From dc1475195f1350745e45a5b7db381354f99d83da Mon Sep 17 00:00:00 2001 From: Andy Fan Date: Wed, 11 Sep 2024 12:19:57 +0800 Subject: [PATCH v20240912 1/4] Refactor float8out_internval for better performance Some users like cube, geo needs calls float8out_internval to get a string, and then copy them into its own StringInfo. In this commit, we would let the user provide a buffer to float8out_internal so that it can put the data to buffer directly. This commit also reuse the existing string length to avoid another strlen call in appendStringInfoString. --- contrib/cube/cube.c | 17 +++++++++++++++-- src/backend/utils/adt/float.c | 14 ++++++++------ src/backend/utils/adt/geo_ops.c | 34 ++++++++++++++++++++++----------- src/include/catalog/pg_type.h | 1 + src/include/utils/float.h | 2 +- 5 files changed, 48 insertions(+), 20 deletions(-) diff --git a/contrib/cube/cube.c b/contrib/cube/cube.c index 1fc447511a..a239acf35c 100644 --- a/contrib/cube/cube.c +++ b/contrib/cube/cube.c @@ -12,6 +12,7 @@ #include "access/gist.h" #include "access/stratnum.h" +#include "catalog/pg_type.h" #include "cubedata.h" #include "libpq/pqformat.h" #include "utils/array.h" @@ -295,26 +296,38 @@ cube_out(PG_FUNCTION_ARGS) StringInfoData buf; int dim = DIM(cube); int i; + int str_len; initStringInfo(&buf); appendStringInfoChar(&buf, '('); + + /* 3 for ", " and 1 for '\0'. */ + enlargeStringInfo(&buf, (MAXFLOAT8LEN + 4) * dim); for (i = 0; i < dim; i++) { if (i > 0) appendStringInfoString(&buf, ", "); - appendStringInfoString(&buf, float8out_internal(LL_COORD(cube, i))); + float8out_internal(LL_COORD(cube, i), buf.data + buf.len, &str_len); + buf.len += str_len; + buf.data[buf.len] = '\0'; } appendStringInfoChar(&buf, ')'); if (!cube_is_point_internal(cube)) { appendStringInfoString(&buf, ",("); + + /* 3 for ", " and 1 for '\0'. */ + enlargeStringInfo(&buf, (MAXFLOAT8LEN + 4) * dim); for (i = 0; i < dim; i++) { if (i > 0) appendStringInfoString(&buf, ", "); - appendStringInfoString(&buf, float8out_internal(UR_COORD(cube, i))); + + float8out_internal(UR_COORD(cube, i), buf.data + buf.len, &str_len); + buf.len += str_len; + buf.data[buf.len] = '\0'; } appendStringInfoChar(&buf, ')'); } diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c index f709c21e1f..1f31f8540e 100644 --- a/src/backend/utils/adt/float.c +++ b/src/backend/utils/adt/float.c @@ -531,22 +531,24 @@ float8out(PG_FUNCTION_ARGS) * float8out_internal - guts of float8out() * * This is exposed for use by functions that want a reasonably - * platform-independent way of outputting doubles. - * The result is always palloc'd. + * platform-independent way of outputting doubles, output the + * string length to *len; */ char * -float8out_internal(double num) +float8out_internal(double num, char *ascii, int *len) { - char *ascii = (char *) palloc(32); int ndig = DBL_DIG + extra_float_digits; + if (ascii == NULL) + ascii = (char *) palloc(MAXFLOAT8LEN); + if (extra_float_digits > 0) { - double_to_shortest_decimal_buf(num, ascii); + *len = double_to_shortest_decimal_buf(num, ascii); return ascii; } - (void) pg_strfromd(ascii, 32, ndig, num); + *len = pg_strfromd(ascii, 32, ndig, num); return ascii; } diff --git a/src/backend/utils/adt/geo_ops.c b/src/backend/utils/adt/geo_ops.c index 07d1649c7b..59f2feaa59 100644 --- a/src/backend/utils/adt/geo_ops.c +++ b/src/backend/utils/adt/geo_ops.c @@ -29,6 +29,7 @@ #include #include +#include "catalog/pg_type.h" #include "libpq/pqformat.h" #include "miscadmin.h" #include "nodes/miscnodes.h" @@ -202,10 +203,12 @@ single_decode(char *num, float8 *x, char **endptr_p, static void single_encode(float8 x, StringInfo str) { - char *xstr = float8out_internal(x); + int str_len; + enlargeStringInfo(str, MAXFLOAT8LEN + 1); + float8out_internal(x, str->data + str->len, &str_len); - appendStringInfoString(str, xstr); - pfree(xstr); + str->len += str_len; + str->data[str->len] = '\0'; } /* single_encode() */ static bool @@ -254,12 +257,20 @@ fail: static void pair_encode(float8 x, float8 y, StringInfo str) { - char *xstr = float8out_internal(x); - char *ystr = float8out_internal(y); + int data_len; + /* the additional 2 is for ',' and '\0' */ + enlargeStringInfo(str, MAXFLOAT8LEN * 2 + 2); - appendStringInfo(str, "%s,%s", xstr, ystr); - pfree(xstr); - pfree(ystr); + float8out_internal(x, str->data + str->len, &data_len); + str->len += data_len; + + str->data[str->len] = ','; + str->len++; + + float8out_internal(y, str->data + str->len, &data_len); + str->len += data_len; + + str->data[str->len] = '\0'; } static bool @@ -1023,9 +1034,10 @@ Datum line_out(PG_FUNCTION_ARGS) { LINE *line = PG_GETARG_LINE_P(0); - char *astr = float8out_internal(line->A); - char *bstr = float8out_internal(line->B); - char *cstr = float8out_internal(line->C); + int datalen; + char *astr = float8out_internal(line->A, NULL, &datalen); + char *bstr = float8out_internal(line->B, NULL, &datalen); + char *cstr = float8out_internal(line->C, NULL, &datalen); PG_RETURN_CSTRING(psprintf("%c%s%c%s%c%s%c", LDELIM_L, astr, DELIM, bstr, DELIM, cstr, RDELIM_L)); diff --git a/src/include/catalog/pg_type.h b/src/include/catalog/pg_type.h index e925969732..1ab8e4e4e9 100644 --- a/src/include/catalog/pg_type.h +++ b/src/include/catalog/pg_type.h @@ -344,6 +344,7 @@ MAKE_SYSCACHE(TYPENAMENSP, pg_type_typname_nsp_index, 64); #endif /* EXPOSE_TO_CLIENT_CODE */ +#define MAXFLOAT8LEN 32 extern ObjectAddress TypeShellMake(const char *typeName, Oid typeNamespace, diff --git a/src/include/utils/float.h b/src/include/utils/float.h index 7d1badd292..65c395299d 100644 --- a/src/include/utils/float.h +++ b/src/include/utils/float.h @@ -47,7 +47,7 @@ extern float8 float8in_internal(char *num, char **endptr_p, extern float4 float4in_internal(char *num, char **endptr_p, const char *type_name, const char *orig_string, struct Node *escontext); -extern char *float8out_internal(float8 num); +extern char *float8out_internal(float8 num, char *ascii, int *len); extern int float4_cmp_internal(float4 a, float4 b); extern int float8_cmp_internal(float8 a, float8 b); -- 2.45.1