Re: Performance improvements for src/port/snprintf.c - Mailing list pgsql-hackers
| From | Tom Lane |
|---|---|
| Subject | Re: Performance improvements for src/port/snprintf.c |
| Date | |
| Msg-id | 30551.1538517271@sss.pgh.pa.us Whole thread Raw |
| In response to | Re: Performance improvements for src/port/snprintf.c (Andres Freund <andres@anarazel.de>) |
| Responses |
Re: Performance improvements for src/port/snprintf.c
Re: Performance improvements for src/port/snprintf.c |
| List | pgsql-hackers |
Here's a version of this patch rebased over commit 625b38ea0.
That commit's fix for the possibly-expensive memset means that we need
to reconsider performance numbers for this patch. I re-ran my previous
tests, and it's still looking like this is a substantial win, as it makes
snprintf.c faster than the native snprintf for most non-float cases.
We're still stuck at something like 10% penalty for float cases.
While there might be value in implementing our own float printing code,
I have a pretty hard time getting excited about the cost/benefit ratio
of that. I think that what we probably really ought to do here is hack
float4out/float8out to bypass the extra overhead, as in the 0002 patch
below.
For reference, I attach the testbed I'm using now plus some results.
I wasn't able to get my cranky NetBSD system up today, so I don't
have results for that. However, I did add recent glibc (Fedora 28)
to the mix, and I was interested to discover that they seem to have
added a fast-path for format strings that are exactly "%s", just as
NetBSD did. I wonder if we should reconsider our position on doing
that. It'd be a simple enough addition...
regards, tom lane
diff --git a/configure b/configure
index 6414ec1..0448c6b 100755
*** a/configure
--- b/configure
*************** fi
*** 15100,15106 ****
LIBS_including_readline="$LIBS"
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
! for ac_func in cbrt clock_gettime fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll posix_fallocate
ppollpstat pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open symlink sync_file_range utime
utimeswcstombs_l
do :
as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
--- 15100,15106 ----
LIBS_including_readline="$LIBS"
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
! for ac_func in cbrt clock_gettime fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll posix_fallocate
ppollpstat pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open strchrnul symlink
sync_file_rangeutime utimes wcstombs_l
do :
as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/configure.in b/configure.in
index 158d5a1..23b5bb8 100644
*** a/configure.in
--- b/configure.in
*************** PGAC_FUNC_WCSTOMBS_L
*** 1571,1577 ****
LIBS_including_readline="$LIBS"
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
! AC_CHECK_FUNCS([cbrt clock_gettime fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll
posix_fallocateppoll pstat pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open symlink
sync_file_rangeutime utimes wcstombs_l])
AC_REPLACE_FUNCS(fseeko)
case $host_os in
--- 1571,1577 ----
LIBS_including_readline="$LIBS"
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
! AC_CHECK_FUNCS([cbrt clock_gettime fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll
posix_fallocateppoll pstat pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open strchrnul
symlinksync_file_range utime utimes wcstombs_l])
AC_REPLACE_FUNCS(fseeko)
case $host_os in
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 90dda8e..7894caa 100644
*** a/src/include/pg_config.h.in
--- b/src/include/pg_config.h.in
***************
*** 523,528 ****
--- 523,531 ----
/* Define to 1 if you have the <stdlib.h> header file. */
#undef HAVE_STDLIB_H
+ /* Define to 1 if you have the `strchrnul' function. */
+ #undef HAVE_STRCHRNUL
+
/* Define to 1 if you have the `strerror_r' function. */
#undef HAVE_STRERROR_R
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 93bb773..f7a051d 100644
*** a/src/include/pg_config.h.win32
--- b/src/include/pg_config.h.win32
***************
*** 394,399 ****
--- 394,402 ----
/* Define to 1 if you have the <stdlib.h> header file. */
#define HAVE_STDLIB_H 1
+ /* Define to 1 if you have the `strchrnul' function. */
+ /* #undef HAVE_STRCHRNUL */
+
/* Define to 1 if you have the `strerror_r' function. */
/* #undef HAVE_STRERROR_R */
diff --git a/src/port/snprintf.c b/src/port/snprintf.c
index 1be5f70..3094ad8 100644
*** a/src/port/snprintf.c
--- b/src/port/snprintf.c
*************** flushbuffer(PrintfTarget *target)
*** 314,320 ****
}
! static void fmtstr(char *value, int leftjust, int minlen, int maxwidth,
int pointflag, PrintfTarget *target);
static void fmtptr(void *value, PrintfTarget *target);
static void fmtint(int64 value, char type, int forcesign,
--- 314,322 ----
}
! static bool find_arguments(const char *format, va_list args,
! PrintfArgValue *argvalues);
! static void fmtstr(const char *value, int leftjust, int minlen, int maxwidth,
int pointflag, PrintfTarget *target);
static void fmtptr(void *value, PrintfTarget *target);
static void fmtint(int64 value, char type, int forcesign,
*************** static void fmtfloat(double value, char
*** 326,336 ****
PrintfTarget *target);
static void dostr(const char *str, int slen, PrintfTarget *target);
static void dopr_outch(int c, PrintfTarget *target);
static int adjust_sign(int is_negative, int forcesign, int *signvalue);
! static void adjust_padlen(int minlen, int vallen, int leftjust, int *padlen);
! static void leading_pad(int zpad, int *signvalue, int *padlen,
PrintfTarget *target);
! static void trailing_pad(int *padlen, PrintfTarget *target);
/*
--- 328,339 ----
PrintfTarget *target);
static void dostr(const char *str, int slen, PrintfTarget *target);
static void dopr_outch(int c, PrintfTarget *target);
+ static void dopr_outchmulti(int c, int slen, PrintfTarget *target);
static int adjust_sign(int is_negative, int forcesign, int *signvalue);
! static int compute_padlen(int minlen, int vallen, int leftjust);
! static void leading_pad(int zpad, int signvalue, int *padlen,
PrintfTarget *target);
! static void trailing_pad(int padlen, PrintfTarget *target);
/*
*************** static void
*** 340,349 ****
dopr(PrintfTarget *target, const char *format, va_list args)
{
int save_errno = errno;
! const char *format_start = format;
int ch;
bool have_dollar;
- bool have_non_dollar;
bool have_star;
bool afterstar;
int accum;
--- 343,351 ----
dopr(PrintfTarget *target, const char *format, va_list args)
{
int save_errno = errno;
! const char *first_pct = NULL;
int ch;
bool have_dollar;
bool have_star;
bool afterstar;
int accum;
*************** dopr(PrintfTarget *target, const char *f
*** 355,580 ****
int precision;
int zpad;
int forcesign;
- int last_dollar;
int fmtpos;
int cvalue;
int64 numvalue;
double fvalue;
char *strvalue;
- int i;
- PrintfArgType argtypes[PG_NL_ARGMAX + 1];
PrintfArgValue argvalues[PG_NL_ARGMAX + 1];
/*
! * Parse the format string to determine whether there are %n$ format
! * specs, and identify the types and order of the format parameters.
*/
! have_dollar = have_non_dollar = false;
! last_dollar = 0;
! MemSet(argtypes, 0, sizeof(argtypes));
! while ((ch = *format++) != '\0')
{
! if (ch != '%')
! continue;
! longflag = longlongflag = pointflag = 0;
! fmtpos = accum = 0;
! afterstar = false;
! nextch1:
! ch = *format++;
! if (ch == '\0')
! break; /* illegal, but we don't complain */
! switch (ch)
{
! case '-':
! case '+':
! goto nextch1;
! case '0':
! case '1':
! case '2':
! case '3':
! case '4':
! case '5':
! case '6':
! case '7':
! case '8':
! case '9':
! accum = accum * 10 + (ch - '0');
! goto nextch1;
! case '.':
! pointflag = 1;
! accum = 0;
! goto nextch1;
! case '*':
! if (afterstar)
! have_non_dollar = true; /* multiple stars */
! afterstar = true;
! accum = 0;
! goto nextch1;
! case '$':
! have_dollar = true;
! if (accum <= 0 || accum > PG_NL_ARGMAX)
! goto bad_format;
! if (afterstar)
! {
! if (argtypes[accum] &&
! argtypes[accum] != ATYPE_INT)
! goto bad_format;
! argtypes[accum] = ATYPE_INT;
! last_dollar = Max(last_dollar, accum);
! afterstar = false;
! }
! else
! fmtpos = accum;
! accum = 0;
! goto nextch1;
! case 'l':
! if (longflag)
! longlongflag = 1;
! else
! longflag = 1;
! goto nextch1;
! case 'z':
! #if SIZEOF_SIZE_T == 8
! #ifdef HAVE_LONG_INT_64
! longflag = 1;
! #elif defined(HAVE_LONG_LONG_INT_64)
! longlongflag = 1;
! #else
! #error "Don't know how to print 64bit integers"
! #endif
#else
! /* assume size_t is same size as int */
#endif
- goto nextch1;
- case 'h':
- case '\'':
- /* ignore these */
- goto nextch1;
- case 'd':
- case 'i':
- case 'o':
- case 'u':
- case 'x':
- case 'X':
- if (fmtpos)
- {
- PrintfArgType atype;
! if (longlongflag)
! atype = ATYPE_LONGLONG;
! else if (longflag)
! atype = ATYPE_LONG;
! else
! atype = ATYPE_INT;
! if (argtypes[fmtpos] &&
! argtypes[fmtpos] != atype)
! goto bad_format;
! argtypes[fmtpos] = atype;
! last_dollar = Max(last_dollar, fmtpos);
! }
! else
! have_non_dollar = true;
! break;
! case 'c':
! if (fmtpos)
! {
! if (argtypes[fmtpos] &&
! argtypes[fmtpos] != ATYPE_INT)
! goto bad_format;
! argtypes[fmtpos] = ATYPE_INT;
! last_dollar = Max(last_dollar, fmtpos);
! }
! else
! have_non_dollar = true;
! break;
! case 's':
! case 'p':
! if (fmtpos)
! {
! if (argtypes[fmtpos] &&
! argtypes[fmtpos] != ATYPE_CHARPTR)
! goto bad_format;
! argtypes[fmtpos] = ATYPE_CHARPTR;
! last_dollar = Max(last_dollar, fmtpos);
! }
! else
! have_non_dollar = true;
! break;
! case 'e':
! case 'E':
! case 'f':
! case 'g':
! case 'G':
! if (fmtpos)
! {
! if (argtypes[fmtpos] &&
! argtypes[fmtpos] != ATYPE_DOUBLE)
! goto bad_format;
! argtypes[fmtpos] = ATYPE_DOUBLE;
! last_dollar = Max(last_dollar, fmtpos);
! }
! else
! have_non_dollar = true;
break;
! case 'm':
! case '%':
break;
}
/*
! * If we finish the spec with afterstar still set, there's a
! * non-dollar star in there.
*/
! if (afterstar)
! have_non_dollar = true;
! }
!
! /* Per spec, you use either all dollar or all not. */
! if (have_dollar && have_non_dollar)
! goto bad_format;
!
! /*
! * In dollar mode, collect the arguments in physical order.
! */
! for (i = 1; i <= last_dollar; i++)
! {
! switch (argtypes[i])
! {
! case ATYPE_NONE:
! goto bad_format;
! case ATYPE_INT:
! argvalues[i].i = va_arg(args, int);
! break;
! case ATYPE_LONG:
! argvalues[i].l = va_arg(args, long);
! break;
! case ATYPE_LONGLONG:
! argvalues[i].ll = va_arg(args, int64);
! break;
! case ATYPE_DOUBLE:
! argvalues[i].d = va_arg(args, double);
! break;
! case ATYPE_CHARPTR:
! argvalues[i].cptr = va_arg(args, char *);
! break;
! }
! }
!
! /*
! * At last we can parse the format for real.
! */
! format = format_start;
! while ((ch = *format++) != '\0')
! {
! if (target->failed)
! break;
! if (ch != '%')
! {
! dopr_outch(ch, target);
! continue;
! }
fieldwidth = precision = zpad = leftjust = forcesign = 0;
longflag = longlongflag = pointflag = 0;
fmtpos = accum = 0;
--- 357,417 ----
int precision;
int zpad;
int forcesign;
int fmtpos;
int cvalue;
int64 numvalue;
double fvalue;
char *strvalue;
PrintfArgValue argvalues[PG_NL_ARGMAX + 1];
/*
! * Initially, we suppose the format string does not use %n$. The first
! * time we come to a conversion spec that has that, we'll call
! * find_arguments() to check for consistent use of %n$ and fill the
! * argvalues array with the argument values in the correct order.
*/
! have_dollar = false;
! while (*format != '\0')
{
! /* Locate next conversion specifier */
! if (*format != '%')
{
! const char *next_pct = format + 1;
!
! /*
! * If strchrnul exists (it's a glibc-ism), it's a good bit faster
! * than the equivalent manual loop. Note: this doesn't compile
! * cleanly without -D_GNU_SOURCE, but we normally use that on
! * glibc platforms.
! */
! #ifdef HAVE_STRCHRNUL
! next_pct = strchrnul(next_pct, '%');
#else
! while (*next_pct != '\0' && *next_pct != '%')
! next_pct++;
#endif
! /* Dump literal data we just scanned over */
! dostr(format, next_pct - format, target);
! if (target->failed)
break;
!
! if (*next_pct == '\0')
break;
+ format = next_pct;
}
/*
! * Remember start of first conversion spec; if we find %n$, then it's
! * sufficient for find_arguments() to start here, without rescanning
! * earlier literal text.
*/
! if (first_pct == NULL)
! first_pct = format;
! /* Process conversion spec starting at *format */
! format++;
fieldwidth = precision = zpad = leftjust = forcesign = 0;
longflag = longlongflag = pointflag = 0;
fmtpos = accum = 0;
*************** nextch2:
*** 618,624 ****
case '*':
if (have_dollar)
{
! /* process value after reading n$ */
afterstar = true;
}
else
--- 455,465 ----
case '*':
if (have_dollar)
{
! /*
! * We'll process value after reading n$. Note it's OK to
! * assume have_dollar is set correctly, because in a valid
! * format string the initial % must have had n$ if * does.
! */
afterstar = true;
}
else
*************** nextch2:
*** 649,654 ****
--- 490,503 ----
accum = 0;
goto nextch2;
case '$':
+ /* First dollar sign? */
+ if (!have_dollar)
+ {
+ /* Yup, so examine all conversion specs in format */
+ if (!find_arguments(first_pct, args, argvalues))
+ goto bad_format;
+ have_dollar = true;
+ }
if (afterstar)
{
/* fetch and process star value */
*************** nextch2:
*** 836,841 ****
--- 685,694 ----
dopr_outch('%', target);
break;
}
+
+ /* Check for failure after each conversion spec */
+ if (target->failed)
+ break;
}
return;
*************** bad_format:
*** 845,852 ****
target->failed = true;
}
static void
! fmtstr(char *value, int leftjust, int minlen, int maxwidth,
int pointflag, PrintfTarget *target)
{
int padlen,
--- 698,933 ----
target->failed = true;
}
+ /*
+ * find_arguments(): sort out the arguments for a format spec with %n$
+ *
+ * If format is valid, return true and fill argvalues[i] with the value
+ * for the conversion spec that has %i$ or *i$. Else return false.
+ */
+ static bool
+ find_arguments(const char *format, va_list args,
+ PrintfArgValue *argvalues)
+ {
+ int ch;
+ bool afterstar;
+ int accum;
+ int longlongflag;
+ int longflag;
+ int fmtpos;
+ int i;
+ int last_dollar;
+ PrintfArgType argtypes[PG_NL_ARGMAX + 1];
+
+ /* Initialize to "no dollar arguments known" */
+ last_dollar = 0;
+ MemSet(argtypes, 0, sizeof(argtypes));
+
+ /*
+ * This loop must accept the same format strings as the one in dopr().
+ * However, we don't need to analyze them to the same level of detail.
+ *
+ * Since we're only called if there's a dollar-type spec somewhere, we can
+ * fail immediately if we find a non-dollar spec. Per the C99 standard,
+ * all argument references in the format string must be one or the other.
+ */
+ while (*format != '\0')
+ {
+ /* Locate next conversion specifier */
+ if (*format != '%')
+ {
+ /* Unlike dopr, we can just quit if there's no more specifiers */
+ format = strchr(format + 1, '%');
+ if (format == NULL)
+ break;
+ }
+
+ /* Process conversion spec starting at *format */
+ format++;
+ longflag = longlongflag = 0;
+ fmtpos = accum = 0;
+ afterstar = false;
+ nextch1:
+ ch = *format++;
+ if (ch == '\0')
+ break; /* illegal, but we don't complain */
+ switch (ch)
+ {
+ case '-':
+ case '+':
+ goto nextch1;
+ case '0':
+ case '1':
+ case '2':
+ case '3':
+ case '4':
+ case '5':
+ case '6':
+ case '7':
+ case '8':
+ case '9':
+ accum = accum * 10 + (ch - '0');
+ goto nextch1;
+ case '.':
+ accum = 0;
+ goto nextch1;
+ case '*':
+ if (afterstar)
+ return false; /* previous star missing dollar */
+ afterstar = true;
+ accum = 0;
+ goto nextch1;
+ case '$':
+ if (accum <= 0 || accum > PG_NL_ARGMAX)
+ return false;
+ if (afterstar)
+ {
+ if (argtypes[accum] &&
+ argtypes[accum] != ATYPE_INT)
+ return false;
+ argtypes[accum] = ATYPE_INT;
+ last_dollar = Max(last_dollar, accum);
+ afterstar = false;
+ }
+ else
+ fmtpos = accum;
+ accum = 0;
+ goto nextch1;
+ case 'l':
+ if (longflag)
+ longlongflag = 1;
+ else
+ longflag = 1;
+ goto nextch1;
+ case 'z':
+ #if SIZEOF_SIZE_T == 8
+ #ifdef HAVE_LONG_INT_64
+ longflag = 1;
+ #elif defined(HAVE_LONG_LONG_INT_64)
+ longlongflag = 1;
+ #else
+ #error "Don't know how to print 64bit integers"
+ #endif
+ #else
+ /* assume size_t is same size as int */
+ #endif
+ goto nextch1;
+ case 'h':
+ case '\'':
+ /* ignore these */
+ goto nextch1;
+ case 'd':
+ case 'i':
+ case 'o':
+ case 'u':
+ case 'x':
+ case 'X':
+ if (fmtpos)
+ {
+ PrintfArgType atype;
+
+ if (longlongflag)
+ atype = ATYPE_LONGLONG;
+ else if (longflag)
+ atype = ATYPE_LONG;
+ else
+ atype = ATYPE_INT;
+ if (argtypes[fmtpos] &&
+ argtypes[fmtpos] != atype)
+ return false;
+ argtypes[fmtpos] = atype;
+ last_dollar = Max(last_dollar, fmtpos);
+ }
+ else
+ return false; /* non-dollar conversion spec */
+ break;
+ case 'c':
+ if (fmtpos)
+ {
+ if (argtypes[fmtpos] &&
+ argtypes[fmtpos] != ATYPE_INT)
+ return false;
+ argtypes[fmtpos] = ATYPE_INT;
+ last_dollar = Max(last_dollar, fmtpos);
+ }
+ else
+ return false; /* non-dollar conversion spec */
+ break;
+ case 's':
+ case 'p':
+ if (fmtpos)
+ {
+ if (argtypes[fmtpos] &&
+ argtypes[fmtpos] != ATYPE_CHARPTR)
+ return false;
+ argtypes[fmtpos] = ATYPE_CHARPTR;
+ last_dollar = Max(last_dollar, fmtpos);
+ }
+ else
+ return false; /* non-dollar conversion spec */
+ break;
+ case 'e':
+ case 'E':
+ case 'f':
+ case 'g':
+ case 'G':
+ if (fmtpos)
+ {
+ if (argtypes[fmtpos] &&
+ argtypes[fmtpos] != ATYPE_DOUBLE)
+ return false;
+ argtypes[fmtpos] = ATYPE_DOUBLE;
+ last_dollar = Max(last_dollar, fmtpos);
+ }
+ else
+ return false; /* non-dollar conversion spec */
+ break;
+ case 'm':
+ case '%':
+ break;
+ }
+
+ /*
+ * If we finish the spec with afterstar still set, there's a
+ * non-dollar star in there.
+ */
+ if (afterstar)
+ return false; /* non-dollar conversion spec */
+ }
+
+ /*
+ * Format appears valid so far, so collect the arguments in physical
+ * order. (Since we rejected any non-dollar specs that would have
+ * collected arguments, we know that dopr() hasn't collected any yet.)
+ */
+ for (i = 1; i <= last_dollar; i++)
+ {
+ switch (argtypes[i])
+ {
+ case ATYPE_NONE:
+ return false;
+ case ATYPE_INT:
+ argvalues[i].i = va_arg(args, int);
+ break;
+ case ATYPE_LONG:
+ argvalues[i].l = va_arg(args, long);
+ break;
+ case ATYPE_LONGLONG:
+ argvalues[i].ll = va_arg(args, int64);
+ break;
+ case ATYPE_DOUBLE:
+ argvalues[i].d = va_arg(args, double);
+ break;
+ case ATYPE_CHARPTR:
+ argvalues[i].cptr = va_arg(args, char *);
+ break;
+ }
+ }
+
+ return true;
+ }
+
static void
! fmtstr(const char *value, int leftjust, int minlen, int maxwidth,
int pointflag, PrintfTarget *target)
{
int padlen,
*************** fmtstr(char *value, int leftjust, int mi
*** 861,877 ****
else
vallen = strlen(value);
! adjust_padlen(minlen, vallen, leftjust, &padlen);
! while (padlen > 0)
{
! dopr_outch(' ', target);
! --padlen;
}
dostr(value, vallen, target);
! trailing_pad(&padlen, target);
}
static void
--- 942,958 ----
else
vallen = strlen(value);
! padlen = compute_padlen(minlen, vallen, leftjust);
! if (padlen > 0)
{
! dopr_outchmulti(' ', padlen, target);
! padlen = 0;
}
dostr(value, vallen, target);
! trailing_pad(padlen, target);
}
static void
*************** fmtint(int64 value, char type, int force
*** 899,905 ****
int signvalue = 0;
char convert[64];
int vallen = 0;
! int padlen = 0; /* amount to pad */
int zeropad; /* extra leading zeroes */
switch (type)
--- 980,986 ----
int signvalue = 0;
char convert[64];
int vallen = 0;
! int padlen; /* amount to pad */
int zeropad; /* extra leading zeroes */
switch (type)
*************** fmtint(int64 value, char type, int force
*** 947,988 ****
do
{
! convert[vallen++] = cvt[uvalue % base];
uvalue = uvalue / base;
} while (uvalue);
}
zeropad = Max(0, precision - vallen);
! adjust_padlen(minlen, vallen + zeropad, leftjust, &padlen);
! leading_pad(zpad, &signvalue, &padlen, target);
! while (zeropad-- > 0)
! dopr_outch('0', target);
! while (vallen > 0)
! dopr_outch(convert[--vallen], target);
! trailing_pad(&padlen, target);
}
static void
fmtchar(int value, int leftjust, int minlen, PrintfTarget *target)
{
! int padlen = 0; /* amount to pad */
! adjust_padlen(minlen, 1, leftjust, &padlen);
! while (padlen > 0)
{
! dopr_outch(' ', target);
! --padlen;
}
dopr_outch(value, target);
! trailing_pad(&padlen, target);
}
static void
--- 1028,1068 ----
do
{
! convert[sizeof(convert) - (++vallen)] = cvt[uvalue % base];
uvalue = uvalue / base;
} while (uvalue);
}
zeropad = Max(0, precision - vallen);
! padlen = compute_padlen(minlen, vallen + zeropad, leftjust);
! leading_pad(zpad, signvalue, &padlen, target);
! if (zeropad > 0)
! dopr_outchmulti('0', zeropad, target);
! dostr(convert + sizeof(convert) - vallen, vallen, target);
! trailing_pad(padlen, target);
}
static void
fmtchar(int value, int leftjust, int minlen, PrintfTarget *target)
{
! int padlen; /* amount to pad */
! padlen = compute_padlen(minlen, 1, leftjust);
! if (padlen > 0)
{
! dopr_outchmulti(' ', padlen, target);
! padlen = 0;
}
dopr_outch(value, target);
! trailing_pad(padlen, target);
}
static void
*************** fmtfloat(double value, char type, int fo
*** 993,1002 ****
int signvalue = 0;
int prec;
int vallen;
! char fmt[32];
char convert[1024];
int zeropadlen = 0; /* amount to pad with zeroes */
! int padlen = 0; /* amount to pad with spaces */
/*
* We rely on the regular C library's sprintf to do the basic conversion,
--- 1073,1086 ----
int signvalue = 0;
int prec;
int vallen;
! char fmt[8];
char convert[1024];
int zeropadlen = 0; /* amount to pad with zeroes */
! int padlen; /* amount to pad with spaces */
!
! /* Handle sign (NaNs have no sign) */
! if (!isnan(value) && adjust_sign((value < 0), forcesign, &signvalue))
! value = -value;
/*
* We rely on the regular C library's sprintf to do the basic conversion,
*************** fmtfloat(double value, char type, int fo
*** 1018,1034 ****
if (pointflag)
{
- if (sprintf(fmt, "%%.%d%c", prec, type) < 0)
- goto fail;
zeropadlen = precision - prec;
}
- else if (sprintf(fmt, "%%%c", type) < 0)
- goto fail;
-
- if (!isnan(value) && adjust_sign((value < 0), forcesign, &signvalue))
- value = -value;
-
- vallen = sprintf(convert, fmt, value);
if (vallen < 0)
goto fail;
--- 1102,1122 ----
if (pointflag)
{
zeropadlen = precision - prec;
+ fmt[0] = '%';
+ fmt[1] = '.';
+ fmt[2] = '*';
+ fmt[3] = type;
+ fmt[4] = '\0';
+ vallen = sprintf(convert, fmt, prec, value);
+ }
+ else
+ {
+ fmt[0] = '%';
+ fmt[1] = type;
+ fmt[2] = '\0';
+ vallen = sprintf(convert, fmt, value);
}
if (vallen < 0)
goto fail;
*************** fmtfloat(double value, char type, int fo
*** 1036,1044 ****
if (zeropadlen > 0 && !isdigit((unsigned char) convert[vallen - 1]))
zeropadlen = 0;
! adjust_padlen(minlen, vallen + zeropadlen, leftjust, &padlen);
! leading_pad(zpad, &signvalue, &padlen, target);
if (zeropadlen > 0)
{
--- 1124,1132 ----
if (zeropadlen > 0 && !isdigit((unsigned char) convert[vallen - 1]))
zeropadlen = 0;
! padlen = compute_padlen(minlen, vallen + zeropadlen, leftjust);
! leading_pad(zpad, signvalue, &padlen, target);
if (zeropadlen > 0)
{
*************** fmtfloat(double value, char type, int fo
*** 1049,1066 ****
epos = strrchr(convert, 'E');
if (epos)
{
! /* pad after exponent */
dostr(convert, epos - convert, target);
! while (zeropadlen-- > 0)
! dopr_outch('0', target);
dostr(epos, vallen - (epos - convert), target);
}
else
{
/* no exponent, pad after the digits */
dostr(convert, vallen, target);
! while (zeropadlen-- > 0)
! dopr_outch('0', target);
}
}
else
--- 1137,1154 ----
epos = strrchr(convert, 'E');
if (epos)
{
! /* pad before exponent */
dostr(convert, epos - convert, target);
! if (zeropadlen > 0)
! dopr_outchmulti('0', zeropadlen, target);
dostr(epos, vallen - (epos - convert), target);
}
else
{
/* no exponent, pad after the digits */
dostr(convert, vallen, target);
! if (zeropadlen > 0)
! dopr_outchmulti('0', zeropadlen, target);
}
}
else
*************** fmtfloat(double value, char type, int fo
*** 1069,1075 ****
dostr(convert, vallen, target);
}
! trailing_pad(&padlen, target);
return;
fail:
--- 1157,1163 ----
dostr(convert, vallen, target);
}
! trailing_pad(padlen, target);
return;
fail:
*************** fail:
*** 1079,1084 ****
--- 1167,1179 ----
static void
dostr(const char *str, int slen, PrintfTarget *target)
{
+ /* fast path for common case of slen == 1 */
+ if (slen == 1)
+ {
+ dopr_outch(*str, target);
+ return;
+ }
+
while (slen > 0)
{
int avail;
*************** dopr_outch(int c, PrintfTarget *target)
*** 1122,1127 ****
--- 1217,1258 ----
*(target->bufptr++) = c;
}
+ static void
+ dopr_outchmulti(int c, int slen, PrintfTarget *target)
+ {
+ /* fast path for common case of slen == 1 */
+ if (slen == 1)
+ {
+ dopr_outch(c, target);
+ return;
+ }
+
+ while (slen > 0)
+ {
+ int avail;
+
+ if (target->bufend != NULL)
+ avail = target->bufend - target->bufptr;
+ else
+ avail = slen;
+ if (avail <= 0)
+ {
+ /* buffer full, can we dump to stream? */
+ if (target->stream == NULL)
+ {
+ target->nchars += slen; /* no, lose the data */
+ return;
+ }
+ flushbuffer(target);
+ continue;
+ }
+ avail = Min(avail, slen);
+ memset(target->bufptr, c, avail);
+ target->bufptr += avail;
+ slen -= avail;
+ }
+ }
+
static int
adjust_sign(int is_negative, int forcesign, int *signvalue)
*************** adjust_sign(int is_negative, int forcesi
*** 1137,1178 ****
}
! static void
! adjust_padlen(int minlen, int vallen, int leftjust, int *padlen)
{
! *padlen = minlen - vallen;
! if (*padlen < 0)
! *padlen = 0;
if (leftjust)
! *padlen = -(*padlen);
}
static void
! leading_pad(int zpad, int *signvalue, int *padlen, PrintfTarget *target)
{
if (*padlen > 0 && zpad)
{
! if (*signvalue)
{
! dopr_outch(*signvalue, target);
--(*padlen);
! *signvalue = 0;
}
! while (*padlen > 0)
{
! dopr_outch(zpad, target);
! --(*padlen);
}
}
! while (*padlen > (*signvalue != 0))
{
! dopr_outch(' ', target);
! --(*padlen);
}
! if (*signvalue)
{
! dopr_outch(*signvalue, target);
if (*padlen > 0)
--(*padlen);
else if (*padlen < 0)
--- 1268,1315 ----
}
! static int
! compute_padlen(int minlen, int vallen, int leftjust)
{
! int padlen;
!
! padlen = minlen - vallen;
! if (padlen < 0)
! padlen = 0;
if (leftjust)
! padlen = -padlen;
! return padlen;
}
static void
! leading_pad(int zpad, int signvalue, int *padlen, PrintfTarget *target)
{
+ int maxpad;
+
if (*padlen > 0 && zpad)
{
! if (signvalue)
{
! dopr_outch(signvalue, target);
--(*padlen);
! signvalue = 0;
}
! if (*padlen > 0)
{
! dopr_outchmulti(zpad, *padlen, target);
! *padlen = 0;
}
}
! maxpad = (signvalue != 0);
! if (*padlen > maxpad)
{
! dopr_outchmulti(' ', *padlen - maxpad, target);
! *padlen = maxpad;
}
! if (signvalue)
{
! dopr_outch(signvalue, target);
if (*padlen > 0)
--(*padlen);
else if (*padlen < 0)
*************** leading_pad(int zpad, int *signvalue, in
*** 1182,1192 ****
static void
! trailing_pad(int *padlen, PrintfTarget *target)
{
! while (*padlen < 0)
! {
! dopr_outch(' ', target);
! ++(*padlen);
! }
}
--- 1319,1326 ----
static void
! trailing_pad(int padlen, PrintfTarget *target)
{
! if (padlen < 0)
! dopr_outchmulti(' ', -padlen, target);
}
diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index df35557..2e68991 100644
*** a/src/backend/utils/adt/float.c
--- b/src/backend/utils/adt/float.c
*************** float4out(PG_FUNCTION_ARGS)
*** 258,269 ****
break;
default:
{
int ndig = FLT_DIG + extra_float_digits;
if (ndig < 1)
ndig = 1;
! ascii = psprintf("%.*g", ndig, num);
}
}
--- 258,287 ----
break;
default:
{
+ /*
+ * We don't go through snprintf.c here because, for this
+ * particular choice of format string, it adds nothing of
+ * value to the native behavior of sprintf() --- except
+ * handling buffer overrun. We just make the buffer big
+ * enough to not have to worry.
+ */
+ #undef sprintf
int ndig = FLT_DIG + extra_float_digits;
+ int len PG_USED_FOR_ASSERTS_ONLY;
+ /* Neither of these limits can trigger, but be paranoid */
if (ndig < 1)
ndig = 1;
+ else if (ndig > 32)
+ ndig = 32;
! ascii = (char *) palloc(64);
!
! len = sprintf(ascii, "%.*g", ndig, num);
!
! Assert(len > 0 && len < 64);
!
! #define sprintf pg_sprintf
}
}
*************** float8out_internal(double num)
*** 494,505 ****
break;
default:
{
int ndig = DBL_DIG + extra_float_digits;
if (ndig < 1)
ndig = 1;
! ascii = psprintf("%.*g", ndig, num);
}
}
--- 512,541 ----
break;
default:
{
+ /*
+ * We don't go through snprintf.c here because, for this
+ * particular choice of format string, it adds nothing of
+ * value to the native behavior of sprintf() --- except
+ * handling buffer overrun. We just make the buffer big
+ * enough to not have to worry.
+ */
+ #undef sprintf
int ndig = DBL_DIG + extra_float_digits;
+ int len PG_USED_FOR_ASSERTS_ONLY;
+ /* Neither of these limits can trigger, but be paranoid */
if (ndig < 1)
ndig = 1;
+ else if (ndig > 32)
+ ndig = 32;
! ascii = (char *) palloc(64);
!
! len = sprintf(ascii, "%.*g", ndig, num);
!
! Assert(len > 0 && len < 64);
!
! #define sprintf pg_sprintf
}
}
old glibc (RHEL6) vs snprintf.c HEAD:
Test case: %2$.*3$f %1$d
snprintf time = 768.907 ms total, 0.000768907 ms per iteration
pg_snprintf time = 1059.85 ms total, 0.00105985 ms per iteration
ratio = 1.378
Test case: %.*g
snprintf time = 782.535 ms total, 0.000782535 ms per iteration
pg_snprintf time = 1061.71 ms total, 0.00106171 ms per iteration
ratio = 1.357
Test case: %d %d
snprintf time = 162.616 ms total, 0.000162616 ms per iteration
pg_snprintf time = 135.103 ms total, 0.000135103 ms per iteration
ratio = 0.831
Test case: %10d
snprintf time = 143.027 ms total, 0.000143027 ms per iteration
pg_snprintf time = 123.307 ms total, 0.000123307 ms per iteration
ratio = 0.862
Test case: %s
snprintf time = 306.78 ms total, 0.00030678 ms per iteration
pg_snprintf time = 89.8803 ms total, 8.98803e-05 ms per iteration
ratio = 0.293
Test case: %sx
snprintf time = 310.329 ms total, 0.000310329 ms per iteration
pg_snprintf time = 97.4798 ms total, 9.74798e-05 ms per iteration
ratio = 0.314
Test case: %d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 155.288 ms total, 0.000155288 ms per iteration
pg_snprintf time = 1393.57 ms total, 0.00139357 ms per iteration
ratio = 8.974
Test case: %1$d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 238.737 ms total, 0.000238737 ms per iteration
pg_snprintf time = 1407 ms total, 0.001407 ms per iteration
ratio = 5.894
old glibc (RHEL6) vs snprintf.c v5 patch:
Test case: %2$.*3$f %1$d
snprintf time = 768.425 ms total, 0.000768425 ms per iteration
pg_snprintf time = 895.599 ms total, 0.000895599 ms per iteration
ratio = 1.165
Test case: %.*g
snprintf time = 781.704 ms total, 0.000781704 ms per iteration
pg_snprintf time = 854.84 ms total, 0.00085484 ms per iteration
ratio = 1.094
Test case: %d %d
snprintf time = 163.596 ms total, 0.000163596 ms per iteration
pg_snprintf time = 134.837 ms total, 0.000134837 ms per iteration
ratio = 0.824
Test case: %10d
snprintf time = 143.684 ms total, 0.000143684 ms per iteration
pg_snprintf time = 91.3437 ms total, 9.13437e-05 ms per iteration
ratio = 0.636
Test case: %s
snprintf time = 307.769 ms total, 0.000307769 ms per iteration
pg_snprintf time = 70.5951 ms total, 7.05951e-05 ms per iteration
ratio = 0.229
Test case: %sx
snprintf time = 309.641 ms total, 0.000309641 ms per iteration
pg_snprintf time = 85.2016 ms total, 8.52016e-05 ms per iteration
ratio = 0.275
Test case: %d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 154.108 ms total, 0.000154108 ms per iteration
pg_snprintf time = 126.425 ms total, 0.000126425 ms per iteration
ratio = 0.820
Test case: %1$d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 239.205 ms total, 0.000239205 ms per iteration
pg_snprintf time = 220.167 ms total, 0.000220167 ms per iteration
ratio = 0.920
new glibc (Fedora 28) vs snprintf.c HEAD:
Test case: %2$.*3$f %1$d
snprintf time = 486.994 ms total, 0.000486994 ms per iteration
pg_snprintf time = 579.769 ms total, 0.000579769 ms per iteration
ratio = 1.191
Test case: %.*g
snprintf time = 472.281 ms total, 0.000472281 ms per iteration
pg_snprintf time = 640.499 ms total, 0.000640499 ms per iteration
ratio = 1.356
Test case: %d %d
snprintf time = 82.5786 ms total, 8.25786e-05 ms per iteration
pg_snprintf time = 82.8582 ms total, 8.28582e-05 ms per iteration
ratio = 1.003
Test case: %10d
snprintf time = 76.3904 ms total, 7.63904e-05 ms per iteration
pg_snprintf time = 68.9414 ms total, 6.89414e-05 ms per iteration
ratio = 0.902
Test case: %s
snprintf time = 7.80277 ms total, 7.80277e-06 ms per iteration
pg_snprintf time = 38.8177 ms total, 3.88177e-05 ms per iteration
ratio = 4.975
Test case: %sx
snprintf time = 58.1852 ms total, 5.81852e-05 ms per iteration
pg_snprintf time = 40.532 ms total, 4.0532e-05 ms per iteration
ratio = 0.697
Test case: %d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 69.3546 ms total, 6.93546e-05 ms per iteration
pg_snprintf time = 578.326 ms total, 0.000578326 ms per iteration
ratio = 8.339
Test case: %1$d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 124.402 ms total, 0.000124402 ms per iteration
pg_snprintf time = 589.417 ms total, 0.000589417 ms per iteration
ratio = 4.738
new glibc (Fedora 28) vs snprintf.c v5 patch:
Test case: %2$.*3$f %1$d
snprintf time = 488.016 ms total, 0.000488016 ms per iteration
pg_snprintf time = 486.862 ms total, 0.000486862 ms per iteration
ratio = 0.998
Test case: %.*g
snprintf time = 472.963 ms total, 0.000472963 ms per iteration
pg_snprintf time = 514.987 ms total, 0.000514987 ms per iteration
ratio = 1.089
Test case: %d %d
snprintf time = 82.7157 ms total, 8.27157e-05 ms per iteration
pg_snprintf time = 80.7262 ms total, 8.07262e-05 ms per iteration
ratio = 0.976
Test case: %10d
snprintf time = 77.337 ms total, 7.7337e-05 ms per iteration
pg_snprintf time = 48.0275 ms total, 4.80275e-05 ms per iteration
ratio = 0.621
Test case: %s
snprintf time = 7.74283 ms total, 7.74283e-06 ms per iteration
pg_snprintf time = 25.7698 ms total, 2.57698e-05 ms per iteration
ratio = 3.328
Test case: %sx
snprintf time = 59.1255 ms total, 5.91255e-05 ms per iteration
pg_snprintf time = 30.5548 ms total, 3.05548e-05 ms per iteration
ratio = 0.517
Test case: %d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 68.0464 ms total, 6.80464e-05 ms per iteration
pg_snprintf time = 55.9024 ms total, 5.59024e-05 ms per iteration
ratio = 0.822
Test case: %1$d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 124.641 ms total, 0.000124641 ms per iteration
pg_snprintf time = 79.1252 ms total, 7.91252e-05 ms per iteration
ratio = 0.635
FreeBSD 11.0 vs snprintf.c HEAD:
Test case: %2$.*3$f %1$d
snprintf time = 592.785 ms total, 0.000592785 ms per iteration
pg_snprintf time = 604.65 ms total, 0.00060465 ms per iteration
ratio = 1.020
Test case: %.*g
snprintf time = 514.67 ms total, 0.00051467 ms per iteration
pg_snprintf time = 822.477 ms total, 0.000822477 ms per iteration
ratio = 1.598
Test case: %d %d
snprintf time = 182.617 ms total, 0.000182617 ms per iteration
pg_snprintf time = 81.1515 ms total, 8.11515e-05 ms per iteration
ratio = 0.444
Test case: %10d
snprintf time = 147.134 ms total, 0.000147134 ms per iteration
pg_snprintf time = 60.1539 ms total, 6.01539e-05 ms per iteration
ratio = 0.409
Test case: %s
snprintf time = 130.103 ms total, 0.000130103 ms per iteration
pg_snprintf time = 65.1186 ms total, 6.51186e-05 ms per iteration
ratio = 0.501
Test case: %sx
snprintf time = 161.099 ms total, 0.000161099 ms per iteration
pg_snprintf time = 67.597 ms total, 6.7597e-05 ms per iteration
ratio = 0.420
Test case: %d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 272.016 ms total, 0.000272016 ms per iteration
pg_snprintf time = 576.049 ms total, 0.000576049 ms per iteration
ratio = 2.118
Test case: %1$d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 377.863 ms total, 0.000377863 ms per iteration
pg_snprintf time = 591.675 ms total, 0.000591675 ms per iteration
ratio = 1.566
FreeBSD 11.0 vs snprintf.c v5 patch:
Test case: %2$.*3$f %1$d
snprintf time = 506.083 ms total, 0.000506083 ms per iteration
pg_snprintf time = 406.696 ms total, 0.000406696 ms per iteration
ratio = 0.804
Test case: %.*g
snprintf time = 516.361 ms total, 0.000516361 ms per iteration
pg_snprintf time = 583.85 ms total, 0.00058385 ms per iteration
ratio = 1.131
Test case: %d %d
snprintf time = 183.341 ms total, 0.000183341 ms per iteration
pg_snprintf time = 115.537 ms total, 0.000115537 ms per iteration
ratio = 0.630
Test case: %10d
snprintf time = 148.071 ms total, 0.000148071 ms per iteration
pg_snprintf time = 77.2526 ms total, 7.72526e-05 ms per iteration
ratio = 0.522
Test case: %s
snprintf time = 130.47 ms total, 0.00013047 ms per iteration
pg_snprintf time = 63.1665 ms total, 6.31665e-05 ms per iteration
ratio = 0.484
Test case: %sx
snprintf time = 161.038 ms total, 0.000161038 ms per iteration
pg_snprintf time = 66.365 ms total, 6.6365e-05 ms per iteration
ratio = 0.412
Test case: %d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 275.3 ms total, 0.0002753 ms per iteration
pg_snprintf time = 169.824 ms total, 0.000169824 ms per iteration
ratio = 0.617
Test case: %1$d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 377.169 ms total, 0.000377169 ms per iteration
pg_snprintf time = 324.277 ms total, 0.000324277 ms per iteration
ratio = 0.860
OpenBSD 6.0 vs snprintf.c HEAD:
Test case: %2$.*3$f %1$d
snprintf time = 366.693 ms total, 0.000366693 ms per iteration
pg_snprintf time = 575.859 ms total, 0.000575859 ms per iteration
ratio = 1.570
Test case: %.*g
snprintf time = 487.42 ms total, 0.00048742 ms per iteration
pg_snprintf time = 783.286 ms total, 0.000783286 ms per iteration
ratio = 1.607
Test case: %d %d
snprintf time = 175.423 ms total, 0.000175423 ms per iteration
pg_snprintf time = 95.583 ms total, 9.5583e-05 ms per iteration
ratio = 0.545
Test case: %10d
snprintf time = 145.509 ms total, 0.000145509 ms per iteration
pg_snprintf time = 80.7363 ms total, 8.07363e-05 ms per iteration
ratio = 0.555
Test case: %s
snprintf time = 160.49 ms total, 0.00016049 ms per iteration
pg_snprintf time = 69.3179 ms total, 6.93179e-05 ms per iteration
ratio = 0.432
Test case: %sx
snprintf time = 179.017 ms total, 0.000179017 ms per iteration
pg_snprintf time = 72.7243 ms total, 7.27243e-05 ms per iteration
ratio = 0.406
Test case: %d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 893.578 ms total, 0.000893578 ms per iteration
pg_snprintf time = 721.957 ms total, 0.000721957 ms per iteration
ratio = 0.808
Test case: %1$d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 1696.39 ms total, 0.00169639 ms per iteration
pg_snprintf time = 731.144 ms total, 0.000731144 ms per iteration
ratio = 0.431
OpenBSD 6.0 vs snprintf.c v5 patch:
Test case: %2$.*3$f %1$d
snprintf time = 368.158 ms total, 0.000368158 ms per iteration
pg_snprintf time = 408.526 ms total, 0.000408526 ms per iteration
ratio = 1.110
Test case: %.*g
snprintf time = 486.741 ms total, 0.000486741 ms per iteration
pg_snprintf time = 548.396 ms total, 0.000548396 ms per iteration
ratio = 1.127
Test case: %d %d
snprintf time = 175.101 ms total, 0.000175101 ms per iteration
pg_snprintf time = 123.1 ms total, 0.0001231 ms per iteration
ratio = 0.703
Test case: %10d
snprintf time = 145.661 ms total, 0.000145661 ms per iteration
pg_snprintf time = 82.1964 ms total, 8.21964e-05 ms per iteration
ratio = 0.564
Test case: %s
snprintf time = 160.213 ms total, 0.000160213 ms per iteration
pg_snprintf time = 62.7285 ms total, 6.27285e-05 ms per iteration
ratio = 0.392
Test case: %sx
snprintf time = 178.462 ms total, 0.000178462 ms per iteration
pg_snprintf time = 66.0236 ms total, 6.60236e-05 ms per iteration
ratio = 0.370
Test case: %d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 892.687 ms total, 0.000892687 ms per iteration
pg_snprintf time = 183.339 ms total, 0.000183339 ms per iteration
ratio = 0.205
Test case: %1$d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 1672.81 ms total, 0.00167281 ms per iteration
pg_snprintf time = 218.761 ms total, 0.000218761 ms per iteration
ratio = 0.131
macOS Mojave vs snprintf.c HEAD:
Test case: %2$.*3$f %1$d
snprintf time = 215.462 ms total, 0.000215462 ms per iteration
pg_snprintf time = 301.006 ms total, 0.000301006 ms per iteration
ratio = 1.397
Test case: %.*g
snprintf time = 329.865 ms total, 0.000329865 ms per iteration
pg_snprintf time = 501.367 ms total, 0.000501367 ms per iteration
ratio = 1.520
Test case: %d %d
snprintf time = 83.8561 ms total, 8.38561e-05 ms per iteration
pg_snprintf time = 65.7689 ms total, 6.57689e-05 ms per iteration
ratio = 0.784
Test case: %10d
snprintf time = 65.5346 ms total, 6.55346e-05 ms per iteration
pg_snprintf time = 59.9587 ms total, 5.99587e-05 ms per iteration
ratio = 0.915
Test case: %s
snprintf time = 67.0085 ms total, 6.70085e-05 ms per iteration
pg_snprintf time = 32.315 ms total, 3.2315e-05 ms per iteration
ratio = 0.482
Test case: %sx
snprintf time = 78.1157 ms total, 7.81157e-05 ms per iteration
pg_snprintf time = 32.7136 ms total, 3.27136e-05 ms per iteration
ratio = 0.419
Test case: %d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 172.349 ms total, 0.000172349 ms per iteration
pg_snprintf time = 412.957 ms total, 0.000412957 ms per iteration
ratio = 2.396
Test case: %1$d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 303.392 ms total, 0.000303392 ms per iteration
pg_snprintf time = 427.246 ms total, 0.000427246 ms per iteration
ratio = 1.408
macOS Mojave vs snprintf.c v5 patch:
Test case: %2$.*3$f %1$d
snprintf time = 212.13 ms total, 0.00021213 ms per iteration
pg_snprintf time = 244.277 ms total, 0.000244277 ms per iteration
ratio = 1.152
Test case: %.*g
snprintf time = 337.137 ms total, 0.000337137 ms per iteration
pg_snprintf time = 371.386 ms total, 0.000371386 ms per iteration
ratio = 1.102
Test case: %d %d
snprintf time = 80.876 ms total, 8.0876e-05 ms per iteration
pg_snprintf time = 64.8164 ms total, 6.48164e-05 ms per iteration
ratio = 0.801
Test case: %10d
snprintf time = 60.1313 ms total, 6.01313e-05 ms per iteration
pg_snprintf time = 40.7794 ms total, 4.07794e-05 ms per iteration
ratio = 0.678
Test case: %s
snprintf time = 61.55 ms total, 6.155e-05 ms per iteration
pg_snprintf time = 24.1078 ms total, 2.41078e-05 ms per iteration
ratio = 0.392
Test case: %sx
snprintf time = 71.2324 ms total, 7.12324e-05 ms per iteration
pg_snprintf time = 35.2292 ms total, 3.52292e-05 ms per iteration
ratio = 0.495
Test case: %d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 149.266 ms total, 0.000149266 ms per iteration
pg_snprintf time = 101.321 ms total, 0.000101321 ms per iteration
ratio = 0.679
Test case: %1$d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890
snprintf time = 306.861 ms total, 0.000306861 ms per iteration
pg_snprintf time = 122.933 ms total, 0.000122933 ms per iteration
ratio = 0.401
#include "postgres_fe.h"
#include "portability/instr_time.h"
#include "snprintf.c"
#define TIMETEST(fmtstr,...) \
printf("Test case: %s\n", fmtstr); \
INSTR_TIME_SET_CURRENT(start); \
for (i = 0; i < count; i++) \
snprintf(buffer, sizeof(buffer), fmtstr, __VA_ARGS__); \
INSTR_TIME_SET_CURRENT(stop); \
INSTR_TIME_SUBTRACT(stop, start); \
elapsed = INSTR_TIME_GET_MILLISEC(stop); \
printf("snprintf time = %g ms total, %g ms per iteration\n", \
elapsed, elapsed / count); \
INSTR_TIME_SET_CURRENT(start); \
for (i = 0; i < count; i++) \
pg_snprintf(buffer, sizeof(buffer), fmtstr, __VA_ARGS__); \
INSTR_TIME_SET_CURRENT(stop); \
INSTR_TIME_SUBTRACT(stop, start); \
elapsed2 = INSTR_TIME_GET_MILLISEC(stop); \
printf("pg_snprintf time = %g ms total, %g ms per iteration\n", \
elapsed2, elapsed2 / count); \
printf("ratio = %.3f\n\n", elapsed2 / elapsed)
int
main(int argc, char **argv)
{
int count = 0;
char buffer[1000];
instr_time start;
instr_time stop;
double elapsed;
double elapsed2;
int i;
if (argc > 1)
count = atoi(argv[1]);
if (count <= 0)
count = 1000000;
TIMETEST("%2$.*3$f %1$d", 42, 123.456, 2);
TIMETEST("%.*g", 15, 123.456);
TIMETEST("%d %d", 15, 16);
TIMETEST("%10d", 15);
TIMETEST("%s",
"0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890");
TIMETEST("%sx",
"0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890");
TIMETEST("%d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890",
42);
TIMETEST("%1$d
0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890012345678900123456789001234567890",
42);
return 0;
}
pgsql-hackers by date: