/*
* The SP-GiST query consistency check for leaf tuples
*/
Datum
inet_spg_leaf_consistent(PG_FUNCTION_ARGS)
{
spgLeafConsistentIn *in = (spgLeafConsistentIn *) PG_GETARG_POINTER(0);
spgLeafConsistentOut *out = (spgLeafConsistentOut *) PG_GETARG_POINTER(1);
inet *leaf = DatumGetInetPP(in->leafDatum);
/* All tests are exact. */
out->recheck = false;
/* Leaf is what it is... */
out->leafValue = InetPGetDatum(leaf);
/* Use common code to apply the tests. */
PG_RETURN_BOOL(inet_spg_consistent_bitmap(leaf, in->nkeys, in->scankeys,
true));
}
/*
* Inet histogram vs single value selectivity estimation
*
* Estimate the fraction of the histogram population that satisfies
* "value OPR CONST". (The result needs to be scaled to reflect the
* proportion of the total population represented by the histogram.)
*
* The histogram is originally for the inet btree comparison operators.
* Only the common bits of the network part and the length of the network part
* (masklen) are interesting for the subnet inclusion operators. Fortunately,
* btree comparison treats the network part as the major sort key. Even so,
* the length of the network part would not really be significant in the
* histogram. This would lead to big mistakes for data sets with uneven
* masklen distribution. To reduce this problem, comparisons with the left
* and the right sides of the buckets are used together.
*
* Histogram bucket matches are calculated in two forms. If the constant
* matches both bucket endpoints the bucket is considered as fully matched.
* The second form is to match the bucket partially; we recognize this when
* the constant matches just one endpoint, or the two endpoints fall on
* opposite sides of the constant. (Note that when the constant matches an
* interior histogram element, it gets credit for partial matches to the
* buckets on both sides, while a match to a histogram endpoint gets credit
* for only one partial match. This is desirable.)
*
* The divider in the partial bucket match is imagined as the distance
* between the decisive bits and the common bits of the addresses. It will
* be used as a power of two as it is the natural scale for the IP network
* inclusion. This partial bucket match divider calculation is an empirical
* formula and subject to change with more experiment.
*
* For a partial match, we try to calculate dividers for both of the
* boundaries. If the address family of a boundary value does not match the
* constant or comparison of the length of the network parts is not correct
* for the operator, the divider for that boundary will not be taken into
* account. If both of the dividers are valid, the greater one will be used
* to minimize the mistake in buckets that have disparate masklens. This
* calculation is unfair when dividers can be calculated for both of the
* boundaries but they are far from each other; but it is not a common
* situation as the boundaries are expected to share most of their significant
* bits of their masklens. The mistake would be greater, if we would use the
* minimum instead of the maximum, and we don't know a sensible way to combine
* them.
*
* For partial match in buckets that have different address families on the
* left and right sides, only the boundary with the same address family is
* taken into consideration. This can cause more mistakes for these buckets
* if the masklens of their boundaries are also disparate. But this can only
* happen in one bucket, since only two address families exist. It seems a
* better option than not considering these buckets at all.
*/
static Selectivity
inet_hist_value_sel(Datum *values, int nvalues, Datum constvalue,
int opr_codenum)
{
Selectivity match = 0.0;
inet *query,
*left,
*right;
int i,
k,
n;
int left_order,
right_order,
left_divider,
right_divider;
/* guard against zero-divide below */
if (nvalues <= 1)
return 0.0;
/* if there are too many histogram elements, decimate to limit runtime */
k = (nvalues - 2) / MAX_CONSIDERED_ELEMS + 1;
query = DatumGetInetPP(constvalue);
/* "left" is the left boundary value of the current bucket ... */
left = DatumGetInetPP(values[0]);
left_order = inet_inclusion_cmp(left, query, opr_codenum);
n = 0;
for (i = k; i < nvalues; i += k)
{
/* ... and "right" is the right boundary value */
right = DatumGetInetPP(values[i]);
right_order = inet_inclusion_cmp(right, query, opr_codenum);
if (left_order == 0 && right_order == 0)
{
/* The whole bucket matches, since both endpoints do. */
match += 1.0;
}
else if ((left_order <= 0 && right_order >= 0) ||
(left_order >= 0 && right_order <= 0))
{
/* Partial bucket match. */
left_divider = inet_hist_match_divider(left, query, opr_codenum);
right_divider = inet_hist_match_divider(right, query, opr_codenum);
if (left_divider >= 0 || right_divider >= 0)
match += 1.0 / pow(2.0, Max(left_divider, right_divider));
}
/* Shift the variables. */
left = right;
left_order = right_order;
/* Count the number of buckets considered. */
n++;
}
return match / n;
}
/*
* The SP-GiST choose function
*/
Datum
inet_spg_choose(PG_FUNCTION_ARGS)
{
spgChooseIn *in = (spgChooseIn *) PG_GETARG_POINTER(0);
spgChooseOut *out = (spgChooseOut *) PG_GETARG_POINTER(1);
inet *val = DatumGetInetPP(in->datum),
*prefix;
int commonbits;
/*
* If we're looking at a tuple that splits by address family, choose the
* appropriate subnode.
*/
if (!in->hasPrefix)
{
/* allTheSame isn't possible for such a tuple */
Assert(!in->allTheSame);
Assert(in->nNodes == 2);
out->resultType = spgMatchNode;
out->result.matchNode.nodeN = (ip_family(val) == PGSQL_AF_INET) ? 0 : 1;
out->result.matchNode.restDatum = InetPGetDatum(val);
PG_RETURN_VOID();
}
/* Else it must split by prefix */
Assert(in->nNodes == 4 || in->allTheSame);
prefix = DatumGetInetPP(in->prefixDatum);
commonbits = ip_bits(prefix);
/*
* We cannot put addresses from different families under the same inner
* node, so we have to split if the new value's family is different.
*/
if (ip_family(val) != ip_family(prefix))
{
/* Set up 2-node tuple */
out->resultType = spgSplitTuple;
out->result.splitTuple.prefixHasPrefix = false;
out->result.splitTuple.prefixNNodes = 2;
out->result.splitTuple.prefixNodeLabels = NULL;
/* Identify which node the existing data goes into */
out->result.splitTuple.childNodeN =
(ip_family(prefix) == PGSQL_AF_INET) ? 0 : 1;
out->result.splitTuple.postfixHasPrefix = true;
out->result.splitTuple.postfixPrefixDatum = InetPGetDatum(prefix);
PG_RETURN_VOID();
}
/*
* If the new value does not match the existing prefix, we have to split.
*/
if (ip_bits(val) < commonbits ||
bitncmp(ip_addr(prefix), ip_addr(val), commonbits) != 0)
{
/* Determine new prefix length for the split tuple */
commonbits = bitncommon(ip_addr(prefix), ip_addr(val),
Min(ip_bits(val), commonbits));
/* Set up 4-node tuple */
out->resultType = spgSplitTuple;
out->result.splitTuple.prefixHasPrefix = true;
out->result.splitTuple.prefixPrefixDatum =
InetPGetDatum(cidr_set_masklen_internal(val, commonbits));
out->result.splitTuple.prefixNNodes = 4;
out->result.splitTuple.prefixNodeLabels = NULL;
/* Identify which node the existing data goes into */
out->result.splitTuple.childNodeN =
inet_spg_node_number(prefix, commonbits);
out->result.splitTuple.postfixHasPrefix = true;
out->result.splitTuple.postfixPrefixDatum = InetPGetDatum(prefix);
PG_RETURN_VOID();
}
/*
* All OK, choose the node to descend into. (If this tuple is marked
* allTheSame, the core code will ignore our choice of nodeN; but we need
* not account for that case explicitly here.)
*/
out->resultType = spgMatchNode;
out->result.matchNode.nodeN = inet_spg_node_number(val, commonbits);
out->result.matchNode.restDatum = InetPGetDatum(val);
PG_RETURN_VOID();
}
/*
* Calculate bitmap of node numbers that are consistent with the query
*
* This can be used either at a 4-way inner tuple, or at a leaf tuple.
* In the latter case, we should return a boolean result (0 or 1)
* not a bitmap.
*
* This definition is pretty odd, but the inner and leaf consistency checks
* are mostly common and it seems best to keep them in one function.
*/
static int
inet_spg_consistent_bitmap(const inet *prefix, int nkeys, ScanKey scankeys,
bool leaf)
{
int bitmap;
int commonbits,
i;
/* Initialize result to allow visiting all children */
if (leaf)
bitmap = 1;
else
bitmap = 1 | (1 << 1) | (1 << 2) | (1 << 3);
commonbits = ip_bits(prefix);
for (i = 0; i < nkeys; i++)
{
inet *argument = DatumGetInetPP(scankeys[i].sk_argument);
StrategyNumber strategy = scankeys[i].sk_strategy;
int order;
/*
* Check 0: different families
*
* Matching families do not help any of the strategies.
*/
if (ip_family(argument) != ip_family(prefix))
{
switch (strategy)
{
case RTLessStrategyNumber:
case RTLessEqualStrategyNumber:
if (ip_family(argument) < ip_family(prefix))
bitmap = 0;
break;
case RTGreaterEqualStrategyNumber:
case RTGreaterStrategyNumber:
if (ip_family(argument) > ip_family(prefix))
bitmap = 0;
break;
case RTNotEqualStrategyNumber:
break;
default:
/* For all other cases, we can be sure there is no match */
bitmap = 0;
break;
}
if (!bitmap)
break;
/* Other checks make no sense with different families. */
continue;
}
/*
* Check 1: network bit count
*
* Network bit count (ip_bits) helps to check leaves for sub network
* and sup network operators. At non-leaf nodes, we know every child
* value has greater ip_bits, so we can avoid descending in some cases
* too.
*
* This check is less expensive than checking the address bits, so we
* are doing this before, but it has to be done after for the basic
* comparison strategies, because ip_bits only affect their results
* when the common network bits are the same.
*/
switch (strategy)
{
case RTSubStrategyNumber:
if (commonbits <= ip_bits(argument))
bitmap &= (1 << 2) | (1 << 3);
break;
case RTSubEqualStrategyNumber:
if (commonbits < ip_bits(argument))
bitmap &= (1 << 2) | (1 << 3);
break;
case RTSuperStrategyNumber:
if (commonbits == ip_bits(argument) - 1)
bitmap &= 1 | (1 << 1);
else if (commonbits >= ip_bits(argument))
bitmap = 0;
break;
case RTSuperEqualStrategyNumber:
if (commonbits == ip_bits(argument))
bitmap &= 1 | (1 << 1);
else if (commonbits > ip_bits(argument))
bitmap = 0;
break;
case RTEqualStrategyNumber:
if (commonbits < ip_bits(argument))
bitmap &= (1 << 2) | (1 << 3);
else if (commonbits == ip_bits(argument))
bitmap &= 1 | (1 << 1);
else
bitmap = 0;
break;
}
if (!bitmap)
break;
/*
* Check 2: common network bits
*
* Compare available common prefix bits to the query, but not beyond
* either the query's netmask or the minimum netmask among the
* represented values. If these bits don't match the query, we can
* eliminate some cases.
*/
order = bitncmp(ip_addr(prefix), ip_addr(argument),
Min(commonbits, ip_bits(argument)));
if (order != 0)
{
switch (strategy)
{
case RTLessStrategyNumber:
case RTLessEqualStrategyNumber:
if (order > 0)
bitmap = 0;
break;
case RTGreaterEqualStrategyNumber:
case RTGreaterStrategyNumber:
if (order < 0)
bitmap = 0;
break;
case RTNotEqualStrategyNumber:
break;
default:
/* For all other cases, we can be sure there is no match */
bitmap = 0;
break;
}
if (!bitmap)
break;
/*
* Remaining checks make no sense when common bits don't match.
*/
continue;
}
/*
* Check 3: next network bit
*
* We can filter out branch 2 or 3 using the next network bit of the
* argument, if it is available.
*
* This check matters for the performance of the search. The results
* would be correct without it.
*/
if (bitmap & ((1 << 2) | (1 << 3)) &&
commonbits < ip_bits(argument))
{
int nextbit;
nextbit = ip_addr(argument)[commonbits / 8] &
(1 << (7 - commonbits % 8));
switch (strategy)
{
case RTLessStrategyNumber:
case RTLessEqualStrategyNumber:
if (!nextbit)
bitmap &= 1 | (1 << 1) | (1 << 2);
break;
case RTGreaterEqualStrategyNumber:
case RTGreaterStrategyNumber:
if (nextbit)
bitmap &= 1 | (1 << 1) | (1 << 3);
break;
case RTNotEqualStrategyNumber:
break;
default:
if (!nextbit)
bitmap &= 1 | (1 << 1) | (1 << 2);
else
bitmap &= 1 | (1 << 1) | (1 << 3);
break;
}
if (!bitmap)
break;
}
/*
* Remaining checks are only for the basic comparison strategies. This
* test relies on the strategy number ordering defined in stratnum.h.
*/
if (strategy < RTEqualStrategyNumber ||
strategy > RTGreaterEqualStrategyNumber)
continue;
/*
* Check 4: network bit count
*
* At this point, we know that the common network bits of the prefix
* and the argument are the same, so we can go forward and check the
* ip_bits.
*/
switch (strategy)
{
case RTLessStrategyNumber:
case RTLessEqualStrategyNumber:
if (commonbits == ip_bits(argument))
bitmap &= 1 | (1 << 1);
else if (commonbits > ip_bits(argument))
bitmap = 0;
break;
case RTGreaterEqualStrategyNumber:
case RTGreaterStrategyNumber:
if (commonbits < ip_bits(argument))
bitmap &= (1 << 2) | (1 << 3);
break;
}
if (!bitmap)
break;
/* Remaining checks don't make sense with different ip_bits. */
if (commonbits != ip_bits(argument))
continue;
/*
* Check 5: next host bit
*
* We can filter out branch 0 or 1 using the next host bit of the
* argument, if it is available.
*
* This check matters for the performance of the search. The results
* would be correct without it. There is no point in running it for
* leafs as we have to check the whole address on the next step.
*/
if (!leaf && bitmap & (1 | (1 << 1)) &&
commonbits < ip_maxbits(argument))
{
int nextbit;
nextbit = ip_addr(argument)[commonbits / 8] &
(1 << (7 - commonbits % 8));
switch (strategy)
{
case RTLessStrategyNumber:
case RTLessEqualStrategyNumber:
if (!nextbit)
bitmap &= 1 | (1 << 2) | (1 << 3);
break;
case RTGreaterEqualStrategyNumber:
case RTGreaterStrategyNumber:
if (nextbit)
bitmap &= (1 << 1) | (1 << 2) | (1 << 3);
break;
case RTNotEqualStrategyNumber:
break;
default:
if (!nextbit)
bitmap &= 1 | (1 << 2) | (1 << 3);
else
bitmap &= (1 << 1) | (1 << 2) | (1 << 3);
break;
}
if (!bitmap)
break;
}
/*
* Check 6: whole address
*
* This is the last check for correctness of the basic comparison
* strategies. It's only appropriate at leaf entries.
*/
if (leaf)
{
/* Redo ordering comparison using all address bits */
order = bitncmp(ip_addr(prefix), ip_addr(argument),
ip_maxbits(prefix));
switch (strategy)
{
case RTLessStrategyNumber:
if (order >= 0)
bitmap = 0;
break;
case RTLessEqualStrategyNumber:
if (order > 0)
bitmap = 0;
break;
case RTEqualStrategyNumber:
if (order != 0)
bitmap = 0;
break;
case RTGreaterEqualStrategyNumber:
if (order < 0)
bitmap = 0;
break;
case RTGreaterStrategyNumber:
if (order <= 0)
bitmap = 0;
break;
case RTNotEqualStrategyNumber:
if (order == 0)
bitmap = 0;
break;
}
if (!bitmap)
break;
}
}
return bitmap;
}
/*
* The SP-GiST query consistency check for inner tuples
*/
Datum
inet_spg_inner_consistent(PG_FUNCTION_ARGS)
{
spgInnerConsistentIn *in = (spgInnerConsistentIn *) PG_GETARG_POINTER(0);
spgInnerConsistentOut *out = (spgInnerConsistentOut *) PG_GETARG_POINTER(1);
int i;
int which;
if (!in->hasPrefix)
{
Assert(!in->allTheSame);
Assert(in->nNodes == 2);
/* Identify which child nodes need to be visited */
which = 1 | (1 << 1);
for (i = 0; i < in->nkeys; i++)
{
StrategyNumber strategy = in->scankeys[i].sk_strategy;
inet *argument = DatumGetInetPP(in->scankeys[i].sk_argument);
switch (strategy)
{
case RTLessStrategyNumber:
case RTLessEqualStrategyNumber:
if (ip_family(argument) == PGSQL_AF_INET)
which &= 1;
break;
case RTGreaterEqualStrategyNumber:
case RTGreaterStrategyNumber:
if (ip_family(argument) == PGSQL_AF_INET6)
which &= (1 << 1);
break;
case RTNotEqualStrategyNumber:
break;
default:
/* all other ops can only match addrs of same family */
if (ip_family(argument) == PGSQL_AF_INET)
which &= 1;
else
which &= (1 << 1);
break;
}
}
}
else if (!in->allTheSame)
{
Assert(in->nNodes == 4);
/* Identify which child nodes need to be visited */
which = inet_spg_consistent_bitmap(DatumGetInetPP(in->prefixDatum),
in->nkeys, in->scankeys, false);
}
else
{
/* Must visit all nodes; we assume there are less than 32 of 'em */
which = ~0;
}
out->nNodes = 0;
if (which)
{
out->nodeNumbers = (int *) palloc(sizeof(int) * in->nNodes);
for (i = 0; i < in->nNodes; i++)
{
if (which & (1 << i))
{
out->nodeNumbers[out->nNodes] = i;
out->nNodes++;
}
}
}
PG_RETURN_VOID();
}
/*
* The GiST PickSplit method
*/
Datum
inet_spg_picksplit(PG_FUNCTION_ARGS)
{
spgPickSplitIn *in = (spgPickSplitIn *) PG_GETARG_POINTER(0);
spgPickSplitOut *out = (spgPickSplitOut *) PG_GETARG_POINTER(1);
inet *prefix,
*tmp;
int i,
commonbits;
bool differentFamilies = false;
/* Initialize the prefix with the first item */
prefix = DatumGetInetPP(in->datums[0]);
commonbits = ip_bits(prefix);
/* Examine remaining items to discover minimum common prefix length */
for (i = 1; i < in->nTuples; i++)
{
tmp = DatumGetInetPP(in->datums[i]);
if (ip_family(tmp) != ip_family(prefix))
{
differentFamilies = true;
break;
}
if (ip_bits(tmp) < commonbits)
commonbits = ip_bits(tmp);
commonbits = bitncommon(ip_addr(prefix), ip_addr(tmp), commonbits);
if (commonbits == 0)
break;
}
/* Don't need labels; allocate output arrays */
out->nodeLabels = NULL;
out->mapTuplesToNodes = (int *) palloc(sizeof(int) * in->nTuples);
out->leafTupleDatums = (Datum *) palloc(sizeof(Datum) * in->nTuples);
if (differentFamilies)
{
/* Set up 2-node tuple */
out->hasPrefix = false;
out->nNodes = 2;
for (i = 0; i < in->nTuples; i++)
{
tmp = DatumGetInetPP(in->datums[i]);
out->mapTuplesToNodes[i] =
(ip_family(tmp) == PGSQL_AF_INET) ? 0 : 1;
out->leafTupleDatums[i] = InetPGetDatum(tmp);
}
}
else
{
/* Set up 4-node tuple */
out->hasPrefix = true;
out->prefixDatum =
InetPGetDatum(cidr_set_masklen_internal(prefix, commonbits));
out->nNodes = 4;
for (i = 0; i < in->nTuples; i++)
{
tmp = DatumGetInetPP(in->datums[i]);
out->mapTuplesToNodes[i] = inet_spg_node_number(tmp, commonbits);
out->leafTupleDatums[i] = InetPGetDatum(tmp);
}
}
PG_RETURN_VOID();
}
