Redis 2.7.102 (2.8 Release Candidate 2).

This fixes issue #1221.

00-RELEASENOTES

@@ -2,8 +2,8 @@ Redis 2.8 release notes
 =======================
 
 ** IMPORTANT ** Check the 'Migrating from 2.6 to 2.8' section at the end of
-                this file for information about what changed between 2.4 and
-                2.6 and how this may affect your application.
+                this file for information about what changed between 2.6 and
+                2.8 and how this may affect your application.
 
 --------------------------------------------------------------------------------
 Upgrade urgency levels:
@@ -14,6 +14,17 @@ HIGH:     There is a critical bug that may affect a subset of users. Upgrade!
 CRITICAL: There is a critical bug affecting MOST USERS. Upgrade ASAP.
 --------------------------------------------------------------------------------
 
+--[ Redis 2.8 Release Candidate 2 (2.7.102) ] Release date: 30 Jul 2013
+
+This is the second release candidate of Redis 2.8 (official version is 2.7.102).
+Important bugs fixed inside.
+
+# UPGRADE URGENCY: HIGH
+
+* [FIX] Fixed a critical replication bug, see issue #1221.
+* [NEW] The new inline protocol now accepts quoted strings like, for example
+        you can now type in a telnet session: set 'foo bar' "hello world\n".
+
 --[ Redis 2.8 Release Candidate 1 (2.7.101) ] Release date: 18 Jul 2013
 
 This is the first release candidate of Redis 2.8 (official version is 2.7.101).
@@ -21,14 +32,14 @@ This is the first release candidate of Redis 2.8 (official version is 2.7.101).
 The following is a list of improvements in Redis 2.8, compared to Redis 2.6.
 
 * [NEW] Slaves are now able to partially resynchronize with the master, so most
-        of the times a full resynchornization with the RDB creation in the master
+        of the times a full resynchronization with the RDB creation in the master
         side is not needed when the master-slave link is disconnected for a short
         amount of time.
-* [NEW] Experimental IPv6 support.4
-* [NEW] Slaves explicitly ping masters now, a master is able to detect a timedout
+* [NEW] Experimental IPv6 support.
+* [NEW] Slaves explicitly ping masters now, a master is able to detect a timed out
         slave independently.
 * [NEW] Masters can stop accepting writes if not enough slaves with a given
-        maxium latency are connected.
+        maximum latency are connected.
 * [NEW] Keyspace changes notifications via Pub/Sub.
 * [NEW] CONFIG SET maxclients is now available.
 * [NEW] Ability to bind multiple IP addresses.
@@ -42,7 +53,7 @@ The following is a list of improvements in Redis 2.8, compared to Redis 2.6.
 * [NEW] EVALSHA can now be replicated as such, without requiring to be expanded
         to a full EVAL for the replication link.
 * [NEW] Better Lua scripts error reporting.
-* [NEW] SDIFF performances improved.
+* [NEW] SDIFF performance improved.
 * [FIX] A number of bugfixes.
 
 Migrating from 2.6 to 2.8
@@ -53,14 +64,14 @@ that you should be aware of:
 
 The following commands changed behavior:
 
-    * SORT with ALPHA now sort according to local collation locale if no STORE
+    * SORT with ALPHA now sorts according to local collation locale if no STORE
       option is used.
     * ZADD/ZINCRBY are now able to accept a bigger range of values as valid
       scores, that is, all the values you may end having as a result of
       calling ZINCRBY multiple times.
     * Many errors are now prefixed by a more specific error code instead of
       the generic -ERR, for example -WRONGTYPE, -NOAUTH, ...
-    * PUBLISH called inside lua scripts is now correctly propagated to slaves.
+    * PUBLISH called inside Lua scripts is now correctly propagated to slaves.
 
 The following redis.conf and CONFIG GET / SET parameters changed:
 
@@ -74,8 +85,8 @@ The following INFO fields changed format in a non-backward compatible way:
 Replication:
 
     Redis 2.8 can be used as slave for Redis 2.6, but doing this is only
-    a good idea for a short amonut of time needed to upgrade your servers.
-    We suggest to update both master and slaves about at the same time.
+    a good idea for the short amount of time needed to upgrade your servers.
+    We suggest to update both master and slaves at about the same time.
 
 --------------------------------------------------------------------------------
 

deps/hiredis/hiredis.c

@@ -650,7 +650,7 @@ int redisReaderGetReply(redisReader *r, void **reply) {
     /* Discard part of the buffer when we've consumed at least 1k, to avoid
      * doing unnecessary calls to memmove() in sds.c. */
     if (r->pos >= 1024) {
-        r->buf = sdsrange(r->buf,r->pos,-1);
+        sdsrange(r->buf,r->pos,-1);
         r->pos = 0;
         r->len = sdslen(r->buf);
     }
@@ -1125,7 +1125,7 @@ int redisBufferWrite(redisContext *c, int *done) {
                 sdsfree(c->obuf);
                 c->obuf = sdsempty();
             } else {
-                c->obuf = sdsrange(c->obuf,nwritten,-1);
+                sdsrange(c->obuf,nwritten,-1);
             }
         }
     }

deps/hiredis/sds.c

@@ -1,6 +1,6 @@
 /* SDSLib, A C dynamic strings library
  *
- * Copyright (c) 2006-2010, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2006-2012, Salvatore Sanfilippo <antirez at gmail dot com>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -32,52 +32,76 @@
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
+#include <assert.h>
 #include "sds.h"
+#include "zmalloc.h"
 
-#ifdef SDS_ABORT_ON_OOM
-static void sdsOomAbort(void) {
-    fprintf(stderr,"SDS: Out Of Memory (SDS_ABORT_ON_OOM defined)\n");
-    abort();
-}
-#endif
-
+/* Create a new sds string with the content specified by the 'init' pointer
+ * and 'initlen'.
+ * If NULL is used for 'init' the string is initialized with zero bytes.
+ *
+ * The string is always null-termined (all the sds strings are, always) so
+ * even if you create an sds string with:
+ *
+ * mystring = sdsnewlen("abc",3");
+ *
+ * You can print the string with printf() as there is an implicit \0 at the
+ * end of the string. However the string is binary safe and can contain
+ * \0 characters in the middle, as the length is stored in the sds header. */
 sds sdsnewlen(const void *init, size_t initlen) {
     struct sdshdr *sh;
 
-    sh = malloc(sizeof(struct sdshdr)+initlen+1);
-#ifdef SDS_ABORT_ON_OOM
-    if (sh == NULL) sdsOomAbort();
-#else
+    if (init) {
+        sh = zmalloc(sizeof(struct sdshdr)+initlen+1);
+    } else {
+        sh = zcalloc(sizeof(struct sdshdr)+initlen+1);
+    }
     if (sh == NULL) return NULL;
-#endif
     sh->len = initlen;
     sh->free = 0;
-    if (initlen) {
-        if (init) memcpy(sh->buf, init, initlen);
-        else memset(sh->buf,0,initlen);
-    }
+    if (initlen && init)
+        memcpy(sh->buf, init, initlen);
     sh->buf[initlen] = '\0';
     return (char*)sh->buf;
 }
 
+/* Create an empty (zero length) sds string. Even in this case the string
+ * always has an implicit null term. */
 sds sdsempty(void) {
     return sdsnewlen("",0);
 }
 
+/* Create a new sds string starting from a null termined C string. */
 sds sdsnew(const char *init) {
     size_t initlen = (init == NULL) ? 0 : strlen(init);
     return sdsnewlen(init, initlen);
 }
 
+/* Duplicate an sds string. */
 sds sdsdup(const sds s) {
     return sdsnewlen(s, sdslen(s));
 }
 
+/* Free an sds string. No operation is performed if 's' is NULL. */
 void sdsfree(sds s) {
     if (s == NULL) return;
-    free(s-sizeof(struct sdshdr));
+    zfree(s-sizeof(struct sdshdr));
 }
 
+/* Set the sds string length to the length as obtained with strlen(), so
+ * considering as content only up to the first null term character.
+ *
+ * This function is useful when the sds string is hacked manually in some
+ * way, like in the following example:
+ *
+ * s = sdsnew("foobar");
+ * s[2] = '\0';
+ * sdsupdatelen(s);
+ * printf("%d\n", sdslen(s));
+ *
+ * The output will be "2", but if we comment out the call to sdsupdatelen()
+ * the output will be "6" as the string was modified but the logical length
+ * remains 6 bytes. */
 void sdsupdatelen(sds s) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     int reallen = strlen(s);
@@ -85,7 +109,24 @@ void sdsupdatelen(sds s) {
     sh->len = reallen;
 }
 
-static sds sdsMakeRoomFor(sds s, size_t addlen) {
+/* Modify an sds string on-place to make it empty (zero length).
+ * However all the existing buffer is not discarded but set as free space
+ * so that next append operations will not require allocations up to the
+ * number of bytes previously available. */
+void sdsclear(sds s) {
+    struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
+    sh->free += sh->len;
+    sh->len = 0;
+    sh->buf[0] = '\0';
+}
+
+/* Enlarge the free space at the end of the sds string so that the caller
+ * is sure that after calling this function can overwrite up to addlen
+ * bytes after the end of the string, plus one more byte for nul term.
+ * 
+ * Note: this does not change the *length* of the sds string as returned
+ * by sdslen(), but only the free buffer space we have. */
+sds sdsMakeRoomFor(sds s, size_t addlen) {
     struct sdshdr *sh, *newsh;
     size_t free = sdsavail(s);
     size_t len, newlen;
@@ -93,20 +134,84 @@ static sds sdsMakeRoomFor(sds s, size_t addlen) {
     if (free >= addlen) return s;
     len = sdslen(s);
     sh = (void*) (s-(sizeof(struct sdshdr)));
-    newlen = (len+addlen)*2;
-    newsh = realloc(sh, sizeof(struct sdshdr)+newlen+1);
-#ifdef SDS_ABORT_ON_OOM
-    if (newsh == NULL) sdsOomAbort();
-#else
+    newlen = (len+addlen);
+    if (newlen < SDS_MAX_PREALLOC)
+        newlen *= 2;
+    else
+        newlen += SDS_MAX_PREALLOC;
+    newsh = zrealloc(sh, sizeof(struct sdshdr)+newlen+1);
     if (newsh == NULL) return NULL;
-#endif
 
     newsh->free = newlen - len;
     return newsh->buf;
 }
 
+/* Reallocate the sds string so that it has no free space at the end. The
+ * contained string remains not altered, but next concatenation operations
+ * will require a reallocation.
+ *
+ * After the call, the passed sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+sds sdsRemoveFreeSpace(sds s) {
+    struct sdshdr *sh;
+
+    sh = (void*) (s-(sizeof(struct sdshdr)));
+    sh = zrealloc(sh, sizeof(struct sdshdr)+sh->len+1);
+    sh->free = 0;
+    return sh->buf;
+}
+
+/* Return the total size of the allocation of the specifed sds string,
+ * including:
+ * 1) The sds header before the pointer.
+ * 2) The string.
+ * 3) The free buffer at the end if any.
+ * 4) The implicit null term.
+ */
+size_t sdsAllocSize(sds s) {
+    struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
+
+    return sizeof(*sh)+sh->len+sh->free+1;
+}
+
+/* Increment the sds length and decrements the left free space at the
+ * end of the string according to 'incr'. Also set the null term
+ * in the new end of the string.
+ *
+ * This function is used in order to fix the string length after the
+ * user calls sdsMakeRoomFor(), writes something after the end of
+ * the current string, and finally needs to set the new length.
+ *
+ * Note: it is possible to use a negative increment in order to
+ * right-trim the string.
+ *
+ * Usage example:
+ *
+ * Using sdsIncrLen() and sdsMakeRoomFor() it is possible to mount the
+ * following schema, to cat bytes coming from the kernel to the end of an
+ * sds string without copying into an intermediate buffer:
+ *
+ * oldlen = sdslen(s);
+ * s = sdsMakeRoomFor(s, BUFFER_SIZE);
+ * nread = read(fd, s+oldlen, BUFFER_SIZE);
+ * ... check for nread <= 0 and handle it ...
+ * sdsIncrLen(s, nread);
+ */
+void sdsIncrLen(sds s, int incr) {
+    struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
+
+    assert(sh->free >= incr);
+    sh->len += incr;
+    sh->free -= incr;
+    assert(sh->free >= 0);
+    s[sh->len] = '\0';
+}
+
 /* Grow the sds to have the specified length. Bytes that were not part of
- * the original length of the sds will be set to zero. */
+ * the original length of the sds will be set to zero.
+ *
+ * if the specified length is smaller than the current length, no operation
+ * is performed. */
 sds sdsgrowzero(sds s, size_t len) {
     struct sdshdr *sh = (void*)(s-(sizeof(struct sdshdr)));
     size_t totlen, curlen = sh->len;
@@ -124,6 +229,11 @@ sds sdsgrowzero(sds s, size_t len) {
     return s;
 }
 
+/* Append the specified binary-safe string pointed by 't' of 'len' bytes to the
+ * end of the specified sds string 's'.
+ *
+ * After the call, the passed sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
 sds sdscatlen(sds s, const void *t, size_t len) {
     struct sdshdr *sh;
     size_t curlen = sdslen(s);
@@ -138,11 +248,25 @@ sds sdscatlen(sds s, const void *t, size_t len) {
     return s;
 }
 
+/* Append the specified null termianted C string to the sds string 's'.
+ *
+ * After the call, the passed sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
 sds sdscat(sds s, const char *t) {
     return sdscatlen(s, t, strlen(t));
 }
 
-sds sdscpylen(sds s, char *t, size_t len) {
+/* Append the specified sds 't' to the existing sds 's'.
+ *
+ * After the call, the modified sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+sds sdscatsds(sds s, const sds t) {
+    return sdscatlen(s, t, sdslen(t));
+}
+
+/* Destructively modify the sds string 's' to hold the specified binary
+ * safe string pointed by 't' of length 'len' bytes. */
+sds sdscpylen(sds s, const char *t, size_t len) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     size_t totlen = sh->free+sh->len;
 
@@ -159,37 +283,52 @@ sds sdscpylen(sds s, char *t, size_t len) {
     return s;
 }
 
-sds sdscpy(sds s, char *t) {
+/* Like sdscpylen() but 't' must be a null-termined string so that the length
+ * of the string is obtained with strlen(). */
+sds sdscpy(sds s, const char *t) {
     return sdscpylen(s, t, strlen(t));
 }
 
+/* Like sdscatpritf() but gets va_list instead of being variadic. */
 sds sdscatvprintf(sds s, const char *fmt, va_list ap) {
     va_list cpy;
     char *buf, *t;
     size_t buflen = 16;
 
     while(1) {
-        buf = malloc(buflen);
-#ifdef SDS_ABORT_ON_OOM
-        if (buf == NULL) sdsOomAbort();
-#else
+        buf = zmalloc(buflen);
         if (buf == NULL) return NULL;
-#endif
         buf[buflen-2] = '\0';
         va_copy(cpy,ap);
         vsnprintf(buf, buflen, fmt, cpy);
         if (buf[buflen-2] != '\0') {
-            free(buf);
+            zfree(buf);
             buflen *= 2;
             continue;
         }
         break;
     }
     t = sdscat(s, buf);
-    free(buf);
+    zfree(buf);
     return t;
 }
 
+/* Append to the sds string 's' a string obtained using printf-alike format
+ * specifier.
+ *
+ * After the call, the modified sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call.
+ *
+ * Example:
+ *
+ * s = sdsempty("Sum is: ");
+ * s = sdscatprintf(s,"%d+%d = %d",a,b,a+b).
+ *
+ * Often you need to create a string from scratch with the printf-alike
+ * format. When this is the need, just use sdsempty() as the target string:
+ *
+ * s = sdscatprintf(sdsempty(), "... your format ...", args);
+ */
 sds sdscatprintf(sds s, const char *fmt, ...) {
     va_list ap;
     char *t;
@@ -199,6 +338,20 @@ sds sdscatprintf(sds s, const char *fmt, ...) {
     return t;
 }
 
+/* Remove the part of the string from left and from right composed just of
+ * contiguous characters found in 'cset', that is a null terminted C string.
+ *
+ * After the call, the modified sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call.
+ *
+ * Example:
+ *
+ * s = sdsnew("AA...AA.a.aa.aHelloWorld     :::");
+ * s = sdstrim(s,"A. :");
+ * printf("%s\n", s);
+ *
+ * Output will be just "Hello World".
+ */
 sds sdstrim(sds s, const char *cset) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     char *start, *end, *sp, *ep;
@@ -216,11 +369,27 @@ sds sdstrim(sds s, const char *cset) {
     return s;
 }
 
-sds sdsrange(sds s, int start, int end) {
+/* Turn the string into a smaller (or equal) string containing only the
+ * substring specified by the 'start' and 'end' indexes.
+ *
+ * start and end can be negative, where -1 means the last character of the
+ * string, -2 the penultimate character, and so forth.
+ *
+ * The interval is inclusive, so the start and end characters will be part
+ * of the resulting string.
+ *
+ * The string is modified in-place.
+ *
+ * Example:
+ *
+ * s = sdsnew("Hello World");
+ * sdstrim(s,1,-1); => "ello Worl"
+ */
+void sdsrange(sds s, int start, int end) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     size_t newlen, len = sdslen(s);
 
-    if (len == 0) return s;
+    if (len == 0) return;
     if (start < 0) {
         start = len+start;
         if (start < 0) start = 0;
@@ -244,22 +413,34 @@ sds sdsrange(sds s, int start, int end) {
     sh->buf[newlen] = 0;
     sh->free = sh->free+(sh->len-newlen);
     sh->len = newlen;
-    return s;
 }
 
+/* Apply tolower() to every character of the sds string 's'. */
 void sdstolower(sds s) {
     int len = sdslen(s), j;
 
     for (j = 0; j < len; j++) s[j] = tolower(s[j]);
 }
 
+/* Apply toupper() to every character of the sds string 's'. */
 void sdstoupper(sds s) {
     int len = sdslen(s), j;
 
     for (j = 0; j < len; j++) s[j] = toupper(s[j]);
 }
 
-int sdscmp(sds s1, sds s2) {
+/* Compare two sds strings s1 and s2 with memcmp().
+ *
+ * Return value:
+ *
+ *     1 if s1 > s2.
+ *    -1 if s1 < s2.
+ *     0 if s1 and s2 are exactly the same binary string.
+ *
+ * If two strings share exactly the same prefix, but one of the two has
+ * additional characters, the longer string is considered to be greater than
+ * the smaller one. */
+int sdscmp(const sds s1, const sds s2) {
     size_t l1, l2, minlen;
     int cmp;
 
@@ -287,14 +468,15 @@ int sdscmp(sds s1, sds s2) {
  * requires length arguments. sdssplit() is just the
  * same function but for zero-terminated strings.
  */
-sds *sdssplitlen(char *s, int len, char *sep, int seplen, int *count) {
+sds *sdssplitlen(const char *s, int len, const char *sep, int seplen, int *count) {
     int elements = 0, slots = 5, start = 0, j;
+    sds *tokens;
+
+    if (seplen < 1 || len < 0) return NULL;
+
+    tokens = zmalloc(sizeof(sds)*slots);
+    if (tokens == NULL) return NULL;
 
-    sds *tokens = malloc(sizeof(sds)*slots);
-#ifdef SDS_ABORT_ON_OOM
-    if (tokens == NULL) sdsOomAbort();
-#endif
-    if (seplen < 1 || len < 0 || tokens == NULL) return NULL;
     if (len == 0) {
         *count = 0;
         return tokens;
@@ -305,26 +487,14 @@ sds *sdssplitlen(char *s, int len, char *sep, int seplen, int *count) {
             sds *newtokens;
 
             slots *= 2;
-            newtokens = realloc(tokens,sizeof(sds)*slots);
-            if (newtokens == NULL) {
-#ifdef SDS_ABORT_ON_OOM
-                sdsOomAbort();
-#else
-                goto cleanup;
-#endif
-            }
+            newtokens = zrealloc(tokens,sizeof(sds)*slots);
+            if (newtokens == NULL) goto cleanup;
             tokens = newtokens;
         }
         /* search the separator */
         if ((seplen == 1 && *(s+j) == sep[0]) || (memcmp(s+j,sep,seplen) == 0)) {
             tokens[elements] = sdsnewlen(s+start,j-start);
-            if (tokens[elements] == NULL) {
-#ifdef SDS_ABORT_ON_OOM
-                sdsOomAbort();
-#else
-                goto cleanup;
-#endif
-            }
+            if (tokens[elements] == NULL) goto cleanup;
             elements++;
             start = j+seplen;
             j = j+seplen-1; /* skip the separator */
@@ -332,35 +502,33 @@ sds *sdssplitlen(char *s, int len, char *sep, int seplen, int *count) {
     }
     /* Add the final element. We are sure there is room in the tokens array. */
     tokens[elements] = sdsnewlen(s+start,len-start);
-    if (tokens[elements] == NULL) {
-#ifdef SDS_ABORT_ON_OOM
-                sdsOomAbort();
-#else
-                goto cleanup;
-#endif
-    }
+    if (tokens[elements] == NULL) goto cleanup;
     elements++;
     *count = elements;
     return tokens;
 
-#ifndef SDS_ABORT_ON_OOM
 cleanup:
     {
         int i;
         for (i = 0; i < elements; i++) sdsfree(tokens[i]);
-        free(tokens);
+        zfree(tokens);
+        *count = 0;
         return NULL;
     }
-#endif
 }
 
+/* Free the result returned by sdssplitlen(), or do nothing if 'tokens' is NULL. */
 void sdsfreesplitres(sds *tokens, int count) {
     if (!tokens) return;
     while(count--)
         sdsfree(tokens[count]);
-    free(tokens);
+    zfree(tokens);
 }
 
+/* Create an sds string from a long long value. It is much faster than:
+ *
+ * sdscatprintf(sdsempty(),"%lld\n", value);
+ */
 sds sdsfromlonglong(long long value) {
     char buf[32], *p;
     unsigned long long v;
@@ -376,10 +544,14 @@ sds sdsfromlonglong(long long value) {
     return sdsnewlen(p,32-(p-buf));
 }
 
-sds sdscatrepr(sds s, char *p, size_t len) {
+/* Append to the sds string "s" an escaped string representation where
+ * all the non-printable characters (tested with isprint()) are turned into
+ * escapes in the form "\n\r\a...." or "\x<hex-number>".
+ *
+ * After the call, the modified sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+sds sdscatrepr(sds s, const char *p, size_t len) {
     s = sdscatlen(s,"\"",1);
-    if (s == NULL) return NULL;
-
     while(len--) {
         switch(*p) {
         case '\\':
@@ -399,27 +571,64 @@ sds sdscatrepr(sds s, char *p, size_t len) {
             break;
         }
         p++;
-        if (s == NULL) return NULL;
     }
     return sdscatlen(s,"\"",1);
 }
 
+/* Helper function for sdssplitargs() that returns non zero if 'c'
+ * is a valid hex digit. */
+int is_hex_digit(char c) {
+    return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') ||
+           (c >= 'A' && c <= 'F');
+}
+
+/* Helper function for sdssplitargs() that converts an hex digit into an
+ * integer from 0 to 15 */
+int hex_digit_to_int(char c) {
+    switch(c) {
+    case '0': return 0;
+    case '1': return 1;
+    case '2': return 2;
+    case '3': return 3;
+    case '4': return 4;
+    case '5': return 5;
+    case '6': return 6;
+    case '7': return 7;
+    case '8': return 8;
+    case '9': return 9;
+    case 'a': case 'A': return 10;
+    case 'b': case 'B': return 11;
+    case 'c': case 'C': return 12;
+    case 'd': case 'D': return 13;
+    case 'e': case 'E': return 14;
+    case 'f': case 'F': return 15;
+    default: return 0;
+    }
+}
+
 /* Split a line into arguments, where every argument can be in the
  * following programming-language REPL-alike form:
  *
  * foo bar "newline are supported\n" and "\xff\x00otherstuff"
  *
  * The number of arguments is stored into *argc, and an array
- * of sds is returned. The caller should sdsfree() all the returned
- * strings and finally free() the array itself.
+ * of sds is returned.
+ *
+ * The caller should free the resulting array of sds strings with
+ * sdsfreesplitres().
  *
  * Note that sdscatrepr() is able to convert back a string into
  * a quoted string in the same format sdssplitargs() is able to parse.
+ *
+ * The function returns the allocated tokens on success, even when the
+ * input string is empty, or NULL if the input contains unbalanced
+ * quotes or closed quotes followed by non space characters
+ * as in: "foo"bar or "foo'
  */
-sds *sdssplitargs(char *line, int *argc) {
-    char *p = line;
+sds *sdssplitargs(const char *line, int *argc) {
+    const char *p = line;
     char *current = NULL;
-    char **vector = NULL, **_vector = NULL;
+    char **vector = NULL;
 
     *argc = 0;
     while(1) {
@@ -427,17 +636,24 @@ sds *sdssplitargs(char *line, int *argc) {
         while(*p && isspace(*p)) p++;
         if (*p) {
             /* get a token */
-            int inq=0; /* set to 1 if we are in "quotes" */
+            int inq=0;  /* set to 1 if we are in "quotes" */
+            int insq=0; /* set to 1 if we are in 'single quotes' */
             int done=0;
 
-            if (current == NULL) {
-                current = sdsempty();
-                if (current == NULL) goto err;
-            }
-
+            if (current == NULL) current = sdsempty();
             while(!done) {
                 if (inq) {
-                    if (*p == '\\' && *(p+1)) {
+                    if (*p == '\\' && *(p+1) == 'x' &&
+                                             is_hex_digit(*(p+2)) &&
+                                             is_hex_digit(*(p+3)))
+                    {
+                        unsigned char byte;
+
+                        byte = (hex_digit_to_int(*(p+2))*16)+
+                                hex_digit_to_int(*(p+3));
+                        current = sdscatlen(current,(char*)&byte,1);
+                        p += 3;
+                    } else if (*p == '\\' && *(p+1)) {
                         char c;
 
                         p++;
@@ -451,7 +667,23 @@ sds *sdssplitargs(char *line, int *argc) {
                         }
                         current = sdscatlen(current,&c,1);
                     } else if (*p == '"') {
-                        /* closing quote must be followed by a space */
+                        /* closing quote must be followed by a space or
+                         * nothing at all. */
+                        if (*(p+1) && !isspace(*(p+1))) goto err;
+                        done=1;
+                    } else if (!*p) {
+                        /* unterminated quotes */
+                        goto err;
+                    } else {
+                        current = sdscatlen(current,p,1);
+                    }
+                } else if (insq) {
+                    if (*p == '\\' && *(p+1) == '\'') {
+                        p++;
+                        current = sdscatlen(current,"'",1);
+                    } else if (*p == '\'') {
+                        /* closing quote must be followed by a space or
+                         * nothing at all. */
                         if (*(p+1) && !isspace(*(p+1))) goto err;
                         done=1;
                     } else if (!*p) {
@@ -472,23 +704,24 @@ sds *sdssplitargs(char *line, int *argc) {
                     case '"':
                         inq=1;
                         break;
+                    case '\'':
+                        insq=1;
+                        break;
                     default:
                         current = sdscatlen(current,p,1);
                         break;
                     }
                 }
                 if (*p) p++;
-                if (current == NULL) goto err;
             }
             /* add the token to the vector */
-            _vector = realloc(vector,((*argc)+1)*sizeof(char*));
-            if (_vector == NULL) goto err;
-
-            vector = _vector;
+            vector = zrealloc(vector,((*argc)+1)*sizeof(char*));
             vector[*argc] = current;
             (*argc)++;
             current = NULL;
         } else {
+            /* Even on empty input string return something not NULL. */
+            if (vector == NULL) vector = zmalloc(sizeof(void*));
             return vector;
         }
     }
@@ -496,30 +729,55 @@ sds *sdssplitargs(char *line, int *argc) {
 err:
     while((*argc)--)
         sdsfree(vector[*argc]);
-    if (vector != NULL) free(vector);
-    if (current != NULL) sdsfree(current);
+    zfree(vector);
+    if (current) sdsfree(current);
+    *argc = 0;
     return NULL;
 }
 
+/* Modify the string substituting all the occurrences of the set of
+ * characters specified in the 'from' string to the corresponding character
+ * in the 'to' array.
+ *
+ * For instance: sdsmapchars(mystring, "ho", "01", 2)
+ * will have the effect of turning the string "hello" into "0ell1".
+ *
+ * The function returns the sds string pointer, that is always the same
+ * as the input pointer since no resize is needed. */
+sds sdsmapchars(sds s, const char *from, const char *to, size_t setlen) {
+    size_t j, i, l = sdslen(s);
+
+    for (j = 0; j < l; j++) {
+        for (i = 0; i < setlen; i++) {
+            if (s[j] == from[i]) {
+                s[j] = to[i];
+                break;
+            }
+        }
+    }
+    return s;
+}
+
+/* Join an array of C strings using the specified separator (also a C string).
+ * Returns the result as an sds string. */
+sds sdsjoin(char **argv, int argc, char *sep) {
+    sds join = sdsempty();
+    int j;
+
+    for (j = 0; j < argc; j++) {
+        join = sdscat(join, argv[j]);
+        if (j != argc-1) join = sdscat(join,sep);
+    }
+    return join;
+}
+
 #ifdef SDS_TEST_MAIN
 #include <stdio.h>
-
-int __failed_tests = 0;
-int __test_num = 0;
-#define test_cond(descr,_c) do { \
-    __test_num++; printf("%d - %s: ", __test_num, descr); \
-    if(_c) printf("PASSED\n"); else {printf("FAILED\n"); __failed_tests++;} \
-} while(0);
-#define test_report() do { \
-    printf("%d tests, %d passed, %d failed\n", __test_num, \
-                    __test_num-__failed_tests, __failed_tests); \
-    if (__failed_tests) { \
-        printf("=== WARNING === We have failed tests here...\n"); \
-    } \
-} while(0);
+#include "testhelp.h"
 
 int main(void) {
     {
+        struct sdshdr *sh;
         sds x = sdsnew("foo"), y;
 
         test_cond("Create a string and obtain the length",
@@ -599,7 +857,26 @@ int main(void) {
         x = sdsnew("aar");
         y = sdsnew("bar");
         test_cond("sdscmp(bar,bar)", sdscmp(x,y) < 0)
+
+        {
+            int oldfree;
+
+            sdsfree(x);
+            x = sdsnew("0");
+            sh = (void*) (x-(sizeof(struct sdshdr)));
+            test_cond("sdsnew() free/len buffers", sh->len == 1 && sh->free == 0);
+            x = sdsMakeRoomFor(x,1);
+            sh = (void*) (x-(sizeof(struct sdshdr)));
+            test_cond("sdsMakeRoomFor()", sh->len == 1 && sh->free > 0);
+            oldfree = sh->free;
+            x[1] = '1';
+            sdsIncrLen(x,1);
+            test_cond("sdsIncrLen() -- content", x[0] == '0' && x[1] == '1');
+            test_cond("sdsIncrLen() -- len", sh->len == 2);
+            test_cond("sdsIncrLen() -- free", sh->free == oldfree-1);
+        }
     }
     test_report()
+    return 0;
 }
 #endif

deps/hiredis/sds.h

@@ -31,6 +31,8 @@
 #ifndef __SDS_H
 #define __SDS_H
 
+#define SDS_MAX_PREALLOC (1024*1024)
+
 #include <sys/types.h>
 #include <stdarg.h>
 
@@ -54,16 +56,17 @@ static inline size_t sdsavail(const sds s) {
 
 sds sdsnewlen(const void *init, size_t initlen);
 sds sdsnew(const char *init);
-sds sdsempty(void);
+sds sdsempty();
 size_t sdslen(const sds s);
 sds sdsdup(const sds s);
 void sdsfree(sds s);
-size_t sdsavail(sds s);
+size_t sdsavail(const sds s);
 sds sdsgrowzero(sds s, size_t len);
 sds sdscatlen(sds s, const void *t, size_t len);
 sds sdscat(sds s, const char *t);
-sds sdscpylen(sds s, char *t, size_t len);
-sds sdscpy(sds s, char *t);
+sds sdscatsds(sds s, const sds t);
+sds sdscpylen(sds s, const char *t, size_t len);
+sds sdscpy(sds s, const char *t);
 
 sds sdscatvprintf(sds s, const char *fmt, va_list ap);
 #ifdef __GNUC__
@@ -74,15 +77,24 @@ sds sdscatprintf(sds s, const char *fmt, ...);
 #endif
 
 sds sdstrim(sds s, const char *cset);
-sds sdsrange(sds s, int start, int end);
+void sdsrange(sds s, int start, int end);
 void sdsupdatelen(sds s);
-int sdscmp(sds s1, sds s2);
-sds *sdssplitlen(char *s, int len, char *sep, int seplen, int *count);
+void sdsclear(sds s);
+int sdscmp(const sds s1, const sds s2);
+sds *sdssplitlen(const char *s, int len, const char *sep, int seplen, int *count);
 void sdsfreesplitres(sds *tokens, int count);
 void sdstolower(sds s);
 void sdstoupper(sds s);
 sds sdsfromlonglong(long long value);
-sds sdscatrepr(sds s, char *p, size_t len);
-sds *sdssplitargs(char *line, int *argc);
+sds sdscatrepr(sds s, const char *p, size_t len);
+sds *sdssplitargs(const char *line, int *argc);
+sds sdsmapchars(sds s, const char *from, const char *to, size_t setlen);
+sds sdsjoin(char **argv, int argc, char *sep);
+
+/* Low level functions exposed to the user API */
+sds sdsMakeRoomFor(sds s, size_t addlen);
+void sdsIncrLen(sds s, int incr);
+sds sdsRemoveFreeSpace(sds s);
+size_t sdsAllocSize(sds s);
 
 #endif

deps/hiredis/zmalloc.h

@@ -0,0 +1,13 @@
+/* Drop in replacement for zmalloc.h in order to just use libc malloc without
+ * any wrappering. */
+
+#ifndef ZMALLOC_H
+#define ZMALLOC_H
+
+#define zmalloc malloc
+#define zrealloc realloc
+#define zcalloc(x) calloc(x,1)
+#define zfree free
+#define zstrdup strdup
+
+#endif

src/networking.c

@@ -829,7 +829,7 @@ void resetClient(redisClient *c) {
 int processInlineBuffer(redisClient *c) {
     char *newline = strstr(c->querybuf,"\r\n");
     int argc, j;
-    sds *argv;
+    sds *argv, aux;
     size_t querylen;
 
     /* Nothing to do without a \r\n */
@@ -843,10 +843,12 @@ int processInlineBuffer(redisClient *c) {
 
     /* Split the input buffer up to the \r\n */
     querylen = newline-(c->querybuf);
-    argv = sdssplitlen(c->querybuf,querylen," ",1,&argc);
+    aux = sdsnewlen(c->querybuf,querylen);
+    argv = sdssplitargs(aux,&argc);
+    sdsfree(aux);
 
     /* Leave data after the first line of the query in the buffer */
-    c->querybuf = sdsrange(c->querybuf,querylen+2,-1);
+    sdsrange(c->querybuf,querylen+2,-1);
 
     /* Setup argv array on client structure */
     if (c->argv) zfree(c->argv);
@@ -875,7 +877,7 @@ static void setProtocolError(redisClient *c, int pos) {
         sdsfree(client);
     }
     c->flags |= REDIS_CLOSE_AFTER_REPLY;
-    c->querybuf = sdsrange(c->querybuf,pos,-1);
+    sdsrange(c->querybuf,pos,-1);
 }
 
 int processMultibulkBuffer(redisClient *c) {
@@ -913,7 +915,7 @@ int processMultibulkBuffer(redisClient *c) {
 
         pos = (newline-c->querybuf)+2;
         if (ll <= 0) {
-            c->querybuf = sdsrange(c->querybuf,pos,-1);
+            sdsrange(c->querybuf,pos,-1);
             return REDIS_OK;
         }
 
@@ -962,7 +964,7 @@ int processMultibulkBuffer(redisClient *c) {
                  * try to make it likely that it will start at c->querybuf
                  * boundary so that we can optimized object creation
                  * avoiding a large copy of data. */
-                c->querybuf = sdsrange(c->querybuf,pos,-1);
+                sdsrange(c->querybuf,pos,-1);
                 pos = 0;
                 /* Hint the sds library about the amount of bytes this string is
                  * going to contain. */
@@ -1001,7 +1003,7 @@ int processMultibulkBuffer(redisClient *c) {
     }
 
     /* Trim to pos */
-    if (pos) c->querybuf = sdsrange(c->querybuf,pos,-1);
+    if (pos) sdsrange(c->querybuf,pos,-1);
 
     /* We're done when c->multibulk == 0 */
     if (c->multibulklen == 0) return REDIS_OK;

src/object.c

@@ -347,13 +347,11 @@ int compareStringObjectsWithFlags(robj *a, robj *b, int flags) {
     redisAssertWithInfo(NULL,a,a->type == REDIS_STRING && b->type == REDIS_STRING);
     char bufa[128], bufb[128], *astr, *bstr;
     size_t alen, blen, minlen;
-    int bothsds = 1;
 
     if (a == b) return 0;
     if (a->encoding != REDIS_ENCODING_RAW) {
         alen = ll2string(bufa,sizeof(bufa),(long) a->ptr);
         astr = bufa;
-        bothsds = 0;
     } else {
         astr = a->ptr;
         alen = sdslen(astr);
@@ -361,7 +359,6 @@ int compareStringObjectsWithFlags(robj *a, robj *b, int flags) {
     if (b->encoding != REDIS_ENCODING_RAW) {
         blen = ll2string(bufb,sizeof(bufb),(long) b->ptr);
         bstr = bufb;
-        bothsds = 0;
     } else {
         bstr = b->ptr;
         blen = sdslen(bstr);

src/replication.c

@@ -188,7 +188,7 @@ void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc) {
     b[0] = '*';
     len = ll2string(b+1,REDIS_LONGSTR_SIZE,argc);
     b += len+1;
-    buf_left -= len;
+    buf_left -= len+1;
     b[0] = '\r';
     b[1] = '\n';
     b += 2;
@@ -218,7 +218,7 @@ void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc) {
         b[0] = '$';
         len = ll2string(b+1,REDIS_LONGSTR_SIZE,objlen);
         b += len+1;
-        buf_left -= len;
+        buf_left -= len+1;
         b[0] = '\r';
         b[1] = '\n';
         b += 2;

src/sds.c

@@ -36,6 +36,18 @@
 #include "sds.h"
 #include "zmalloc.h"
 
+/* Create a new sds string with the content specified by the 'init' pointer
+ * and 'initlen'.
+ * If NULL is used for 'init' the string is initialized with zero bytes.
+ *
+ * The string is always null-termined (all the sds strings are, always) so
+ * even if you create an sds string with:
+ *
+ * mystring = sdsnewlen("abc",3");
+ *
+ * You can print the string with printf() as there is an implicit \0 at the
+ * end of the string. However the string is binary safe and can contain
+ * \0 characters in the middle, as the length is stored in the sds header. */
 sds sdsnewlen(const void *init, size_t initlen) {
     struct sdshdr *sh;
 
@@ -53,24 +65,43 @@ sds sdsnewlen(const void *init, size_t initlen) {
     return (char*)sh->buf;
 }
 
+/* Create an empty (zero length) sds string. Even in this case the string
+ * always has an implicit null term. */
 sds sdsempty(void) {
     return sdsnewlen("",0);
 }
 
+/* Create a new sds string starting from a null termined C string. */
 sds sdsnew(const char *init) {
     size_t initlen = (init == NULL) ? 0 : strlen(init);
     return sdsnewlen(init, initlen);
 }
 
+/* Duplicate an sds string. */
 sds sdsdup(const sds s) {
     return sdsnewlen(s, sdslen(s));
 }
 
+/* Free an sds string. No operation is performed if 's' is NULL. */
 void sdsfree(sds s) {
     if (s == NULL) return;
     zfree(s-sizeof(struct sdshdr));
 }
 
+/* Set the sds string length to the length as obtained with strlen(), so
+ * considering as content only up to the first null term character.
+ *
+ * This function is useful when the sds string is hacked manually in some
+ * way, like in the following example:
+ *
+ * s = sdsnew("foobar");
+ * s[2] = '\0';
+ * sdsupdatelen(s);
+ * printf("%d\n", sdslen(s));
+ *
+ * The output will be "2", but if we comment out the call to sdsupdatelen()
+ * the output will be "6" as the string was modified but the logical length
+ * remains 6 bytes. */
 void sdsupdatelen(sds s) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     int reallen = strlen(s);
@@ -78,6 +109,10 @@ void sdsupdatelen(sds s) {
     sh->len = reallen;
 }
 
+/* Modify an sds string on-place to make it empty (zero length).
+ * However all the existing buffer is not discarded but set as free space
+ * so that next append operations will not require allocations up to the
+ * number of bytes previously available. */
 void sdsclear(sds s) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     sh->free += sh->len;
@@ -89,7 +124,7 @@ void sdsclear(sds s) {
  * is sure that after calling this function can overwrite up to addlen
  * bytes after the end of the string, plus one more byte for nul term.
  * 
- * Note: this does not change the *size* of the sds string as returned
+ * Note: this does not change the *length* of the sds string as returned
  * by sdslen(), but only the free buffer space we have. */
 sds sdsMakeRoomFor(sds s, size_t addlen) {
     struct sdshdr *sh, *newsh;
@@ -113,7 +148,10 @@ sds sdsMakeRoomFor(sds s, size_t addlen) {
 
 /* Reallocate the sds string so that it has no free space at the end. The
  * contained string remains not altered, but next concatenation operations
- * will require a reallocation. */
+ * will require a reallocation.
+ *
+ * After the call, the passed sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
 sds sdsRemoveFreeSpace(sds s) {
     struct sdshdr *sh;
 
@@ -123,6 +161,13 @@ sds sdsRemoveFreeSpace(sds s) {
     return sh->buf;
 }
 
+/* Return the total size of the allocation of the specifed sds string,
+ * including:
+ * 1) The sds header before the pointer.
+ * 2) The string.
+ * 3) The free buffer at the end if any.
+ * 4) The implicit null term.
+ */
 size_t sdsAllocSize(sds s) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
 
@@ -130,7 +175,7 @@ size_t sdsAllocSize(sds s) {
 }
 
 /* Increment the sds length and decrements the left free space at the
- * end of the string accordingly to 'incr'. Also set the null term
+ * end of the string according to 'incr'. Also set the null term
  * in the new end of the string.
  *
  * This function is used in order to fix the string length after the
@@ -140,15 +185,17 @@ size_t sdsAllocSize(sds s) {
  * Note: it is possible to use a negative increment in order to
  * right-trim the string.
  *
+ * Usage example:
+ *
  * Using sdsIncrLen() and sdsMakeRoomFor() it is possible to mount the
- * following schema to cat bytes coming from the kernel to the end of an
- * sds string new things without copying into an intermediate buffer:
+ * following schema, to cat bytes coming from the kernel to the end of an
+ * sds string without copying into an intermediate buffer:
  *
  * oldlen = sdslen(s);
  * s = sdsMakeRoomFor(s, BUFFER_SIZE);
  * nread = read(fd, s+oldlen, BUFFER_SIZE);
  * ... check for nread <= 0 and handle it ...
- * sdsIncrLen(s, nhread);
+ * sdsIncrLen(s, nread);
  */
 void sdsIncrLen(sds s, int incr) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
@@ -161,7 +208,10 @@ void sdsIncrLen(sds s, int incr) {
 }
 
 /* Grow the sds to have the specified length. Bytes that were not part of
- * the original length of the sds will be set to zero. */
+ * the original length of the sds will be set to zero.
+ *
+ * if the specified length is smaller than the current length, no operation
+ * is performed. */
 sds sdsgrowzero(sds s, size_t len) {
     struct sdshdr *sh = (void*)(s-(sizeof(struct sdshdr)));
     size_t totlen, curlen = sh->len;
@@ -179,6 +229,11 @@ sds sdsgrowzero(sds s, size_t len) {
     return s;
 }
 
+/* Append the specified binary-safe string pointed by 't' of 'len' bytes to the
+ * end of the specified sds string 's'.
+ *
+ * After the call, the passed sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
 sds sdscatlen(sds s, const void *t, size_t len) {
     struct sdshdr *sh;
     size_t curlen = sdslen(s);
@@ -193,14 +248,24 @@ sds sdscatlen(sds s, const void *t, size_t len) {
     return s;
 }
 
+/* Append the specified null termianted C string to the sds string 's'.
+ *
+ * After the call, the passed sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
 sds sdscat(sds s, const char *t) {
     return sdscatlen(s, t, strlen(t));
 }
 
+/* Append the specified sds 't' to the existing sds 's'.
+ *
+ * After the call, the modified sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
 sds sdscatsds(sds s, const sds t) {
     return sdscatlen(s, t, sdslen(t));
 }
 
+/* Destructively modify the sds string 's' to hold the specified binary
+ * safe string pointed by 't' of length 'len' bytes. */
 sds sdscpylen(sds s, const char *t, size_t len) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     size_t totlen = sh->free+sh->len;
@@ -218,10 +283,13 @@ sds sdscpylen(sds s, const char *t, size_t len) {
     return s;
 }
 
+/* Like sdscpylen() but 't' must be a null-termined string so that the length
+ * of the string is obtained with strlen(). */
 sds sdscpy(sds s, const char *t) {
     return sdscpylen(s, t, strlen(t));
 }
 
+/* Like sdscatpritf() but gets va_list instead of being variadic. */
 sds sdscatvprintf(sds s, const char *fmt, va_list ap) {
     va_list cpy;
     char *buf, *t;
@@ -245,6 +313,22 @@ sds sdscatvprintf(sds s, const char *fmt, va_list ap) {
     return t;
 }
 
+/* Append to the sds string 's' a string obtained using printf-alike format
+ * specifier.
+ *
+ * After the call, the modified sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call.
+ *
+ * Example:
+ *
+ * s = sdsempty("Sum is: ");
+ * s = sdscatprintf(s,"%d+%d = %d",a,b,a+b).
+ *
+ * Often you need to create a string from scratch with the printf-alike
+ * format. When this is the need, just use sdsempty() as the target string:
+ *
+ * s = sdscatprintf(sdsempty(), "... your format ...", args);
+ */
 sds sdscatprintf(sds s, const char *fmt, ...) {
     va_list ap;
     char *t;
@@ -254,6 +338,20 @@ sds sdscatprintf(sds s, const char *fmt, ...) {
     return t;
 }
 
+/* Remove the part of the string from left and from right composed just of
+ * contiguous characters found in 'cset', that is a null terminted C string.
+ *
+ * After the call, the modified sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call.
+ *
+ * Example:
+ *
+ * s = sdsnew("AA...AA.a.aa.aHelloWorld     :::");
+ * s = sdstrim(s,"A. :");
+ * printf("%s\n", s);
+ *
+ * Output will be just "Hello World".
+ */
 sds sdstrim(sds s, const char *cset) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     char *start, *end, *sp, *ep;
@@ -271,11 +369,27 @@ sds sdstrim(sds s, const char *cset) {
     return s;
 }
 
-sds sdsrange(sds s, int start, int end) {
+/* Turn the string into a smaller (or equal) string containing only the
+ * substring specified by the 'start' and 'end' indexes.
+ *
+ * start and end can be negative, where -1 means the last character of the
+ * string, -2 the penultimate character, and so forth.
+ *
+ * The interval is inclusive, so the start and end characters will be part
+ * of the resulting string.
+ *
+ * The string is modified in-place.
+ *
+ * Example:
+ *
+ * s = sdsnew("Hello World");
+ * sdstrim(s,1,-1); => "ello Worl"
+ */
+void sdsrange(sds s, int start, int end) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     size_t newlen, len = sdslen(s);
 
-    if (len == 0) return s;
+    if (len == 0) return;
     if (start < 0) {
         start = len+start;
         if (start < 0) start = 0;
@@ -299,21 +413,33 @@ sds sdsrange(sds s, int start, int end) {
     sh->buf[newlen] = 0;
     sh->free = sh->free+(sh->len-newlen);
     sh->len = newlen;
-    return s;
 }
 
+/* Apply tolower() to every character of the sds string 's'. */
 void sdstolower(sds s) {
     int len = sdslen(s), j;
 
     for (j = 0; j < len; j++) s[j] = tolower(s[j]);
 }
 
+/* Apply toupper() to every character of the sds string 's'. */
 void sdstoupper(sds s) {
     int len = sdslen(s), j;
 
     for (j = 0; j < len; j++) s[j] = toupper(s[j]);
 }
 
+/* Compare two sds strings s1 and s2 with memcmp().
+ *
+ * Return value:
+ *
+ *     1 if s1 > s2.
+ *    -1 if s1 < s2.
+ *     0 if s1 and s2 are exactly the same binary string.
+ *
+ * If two strings share exactly the same prefix, but one of the two has
+ * additional characters, the longer string is considered to be greater than
+ * the smaller one. */
 int sdscmp(const sds s1, const sds s2) {
     size_t l1, l2, minlen;
     int cmp;
@@ -391,6 +517,7 @@ cleanup:
     }
 }
 
+/* Free the result returned by sdssplitlen(), or do nothing if 'tokens' is NULL. */
 void sdsfreesplitres(sds *tokens, int count) {
     if (!tokens) return;
     while(count--)
@@ -398,6 +525,10 @@ void sdsfreesplitres(sds *tokens, int count) {
     zfree(tokens);
 }
 
+/* Create an sds string from a long long value. It is much faster than:
+ *
+ * sdscatprintf(sdsempty(),"%lld\n", value);
+ */
 sds sdsfromlonglong(long long value) {
     char buf[32], *p;
     unsigned long long v;
@@ -413,6 +544,12 @@ sds sdsfromlonglong(long long value) {
     return sdsnewlen(p,32-(p-buf));
 }
 
+/* Append to the sds string "s" an escaped string representation where
+ * all the non-printable characters (tested with isprint()) are turned into
+ * escapes in the form "\n\r\a...." or "\x<hex-number>".
+ *
+ * After the call, the modified sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
 sds sdscatrepr(sds s, const char *p, size_t len) {
     s = sdscatlen(s,"\"",1);
     while(len--) {

src/sds.h

@@ -77,7 +77,7 @@ sds sdscatprintf(sds s, const char *fmt, ...);
 #endif
 
 sds sdstrim(sds s, const char *cset);
-sds sdsrange(sds s, int start, int end);
+void sdsrange(sds s, int start, int end);
 void sdsupdatelen(sds s);
 void sdsclear(sds s);
 int sdscmp(const sds s1, const sds s2);

src/sentinel.c

@@ -1920,7 +1920,7 @@ void addReplySentinelRedisInstance(redisClient *c, sentinelRedisInstance *ri) {
     if (ri->flags & SRI_RECONF_DONE) flags = sdscat(flags,"reconf_done,");
     if (ri->flags & SRI_DEMOTE) flags = sdscat(flags,"demote,");
 
-    if (sdslen(flags) != 0) flags = sdsrange(flags,0,-2); /* remove last "," */
+    if (sdslen(flags) != 0) sdsrange(flags,0,-2); /* remove last "," */
     addReplyBulkCString(c,flags);
     sdsfree(flags);
     fields++;

src/util.c

@@ -438,7 +438,7 @@ sds getAbsolutePath(char *filename) {
     while (sdslen(relpath) >= 3 &&
            relpath[0] == '.' && relpath[1] == '.' && relpath[2] == '/')
     {
-        relpath = sdsrange(relpath,3,-1);
+        sdsrange(relpath,3,-1);
         if (sdslen(abspath) > 1) {
             char *p = abspath + sdslen(abspath)-2;
             int trimlen = 1;
@@ -447,7 +447,7 @@ sds getAbsolutePath(char *filename) {
                 p--;
                 trimlen++;
             }
-            abspath = sdsrange(abspath,0,-(trimlen+1));
+            sdsrange(abspath,0,-(trimlen+1));
         }
     }
 

src/version.h

@@ -1 +1 @@
-#define REDIS_VERSION "2.7.101"
+#define REDIS_VERSION "2.7.102"

tests/integration/replication-4.tcl

@@ -96,3 +96,41 @@ start_server {tags {"repl"}} {
         } {NOREPLICAS*}
     }
 }
+
+start_server {tags {"repl"}} {
+    start_server {} {
+        set master [srv -1 client]
+        set master_host [srv -1 host]
+        set master_port [srv -1 port]
+        set slave [srv 0 client]
+
+        test {First server should have role slave after SLAVEOF} {
+            $slave slaveof $master_host $master_port
+            wait_for_condition 50 100 {
+                [s 0 role] eq {slave}
+            } else {
+                fail "Replication not started."
+            }
+        }
+
+        test {Replication: commands with many arguments (issue #1221)} {
+            # We now issue large MSET commands, that may trigger a specific
+            # class of bugs, see issue #1221.
+            for {set j 0} {$j < 100} {incr j} {
+                set cmd [list mset]
+                for {set x 0} {$x < 1000} {incr x} {
+                    lappend cmd [randomKey] [randomValue]
+                }
+                $master {*}$cmd
+            }
+
+            set retry 10
+            while {$retry && ([$master debug digest] ne [$slave debug digest])}\
+            {
+                after 1000
+                incr retry -1
+            }
+            assert {[$master dbsize] > 0}
+        }
+    }
+}