postgresql/contrib/btree_gin/btree_gin.c

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2023-05-09 21:11:15 +00:00
/*
* contrib/btree_gin/btree_gin.c
*/
#include "postgres.h"
#include <limits.h>
#include "access/stratnum.h"
#include "utils/builtins.h"
#include "utils/bytea.h"
#include "utils/cash.h"
#include "utils/date.h"
#include "utils/float.h"
#include "utils/inet.h"
#include "utils/numeric.h"
#include "utils/timestamp.h"
#include "utils/uuid.h"
#include "utils/varbit.h"
PG_MODULE_MAGIC;
typedef struct QueryInfo
{
StrategyNumber strategy;
Datum datum;
bool is_varlena;
Datum (*typecmp) (FunctionCallInfo);
} QueryInfo;
/*** GIN support functions shared by all datatypes ***/
static Datum
gin_btree_extract_value(FunctionCallInfo fcinfo, bool is_varlena)
{
Datum datum = PG_GETARG_DATUM(0);
int32 *nentries = (int32 *) PG_GETARG_POINTER(1);
Datum *entries = (Datum *) palloc(sizeof(Datum));
if (is_varlena)
datum = PointerGetDatum(PG_DETOAST_DATUM(datum));
entries[0] = datum;
*nentries = 1;
PG_RETURN_POINTER(entries);
}
/*
* For BTGreaterEqualStrategyNumber, BTGreaterStrategyNumber, and
* BTEqualStrategyNumber we want to start the index scan at the
* supplied query datum, and work forward. For BTLessStrategyNumber
* and BTLessEqualStrategyNumber, we need to start at the leftmost
* key, and work forward until the supplied query datum (which must be
* sent along inside the QueryInfo structure).
*/
static Datum
gin_btree_extract_query(FunctionCallInfo fcinfo,
bool is_varlena,
Datum (*leftmostvalue) (void),
Datum (*typecmp) (FunctionCallInfo))
{
Datum datum = PG_GETARG_DATUM(0);
int32 *nentries = (int32 *) PG_GETARG_POINTER(1);
StrategyNumber strategy = PG_GETARG_UINT16(2);
bool **partialmatch = (bool **) PG_GETARG_POINTER(3);
Pointer **extra_data = (Pointer **) PG_GETARG_POINTER(4);
Datum *entries = (Datum *) palloc(sizeof(Datum));
QueryInfo *data = (QueryInfo *) palloc(sizeof(QueryInfo));
bool *ptr_partialmatch;
*nentries = 1;
ptr_partialmatch = *partialmatch = (bool *) palloc(sizeof(bool));
*ptr_partialmatch = false;
if (is_varlena)
datum = PointerGetDatum(PG_DETOAST_DATUM(datum));
data->strategy = strategy;
data->datum = datum;
data->is_varlena = is_varlena;
data->typecmp = typecmp;
*extra_data = (Pointer *) palloc(sizeof(Pointer));
**extra_data = (Pointer) data;
switch (strategy)
{
case BTLessStrategyNumber:
case BTLessEqualStrategyNumber:
entries[0] = leftmostvalue();
*ptr_partialmatch = true;
break;
case BTGreaterEqualStrategyNumber:
case BTGreaterStrategyNumber:
*ptr_partialmatch = true;
/* FALLTHROUGH */
case BTEqualStrategyNumber:
entries[0] = datum;
break;
default:
elog(ERROR, "unrecognized strategy number: %d", strategy);
}
PG_RETURN_POINTER(entries);
}
/*
* Datum a is a value from extract_query method and for BTLess*
* strategy it is a left-most value. So, use original datum from QueryInfo
* to decide to stop scanning or not. Datum b is always from index.
*/
static Datum
gin_btree_compare_prefix(FunctionCallInfo fcinfo)
{
Datum a = PG_GETARG_DATUM(0);
Datum b = PG_GETARG_DATUM(1);
QueryInfo *data = (QueryInfo *) PG_GETARG_POINTER(3);
int32 res,
cmp;
cmp = DatumGetInt32(CallerFInfoFunctionCall2(data->typecmp,
fcinfo->flinfo,
PG_GET_COLLATION(),
(data->strategy == BTLessStrategyNumber ||
data->strategy == BTLessEqualStrategyNumber)
? data->datum : a,
b));
switch (data->strategy)
{
case BTLessStrategyNumber:
/* If original datum > indexed one then return match */
if (cmp > 0)
res = 0;
else
res = 1;
break;
case BTLessEqualStrategyNumber:
/* The same except equality */
if (cmp >= 0)
res = 0;
else
res = 1;
break;
case BTEqualStrategyNumber:
if (cmp != 0)
res = 1;
else
res = 0;
break;
case BTGreaterEqualStrategyNumber:
/* If original datum <= indexed one then return match */
if (cmp <= 0)
res = 0;
else
res = 1;
break;
case BTGreaterStrategyNumber:
/* If original datum <= indexed one then return match */
/* If original datum == indexed one then continue scan */
if (cmp < 0)
res = 0;
else if (cmp == 0)
res = -1;
else
res = 1;
break;
default:
elog(ERROR, "unrecognized strategy number: %d",
data->strategy);
res = 0;
}
PG_RETURN_INT32(res);
}
PG_FUNCTION_INFO_V1(gin_btree_consistent);
Datum
gin_btree_consistent(PG_FUNCTION_ARGS)
{
bool *recheck = (bool *) PG_GETARG_POINTER(5);
*recheck = false;
PG_RETURN_BOOL(true);
}
/*** GIN_SUPPORT macro defines the datatype specific functions ***/
#define GIN_SUPPORT(type, is_varlena, leftmostvalue, typecmp) \
PG_FUNCTION_INFO_V1(gin_extract_value_##type); \
Datum \
gin_extract_value_##type(PG_FUNCTION_ARGS) \
{ \
return gin_btree_extract_value(fcinfo, is_varlena); \
} \
PG_FUNCTION_INFO_V1(gin_extract_query_##type); \
Datum \
gin_extract_query_##type(PG_FUNCTION_ARGS) \
{ \
return gin_btree_extract_query(fcinfo, \
is_varlena, leftmostvalue, typecmp); \
} \
PG_FUNCTION_INFO_V1(gin_compare_prefix_##type); \
Datum \
gin_compare_prefix_##type(PG_FUNCTION_ARGS) \
{ \
return gin_btree_compare_prefix(fcinfo); \
}
/*** Datatype specifications ***/
static Datum
leftmostvalue_int2(void)
{
return Int16GetDatum(SHRT_MIN);
}
GIN_SUPPORT(int2, false, leftmostvalue_int2, btint2cmp)
static Datum
leftmostvalue_int4(void)
{
return Int32GetDatum(INT_MIN);
}
GIN_SUPPORT(int4, false, leftmostvalue_int4, btint4cmp)
static Datum
leftmostvalue_int8(void)
{
return Int64GetDatum(PG_INT64_MIN);
}
GIN_SUPPORT(int8, false, leftmostvalue_int8, btint8cmp)
static Datum
leftmostvalue_float4(void)
{
return Float4GetDatum(-get_float4_infinity());
}
GIN_SUPPORT(float4, false, leftmostvalue_float4, btfloat4cmp)
static Datum
leftmostvalue_float8(void)
{
return Float8GetDatum(-get_float8_infinity());
}
GIN_SUPPORT(float8, false, leftmostvalue_float8, btfloat8cmp)
static Datum
leftmostvalue_money(void)
{
return Int64GetDatum(PG_INT64_MIN);
}
GIN_SUPPORT(money, false, leftmostvalue_money, cash_cmp)
static Datum
leftmostvalue_oid(void)
{
return ObjectIdGetDatum(0);
}
GIN_SUPPORT(oid, false, leftmostvalue_oid, btoidcmp)
static Datum
leftmostvalue_timestamp(void)
{
return TimestampGetDatum(DT_NOBEGIN);
}
GIN_SUPPORT(timestamp, false, leftmostvalue_timestamp, timestamp_cmp)
GIN_SUPPORT(timestamptz, false, leftmostvalue_timestamp, timestamp_cmp)
static Datum
leftmostvalue_time(void)
{
return TimeADTGetDatum(0);
}
GIN_SUPPORT(time, false, leftmostvalue_time, time_cmp)
static Datum
leftmostvalue_timetz(void)
{
TimeTzADT *v = palloc(sizeof(TimeTzADT));
v->time = 0;
v->zone = -24 * 3600; /* XXX is that true? */
return TimeTzADTPGetDatum(v);
}
GIN_SUPPORT(timetz, false, leftmostvalue_timetz, timetz_cmp)
static Datum
leftmostvalue_date(void)
{
return DateADTGetDatum(DATEVAL_NOBEGIN);
}
GIN_SUPPORT(date, false, leftmostvalue_date, date_cmp)
static Datum
leftmostvalue_interval(void)
{
Interval *v = palloc(sizeof(Interval));
v->time = DT_NOBEGIN;
v->day = 0;
v->month = 0;
return IntervalPGetDatum(v);
}
GIN_SUPPORT(interval, false, leftmostvalue_interval, interval_cmp)
static Datum
leftmostvalue_macaddr(void)
{
macaddr *v = palloc0(sizeof(macaddr));
return MacaddrPGetDatum(v);
}
GIN_SUPPORT(macaddr, false, leftmostvalue_macaddr, macaddr_cmp)
static Datum
leftmostvalue_macaddr8(void)
{
macaddr8 *v = palloc0(sizeof(macaddr8));
return Macaddr8PGetDatum(v);
}
GIN_SUPPORT(macaddr8, false, leftmostvalue_macaddr8, macaddr8_cmp)
static Datum
leftmostvalue_inet(void)
{
return DirectFunctionCall1(inet_in, CStringGetDatum("0.0.0.0/0"));
}
GIN_SUPPORT(inet, true, leftmostvalue_inet, network_cmp)
GIN_SUPPORT(cidr, true, leftmostvalue_inet, network_cmp)
static Datum
leftmostvalue_text(void)
{
return PointerGetDatum(cstring_to_text_with_len("", 0));
}
GIN_SUPPORT(text, true, leftmostvalue_text, bttextcmp)
GIN_SUPPORT(bpchar, true, leftmostvalue_text, bpcharcmp)
static Datum
leftmostvalue_char(void)
{
return CharGetDatum(0);
}
GIN_SUPPORT(char, false, leftmostvalue_char, btcharcmp)
GIN_SUPPORT(bytea, true, leftmostvalue_text, byteacmp)
static Datum
leftmostvalue_bit(void)
{
return DirectFunctionCall3(bit_in,
CStringGetDatum(""),
ObjectIdGetDatum(0),
Int32GetDatum(-1));
}
GIN_SUPPORT(bit, true, leftmostvalue_bit, bitcmp)
static Datum
leftmostvalue_varbit(void)
{
return DirectFunctionCall3(varbit_in,
CStringGetDatum(""),
ObjectIdGetDatum(0),
Int32GetDatum(-1));
}
GIN_SUPPORT(varbit, true, leftmostvalue_varbit, bitcmp)
/*
* Numeric type hasn't a real left-most value, so we use PointerGetDatum(NULL)
* (*not* a SQL NULL) to represent that. We can get away with that because
* the value returned by our leftmostvalue function will never be stored in
* the index nor passed to anything except our compare and prefix-comparison
* functions. The same trick could be used for other pass-by-reference types.
*/
#define NUMERIC_IS_LEFTMOST(x) ((x) == NULL)
PG_FUNCTION_INFO_V1(gin_numeric_cmp);
Datum
gin_numeric_cmp(PG_FUNCTION_ARGS)
{
Numeric a = (Numeric) PG_GETARG_POINTER(0);
Numeric b = (Numeric) PG_GETARG_POINTER(1);
int res = 0;
if (NUMERIC_IS_LEFTMOST(a))
{
res = (NUMERIC_IS_LEFTMOST(b)) ? 0 : -1;
}
else if (NUMERIC_IS_LEFTMOST(b))
{
res = 1;
}
else
{
res = DatumGetInt32(DirectFunctionCall2(numeric_cmp,
NumericGetDatum(a),
NumericGetDatum(b)));
}
PG_RETURN_INT32(res);
}
static Datum
leftmostvalue_numeric(void)
{
return PointerGetDatum(NULL);
}
GIN_SUPPORT(numeric, true, leftmostvalue_numeric, gin_numeric_cmp)
/*
* Use a similar trick to that used for numeric for enums, since we don't
* actually know the leftmost value of any enum without knowing the concrete
* type, so we use a dummy leftmost value of InvalidOid.
*
* Note that we use CallerFInfoFunctionCall2 here so that enum_cmp
* gets a valid fn_extra to work with. Unlike most other type comparison
* routines it needs it, so we can't use DirectFunctionCall2.
*/
#define ENUM_IS_LEFTMOST(x) ((x) == InvalidOid)
PG_FUNCTION_INFO_V1(gin_enum_cmp);
Datum
gin_enum_cmp(PG_FUNCTION_ARGS)
{
Oid a = PG_GETARG_OID(0);
Oid b = PG_GETARG_OID(1);
int res = 0;
if (ENUM_IS_LEFTMOST(a))
{
res = (ENUM_IS_LEFTMOST(b)) ? 0 : -1;
}
else if (ENUM_IS_LEFTMOST(b))
{
res = 1;
}
else
{
res = DatumGetInt32(CallerFInfoFunctionCall2(enum_cmp,
fcinfo->flinfo,
PG_GET_COLLATION(),
ObjectIdGetDatum(a),
ObjectIdGetDatum(b)));
}
PG_RETURN_INT32(res);
}
static Datum
leftmostvalue_enum(void)
{
return ObjectIdGetDatum(InvalidOid);
}
GIN_SUPPORT(anyenum, false, leftmostvalue_enum, gin_enum_cmp)
static Datum
leftmostvalue_uuid(void)
{
/*
* palloc0 will create the UUID with all zeroes:
* "00000000-0000-0000-0000-000000000000"
*/
pg_uuid_t *retval = (pg_uuid_t *) palloc0(sizeof(pg_uuid_t));
return UUIDPGetDatum(retval);
}
GIN_SUPPORT(uuid, false, leftmostvalue_uuid, uuid_cmp)
static Datum
leftmostvalue_name(void)
{
NameData *result = (NameData *) palloc0(NAMEDATALEN);
return NameGetDatum(result);
}
GIN_SUPPORT(name, false, leftmostvalue_name, btnamecmp)
static Datum
leftmostvalue_bool(void)
{
return BoolGetDatum(false);
}
GIN_SUPPORT(bool, false, leftmostvalue_bool, btboolcmp)