Adding upstream version 5:7.0.15.upstream/5%7.0.15upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1326 insertions, 0 deletions

diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..8ce2c5f
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,1326 @@
+/*
+ * 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 <time.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <libgen.h>
+
+#include "util.h"
+#include "sha256.h"
+#include "config.h"
+
+/* Glob-style pattern matching. */
+static int stringmatchlen_impl(const char *pattern, int patternLen,
+        const char *string, int stringLen, int nocase, int *skipLongerMatches)
+{
+    while(patternLen && stringLen) {
+        switch(pattern[0]) {
+        case '*':
+            while (patternLen && pattern[1] == '*') {
+                pattern++;
+                patternLen--;
+            }
+            if (patternLen == 1)
+                return 1; /* match */
+            while(stringLen) {
+                if (stringmatchlen_impl(pattern+1, patternLen-1,
+                            string, stringLen, nocase, skipLongerMatches))
+                    return 1; /* match */
+                if (*skipLongerMatches)
+                    return 0; /* no match */
+                string++;
+                stringLen--;
+            }
+            /* There was no match for the rest of the pattern starting
+             * from anywhere in the rest of the string. If there were
+             * any '*' earlier in the pattern, we can terminate the
+             * search early without trying to match them to longer
+             * substrings. This is because a longer match for the
+             * earlier part of the pattern would require the rest of the
+             * pattern to match starting later in the string, and we
+             * have just determined that there is no match for the rest
+             * of the pattern starting from anywhere in the current
+             * string. */
+            *skipLongerMatches = 1;
+            return 0; /* no match */
+            break;
+        case '?':
+            string++;
+            stringLen--;
+            break;
+        case '[':
+        {
+            int not, match;
+
+            pattern++;
+            patternLen--;
+            not = pattern[0] == '^';
+            if (not) {
+                pattern++;
+                patternLen--;
+            }
+            match = 0;
+            while(1) {
+                if (pattern[0] == '\\' && patternLen >= 2) {
+                    pattern++;
+                    patternLen--;
+                    if (pattern[0] == string[0])
+                        match = 1;
+                } else if (pattern[0] == ']') {
+                    break;
+                } else if (patternLen == 0) {
+                    pattern--;
+                    patternLen++;
+                    break;
+                } else if (patternLen >= 3 && pattern[1] == '-') {
+                    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 stringmatchlen(const char *pattern, int patternLen,
+        const char *string, int stringLen, int nocase) {
+    int skipLongerMatches = 0;
+    return stringmatchlen_impl(pattern,patternLen,string,stringLen,nocase,&skipLongerMatches);
+}
+
+int stringmatch(const char *pattern, const char *string, int nocase) {
+    return stringmatchlen(pattern,strlen(pattern),string,strlen(string),nocase);
+}
+
+/* Fuzz stringmatchlen() trying to crash it with bad input. */
+int stringmatchlen_fuzz_test(void) {
+    char str[32];
+    char pat[32];
+    int cycles = 10000000;
+    int total_matches = 0;
+    while(cycles--) {
+        int strlen = rand() % sizeof(str);
+        int patlen = rand() % sizeof(pat);
+        for (int j = 0; j < strlen; j++) str[j] = rand() % 128;
+        for (int j = 0; j < patlen; j++) pat[j] = rand() % 128;
+        total_matches += stringmatchlen(pat, patlen, str, strlen, 0);
+    }
+    return total_matches;
+}
+
+
+/* Convert a string representing an amount of memory into the number of
+ * bytes, so for instance memtoull("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. */
+unsigned long long memtoull(const char *p, int *err) {
+    const char *u;
+    char buf[128];
+    long mul; /* unit multiplier */
+    unsigned long long val;
+    unsigned int digits;
+
+    if (err) *err = 0;
+
+    /* Search the first non digit character. */
+    u = p;
+    if (*u == '-') {
+        if (err) *err = 1;
+        return 0;
+    }
+    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 = strtoull(buf,&endptr,10);
+    if ((val == 0 && errno == EINVAL) || *endptr != '\0') {
+        if (err) *err = 1;
+        return 0;
+    }
+    return val*mul;
+}
+
+/* Search a memory buffer for any set of bytes, like strpbrk().
+ * Returns pointer to first found char or NULL.
+ */
+const char *mempbrk(const char *s, size_t len, const char *chars, size_t charslen) {
+    for (size_t j = 0; j < len; j++) {
+        for (size_t n = 0; n < charslen; n++)
+            if (s[j] == chars[n]) return &s[j];
+    }
+
+    return NULL;
+}
+
+/* Modify the buffer replacing all occurrences of chars from the 'from'
+ * set with the corresponding char in the 'to' set. Always returns s.
+ */
+char *memmapchars(char *s, size_t len, const char *from, const char *to, size_t setlen) {
+    for (size_t j = 0; j < len; j++) {
+        for (size_t i = 0; i < setlen; i++) {
+            if (s[j] == from[i]) {
+                s[j] = to[i];
+                break;
+            }
+        }
+    }
+    return s;
+}
+
+/* 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. */
+int ll2string(char *dst, size_t dstlen, long long svalue) {
+    unsigned long long value;
+    int negative = 0;
+
+    /* The ull2string function 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;
+        }
+        if (dstlen < 2)
+            return 0;
+        negative = 1;
+        dst[0] = '-';
+        dst++;
+        dstlen--;
+    } else {
+        value = svalue;
+    }
+
+    /* Converts the unsigned long long value to string*/
+    int length = ull2string(dst, dstlen, value);
+    if (length == 0) return 0;
+    return length + negative;
+}
+
+/* Convert a unsigned 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 */
+int ull2string(char *dst, size_t dstlen, unsigned long long value) {
+    static const char digits[201] =
+        "0001020304050607080910111213141516171819"
+        "2021222324252627282930313233343536373839"
+        "4041424344454647484950515253545556575859"
+        "6061626364656667686970717273747576777879"
+        "8081828384858687888990919293949596979899";
+
+    /* Check length. */
+    uint32_t length = digits10(value);
+    if (length >= dstlen) return 0;
+
+    /* Null term. */
+    uint32_t next = length - 1;
+    dst[next + 1] = '\0';
+    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];
+    }
+
+    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;
+
+    /* A string of zero length or excessive length is not a valid number. */
+    if (plen == slen || slen >= LONG_STR_SIZE)
+        return 0;
+
+    /* Special case: first and only digit is 0. */
+    if (slen == 1 && p[0] == '0') {
+        if (value != NULL) *value = 0;
+        return 1;
+    }
+
+    /* Handle negative numbers: just set a flag and continue like if it
+     * was a positive number. Later convert into negative. */
+    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 {
+        return 0;
+    }
+
+    /* Parse all the other digits, checking for overflow at every step. */
+    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;
+
+    /* Convert to negative if needed, and do the final overflow check when
+     * converting from unsigned long long to long long. */
+    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;
+}
+
+/* Helper function to convert a string to an unsigned long long value.
+ * The function attempts to use the faster string2ll() function inside
+ * Redis: if it fails, strtoull() is used instead. The function returns
+ * 1 if the conversion happened successfully or 0 if the number is
+ * invalid or out of range. */
+int string2ull(const char *s, unsigned long long *value) {
+    long long ll;
+    if (string2ll(s,strlen(s),&ll)) {
+        if (ll < 0) return 0; /* Negative values are out of range. */
+        *value = ll;
+        return 1;
+    }
+    errno = 0;
+    char *endptr = NULL;
+    *value = strtoull(s,&endptr,10);
+    if (errno == EINVAL || errno == ERANGE || !(*s != '\0' && *endptr == '\0'))
+        return 0; /* strtoull() failed. */
+    return 1; /* Conversion done! */
+}
+
+/* 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[MAX_LONG_DOUBLE_CHARS];
+    long double value;
+    char *eptr;
+
+    if (slen == 0 || 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' ||
+        (size_t)(eptr-buf) != slen ||
+        (errno == ERANGE &&
+            (value == HUGE_VAL || value == -HUGE_VAL || fpclassify(value) == FP_ZERO)) ||
+        errno == EINVAL ||
+        isnan(value))
+        return 0;
+
+    if (dp) *dp = value;
+    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 string2d(const char *s, size_t slen, double *dp) {
+    errno = 0;
+    char *eptr;
+    *dp = strtod(s, &eptr);
+    if (slen == 0 ||
+        isspace(((const char*)s)[0]) ||
+        (size_t)(eptr-(char*)s) != slen ||
+        (errno == ERANGE &&
+            (*dp == HUGE_VAL || *dp == -HUGE_VAL || fpclassify(*dp) == FP_ZERO)) ||
+        isnan(*dp))
+        return 0;
+    return 1;
+}
+
+/* Returns 1 if the double value can safely be represented in long long without
+ * precision loss, in which case the corresponding long long is stored in the out variable. */
+int double2ll(double d, long long *out) {
+#if (DBL_MANT_DIG >= 52) && (DBL_MANT_DIG <= 63) && (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 a range
+     * 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 can use
+     * integer without precision loss.
+     *
+     * Note that numbers above 2^52 and below 2^63 use all the fraction bits as real part,
+     * and the exponent bits are positive, which means the "decimal" part must be 0.
+     * i.e. all double values in that range are representable as a long without precision loss,
+     * but not all long values in that range can be represented as a double.
+     * we only care about the first part here. */
+    if (d < (double)(-LLONG_MAX/2) || d > (double)(LLONG_MAX/2))
+        return 0;
+    long long ll = d;
+    if (ll == d) {
+        *out = ll;
+        return 1;
+    }
+#endif
+    return 0;
+}
+
+/* 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 listpack 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 {
+        long long lvalue;
+        /* Integer printing function is much faster, check if we can safely use it. */
+        if (double2ll(value, &lvalue))
+            len = ll2string(buf,len,lvalue);
+        else
+            len = snprintf(buf,len,"%.17g",value);
+    }
+
+    return len;
+}
+
+/* Convert a double into a string with 'fractional_digits' digits after the dot precision.
+ * This is an optimized version of snprintf "%.<fractional_digits>f".
+ * We convert the double to long and multiply it  by 10 ^ <fractional_digits> to shift
+ * the decimal places.
+ * Note that multiply it of input value by 10 ^ <fractional_digits> can overflow but on the scenario
+ * that we currently use within redis this that is not possible.
+ * After we get the long representation we use the logic from ull2string function on this file
+ * which is based on the following article:
+ * https://www.facebook.com/notes/facebook-engineering/three-optimization-tips-for-c/10151361643253920
+ *
+ * Input values:
+ * char: the buffer to store the string representation
+ * dstlen: the buffer length
+ * dvalue: the input double
+ * fractional_digits: the number of fractional digits after the dot precision. between 1 and 17
+ *
+ * Return values:
+ * Returns the number of characters needed to represent the number.
+ * If the buffer is not big enough to store the string, 0 is returned.
+ */
+int fixedpoint_d2string(char *dst, size_t dstlen, double dvalue, int fractional_digits) {
+    if (fractional_digits < 1 || fractional_digits > 17)
+        goto err;
+    /* min size of 2 ( due to 0. ) + n fractional_digitits + \0 */
+    if ((int)dstlen < (fractional_digits+3))
+        goto err;
+    if (dvalue == 0) {
+        dst[0] = '0';
+        dst[1] = '.';
+        memset(dst + 2, '0', fractional_digits);
+        dst[fractional_digits+2] = '\0';
+        return fractional_digits + 2;
+    }
+    /* scale and round */
+    static double powers_of_ten[] = {1.0, 10.0, 100.0, 1000.0, 10000.0, 100000.0, 1000000.0,
+    10000000.0, 100000000.0, 1000000000.0, 10000000000.0, 100000000000.0, 1000000000000.0,
+    10000000000000.0, 100000000000000.0, 1000000000000000.0, 10000000000000000.0,
+    100000000000000000.0 };
+    long long svalue = llrint(dvalue * powers_of_ten[fractional_digits]);
+    unsigned long long value;
+    /* write sign */
+    int negative = 0;
+    if (svalue < 0) {
+        if (svalue != LLONG_MIN) {
+            value = -svalue;
+        } else {
+            value = ((unsigned long long) LLONG_MAX)+1;
+        }
+        if (dstlen < 2)
+            goto err;
+        negative = 1;
+        dst[0] = '-';
+        dst++;
+        dstlen--;
+    } else {
+        value = svalue;
+    }
+
+    static const char digitsd[201] =
+        "0001020304050607080910111213141516171819"
+        "2021222324252627282930313233343536373839"
+        "4041424344454647484950515253545556575859"
+        "6061626364656667686970717273747576777879"
+        "8081828384858687888990919293949596979899";
+
+    /* Check length. */
+    uint32_t ndigits = digits10(value);
+    if (ndigits >= dstlen) goto err;
+    int integer_digits = ndigits - fractional_digits;
+    /* Fractional only check to avoid representing 0.7750 as .7750.
+     * This means we need to increment the length and store 0 as the first character.
+     */
+    if (integer_digits < 1) {
+        dst[0] = '0';
+        integer_digits = 1;
+    }
+    dst[integer_digits] = '.';
+    int size = integer_digits + 1 + fractional_digits;
+    /* fill with 0 from fractional digits until size */
+    memset(dst + integer_digits + 1, '0', fractional_digits);
+    int next = size - 1;
+    while (value >= 100) {
+        int const i = (value % 100) * 2;
+        value /= 100;
+        dst[next] = digitsd[i + 1];
+        dst[next - 1] = digitsd[i];
+        next -= 2;
+        /* dot position */
+        if (next == integer_digits) {
+            next--;
+        }
+    }
+
+    /* Handle last 1-2 digits. */
+    if (value < 10) {
+        dst[next] = '0' + (uint32_t) value;
+    } else {
+        int i = (uint32_t) value * 2;
+        dst[next] = digitsd[i + 1];
+        dst[next - 1] = digitsd[i];
+    }
+    /* Null term. */
+    dst[size] = '\0';
+    return size + negative;
+err:
+    /* force add Null termination */
+    if (dstlen > 0)
+        dst[0] = '\0';
+    return 0;
+}
+
+/* Trims off trailing zeros from a string representing a double. */
+int trimDoubleString(char *buf, size_t len) {
+    if (strchr(buf,'.') != NULL) {
+        char *p = buf+len-1;
+        while(*p == '0') {
+            p--;
+            len--;
+        }
+        if (*p == '.') len--;
+    }
+    buf[len] = '\0';
+    return len;
+}
+
+/* Create a string object from a long double.
+ * If mode is humanfriendly it does not use exponential format and trims trailing
+ * zeroes at the end (may result in loss of precision).
+ * If mode is default exp format is used and the output of snprintf()
+ * is not modified (may result in loss of precision).
+ * If mode is hex hexadecimal format is used (no loss of precision)
+ *
+ * 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, ld2string_mode mode) {
+    size_t l = 0;
+
+    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 {
+        switch (mode) {
+        case LD_STR_AUTO:
+            l = snprintf(buf,len,"%.17Lg",value);
+            if (l+1 > len) return 0; /* No room. */
+            break;
+        case LD_STR_HEX:
+            l = snprintf(buf,len,"%La",value);
+            if (l+1 > len) return 0; /* No room. */
+            break;
+        case LD_STR_HUMAN:
+            /* 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--;
+            }
+            if (l == 2 && buf[0] == '-' && buf[1] == '0') {
+                buf[0] = '0';
+                l = 1;
+            }
+            break;
+        default: return 0; /* Invalid mode. */
+        }
+    }
+    buf[l] = '\0';
+    return l;
+}
+
+/* Get random bytes, attempts to get an initial seed from /dev/urandom and
+ * the uses a one way hash function in counter mode to generate a random
+ * stream. However if /dev/urandom is not available, a weaker seed is used.
+ *
+ * This function is not thread safe, since the state is global. */
+void getRandomBytes(unsigned char *p, size_t len) {
+    /* Global state. */
+    static int seed_initialized = 0;
+    static unsigned char seed[64]; /* 512 bit internal block size. */
+    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 == NULL || fread(seed,sizeof(seed),1,fp) != 1) {
+            /* Revert to a weaker seed, and in this case reseed again
+             * at every call.*/
+            for (unsigned int j = 0; j < sizeof(seed); j++) {
+                struct timeval tv;
+                gettimeofday(&tv,NULL);
+                pid_t pid = getpid();
+                seed[j] = tv.tv_sec ^ tv.tv_usec ^ pid ^ (long)fp;
+            }
+        } else {
+            seed_initialized = 1;
+        }
+        if (fp) fclose(fp);
+    }
+
+    while(len) {
+        /* This implements SHA256-HMAC. */
+        unsigned char digest[SHA256_BLOCK_SIZE];
+        unsigned char kxor[64];
+        unsigned int copylen =
+            len > SHA256_BLOCK_SIZE ? SHA256_BLOCK_SIZE : len;
+
+        /* IKEY: key xored with 0x36. */
+        memcpy(kxor,seed,sizeof(kxor));
+        for (unsigned int i = 0; i < sizeof(kxor); i++) kxor[i] ^= 0x36;
+
+        /* Obtain HASH(IKEY||MESSAGE). */
+        SHA256_CTX ctx;
+        sha256_init(&ctx);
+        sha256_update(&ctx,kxor,sizeof(kxor));
+        sha256_update(&ctx,(unsigned char*)&counter,sizeof(counter));
+        sha256_final(&ctx,digest);
+
+        /* OKEY: key xored with 0x5c. */
+        memcpy(kxor,seed,sizeof(kxor));
+        for (unsigned int i = 0; i < sizeof(kxor); i++) kxor[i] ^= 0x5C;
+
+        /* Obtain HASH(OKEY || HASH(IKEY||MESSAGE)). */
+        sha256_init(&ctx);
+        sha256_update(&ctx,kxor,sizeof(kxor));
+        sha256_update(&ctx,digest,SHA256_BLOCK_SIZE);
+        sha256_final(&ctx,digest);
+
+        /* Increment the counter for the next iteration. */
+        counter++;
+
+        memcpy(p,digest,copylen);
+        len -= copylen;
+        p += copylen;
+    }
+}
+
+/* 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, size_t len) {
+    char *charset = "0123456789abcdef";
+    size_t j;
+
+    getRandomBytes((unsigned char*)p,len);
+    for (j = 0; j < len; j++) 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 "../" appearing 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;
+}
+
+/*
+ * Gets the proper timezone in a more portable fashion
+ * i.e timezone variables are linux specific.
+ */
+long getTimeZone(void) {
+#if defined(__linux__) || defined(__sun)
+    return timezone;
+#else
+    struct timeval tv;
+    struct timezone tz;
+
+    gettimeofday(&tv, &tz);
+
+    return tz.tz_minuteswest * 60L;
+#endif
+}
+
+/* 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;
+}
+
+int fileExist(char *filename) {
+    struct stat statbuf;
+    return stat(filename, &statbuf) == 0 && S_ISREG(statbuf.st_mode);
+}
+
+int dirExists(char *dname) {
+    struct stat statbuf;
+    return stat(dname, &statbuf) == 0 && S_ISDIR(statbuf.st_mode);
+}
+
+int dirCreateIfMissing(char *dname) {
+    if (mkdir(dname, 0755) != 0) {
+        if (errno != EEXIST) {
+            return -1;
+        } else if (!dirExists(dname)) {
+            errno = ENOTDIR;
+            return -1;
+        }
+    }
+    return 0;
+}
+
+int dirRemove(char *dname) {
+    DIR *dir;
+    struct stat stat_entry;
+    struct dirent *entry;
+    char full_path[PATH_MAX + 1];
+
+    if ((dir = opendir(dname)) == NULL) {
+        return -1;
+    }
+
+    while ((entry = readdir(dir)) != NULL) {
+        if (!strcmp(entry->d_name, ".") || !strcmp(entry->d_name, "..")) continue;
+
+        snprintf(full_path, sizeof(full_path), "%s/%s", dname, entry->d_name);
+
+        int fd = open(full_path, O_RDONLY|O_NONBLOCK);
+        if (fd == -1) {
+            closedir(dir);
+            return -1;
+        }
+
+        if (fstat(fd, &stat_entry) == -1) {
+            close(fd);
+            closedir(dir);
+            return -1;
+        }
+        close(fd);
+
+        if (S_ISDIR(stat_entry.st_mode) != 0) {
+            if (dirRemove(full_path) == -1) {
+                return -1;
+            }
+            continue;
+        }
+
+        if (unlink(full_path) != 0) {
+            closedir(dir);
+            return -1;
+        }
+    }
+
+    if (rmdir(dname) != 0) {
+        closedir(dir);
+        return -1;
+    }
+
+    closedir(dir);
+    return 0;
+}
+
+sds makePath(char *path, char *filename) {
+    return sdscatfmt(sdsempty(), "%s/%s", path, filename);
+}
+
+/* Given the filename, sync the corresponding directory.
+ *
+ * Usually a portable and safe pattern to overwrite existing files would be like:
+ * 1. create a new temp file (on the same file system!)
+ * 2. write data to the temp file
+ * 3. fsync() the temp file
+ * 4. rename the temp file to the appropriate name
+ * 5. fsync() the containing directory */
+int fsyncFileDir(const char *filename) {
+#ifdef _AIX
+    /* AIX is unable to fsync a directory */
+    return 0;
+#endif
+    char temp_filename[PATH_MAX + 1];
+    char *dname;
+    int dir_fd;
+
+    if (strlen(filename) > PATH_MAX) {
+        errno = ENAMETOOLONG;
+        return -1;
+    }
+
+    /* In the glibc implementation dirname may modify their argument. */
+    memcpy(temp_filename, filename, strlen(filename) + 1);
+    dname = dirname(temp_filename);
+
+    dir_fd = open(dname, O_RDONLY);
+    if (dir_fd == -1) {
+        /* Some OSs don't allow us to open directories at all, just
+         * ignore the error in that case */
+        if (errno == EISDIR) {
+            return 0;
+        }
+        return -1;
+    }
+    /* Some OSs don't allow us to fsync directories at all, so we can ignore
+     * those errors. */
+    if (redis_fsync(dir_fd) == -1 && !(errno == EBADF || errno == EINVAL)) {
+        int save_errno = errno;
+        close(dir_fd);
+        errno = save_errno;
+        return -1;
+    }
+    
+    close(dir_fd);
+    return 0;
+}
+
+#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"));
+}
+
+static void test_fixedpoint_d2string(void) {
+    char buf[32];
+    double v;
+    int sz;
+    v = 0.0;
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 4);
+    assert(sz == 6);
+    assert(!strcmp(buf, "0.0000"));
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 1);
+    assert(sz == 3);
+    assert(!strcmp(buf, "0.0"));
+    /* set junk in buffer */
+    memset(buf,'A',32);
+    v = 0.0001;
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 4);
+    assert(sz == 6);
+    assert(buf[sz] == '\0');
+    assert(!strcmp(buf, "0.0001"));
+    /* set junk in buffer */
+    memset(buf,'A',32);
+    v = 6.0642951598391699e-05;
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 4);
+    assert(sz == 6);
+    assert(buf[sz] == '\0');
+    assert(!strcmp(buf, "0.0001"));
+    v = 0.01;
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 4);
+    assert(sz == 6);
+    assert(!strcmp(buf, "0.0100"));
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 1);
+    assert(sz == 3);
+    assert(!strcmp(buf, "0.0"));
+    v = -0.01;
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 4);
+    assert(sz == 7);
+    assert(!strcmp(buf, "-0.0100"));
+     v = -0.1;
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 1);
+    assert(sz == 4);
+    assert(!strcmp(buf, "-0.1"));
+    v = 0.1;
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 1);
+    assert(sz == 3);
+    assert(!strcmp(buf, "0.1"));
+    v = 0.01;
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 17);
+    assert(sz == 19);
+    assert(!strcmp(buf, "0.01000000000000000"));
+    v = 10.01;
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 4);
+    assert(sz == 7);
+    assert(!strcmp(buf, "10.0100"));
+    /* negative tests */
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 18);
+    assert(sz == 0);
+    sz = fixedpoint_d2string(buf, sizeof buf, v, 0);
+    assert(sz == 0);
+    sz = fixedpoint_d2string(buf, 1, v, 1);
+    assert(sz == 0);
+}
+
+#define UNUSED(x) (void)(x)
+int utilTest(int argc, char **argv, int flags) {
+    UNUSED(argc);
+    UNUSED(argv);
+    UNUSED(flags);
+
+    test_string2ll();
+    test_string2l();
+    test_ll2string();
+    test_fixedpoint_d2string();
+    return 0;
+}
+#endif