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-rw-r--r--src/backend/statistics/dependencies.c40
-rw-r--r--src/backend/statistics/mvdistinct.c37
-rw-r--r--src/include/statistics/statistics.h19
3 files changed, 56 insertions, 40 deletions
diff --git a/src/backend/statistics/dependencies.c b/src/backend/statistics/dependencies.c
index f11cced2936..0b26e4166d9 100644
--- a/src/backend/statistics/dependencies.c
+++ b/src/backend/statistics/dependencies.c
@@ -32,6 +32,20 @@
#include "utils/syscache.h"
#include "utils/typcache.h"
+/* size of the struct header fields (magic, type, ndeps) */
+#define SizeOfHeader (3 * sizeof(uint32))
+
+/* size of a serialized dependency (degree, natts, atts) */
+#define SizeOfItem(natts) \
+ (sizeof(double) + sizeof(AttrNumber) * (1 + (natts)))
+
+/* minimal size of a dependency (with two attributes) */
+#define MinSizeOfItem SizeOfItem(2)
+
+/* minimal size of dependencies, when all deps are minimal */
+#define MinSizeOfItems(ndeps) \
+ (SizeOfHeader + (ndeps) * MinSizeOfItem)
+
/*
* Internal state for DependencyGenerator of dependencies. Dependencies are similar to
* k-permutations of n elements, except that the order does not matter for the
@@ -408,7 +422,7 @@ statext_dependencies_build(int numrows, HeapTuple *rows, Bitmapset *attrs,
dependencies->ndeps++;
dependencies = (MVDependencies *) repalloc(dependencies,
offsetof(MVDependencies, deps)
- + dependencies->ndeps * sizeof(MVDependency));
+ + dependencies->ndeps * sizeof(MVDependency *));
dependencies->deps[dependencies->ndeps - 1] = d;
}
@@ -436,12 +450,11 @@ statext_dependencies_serialize(MVDependencies *dependencies)
Size len;
/* we need to store ndeps, with a number of attributes for each one */
- len = VARHDRSZ + SizeOfDependencies
- + dependencies->ndeps * SizeOfDependency;
+ len = VARHDRSZ + SizeOfHeader;
/* and also include space for the actual attribute numbers and degrees */
for (i = 0; i < dependencies->ndeps; i++)
- len += (sizeof(AttrNumber) * dependencies->deps[i]->nattributes);
+ len += SizeOfItem(dependencies->deps[i]->nattributes);
output = (bytea *) palloc0(len);
SET_VARSIZE(output, len);
@@ -461,15 +474,22 @@ statext_dependencies_serialize(MVDependencies *dependencies)
{
MVDependency *d = dependencies->deps[i];
- memcpy(tmp, d, SizeOfDependency);
- tmp += SizeOfDependency;
+ memcpy(tmp, &d->degree, sizeof(double));
+ tmp += sizeof(double);
+
+ memcpy(tmp, &d->nattributes, sizeof(AttrNumber));
+ tmp += sizeof(AttrNumber);
memcpy(tmp, d->attributes, sizeof(AttrNumber) * d->nattributes);
tmp += sizeof(AttrNumber) * d->nattributes;
+ /* protect against overflow */
Assert(tmp <= ((char *) output + len));
}
+ /* make sure we've produced exactly the right amount of data */
+ Assert(tmp == ((char *) output + len));
+
return output;
}
@@ -487,9 +507,9 @@ statext_dependencies_deserialize(bytea *data)
if (data == NULL)
return NULL;
- if (VARSIZE_ANY_EXHDR(data) < SizeOfDependencies)
+ if (VARSIZE_ANY_EXHDR(data) < SizeOfHeader)
elog(ERROR, "invalid MVDependencies size %zd (expected at least %zd)",
- VARSIZE_ANY_EXHDR(data), SizeOfDependencies);
+ VARSIZE_ANY_EXHDR(data), SizeOfHeader);
/* read the MVDependencies header */
dependencies = (MVDependencies *) palloc0(sizeof(MVDependencies));
@@ -519,9 +539,7 @@ statext_dependencies_deserialize(bytea *data)
errmsg("invalid zero-length item array in MVDependencies")));
/* what minimum bytea size do we expect for those parameters */
- min_expected_size = SizeOfDependencies +
- dependencies->ndeps * (SizeOfDependency +
- sizeof(AttrNumber) * 2);
+ min_expected_size = SizeOfItem(dependencies->ndeps);
if (VARSIZE_ANY_EXHDR(data) < min_expected_size)
elog(ERROR, "invalid dependencies size %zd (expected at least %zd)",
diff --git a/src/backend/statistics/mvdistinct.c b/src/backend/statistics/mvdistinct.c
index b477c18c46a..133503cb9b3 100644
--- a/src/backend/statistics/mvdistinct.c
+++ b/src/backend/statistics/mvdistinct.c
@@ -43,6 +43,20 @@ static double estimate_ndistinct(double totalrows, int numrows, int d, int f1);
static int n_choose_k(int n, int k);
static int num_combinations(int n);
+/* size of the struct header fields (magic, type, nitems) */
+#define SizeOfHeader (3 * sizeof(uint32))
+
+/* size of a serialized ndistinct item (coefficient, natts, atts) */
+#define SizeOfItem(natts) \
+ (sizeof(double) + sizeof(int) + (natts) * sizeof(AttrNumber))
+
+/* minimal size of a ndistinct item (with two attributes) */
+#define MinSizeOfItem SizeOfItem(2)
+
+/* minimal size of mvndistinct, when all items are minimal */
+#define MinSizeOfItems(nitems) \
+ (SizeOfHeader + (nitems) * MinSizeOfItem)
+
/* Combination generator API */
/* internal state for generator of k-combinations of n elements */
@@ -168,8 +182,7 @@ statext_ndistinct_serialize(MVNDistinct *ndistinct)
* Base size is size of scalar fields in the struct, plus one base struct
* for each item, including number of items for each.
*/
- len = VARHDRSZ + SizeOfMVNDistinct +
- ndistinct->nitems * (offsetof(MVNDistinctItem, attrs) + sizeof(int));
+ len = VARHDRSZ + SizeOfHeader;
/* and also include space for the actual attribute numbers */
for (i = 0; i < ndistinct->nitems; i++)
@@ -178,7 +191,8 @@ statext_ndistinct_serialize(MVNDistinct *ndistinct)
nmembers = bms_num_members(ndistinct->items[i].attrs);
Assert(nmembers >= 2);
- len += sizeof(AttrNumber) * nmembers;
+
+ len += SizeOfItem(nmembers);
}
output = (bytea *) palloc(len);
@@ -195,8 +209,7 @@ statext_ndistinct_serialize(MVNDistinct *ndistinct)
tmp += sizeof(uint32);
/*
- * store number of attributes and attribute numbers for each ndistinct
- * entry
+ * store number of attributes and attribute numbers for each entry
*/
for (i = 0; i < ndistinct->nitems; i++)
{
@@ -218,9 +231,13 @@ statext_ndistinct_serialize(MVNDistinct *ndistinct)
tmp += sizeof(AttrNumber);
}
+ /* protect against overflows */
Assert(tmp <= ((char *) output + len));
}
+ /* check we used exactly the expected space */
+ Assert(tmp == ((char *) output + len));
+
return output;
}
@@ -241,9 +258,9 @@ statext_ndistinct_deserialize(bytea *data)
return NULL;
/* we expect at least the basic fields of MVNDistinct struct */
- if (VARSIZE_ANY_EXHDR(data) < SizeOfMVNDistinct)
+ if (VARSIZE_ANY_EXHDR(data) < SizeOfHeader)
elog(ERROR, "invalid MVNDistinct size %zd (expected at least %zd)",
- VARSIZE_ANY_EXHDR(data), SizeOfMVNDistinct);
+ VARSIZE_ANY_EXHDR(data), SizeOfHeader);
/* initialize pointer to the data part (skip the varlena header) */
tmp = VARDATA_ANY(data);
@@ -272,9 +289,7 @@ statext_ndistinct_deserialize(bytea *data)
errmsg("invalid zero-length item array in MVNDistinct")));
/* what minimum bytea size do we expect for those parameters */
- minimum_size = (SizeOfMVNDistinct +
- ndist.nitems * (SizeOfMVNDistinctItem +
- sizeof(AttrNumber) * 2));
+ minimum_size = MinSizeOfItems(ndist.nitems);
if (VARSIZE_ANY_EXHDR(data) < minimum_size)
ereport(ERROR,
(errcode(ERRCODE_DATA_CORRUPTED),
@@ -285,7 +300,7 @@ statext_ndistinct_deserialize(bytea *data)
* Allocate space for the ndistinct items (no space for each item's
* attnos: those live in bitmapsets allocated separately)
*/
- ndistinct = palloc0(MAXALIGN(SizeOfMVNDistinct) +
+ ndistinct = palloc0(MAXALIGN(offsetof(MVNDistinct, items)) +
(ndist.nitems * sizeof(MVNDistinctItem)));
ndistinct->magic = ndist.magic;
ndistinct->type = ndist.type;
diff --git a/src/include/statistics/statistics.h b/src/include/statistics/statistics.h
index 6fafbbf11c0..69724cc1070 100644
--- a/src/include/statistics/statistics.h
+++ b/src/include/statistics/statistics.h
@@ -29,10 +29,6 @@ typedef struct MVNDistinctItem
Bitmapset *attrs; /* attr numbers of items */
} MVNDistinctItem;
-/* size of the struct, excluding attribute list */
-#define SizeOfMVNDistinctItem \
- (offsetof(MVNDistinctItem, ndistinct) + sizeof(double))
-
/* A MVNDistinct object, comprising all possible combinations of columns */
typedef struct MVNDistinct
{
@@ -42,13 +38,7 @@ typedef struct MVNDistinct
MVNDistinctItem items[FLEXIBLE_ARRAY_MEMBER];
} MVNDistinct;
-/* size of the struct excluding the items array */
-#define SizeOfMVNDistinct (offsetof(MVNDistinct, nitems) + sizeof(uint32))
-
-
-/* size of the struct excluding the items array */
-#define SizeOfMVNDistinct (offsetof(MVNDistinct, nitems) + sizeof(uint32))
-
+/* Multivariate functional dependencies */
#define STATS_DEPS_MAGIC 0xB4549A2C /* marks serialized bytea */
#define STATS_DEPS_TYPE_BASIC 1 /* basic dependencies type */
@@ -63,10 +53,6 @@ typedef struct MVDependency
AttrNumber attributes[FLEXIBLE_ARRAY_MEMBER]; /* attribute numbers */
} MVDependency;
-/* size of the struct excluding the deps array */
-#define SizeOfDependency \
- (offsetof(MVDependency, nattributes) + sizeof(AttrNumber))
-
typedef struct MVDependencies
{
uint32 magic; /* magic constant marker */
@@ -75,9 +61,6 @@ typedef struct MVDependencies
MVDependency *deps[FLEXIBLE_ARRAY_MEMBER]; /* dependencies */
} MVDependencies;
-/* size of the struct excluding the deps array */
-#define SizeOfDependencies (offsetof(MVDependencies, ndeps) + sizeof(uint32))
-
/* used to flag stats serialized to bytea */
#define STATS_MCV_MAGIC 0xE1A651C2 /* marks serialized bytea */
#define STATS_MCV_TYPE_BASIC 1 /* basic MCV list type */
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-31 07:12:57 +0000