database/postgres
database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-04-21 12:05:57 +03:00
Code

Make assorted performance improvements in snprintf.c.

Browse Source 
In combination, these changes make our version of snprintf as fast
or faster than most platforms' native snprintf, except for cases
involving floating-point conversion (which we still delegate to
the native sprintf).  The speed penalty for a float conversion
is down to around 10% though, much better than before.

Notable changes:

* Rather than always parsing the format twice to see if it contains
instances of %n$, do the extra scan only if we actually find a $.
This obviously wins for non-localized formats, and even when there
is use of %n$, we can avoid scanning text before the first % twice.

* Use strchrnul() if available to find the next %, and emit the
literal text between % escapes as strings rather than char-by-char.

* Create a bespoke function (dopr_outchmulti) for the common case
of emitting N copies of the same character, in place of writing
loops around dopr_outch.

* Simplify construction of the format string for invocations of sprintf
for floats.

* Const-ify some internal functions, and avoid unnecessary use of
pass-by-reference arguments.

Patch by me, reviewed by Andres Freund

Discussion: https://postgr.es/m/11787.1534530779@sss.pgh.pa.us
This commit is contained in:
Tom Lane 2018-10-03 10:18:15 -04:00
parent 9bc9f72b28
commit abd9ca377d
5 changed files with 432 additions and 273 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
configure vendored
View File

@ -15100,7 +15100,7 @@ fi
LIBS_including_readline="$LIBS" LIBS_including_readline="$LIBS"
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'` LIBS=`echo "$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 ppoll pstat pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open symlink sync_file_range utime utimes wcstombs_l for ac_func in cbrt clock_gettime fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll posix_fallocate ppoll pstat pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open strchrnul symlink sync_file_range utime utimes wcstombs_l
do : do :
as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh` as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var" ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"

2
configure.in
View File

@ -1571,7 +1571,7 @@ PGAC_FUNC_WCSTOMBS_L
LIBS_including_readline="$LIBS" LIBS_including_readline="$LIBS"
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'` LIBS=`echo "$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_fallocate ppoll pstat pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open symlink sync_file_range utime utimes wcstombs_l]) AC_CHECK_FUNCS([cbrt clock_gettime fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll posix_fallocate ppoll pstat pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open strchrnul symlink sync_file_range utime utimes wcstombs_l])
AC_REPLACE_FUNCS(fseeko) AC_REPLACE_FUNCS(fseeko)
case $host_os in case $host_os in

3
src/include/pg_config.h.in
View File

@ -523,6 +523,9 @@
/* Define to 1 if you have the <stdlib.h> header file. */ /* Define to 1 if you have the <stdlib.h> header file. */
#undef HAVE_STDLIB_H #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. */ /* Define to 1 if you have the `strerror_r' function. */
#undef HAVE_STRERROR_R #undef HAVE_STRERROR_R

3
src/include/pg_config.h.win32
View File

@ -394,6 +394,9 @@
/* Define to 1 if you have the <stdlib.h> header file. */ /* Define to 1 if you have the <stdlib.h> header file. */
#define HAVE_STDLIB_H 1 #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. */ /* Define to 1 if you have the `strerror_r' function. */
/* #undef HAVE_STRERROR_R */ /* #undef HAVE_STRERROR_R */

695
src/port/snprintf.c
View File

@ -314,7 +314,9 @@ flushbuffer(PrintfTarget *target)
} }
static void fmtstr(char *value, int leftjust, int minlen, int maxwidth, 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); int pointflag, PrintfTarget *target);
static void fmtptr(void *value, PrintfTarget *target); static void fmtptr(void *value, PrintfTarget *target);
static void fmtint(int64 value, char type, int forcesign, static void fmtint(int64 value, char type, int forcesign,
@ -326,11 +328,43 @@ static void fmtfloat(double value, char type, int forcesign,
PrintfTarget *target); PrintfTarget *target);
static void dostr(const char *str, int slen, PrintfTarget *target); static void dostr(const char *str, int slen, PrintfTarget *target);
static void dopr_outch(int c, 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 adjust_sign(int is_negative, int forcesign, int *signvalue);
static void adjust_padlen(int minlen, int vallen, int leftjust, int *padlen); static int compute_padlen(int minlen, int vallen, int leftjust);
static void leading_pad(int zpad, int *signvalue, int *padlen, static void leading_pad(int zpad, int signvalue, int *padlen,
PrintfTarget *target); PrintfTarget *target);
static void trailing_pad(int *padlen, PrintfTarget *target); static void trailing_pad(int padlen, PrintfTarget *target);
/*
* If strchrnul exists (it's a glibc-ism), it's a good bit faster than the
* equivalent manual loop. If it doesn't exist, provide a replacement.
*
* Note: glibc declares this as returning "char *", but that would require
* casting away const internally, so we don't follow that detail.
*/
#ifndef HAVE_STRCHRNUL
static inline const char *
strchrnul(const char *s, int c)
{
while (*s != '\0' && *s != c)
s++;
return s;
}
#else
/*
* glibc's <string.h> declares strchrnul only if _GNU_SOURCE is defined.
* While we typically use that on glibc platforms, configure will set
* HAVE_STRCHRNUL whether it's used or not. Fill in the missing declaration
* so that this file will compile cleanly with or without _GNU_SOURCE.
*/
#ifndef _GNU_SOURCE
extern char *strchrnul(const char *s, int c);
#endif
#endif /* HAVE_STRCHRNUL */
/* /*
@ -340,10 +374,9 @@ static void
dopr(PrintfTarget *target, const char *format, va_list args) dopr(PrintfTarget *target, const char *format, va_list args)
{ {
int save_errno = errno; int save_errno = errno;
const char *format_start = format; const char *first_pct = NULL;
int ch; int ch;
bool have_dollar; bool have_dollar;
bool have_non_dollar;
bool have_star; bool have_star;
bool afterstar; bool afterstar;
int accum; int accum;
@ -355,226 +388,49 @@ dopr(PrintfTarget *target, const char *format, va_list args)
int precision; int precision;
int zpad; int zpad;
int forcesign; int forcesign;
int last_dollar;
int fmtpos; int fmtpos;
int cvalue; int cvalue;
int64 numvalue; int64 numvalue;
double fvalue; double fvalue;
char *strvalue; char *strvalue;
int i;
PrintfArgType argtypes[PG_NL_ARGMAX + 1];
PrintfArgValue argvalues[PG_NL_ARGMAX + 1]; PrintfArgValue argvalues[PG_NL_ARGMAX + 1];
/* /*
* Parse the format string to determine whether there are %n$ format * Initially, we suppose the format string does not use %n$. The first
* specs, and identify the types and order of the format parameters. * time we come to a conversion spec that has that, we'll call
* find_arguments() to check for consistent use of %n$ and fill the
* argvalues array with the argument values in the correct order.
*/ */
have_dollar = have_non_dollar = false; have_dollar = false;
last_dollar = 0;
MemSet(argtypes, 0, sizeof(argtypes));
while ((ch = *format++) != '\0') while (*format != '\0')
{ {
if (ch != '%') /* Locate next conversion specifier */
continue; if (*format != '%')
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 '-': /* Scan to next '%' or end of string */
case '+': const char *next_pct = strchrnul(format + 1, '%');
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) /* Dump literal data we just scanned over */
atype = ATYPE_LONGLONG; dostr(format, next_pct - format, target);
else if (longflag) if (target->failed)
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; break;
case 'c':
if (fmtpos) if (*next_pct == '\0')
{
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; break;
format = next_pct;
} }
/* /*
* If we finish the spec with afterstar still set, there's a * Remember start of first conversion spec; if we find %n$, then it's
* non-dollar star in there. * sufficient for find_arguments() to start here, without rescanning
* earlier literal text.
*/ */
if (afterstar) if (first_pct == NULL)
have_non_dollar = true; first_pct = format;
}
/* Per spec, you use either all dollar or all not. */ /* Process conversion spec starting at *format */
if (have_dollar && have_non_dollar) format++;
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; fieldwidth = precision = zpad = leftjust = forcesign = 0;
longflag = longlongflag = pointflag = 0; longflag = longlongflag = pointflag = 0;
fmtpos = accum = 0; fmtpos = accum = 0;
@ -618,7 +474,11 @@ nextch2:
case '*': case '*':
if (have_dollar) if (have_dollar)
{ {
/* process value after reading n$ */ /*
* 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; afterstar = true;
} }
else else
@ -649,6 +509,14 @@ nextch2:
accum = 0; accum = 0;
goto nextch2; goto nextch2;
case '$': case '$':
/* 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) if (afterstar)
{ {
/* fetch and process star value */ /* fetch and process star value */
@ -836,6 +704,10 @@ nextch2:
dopr_outch('%', target); dopr_outch('%', target);
break; break;
} }
/* Check for failure after each conversion spec */
if (target->failed)
break;
} }
return; return;
@ -845,8 +717,236 @@ bad_format:
target->failed = true; 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 static void
fmtstr(char *value, int leftjust, int minlen, int maxwidth, fmtstr(const char *value, int leftjust, int minlen, int maxwidth,
int pointflag, PrintfTarget *target) int pointflag, PrintfTarget *target)
{ {
int padlen, int padlen,
@ -861,17 +961,17 @@ fmtstr(char *value, int leftjust, int minlen, int maxwidth,
else else
vallen = strlen(value); vallen = strlen(value);
adjust_padlen(minlen, vallen, leftjust, &padlen); padlen = compute_padlen(minlen, vallen, leftjust);
while (padlen > 0) if (padlen > 0)
{ {
dopr_outch(' ', target); dopr_outchmulti(' ', padlen, target);
--padlen; padlen = 0;
} }
dostr(value, vallen, target); dostr(value, vallen, target);
trailing_pad(&padlen, target); trailing_pad(padlen, target);
} }
static void static void
@ -899,7 +999,7 @@ fmtint(int64 value, char type, int forcesign, int leftjust,
int signvalue = 0; int signvalue = 0;
char convert[64]; char convert[64];
int vallen = 0; int vallen = 0;
int padlen = 0; /* amount to pad */ int padlen; /* amount to pad */
int zeropad; /* extra leading zeroes */ int zeropad; /* extra leading zeroes */
switch (type) switch (type)
@ -947,42 +1047,41 @@ fmtint(int64 value, char type, int forcesign, int leftjust,
do do
{ {
convert[vallen++] = cvt[uvalue % base]; convert[sizeof(convert) - (++vallen)] = cvt[uvalue % base];
uvalue = uvalue / base; uvalue = uvalue / base;
} while (uvalue); } while (uvalue);
} }
zeropad = Max(0, precision - vallen); zeropad = Max(0, precision - vallen);
adjust_padlen(minlen, vallen + zeropad, leftjust, &padlen); padlen = compute_padlen(minlen, vallen + zeropad, leftjust);
leading_pad(zpad, &signvalue, &padlen, target); leading_pad(zpad, signvalue, &padlen, target);
while (zeropad-- > 0) if (zeropad > 0)
dopr_outch('0', target); dopr_outchmulti('0', zeropad, target);
while (vallen > 0) dostr(convert + sizeof(convert) - vallen, vallen, target);
dopr_outch(convert[--vallen], target);
trailing_pad(&padlen, target); trailing_pad(padlen, target);
} }
static void static void
fmtchar(int value, int leftjust, int minlen, PrintfTarget *target) fmtchar(int value, int leftjust, int minlen, PrintfTarget *target)
{ {
int padlen = 0; /* amount to pad */ int padlen; /* amount to pad */
adjust_padlen(minlen, 1, leftjust, &padlen); padlen = compute_padlen(minlen, 1, leftjust);
while (padlen > 0) if (padlen > 0)
{ {
dopr_outch(' ', target); dopr_outchmulti(' ', padlen, target);
--padlen; padlen = 0;
} }
dopr_outch(value, target); dopr_outch(value, target);
trailing_pad(&padlen, target); trailing_pad(padlen, target);
} }
static void static void
@ -993,10 +1092,14 @@ fmtfloat(double value, char type, int forcesign, int leftjust,
int signvalue = 0; int signvalue = 0;
int prec; int prec;
int vallen; int vallen;
char fmt[32]; char fmt[8];
char convert[1024]; char convert[1024];
int zeropadlen = 0; /* amount to pad with zeroes */ int zeropadlen = 0; /* amount to pad with zeroes */
int padlen = 0; /* amount to pad with spaces */ 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, * We rely on the regular C library's sprintf to do the basic conversion,
@ -1018,17 +1121,21 @@ fmtfloat(double value, char type, int forcesign, int leftjust,
if (pointflag) if (pointflag)
{ {
if (sprintf(fmt, "%%.%d%c", prec, type) < 0)
goto fail;
zeropadlen = precision - prec; 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);
} }
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) if (vallen < 0)
goto fail; goto fail;
@ -1036,9 +1143,9 @@ fmtfloat(double value, char type, int forcesign, int leftjust,
if (zeropadlen > 0 && !isdigit((unsigned char) convert[vallen - 1])) if (zeropadlen > 0 && !isdigit((unsigned char) convert[vallen - 1]))
zeropadlen = 0; zeropadlen = 0;
adjust_padlen(minlen, vallen + zeropadlen, leftjust, &padlen); padlen = compute_padlen(minlen, vallen + zeropadlen, leftjust);
leading_pad(zpad, &signvalue, &padlen, target); leading_pad(zpad, signvalue, &padlen, target);
if (zeropadlen > 0) if (zeropadlen > 0)
{ {
@ -1049,18 +1156,18 @@ fmtfloat(double value, char type, int forcesign, int leftjust,
epos = strrchr(convert, 'E'); epos = strrchr(convert, 'E');
if (epos) if (epos)
{ {
/* pad after exponent */ /* pad before exponent */
dostr(convert, epos - convert, target); dostr(convert, epos - convert, target);
while (zeropadlen-- > 0) if (zeropadlen > 0)
dopr_outch('0', target); dopr_outchmulti('0', zeropadlen, target);
dostr(epos, vallen - (epos - convert), target); dostr(epos, vallen - (epos - convert), target);
} }
else else
{ {
/* no exponent, pad after the digits */ /* no exponent, pad after the digits */
dostr(convert, vallen, target); dostr(convert, vallen, target);
while (zeropadlen-- > 0) if (zeropadlen > 0)
dopr_outch('0', target); dopr_outchmulti('0', zeropadlen, target);
} }
} }
else else
@ -1069,7 +1176,7 @@ fmtfloat(double value, char type, int forcesign, int leftjust,
dostr(convert, vallen, target); dostr(convert, vallen, target);
} }
trailing_pad(&padlen, target); trailing_pad(padlen, target);
return; return;
fail: fail:
@ -1079,6 +1186,13 @@ fail:
static void static void
dostr(const char *str, int slen, PrintfTarget *target) 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) while (slen > 0)
{ {
int avail; int avail;
@ -1122,6 +1236,42 @@ dopr_outch(int c, PrintfTarget *target)
*(target->bufptr++) = c; *(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 static int
adjust_sign(int is_negative, int forcesign, int *signvalue) adjust_sign(int is_negative, int forcesign, int *signvalue)
@ -1137,42 +1287,48 @@ adjust_sign(int is_negative, int forcesign, int *signvalue)
} }
static void static int
adjust_padlen(int minlen, int vallen, int leftjust, int *padlen) compute_padlen(int minlen, int vallen, int leftjust)
{ {
*padlen = minlen - vallen; int padlen;
if (*padlen < 0)
*padlen = 0; padlen = minlen - vallen;
if (padlen < 0)
padlen = 0;
if (leftjust) if (leftjust)
*padlen = -(*padlen); padlen = -padlen;
return padlen;
} }
static void static void
leading_pad(int zpad, int *signvalue, int *padlen, PrintfTarget *target) leading_pad(int zpad, int signvalue, int *padlen, PrintfTarget *target)
{ {
int maxpad;
if (*padlen > 0 && zpad) if (*padlen > 0 && zpad)
{ {
if (*signvalue) if (signvalue)
{ {
dopr_outch(*signvalue, target); dopr_outch(signvalue, target);
--(*padlen); --(*padlen);
*signvalue = 0; signvalue = 0;
} }
while (*padlen > 0) if (*padlen > 0)
{ {
dopr_outch(zpad, target); dopr_outchmulti(zpad, *padlen, target);
--(*padlen); *padlen = 0;
} }
} }
while (*padlen > (*signvalue != 0)) maxpad = (signvalue != 0);
if (*padlen > maxpad)
{ {
dopr_outch(' ', target); dopr_outchmulti(' ', *padlen - maxpad, target);
--(*padlen); *padlen = maxpad;
} }
if (*signvalue) if (signvalue)
{ {
dopr_outch(*signvalue, target); dopr_outch(signvalue, target);
if (*padlen > 0) if (*padlen > 0)
--(*padlen); --(*padlen);
else if (*padlen < 0) else if (*padlen < 0)
@ -1182,11 +1338,8 @@ leading_pad(int zpad, int *signvalue, int *padlen, PrintfTarget *target)
static void static void
trailing_pad(int *padlen, PrintfTarget *target) trailing_pad(int padlen, PrintfTarget *target)
{ {
while (*padlen < 0) if (padlen < 0)
{ dopr_outchmulti(' ', -padlen, target);
dopr_outch(' ', target);
++(*padlen);
}
} }