diff options
Diffstat (limited to 'src/backend/utils/adt/varbit.c')
| -rw-r--r-- | src/backend/utils/adt/varbit.c | 137 |
1 files changed, 86 insertions, 51 deletions
diff --git a/src/backend/utils/adt/varbit.c b/src/backend/utils/adt/varbit.c index 81da4fc1749..7fd7727e421 100644 --- a/src/backend/utils/adt/varbit.c +++ b/src/backend/utils/adt/varbit.c @@ -9,7 +9,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/varbit.c,v 1.38 2003/11/29 19:51:59 pgsql Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/varbit.c,v 1.39 2004/06/16 01:26:47 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1166,32 +1166,58 @@ bitshiftright(PG_FUNCTION_ARGS) PG_RETURN_VARBIT_P(result); } -/* This is not defined in any standard. We retain the natural ordering of +/* + * This is not defined in any standard. We retain the natural ordering of * bits here, as it just seems more intuitive. */ Datum bitfromint4(PG_FUNCTION_ARGS) { int32 a = PG_GETARG_INT32(0); + int32 typmod = PG_GETARG_INT32(1); VarBit *result; bits8 *r; - int len; + int rlen; + int destbitsleft, + srcbitsleft; - /* allocate enough space for the bits in an int4 */ - len = VARBITTOTALLEN(sizeof(int4) * BITS_PER_BYTE); - result = (VarBit *) palloc(len); - VARATT_SIZEP(result) = len; - VARBITLEN(result) = sizeof(int4) * BITS_PER_BYTE; + if (typmod <= 0) + typmod = 1; /* default bit length */ + + rlen = VARBITTOTALLEN(typmod); + result = (VarBit *) palloc(rlen); + VARATT_SIZEP(result) = rlen; + VARBITLEN(result) = typmod; - /* - * masks and shifts here are just too painful and we know that an int4 - * has got 4 bytes - */ r = VARBITS(result); - r[0] = (bits8) ((a >> (3 * BITS_PER_BYTE)) & BITMASK); - r[1] = (bits8) ((a >> (2 * BITS_PER_BYTE)) & BITMASK); - r[2] = (bits8) ((a >> (1 * BITS_PER_BYTE)) & BITMASK); - r[3] = (bits8) (a & BITMASK); + destbitsleft = typmod; + srcbitsleft = 32; + /* drop any input bits that don't fit */ + srcbitsleft = Min(srcbitsleft, destbitsleft); + /* sign-fill any excess bytes in output */ + while (destbitsleft >= srcbitsleft + 8) + { + *r++ = (bits8) ((a < 0) ? BITMASK : 0); + destbitsleft -= 8; + } + /* store first fractional byte */ + if (destbitsleft > srcbitsleft) + { + *r++ = (bits8) ((a >> (srcbitsleft - 8)) & BITMASK); + destbitsleft -= 8; + } + /* Now srcbitsleft and destbitsleft are the same, need not track both */ + /* store whole bytes */ + while (destbitsleft >= 8) + { + *r++ = (bits8) ((a >> (destbitsleft - 8)) & BITMASK); + destbitsleft -= 8; + } + /* store last fractional byte */ + if (destbitsleft > 0) + { + *r = (bits8) ((a << (8 - destbitsleft)) & BITMASK); + } PG_RETURN_VARBIT_P(result); } @@ -1204,7 +1230,7 @@ bittoint4(PG_FUNCTION_ARGS) bits8 *r; /* Check that the bit string is not too long */ - if (VARBITLEN(arg) > sizeof(int4) * BITS_PER_BYTE) + if (VARBITLEN(arg) > sizeof(result) * BITS_PER_BYTE) ereport(ERROR, (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), errmsg("integer out of range"))); @@ -1224,46 +1250,62 @@ bittoint4(PG_FUNCTION_ARGS) Datum bitfromint8(PG_FUNCTION_ARGS) { -#ifndef INT64_IS_BUSTED int64 a = PG_GETARG_INT64(0); + int32 typmod = PG_GETARG_INT32(1); VarBit *result; bits8 *r; - int len; + int rlen; + int destbitsleft, + srcbitsleft; - /* allocate enough space for the bits in an int64 */ - len = VARBITTOTALLEN(sizeof(a) * BITS_PER_BYTE); - result = (VarBit *) palloc(len); - VARATT_SIZEP(result) = len; - VARBITLEN(result) = sizeof(a) * BITS_PER_BYTE; + if (typmod <= 0) + typmod = 1; /* default bit length */ - /* - * masks and shifts here are just too painful and we know that an - * int64 has got 8 bytes - */ - r = VARBITS(result); - r[0] = (bits8) ((a >> (7 * BITS_PER_BYTE)) & BITMASK); - r[1] = (bits8) ((a >> (6 * BITS_PER_BYTE)) & BITMASK); - r[2] = (bits8) ((a >> (5 * BITS_PER_BYTE)) & BITMASK); - r[3] = (bits8) ((a >> (4 * BITS_PER_BYTE)) & BITMASK); - r[4] = (bits8) ((a >> (3 * BITS_PER_BYTE)) & BITMASK); - r[5] = (bits8) ((a >> (2 * BITS_PER_BYTE)) & BITMASK); - r[6] = (bits8) ((a >> (1 * BITS_PER_BYTE)) & BITMASK); - r[7] = (bits8) (a & BITMASK); + rlen = VARBITTOTALLEN(typmod); + result = (VarBit *) palloc(rlen); + VARATT_SIZEP(result) = rlen; + VARBITLEN(result) = typmod; - PG_RETURN_VARBIT_P(result); + r = VARBITS(result); + destbitsleft = typmod; +#ifndef INT64_IS_BUSTED + srcbitsleft = 64; #else - ereport(ERROR, - (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), - errmsg("64-bit integers not supported on this platform"))); - - PG_RETURN_NULL(); + srcbitsleft = 32; /* don't try to shift more than 32 */ #endif + /* drop any input bits that don't fit */ + srcbitsleft = Min(srcbitsleft, destbitsleft); + /* sign-fill any excess bytes in output */ + while (destbitsleft >= srcbitsleft + 8) + { + *r++ = (bits8) ((a < 0) ? BITMASK : 0); + destbitsleft -= 8; + } + /* store first fractional byte */ + if (destbitsleft > srcbitsleft) + { + *r++ = (bits8) ((a >> (srcbitsleft - 8)) & BITMASK); + destbitsleft -= 8; + } + /* Now srcbitsleft and destbitsleft are the same, need not track both */ + /* store whole bytes */ + while (destbitsleft >= 8) + { + *r++ = (bits8) ((a >> (destbitsleft - 8)) & BITMASK); + destbitsleft -= 8; + } + /* store last fractional byte */ + if (destbitsleft > 0) + { + *r = (bits8) ((a << (8 - destbitsleft)) & BITMASK); + } + + PG_RETURN_VARBIT_P(result); } Datum bittoint8(PG_FUNCTION_ARGS) { -#ifndef INT64_IS_BUSTED VarBit *arg = PG_GETARG_VARBIT_P(0); uint64 result; bits8 *r; @@ -1284,13 +1326,6 @@ bittoint8(PG_FUNCTION_ARGS) result >>= VARBITPAD(arg); PG_RETURN_INT64(result); -#else - ereport(ERROR, - (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), - errmsg("64-bit integers not supported on this platform"))); - - PG_RETURN_NULL(); -#endif } |