X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/9ea54feef0f2e62f7618da9b0ce3acce9f474db6..989a7820ca0cb1b88493797fdecd2e7168558859:/src/util.c

diff --git a/src/util.c b/src/util.c
index f7437e1c..24f936b6 100644
--- a/src/util.c
+++ b/src/util.c
@@ -1,3 +1,32 @@
+/*
+ * 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>
@@ -5,6 +34,9 @@
 #include <ctype.h>
 #include <limits.h>
 #include <math.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include <float.h>
 
 #include "util.h"
 
@@ -317,7 +349,7 @@ int d2string(char *buf, size_t len, double value) {
          * integer printing function that is much faster. */
         double min = -4503599627370495; /* (2^52)-1 */
         double max = 4503599627370496; /* -(2^52) */
-        if (val > min && val < max && value == ((double)((long long)value)))
+        if (value > min && value < max && value == ((double)((long long)value)))
             len = ll2string(buf,len,(long long)value);
         else
 #endif
@@ -327,6 +359,52 @@ int d2string(char *buf, size_t len, double 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 <assert.h>