redis/src/util.c

835 lines
26 KiB
C

/*
* Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "fmacros.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <limits.h>
#include <math.h>
#include <unistd.h>
#include <sys/time.h>
#include <float.h>
#include <stdint.h>
#include <errno.h>
#include "util.h"
#include "sha1.h"
/* Glob-style pattern matching. */
int stringmatchlen(const char *pattern, int patternLen,
const char *string, int stringLen, int nocase)
{
while(patternLen) {
switch(pattern[0]) {
case '*':
while (pattern[1] == '*') {
pattern++;
patternLen--;
}
if (patternLen == 1)
return 1; /* match */
while(stringLen) {
if (stringmatchlen(pattern+1, patternLen-1,
string, stringLen, nocase))
return 1; /* match */
string++;
stringLen--;
}
return 0; /* no match */
break;
case '?':
if (stringLen == 0)
return 0; /* no match */
string++;
stringLen--;
break;
case '[':
{
int not, match;
pattern++;
patternLen--;
not = pattern[0] == '^';
if (not) {
pattern++;
patternLen--;
}
match = 0;
while(1) {
if (pattern[0] == '\\') {
pattern++;
patternLen--;
if (pattern[0] == string[0])
match = 1;
} else if (pattern[0] == ']') {
break;
} else if (patternLen == 0) {
pattern--;
patternLen++;
break;
} else if (pattern[1] == '-' && patternLen >= 3) {
int start = pattern[0];
int end = pattern[2];
int c = string[0];
if (start > end) {
int t = start;
start = end;
end = t;
}
if (nocase) {
start = tolower(start);
end = tolower(end);
c = tolower(c);
}
pattern += 2;
patternLen -= 2;
if (c >= start && c <= end)
match = 1;
} else {
if (!nocase) {
if (pattern[0] == string[0])
match = 1;
} else {
if (tolower((int)pattern[0]) == tolower((int)string[0]))
match = 1;
}
}
pattern++;
patternLen--;
}
if (not)
match = !match;
if (!match)
return 0; /* no match */
string++;
stringLen--;
break;
}
case '\\':
if (patternLen >= 2) {
pattern++;
patternLen--;
}
/* fall through */
default:
if (!nocase) {
if (pattern[0] != string[0])
return 0; /* no match */
} else {
if (tolower((int)pattern[0]) != tolower((int)string[0]))
return 0; /* no match */
}
string++;
stringLen--;
break;
}
pattern++;
patternLen--;
if (stringLen == 0) {
while(*pattern == '*') {
pattern++;
patternLen--;
}
break;
}
}
if (patternLen == 0 && stringLen == 0)
return 1;
return 0;
}
int stringmatch(const char *pattern, const char *string, int nocase) {
return stringmatchlen(pattern,strlen(pattern),string,strlen(string),nocase);
}
/* Convert a string representing an amount of memory into the number of
* bytes, so for instance memtoll("1Gb") will return 1073741824 that is
* (1024*1024*1024).
*
* On parsing error, if *err is not NULL, it's set to 1, otherwise it's
* set to 0. On error the function return value is 0, regardless of the
* fact 'err' is NULL or not. */
long long memtoll(const char *p, int *err) {
const char *u;
char buf[128];
long mul; /* unit multiplier */
long long val;
unsigned int digits;
if (err) *err = 0;
/* Search the first non digit character. */
u = p;
if (*u == '-') u++;
while(*u && isdigit(*u)) u++;
if (*u == '\0' || !strcasecmp(u,"b")) {
mul = 1;
} else if (!strcasecmp(u,"k")) {
mul = 1000;
} else if (!strcasecmp(u,"kb")) {
mul = 1024;
} else if (!strcasecmp(u,"m")) {
mul = 1000*1000;
} else if (!strcasecmp(u,"mb")) {
mul = 1024*1024;
} else if (!strcasecmp(u,"g")) {
mul = 1000L*1000*1000;
} else if (!strcasecmp(u,"gb")) {
mul = 1024L*1024*1024;
} else {
if (err) *err = 1;
return 0;
}
/* Copy the digits into a buffer, we'll use strtoll() to convert
* the digit (without the unit) into a number. */
digits = u-p;
if (digits >= sizeof(buf)) {
if (err) *err = 1;
return 0;
}
memcpy(buf,p,digits);
buf[digits] = '\0';
char *endptr;
errno = 0;
val = strtoll(buf,&endptr,10);
if ((val == 0 && errno == EINVAL) || *endptr != '\0') {
if (err) *err = 1;
return 0;
}
return val*mul;
}
/* Return the number of digits of 'v' when converted to string in radix 10.
* See ll2string() for more information. */
uint32_t digits10(uint64_t v) {
if (v < 10) return 1;
if (v < 100) return 2;
if (v < 1000) return 3;
if (v < 1000000000000UL) {
if (v < 100000000UL) {
if (v < 1000000) {
if (v < 10000) return 4;
return 5 + (v >= 100000);
}
return 7 + (v >= 10000000UL);
}
if (v < 10000000000UL) {
return 9 + (v >= 1000000000UL);
}
return 11 + (v >= 100000000000UL);
}
return 12 + digits10(v / 1000000000000UL);
}
/* Like digits10() but for signed values. */
uint32_t sdigits10(int64_t v) {
if (v < 0) {
/* Abs value of LLONG_MIN requires special handling. */
uint64_t uv = (v != LLONG_MIN) ?
(uint64_t)-v : ((uint64_t) LLONG_MAX)+1;
return digits10(uv)+1; /* +1 for the minus. */
} else {
return digits10(v);
}
}
/* Convert a long long into a string. Returns the number of
* characters needed to represent the number.
* If the buffer is not big enough to store the string, 0 is returned.
*
* Based on the following article (that apparently does not provide a
* novel approach but only publicizes an already used technique):
*
* https://www.facebook.com/notes/facebook-engineering/three-optimization-tips-for-c/10151361643253920
*
* Modified in order to handle signed integers since the original code was
* designed for unsigned integers. */
int ll2string(char *dst, size_t dstlen, long long svalue) {
static const char digits[201] =
"0001020304050607080910111213141516171819"
"2021222324252627282930313233343536373839"
"4041424344454647484950515253545556575859"
"6061626364656667686970717273747576777879"
"8081828384858687888990919293949596979899";
int negative;
unsigned long long value;
/* The main loop works with 64bit unsigned integers for simplicity, so
* we convert the number here and remember if it is negative. */
if (svalue < 0) {
if (svalue != LLONG_MIN) {
value = -svalue;
} else {
value = ((unsigned long long) LLONG_MAX)+1;
}
negative = 1;
} else {
value = svalue;
negative = 0;
}
/* Check length. */
uint32_t const length = digits10(value)+negative;
if (length >= dstlen) return 0;
/* Null term. */
uint32_t next = length;
dst[next] = '\0';
next--;
while (value >= 100) {
int const i = (value % 100) * 2;
value /= 100;
dst[next] = digits[i + 1];
dst[next - 1] = digits[i];
next -= 2;
}
/* Handle last 1-2 digits. */
if (value < 10) {
dst[next] = '0' + (uint32_t) value;
} else {
int i = (uint32_t) value * 2;
dst[next] = digits[i + 1];
dst[next - 1] = digits[i];
}
/* Add sign. */
if (negative) dst[0] = '-';
return length;
}
/* Convert a string into a long long. Returns 1 if the string could be parsed
* into a (non-overflowing) long long, 0 otherwise. The value will be set to
* the parsed value when appropriate.
*
* Note that this function demands that the string strictly represents
* a long long: no spaces or other characters before or after the string
* representing the number are accepted, nor zeroes at the start if not
* for the string "0" representing the zero number.
*
* Because of its strictness, it is safe to use this function to check if
* you can convert a string into a long long, and obtain back the string
* from the number without any loss in the string representation. */
int string2ll(const char *s, size_t slen, long long *value) {
const char *p = s;
size_t plen = 0;
int negative = 0;
unsigned long long v;
if (plen == slen)
return 0;
/* Special case: first and only digit is 0. */
if (slen == 1 && p[0] == '0') {
if (value != NULL) *value = 0;
return 1;
}
if (p[0] == '-') {
negative = 1;
p++; plen++;
/* Abort on only a negative sign. */
if (plen == slen)
return 0;
}
/* First digit should be 1-9, otherwise the string should just be 0. */
if (p[0] >= '1' && p[0] <= '9') {
v = p[0]-'0';
p++; plen++;
} else if (p[0] == '0' && slen == 1) {
*value = 0;
return 1;
} else {
return 0;
}
while (plen < slen && p[0] >= '0' && p[0] <= '9') {
if (v > (ULLONG_MAX / 10)) /* Overflow. */
return 0;
v *= 10;
if (v > (ULLONG_MAX - (p[0]-'0'))) /* Overflow. */
return 0;
v += p[0]-'0';
p++; plen++;
}
/* Return if not all bytes were used. */
if (plen < slen)
return 0;
if (negative) {
if (v > ((unsigned long long)(-(LLONG_MIN+1))+1)) /* Overflow. */
return 0;
if (value != NULL) *value = -v;
} else {
if (v > LLONG_MAX) /* Overflow. */
return 0;
if (value != NULL) *value = v;
}
return 1;
}
/* Convert a string into a long. Returns 1 if the string could be parsed into a
* (non-overflowing) long, 0 otherwise. The value will be set to the parsed
* value when appropriate. */
int string2l(const char *s, size_t slen, long *lval) {
long long llval;
if (!string2ll(s,slen,&llval))
return 0;
if (llval < LONG_MIN || llval > LONG_MAX)
return 0;
*lval = (long)llval;
return 1;
}
/* Convert a string into a double. Returns 1 if the string could be parsed
* into a (non-overflowing) double, 0 otherwise. The value will be set to
* the parsed value when appropriate.
*
* Note that this function demands that the string strictly represents
* a double: no spaces or other characters before or after the string
* representing the number are accepted. */
int string2ld(const char *s, size_t slen, long double *dp) {
char buf[256];
long double value;
char *eptr;
if (slen >= sizeof(buf)) return 0;
memcpy(buf,s,slen);
buf[slen] = '\0';
errno = 0;
value = strtold(buf, &eptr);
if (isspace(buf[0]) || eptr[0] != '\0' ||
(errno == ERANGE &&
(value == HUGE_VAL || value == -HUGE_VAL || value == 0)) ||
errno == EINVAL ||
isnan(value))
return 0;
if (dp) *dp = value;
return 1;
}
/* Convert a double to a string representation. Returns the number of bytes
* required. The representation should always be parsable by strtod(3).
* This function does not support human-friendly formatting like ld2string
* does. It is intended mainly to be used inside t_zset.c when writing scores
* into a ziplist representing a sorted set. */
int d2string(char *buf, size_t len, double value) {
if (isnan(value)) {
len = snprintf(buf,len,"nan");
} else if (isinf(value)) {
if (value < 0)
len = snprintf(buf,len,"-inf");
else
len = snprintf(buf,len,"inf");
} else if (value == 0) {
/* See: http://en.wikipedia.org/wiki/Signed_zero, "Comparisons". */
if (1.0/value < 0)
len = snprintf(buf,len,"-0");
else
len = snprintf(buf,len,"0");
} else {
#if (DBL_MANT_DIG >= 52) && (LLONG_MAX == 0x7fffffffffffffffLL)
/* Check if the float is in a safe range to be casted into a
* long long. We are assuming that long long is 64 bit here.
* Also we are assuming that there are no implementations around where
* double has precision < 52 bit.
*
* Under this assumptions we test if a double is inside an interval
* where casting to long long is safe. Then using two castings we
* make sure the decimal part is zero. If all this is true we use
* integer printing function that is much faster. */
double min = -4503599627370495; /* (2^52)-1 */
double max = 4503599627370496; /* -(2^52) */
if (value > min && value < max && value == ((double)((long long)value)))
len = ll2string(buf,len,(long long)value);
else
#endif
len = snprintf(buf,len,"%.17g",value);
}
return len;
}
/* Convert a long double into a string. If humanfriendly is non-zero
* it does not use exponential format and trims trailing zeroes at the end,
* however this results in loss of precision. Otherwise exp format is used
* and the output of snprintf() is not modified.
*
* The function returns the length of the string or zero if there was not
* enough buffer room to store it. */
int ld2string(char *buf, size_t len, long double value, int humanfriendly) {
size_t l;
if (isinf(value)) {
/* Libc in odd systems (Hi Solaris!) will format infinite in a
* different way, so better to handle it in an explicit way. */
if (len < 5) return 0; /* No room. 5 is "-inf\0" */
if (value > 0) {
memcpy(buf,"inf",3);
l = 3;
} else {
memcpy(buf,"-inf",4);
l = 4;
}
} else if (humanfriendly) {
/* We use 17 digits precision since with 128 bit floats that precision
* after rounding is able to represent most small decimal numbers in a
* way that is "non surprising" for the user (that is, most small
* decimal numbers will be represented in a way that when converted
* back into a string are exactly the same as what the user typed.) */
l = snprintf(buf,len,"%.17Lf", value);
if (l+1 > len) return 0; /* No room. */
/* Now remove trailing zeroes after the '.' */
if (strchr(buf,'.') != NULL) {
char *p = buf+l-1;
while(*p == '0') {
p--;
l--;
}
if (*p == '.') l--;
}
} else {
l = snprintf(buf,len,"%.17Lg", value);
if (l+1 > len) return 0; /* No room. */
}
buf[l] = '\0';
return l;
}
/* Generate the Redis "Run ID", a SHA1-sized random number that identifies a
* given execution of Redis, so that if you are talking with an instance
* having run_id == A, and you reconnect and it has run_id == B, you can be
* sure that it is either a different instance or it was restarted. */
void getRandomHexChars(char *p, unsigned int len) {
char *charset = "0123456789abcdef";
unsigned int j;
/* Global state. */
static int seed_initialized = 0;
static unsigned char seed[20]; /* The SHA1 seed, from /dev/urandom. */
static uint64_t counter = 0; /* The counter we hash with the seed. */
if (!seed_initialized) {
/* Initialize a seed and use SHA1 in counter mode, where we hash
* the same seed with a progressive counter. For the goals of this
* function we just need non-colliding strings, there are no
* cryptographic security needs. */
FILE *fp = fopen("/dev/urandom","r");
if (fp && fread(seed,sizeof(seed),1,fp) == 1)
seed_initialized = 1;
if (fp) fclose(fp);
}
if (seed_initialized) {
while(len) {
unsigned char digest[20];
SHA1_CTX ctx;
unsigned int copylen = len > 20 ? 20 : len;
SHA1Init(&ctx);
SHA1Update(&ctx, seed, sizeof(seed));
SHA1Update(&ctx, (unsigned char*)&counter,sizeof(counter));
SHA1Final(digest, &ctx);
counter++;
memcpy(p,digest,copylen);
/* Convert to hex digits. */
for (j = 0; j < copylen; j++) p[j] = charset[p[j] & 0x0F];
len -= copylen;
p += copylen;
}
} else {
/* If we can't read from /dev/urandom, do some reasonable effort
* in order to create some entropy, since this function is used to
* generate run_id and cluster instance IDs */
char *x = p;
unsigned int l = len;
struct timeval tv;
pid_t pid = getpid();
/* Use time and PID to fill the initial array. */
gettimeofday(&tv,NULL);
if (l >= sizeof(tv.tv_usec)) {
memcpy(x,&tv.tv_usec,sizeof(tv.tv_usec));
l -= sizeof(tv.tv_usec);
x += sizeof(tv.tv_usec);
}
if (l >= sizeof(tv.tv_sec)) {
memcpy(x,&tv.tv_sec,sizeof(tv.tv_sec));
l -= sizeof(tv.tv_sec);
x += sizeof(tv.tv_sec);
}
if (l >= sizeof(pid)) {
memcpy(x,&pid,sizeof(pid));
l -= sizeof(pid);
x += sizeof(pid);
}
/* Finally xor it with rand() output, that was already seeded with
* time() at startup, and convert to hex digits. */
for (j = 0; j < len; j++) {
p[j] ^= rand();
p[j] = charset[p[j] & 0x0F];
}
}
}
/* Given the filename, return the absolute path as an SDS string, or NULL
* if it fails for some reason. Note that "filename" may be an absolute path
* already, this will be detected and handled correctly.
*
* The function does not try to normalize everything, but only the obvious
* case of one or more "../" appearning at the start of "filename"
* relative path. */
sds getAbsolutePath(char *filename) {
char cwd[1024];
sds abspath;
sds relpath = sdsnew(filename);
relpath = sdstrim(relpath," \r\n\t");
if (relpath[0] == '/') return relpath; /* Path is already absolute. */
/* If path is relative, join cwd and relative path. */
if (getcwd(cwd,sizeof(cwd)) == NULL) {
sdsfree(relpath);
return NULL;
}
abspath = sdsnew(cwd);
if (sdslen(abspath) && abspath[sdslen(abspath)-1] != '/')
abspath = sdscat(abspath,"/");
/* At this point we have the current path always ending with "/", and
* the trimmed relative path. Try to normalize the obvious case of
* trailing ../ elements at the start of the path.
*
* For every "../" we find in the filename, we remove it and also remove
* the last element of the cwd, unless the current cwd is "/". */
while (sdslen(relpath) >= 3 &&
relpath[0] == '.' && relpath[1] == '.' && relpath[2] == '/')
{
sdsrange(relpath,3,-1);
if (sdslen(abspath) > 1) {
char *p = abspath + sdslen(abspath)-2;
int trimlen = 1;
while(*p != '/') {
p--;
trimlen++;
}
sdsrange(abspath,0,-(trimlen+1));
}
}
/* Finally glue the two parts together. */
abspath = sdscatsds(abspath,relpath);
sdsfree(relpath);
return abspath;
}
/* Return true if the specified path is just a file basename without any
* relative or absolute path. This function just checks that no / or \
* character exists inside the specified path, that's enough in the
* environments where Redis runs. */
int pathIsBaseName(char *path) {
return strchr(path,'/') == NULL && strchr(path,'\\') == NULL;
}
#ifdef REDIS_TEST
#include <assert.h>
static void test_string2ll(void) {
char buf[32];
long long v;
/* May not start with +. */
strcpy(buf,"+1");
assert(string2ll(buf,strlen(buf),&v) == 0);
/* Leading space. */
strcpy(buf," 1");
assert(string2ll(buf,strlen(buf),&v) == 0);
/* Trailing space. */
strcpy(buf,"1 ");
assert(string2ll(buf,strlen(buf),&v) == 0);
/* May not start with 0. */
strcpy(buf,"01");
assert(string2ll(buf,strlen(buf),&v) == 0);
strcpy(buf,"-1");
assert(string2ll(buf,strlen(buf),&v) == 1);
assert(v == -1);
strcpy(buf,"0");
assert(string2ll(buf,strlen(buf),&v) == 1);
assert(v == 0);
strcpy(buf,"1");
assert(string2ll(buf,strlen(buf),&v) == 1);
assert(v == 1);
strcpy(buf,"99");
assert(string2ll(buf,strlen(buf),&v) == 1);
assert(v == 99);
strcpy(buf,"-99");
assert(string2ll(buf,strlen(buf),&v) == 1);
assert(v == -99);
strcpy(buf,"-9223372036854775808");
assert(string2ll(buf,strlen(buf),&v) == 1);
assert(v == LLONG_MIN);
strcpy(buf,"-9223372036854775809"); /* overflow */
assert(string2ll(buf,strlen(buf),&v) == 0);
strcpy(buf,"9223372036854775807");
assert(string2ll(buf,strlen(buf),&v) == 1);
assert(v == LLONG_MAX);
strcpy(buf,"9223372036854775808"); /* overflow */
assert(string2ll(buf,strlen(buf),&v) == 0);
}
static void test_string2l(void) {
char buf[32];
long v;
/* May not start with +. */
strcpy(buf,"+1");
assert(string2l(buf,strlen(buf),&v) == 0);
/* May not start with 0. */
strcpy(buf,"01");
assert(string2l(buf,strlen(buf),&v) == 0);
strcpy(buf,"-1");
assert(string2l(buf,strlen(buf),&v) == 1);
assert(v == -1);
strcpy(buf,"0");
assert(string2l(buf,strlen(buf),&v) == 1);
assert(v == 0);
strcpy(buf,"1");
assert(string2l(buf,strlen(buf),&v) == 1);
assert(v == 1);
strcpy(buf,"99");
assert(string2l(buf,strlen(buf),&v) == 1);
assert(v == 99);
strcpy(buf,"-99");
assert(string2l(buf,strlen(buf),&v) == 1);
assert(v == -99);
#if LONG_MAX != LLONG_MAX
strcpy(buf,"-2147483648");
assert(string2l(buf,strlen(buf),&v) == 1);
assert(v == LONG_MIN);
strcpy(buf,"-2147483649"); /* overflow */
assert(string2l(buf,strlen(buf),&v) == 0);
strcpy(buf,"2147483647");
assert(string2l(buf,strlen(buf),&v) == 1);
assert(v == LONG_MAX);
strcpy(buf,"2147483648"); /* overflow */
assert(string2l(buf,strlen(buf),&v) == 0);
#endif
}
static void test_ll2string(void) {
char buf[32];
long long v;
int sz;
v = 0;
sz = ll2string(buf, sizeof buf, v);
assert(sz == 1);
assert(!strcmp(buf, "0"));
v = -1;
sz = ll2string(buf, sizeof buf, v);
assert(sz == 2);
assert(!strcmp(buf, "-1"));
v = 99;
sz = ll2string(buf, sizeof buf, v);
assert(sz == 2);
assert(!strcmp(buf, "99"));
v = -99;
sz = ll2string(buf, sizeof buf, v);
assert(sz == 3);
assert(!strcmp(buf, "-99"));
v = -2147483648;
sz = ll2string(buf, sizeof buf, v);
assert(sz == 11);
assert(!strcmp(buf, "-2147483648"));
v = LLONG_MIN;
sz = ll2string(buf, sizeof buf, v);
assert(sz == 20);
assert(!strcmp(buf, "-9223372036854775808"));
v = LLONG_MAX;
sz = ll2string(buf, sizeof buf, v);
assert(sz == 19);
assert(!strcmp(buf, "9223372036854775807"));
}
#define UNUSED(x) (void)(x)
int utilTest(int argc, char **argv) {
UNUSED(argc);
UNUSED(argv);
test_string2ll();
test_string2l();
test_ll2string();
return 0;
}
#endif