "utils/exc.h"
+#include "utils/palloc.h"
+
+PortalEntry** portals = (PortalEntry**) NULL;
+size_t portals_array_size = 0;
+
+/* portals array memory is malloc'd instead of using MemoryContexts */
+/* since it will be used by both front and backend programs*/
+/* GlobalMemory portals_mmcxt = (GlobalMemory) NULL; */
+
+/* -------------------------------
+ * portals_realloc --
+ * grow the size of the portals array by size
+ *
+ * also ensures that elements are initially NULL
+ */
+
+static void
+portals_realloc(size_t size)
+{
+ size_t oldsize;
+ int i;
+ PortalEntry** newp;
+
+ oldsize = portals_array_size;
+
+ portals_array_size += size;
+ if (portals)
+ newp= (PortalEntry**)realloc(portals,
+ portals_array_size*sizeof(PortalEntry*));
+ else
+ newp= (PortalEntry**)malloc(portals_array_size*sizeof(PortalEntry*));
+
+ if (newp)
+ portals = newp;
+ else
+ libpq_raise(&PortalError,
+ form("Cannot alloc more memory in portals_realloc"));
+
+ for (i=oldsize;i<portals_array_size;i++)
+ portals[i]=(PortalEntry*)NULL;
+
+}
+
+/* --------------------------------
+ * pbuf_alloc - allocate memory for portal buffers
+ *
+ * remember: palloc() in the backend uses the postgres MemoryContext
+ * library and palloc() in the frontend (fe-pqstubs.c) calls malloc().
+ * --------------------------------
+ */
+caddr_t
+pbuf_alloc(size_t size)
+{
+ caddr_t addr;
+
+ if (size <= 0)
+ libpq_raise(&MemoryError, form("Invalid argument to pbuf_alloc()."));
+
+ addr = (caddr_t) palloc(size);
+ if (addr == (caddr_t) NULL)
+ libpq_raise(&MemoryError, form("Cannot Allocate space."));
+
+ return (addr);
+}
+
+/* --------------------------------
+ * pbuf_free - free memory for portal buffers
+ *
+ * remember: pfree() in the backend uses the postgres MemoryContext
+ * library and pfree() in the frontend (fe-pqstubs.c) calls free().
+ * --------------------------------
+ */
+void
+pbuf_free(caddr_t pointer)
+{
+ if (pointer)
+ pfree(pointer);
+ else
+ libpq_raise(&MemoryError, form("Tried to free NULL memory pointer"));
+
+}
+
+/* --------------------------------
+ * pbuf_addPortal - Allocate a new portal buffer
+ * --------------------------------
+ */
+PortalBuffer *
+pbuf_addPortal()
+{
+ PortalBuffer *portal;
+
+ portal = (PortalBuffer *)
+ pbuf_alloc(sizeof (PortalBuffer));
+
+ portal->rule_p = 0;
+ portal->no_tuples = 0;
+ portal->no_groups = 0;
+ portal->groups = NULL;
+
+ return (portal);
+}
+
+/* --------------------------------
+ * pbuf_addGroup - Add a new tuple group to the portal
+ * --------------------------------
+ */
+GroupBuffer *
+pbuf_addGroup(PortalBuffer *portal)
+{
+ GroupBuffer *group, *group1;
+
+ group = (GroupBuffer *)
+ pbuf_alloc(sizeof (GroupBuffer));
+
+ /* Initialize the new group buffer. */
+ group->no_tuples = 0;
+ group->no_fields = 0;
+ group->types = NULL;
+ group->tuples = NULL;
+ group->next = NULL;
+
+ if ((group1 = portal->groups) == NULL)
+ portal->groups = group;
+ else {
+ while (group1->next != NULL)
+ group1 = group1->next;
+ group1->next = group;
+ }
+
+ return (group);
+}
+
+/* --------------------------------
+ * pbuf_addTypes - Allocate n type blocks
+ * --------------------------------
+ */
+TypeBlock *
+pbuf_addTypes(int n)
+{
+ TypeBlock *types;
+
+ types = (TypeBlock *)
+ pbuf_alloc(n * sizeof (TypeBlock));
+
+ return (types);
+}
+
+/* --------------------------------
+ * pbuf_addTuples - Allocate a tuple block
+ * --------------------------------
+ */
+TupleBlock *
+pbuf_addTuples()
+{
+ TupleBlock *tuples;
+
+ tuples = (TupleBlock *)
+ pbuf_alloc(sizeof (TupleBlock));
+
+ tuples->next = NULL;
+ tuples->tuple_index = 0;
+
+ return (tuples);
+}
+
+/* --------------------------------
+ * pbuf_addTuple - Allocate a tuple of n fields (attributes)
+ * --------------------------------
+ */
+char **
+pbuf_addTuple(int n)
+{
+ return (char **)
+ pbuf_alloc(n * sizeof (char *));
+}
+
+/* --------------------------------
+ * pbuf_addTupleValueLengths - Allocate a tuple of n lengths (attributes)
+ * --------------------------------
+ */
+int *
+pbuf_addTupleValueLengths(int n)
+{
+ return (int *)
+ pbuf_alloc(n * sizeof(int));
+}
+
+/* --------------------------------
+ * pbuf_addValues - Allocate n bytes for a value
+ * --------------------------------
+ */
+char *
+pbuf_addValues(int n)
+{
+ return
+ pbuf_alloc(n);
+}
+
+/* --------------------------------
+ * pbuf_addEntry - Allocate a portal entry
+ * --------------------------------
+ */
+PortalEntry *pbuf_addEntry()
+{
+ return (PortalEntry *)
+ pbuf_alloc (sizeof (PortalEntry));
+}
+
+/* --------------------------------
+ * pbuf_freeEntry - Free a portal entry in the portal table
+ * the portal is freed separately.
+ * --------------------------------
+ */
+void
+pbuf_freeEntry(int i)
+{
+ if (portals)
+ {
+ pbuf_free ((caddr_t)portals[i]);
+ portals[i] = NULL;
+ }
+}
+
+
+/* --------------------------------
+ * pbuf_freeTypes - Free up the space used by a portal
+ * --------------------------------
+ */
+void
+pbuf_freeTypes(TypeBlock *types)
+{
+ pbuf_free((caddr_t)types);
+}
+
+/* --------------------------------
+ * pbuf_freeTuples - free space used by tuple block
+ * --------------------------------
+ */
+void
+pbuf_freeTuples(TupleBlock *tuples,
+ int no_tuples,
+ int no_fields)
+{
+ int i, j;
+
+ if (no_tuples > TupleBlockSize) {
+ pbuf_freeTuples (tuples->next, no_tuples - TupleBlockSize, no_fields);
+ no_tuples = TupleBlockSize;
+ }
+
+ /* For each tuple, free all its attribute values. */
+ for (i = 0; i < no_tuples; i++) {
+ for (j = 0; j < no_fields; j++)
+ if (tuples->values[i][j] != NULL)
+ pbuf_free((caddr_t)tuples->values[i][j]);
+ if (tuples->lengths[i])
+ pbuf_free((caddr_t)tuples->lengths[i]);
+ if (tuples->values[i])
+ pbuf_free((caddr_t)tuples->values[i]);
+ }
+
+ pbuf_free((caddr_t)tuples);
+}
+
+/* --------------------------------
+ * pbuf_freeGroup - free space used by group, types and tuples
+ * --------------------------------
+ */
+void
+pbuf_freeGroup(GroupBuffer *group)
+{
+ if (group->next != NULL)
+ pbuf_freeGroup(group->next);
+
+ if (group->types != NULL)
+ pbuf_freeTypes(group->types);
+
+ if (group->tuples != NULL)
+ pbuf_freeTuples(group->tuples, group->no_tuples,group->no_fields);
+
+ pbuf_free((caddr_t)group);
+}
+
+/* --------------------------------
+ * pbuf_freePortal - free space used by portal and portal's group
+ * --------------------------------
+ */
+void
+pbuf_freePortal(PortalBuffer *portal)
+{
+ if (portal->groups != NULL)
+ pbuf_freeGroup(portal->groups);
+
+ pbuf_free((caddr_t)portal);
+}
+
+/* --------------------------------
+ * pbuf_getIndex - Return the index of the portal entry
+ * note: portals[] maps portal names to portal buffers.
+ * --------------------------------
+ */
+int
+pbuf_getIndex(char *pname)
+{
+ int i;
+
+ if (portals) {
+ for (i = 0; i < portals_array_size; i++)
+ if (portals[i] != NULL &&
+ strncmp(portals[i]->name, pname, PortalNameLength) == 0)
+ return i;
+ }
+
+ return (-1);
+}
+
+/* --------------------------------
+ * pbuf_setportalname - assign a user given name to a portal
+ * --------------------------------
+ */
+void
+pbuf_setportalinfo(PortalEntry *entry, char *pname)
+{
+ if (entry)
+ strncpy(entry->name, pname, PortalNameLength-1);
+ entry->name[PortalNameLength-1] = '\0';
+}
+
+/* --------------------------------
+ * pbuf_setup - Set up a portal for dumping data
+ * --------------------------------
+ */
+PortalEntry *
+pbuf_setup(char *pname)
+{
+ int i;
+
+ if (!portals) /* the portals array has not been allocated yet */
+ {
+ /* allocate portals[] array here */
+ portals_realloc(PORTALS_INITIAL_SIZE);
+ }
+
+ /* If a portal with the same name already exists, close it. */
+ /* else look for an empty entry in the portal table. */
+ if ((i = pbuf_getIndex(pname)) != -1)
+ pbuf_freePortal(portals[i]->portal);
+ else {
+ for (i = 0; i < portals_array_size; i++)
+ if (portals[i] == NULL)
+ break;
+
+ /* If the portal table is full, enlarge it */
+ if (i >= portals_array_size)
+ portals_realloc(PORTALS_GROW_BY);
+
+ portals[i] = pbuf_addEntry();
+ strncpy(portals[i]->name, pname, PortalNameLength);
+ }
+ portals[i]->portal = pbuf_addPortal();
+ portals[i]->portalcxt = NULL;
+ portals[i]->result = NULL;
+
+ return portals[i];
+}
+
+/* --------------------------------
+ * pbuf_close - Close a portal, remove it from the portal table
+ * and free up the space
+ * --------------------------------
+ */
+void
+pbuf_close(char *pname)
+{
+ int i;
+
+ if ((i = pbuf_getIndex(pname)) == -1)
+ libpq_raise(&PortalError, form("Portal %s does not exist.", pname));
+
+ pbuf_freePortal(portals[i]->portal);
+ pbuf_freeEntry(i);
+}
+
+/* --------------------------------
+ * pbuf_findGroup - Return the group given the group_index
+ * --------------------------------
+ */
+GroupBuffer *
+pbuf_findGroup(PortalBuffer *portal,
+ int group_index)
+{
+ GroupBuffer *group;
+
+ group = portal->groups;
+ while (group_index > 0 && group != NULL) {
+ group = group->next;
+ group_index--;
+ }
+
+ if (group == NULL)
+ libpq_raise(&PortalError,
+ form("Group index %d out of bound.", group_index));
+
+ return (group);
+}
+
+/* --------------------------------
+ * pbuf_findFnumber - Return the field index of a given field within a group
+ * --------------------------------
+ */
+int
+pbuf_findFnumber(GroupBuffer *group,
+ char *field_name)
+{
+ TypeBlock *types;
+ int i;
+
+ types = group->types;
+
+ for (i = 0; i < group->no_fields; i++)
+ if (strncmp(types[i].name, field_name, NAMEDATALEN) == 0)
+ return (i);
+
+ libpq_raise(&PortalError,
+ form("Field-name %s does not exist.", field_name));
+
+ /* not reached, here to make compiler happy */
+ return 0;
+
+}
+
+/* --------------------------------
+ * pbuf_checkFnumber - signal an error if field number is out of bounds
+ * --------------------------------
+ */
+void
+pbuf_checkFnumber(GroupBuffer *group,
+ int field_number)
+{
+ if (field_number < 0 || field_number >= group->no_fields)
+ libpq_raise(&PortalError,
+ form("Field number %d out of bound.", field_number));
+}
+
+/* --------------------------------
+ * pbuf_findFname - Find the field name given the field index
+ * --------------------------------
+ */
+char *
+pbuf_findFname(GroupBuffer *group,
+ int field_number)
+{
+ pbuf_checkFnumber(group, field_number);
+ return
+ (group->types[field_number]).name;
+}
+
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