From 86eaf208ea048936df6be77276a246d3f92e9620 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Sun, 22 Jul 2018 14:58:01 -0700 Subject: Hand code string to integer conversion for performance. As benchmarks show, using libc's string-to-integer conversion is pretty slow. At least part of the reason for that is that strtol[l] have to be more generic than what largely is required inside pg. This patch considerably speeds up int2/int4 input (int8 already was already using hand-rolled code). Most of the existing pg_atoi callers have been converted. But as one requires pg_atoi's custom delimiter functionality, and as it seems likely that there's external pg_atoi users, it seems sensible to just keep pg_atoi around. Author: Andres Freund Reviewed-By: Robert Haas Discussion: https://postgr.es/m/20171208214437.qgn6zdltyq5hmjpk@alap3.anarazel.de --- src/backend/utils/adt/numutils.c | 149 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 149 insertions(+) (limited to 'src/backend/utils/adt/numutils.c') diff --git a/src/backend/utils/adt/numutils.c b/src/backend/utils/adt/numutils.c index fb46f692e3a..49055d519cb 100644 --- a/src/backend/utils/adt/numutils.c +++ b/src/backend/utils/adt/numutils.c @@ -18,6 +18,7 @@ #include #include +#include "common/int.h" #include "utils/builtins.h" /* @@ -108,6 +109,154 @@ pg_atoi(const char *s, int size, int c) return (int32) l; } +/* + * Convert input string to a signed 16 bit integer. + * + * Allows any number of leading or trailing whitespace characters. Will throw + * ereport() upon bad input format or overflow. + * + * NB: Accumulate input as a negative number, to deal with two's complement + * representation of the most negative number, which can't be represented as a + * positive number. + */ +int16 +pg_strtoint16(const char *s) +{ + const char *ptr = s; + int16 tmp = 0; + bool neg = false; + + /* skip leading spaces */ + while (likely(*ptr) && isspace((unsigned char) *ptr)) + ptr++; + + /* handle sign */ + if (*ptr == '-') + { + ptr++; + neg = true; + } + else if (*ptr == '+') + ptr++; + + /* require at least one digit */ + if (unlikely(!isdigit((unsigned char) *ptr))) + goto invalid_syntax; + + /* process digits */ + while (*ptr && isdigit((unsigned char) *ptr)) + { + int8 digit = (*ptr++ - '0'); + + if (unlikely(pg_mul_s16_overflow(tmp, 10, &tmp)) || + unlikely(pg_sub_s16_overflow(tmp, digit, &tmp))) + goto out_of_range; + } + + /* allow trailing whitespace, but not other trailing chars */ + while (*ptr != '\0' && isspace((unsigned char) *ptr)) + ptr++; + + if (unlikely(*ptr != '\0')) + goto invalid_syntax; + + if (!neg) + { + /* could fail if input is most negative number */ + if (unlikely(tmp == PG_INT16_MIN)) + goto out_of_range; + tmp = -tmp; + } + + return tmp; + +out_of_range: + ereport(ERROR, + (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), + errmsg("value \"%s\" is out of range for type %s", + s, "smallint"))); + +invalid_syntax: + ereport(ERROR, + (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), + errmsg("invalid input syntax for type %s: \"%s\"", + "smallint", s))); +} + +/* + * Convert input string to a signed 32 bit integer. + * + * Allows any number of leading or trailing whitespace characters. Will throw + * ereport() upon bad input format or overflow. + * + * NB: Accumulate input as a negative number, to deal with two's complement + * representation of the most negative number, which can't be represented as a + * positive number. + */ +int32 +pg_strtoint32(const char *s) +{ + const char *ptr = s; + int32 tmp = 0; + bool neg = false; + + /* skip leading spaces */ + while (likely(*ptr) && isspace((unsigned char) *ptr)) + ptr++; + + /* handle sign */ + if (*ptr == '-') + { + ptr++; + neg = true; + } + else if (*ptr == '+') + ptr++; + + /* require at least one digit */ + if (unlikely(!isdigit((unsigned char) *ptr))) + goto invalid_syntax; + + /* process digits */ + while (*ptr && isdigit((unsigned char) *ptr)) + { + int8 digit = (*ptr++ - '0'); + + if (unlikely(pg_mul_s32_overflow(tmp, 10, &tmp)) || + unlikely(pg_sub_s32_overflow(tmp, digit, &tmp))) + goto out_of_range; + } + + /* allow trailing whitespace, but not other trailing chars */ + while (*ptr != '\0' && isspace((unsigned char) *ptr)) + ptr++; + + if (unlikely(*ptr != '\0')) + goto invalid_syntax; + + if (!neg) + { + /* could fail if input is most negative number */ + if (unlikely(tmp == PG_INT32_MIN)) + goto out_of_range; + tmp = -tmp; + } + + return tmp; + +out_of_range: + ereport(ERROR, + (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), + errmsg("value \"%s\" is out of range for type %s", + s, "integer"))); + +invalid_syntax: + ereport(ERROR, + (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), + errmsg("invalid input syntax for type %s: \"%s\"", + "integer", s))); +} + /* * pg_itoa: converts a signed 16-bit integer to its string representation * -- cgit v1.2.3