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29380ff77d
All commands / use cases that heavily rely on double to a string representation conversion, (e.g. meaning take a double-precision floating-point number like 1.5 and return a string like "1.5" ), could benefit from a performance boost by swapping snprintf(buf,len,"%.17g",value) by the equivalent [fpconv_dtoa](https://github.com/night-shift/fpconv) or any other algorithm that ensures 100% coverage of conversion. This is a well-studied topic and Projects like MongoDB. RedPanda, PyTorch leverage libraries ( fmtlib ) that use the optimized double to string conversion underneath. The positive impact can be substantial. This PR uses the grisu2 approach ( grisu explained on https://www.cs.tufts.edu/~nr/cs257/archive/florian-loitsch/printf.pdf section 5 ). test suite changes: Despite being compatible, in some cases it produces a different result from printf, and some tests had to be adjusted. one case is that `%.17g` (which means %e or %f which ever is shorter), chose to use `5000000000` instead of 5e+9, which sounds like a bug? In other cases, we changed TCL to compare numbers instead of strings to ignore minor rounding issues (`expr 0.8 == 0.79999999999999999`)
98 lines
4.2 KiB
C
98 lines
4.2 KiB
C
/*
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* Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* * Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* * Neither the name of Redis nor the names of its contributors may be used
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* to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef __REDIS_UTIL_H
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#define __REDIS_UTIL_H
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#include <stdint.h>
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#include "sds.h"
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/* The maximum number of characters needed to represent a long double
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* as a string (long double has a huge range of some 4952 chars, see LDBL_MAX).
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* This should be the size of the buffer given to ld2string */
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#define MAX_LONG_DOUBLE_CHARS 5*1024
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/* The maximum number of characters needed to represent a double
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* as a string (double has a huge range of some 328 chars, see DBL_MAX).
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* This should be the size of the buffer for sprintf with %f */
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#define MAX_DOUBLE_CHARS 400
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/* The maximum number of characters needed to for d2string/fpconv_dtoa call.
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* Since it uses %g and not %f, some 40 chars should be enough. */
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#define MAX_D2STRING_CHARS 128
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/* Bytes needed for long -> str + '\0' */
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#define LONG_STR_SIZE 21
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/* long double to string conversion options */
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typedef enum {
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LD_STR_AUTO, /* %.17Lg */
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LD_STR_HUMAN, /* %.17Lf + Trimming of trailing zeros */
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LD_STR_HEX /* %La */
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} ld2string_mode;
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int stringmatchlen(const char *p, int plen, const char *s, int slen, int nocase);
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int stringmatch(const char *p, const char *s, int nocase);
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int stringmatchlen_fuzz_test(void);
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unsigned long long memtoull(const char *p, int *err);
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const char *mempbrk(const char *s, size_t len, const char *chars, size_t charslen);
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char *memmapchars(char *s, size_t len, const char *from, const char *to, size_t setlen);
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uint32_t digits10(uint64_t v);
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uint32_t sdigits10(int64_t v);
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int ll2string(char *s, size_t len, long long value);
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int ull2string(char *s, size_t len, unsigned long long value);
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int string2ll(const char *s, size_t slen, long long *value);
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int string2ull(const char *s, unsigned long long *value);
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int string2l(const char *s, size_t slen, long *value);
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int string2ld(const char *s, size_t slen, long double *dp);
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int string2d(const char *s, size_t slen, double *dp);
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int trimDoubleString(char *buf, size_t len);
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int d2string(char *buf, size_t len, double value);
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int ld2string(char *buf, size_t len, long double value, ld2string_mode mode);
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int double2ll(double d, long long *out);
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int yesnotoi(char *s);
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sds getAbsolutePath(char *filename);
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long getTimeZone(void);
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int pathIsBaseName(char *path);
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int dirCreateIfMissing(char *dname);
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int dirExists(char *dname);
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int dirRemove(char *dname);
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int fileExist(char *filename);
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sds makePath(char *path, char *filename);
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int fsyncFileDir(const char *filename);
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size_t redis_strlcpy(char *dst, const char *src, size_t dsize);
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size_t redis_strlcat(char *dst, const char *src, size_t dsize);
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#ifdef REDIS_TEST
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int utilTest(int argc, char **argv, int flags);
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#endif
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#endif
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