X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/af4e866dbb1455a50d51b3d5f46832f1a36e2080..7eb850ef0e437323e2d84157ddc2e6e82af57bbc:/src/util.c diff --git a/src/util.c b/src/util.c index cc2794f6..e3224f50 100644 --- a/src/util.c +++ b/src/util.c @@ -1,6 +1,15 @@ -#include "redis.h" +#include "fmacros.h" +#include +#include +#include #include #include +#include +#include +#include +#include + +#include "util.h" /* Glob-style pattern matching. */ int stringmatchlen(const char *pattern, int patternLen, @@ -200,24 +209,283 @@ int ll2string(char *s, size_t len, long long value) { return l; } -/* Check if the nul-terminated string 's' can be represented by a long - * (that is, is a number that fits into long without any other space or - * character before or after the digits). - * - * If so, the function returns REDIS_OK and *longval is set to the value - * of the number. Otherwise REDIS_ERR is returned */ -int isStringRepresentableAsLong(sds s, long *longval) { - char buf[32], *endptr; - long value; - int slen; - - value = strtol(s, &endptr, 10); - if (endptr[0] != '\0') return REDIS_ERR; - slen = ll2string(buf,32,value); - - /* If the number converted back into a string is not identical - * then it's not possible to encode the string as integer */ - if (sdslen(s) != (unsigned)slen || memcmp(buf,s,slen)) return REDIS_ERR; - if (longval) *longval = value; - return REDIS_OK; +/* 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. */ +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 double to a string representation. Returns the number of bytes + * required. The representation should always be parsable by stdtod(3). */ +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; +} + +/* 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) { + FILE *fp = fopen("/dev/urandom","r"); + char *charset = "0123456789abcdef"; + unsigned int j; + + if (fp == NULL || fread(p,len,1,fp) == 0) { + /* 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. */ + for (j = 0; j < len; j++) + p[j] ^= rand(); + } + /* Turn it into hex digits taking just 4 bits out of 8 for every byte. */ + for (j = 0; j < len; j++) + p[j] = charset[p[j] & 0x0F]; + fclose(fp); +} + +#ifdef UTIL_TEST_MAIN +#include + +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); +} + +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 +} + +int main(int argc, char **argv) { + test_string2ll(); + test_string2l(); + return 0; } +#endif