Issue 804 Add Default-Start and Default-Stop LSB tags for RedHat startup and update...

[redis.git] / src / sds.c

diff --git a/src/sds.c b/src/sds.c
index 4878f8a625714ce4190555953954f5e24fbcd2af..e8491acfae9c56e19a923b24e7bdcb6ce2068564 100644 (file)
--- a/src/sds.c
+++ b/src/sds.c
@@ -1,6 +1,6 @@
 /* SDSLib, A C dynamic strings library
  *
 /* 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
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without


@@ -28,36 +28,27 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
  * POSSIBILITY OF SUCH DAMAGE.
  */
 

-#define SDS_ABORT_ON_OOM
-
-#include "sds.h"

 #include <stdio.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdlib.h>

-#include <stdarg.h>

 #include <string.h>
 #include <ctype.h>
 #include <string.h>
 #include <ctype.h>

+#include <assert.h>
+#include "sds.h"

 #include "zmalloc.h"
 
 #include "zmalloc.h"
 

-static void sdsOomAbort(void) {
-    fprintf(stderr,"SDS: Out Of Memory (SDS_ABORT_ON_OOM defined)\n");
-    abort();
-}
-

 sds sdsnewlen(const void *init, size_t initlen) {
     struct sdshdr *sh;
 
 sds sdsnewlen(const void *init, size_t initlen) {
     struct sdshdr *sh;
 

-    sh = zmalloc(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;
     if (sh == NULL) return NULL;

-#endif

     sh->len = initlen;
     sh->free = 0;
     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;
 }
     sh->buf[initlen] = '\0';
     return (char*)sh->buf;
 }


@@ -71,11 +62,6 @@ sds sdsnew(const char *init) {
     return sdsnewlen(init, initlen);
 }
 
     return sdsnewlen(init, initlen);
 }
 

-size_t sdslen(const sds s) {
-    struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
-    return sh->len;
-}
-

 sds sdsdup(const sds s) {
     return sdsnewlen(s, sdslen(s));
 }
 sds sdsdup(const sds s) {
     return sdsnewlen(s, sdslen(s));
 }


@@ -85,11 +71,6 @@ void sdsfree(sds s) {
     zfree(s-sizeof(struct sdshdr));
 }
 
     zfree(s-sizeof(struct sdshdr));
 }
 

-size_t sdsavail(sds s) {
-    struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
-    return sh->free;
-}
-

 void sdsupdatelen(sds s) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     int reallen = strlen(s);
 void sdsupdatelen(sds s) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     int reallen = strlen(s);


@@ -97,7 +78,20 @@ void sdsupdatelen(sds s) {
     sh->len = reallen;
 }
 
     sh->len = reallen;
 }
 

-static sds sdsMakeRoomFor(sds s, size_t addlen) {
+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 *size* 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;
     struct sdshdr *sh, *newsh;
     size_t free = sdsavail(s);
     size_t len, newlen;


@@ -105,19 +99,87 @@ static sds sdsMakeRoomFor(sds s, size_t addlen) {
     if (free >= addlen) return s;
     len = sdslen(s);
     sh = (void*) (s-(sizeof(struct sdshdr)));
     if (free >= addlen) return s;
     len = sdslen(s);
     sh = (void*) (s-(sizeof(struct sdshdr)));

-    newlen = (len+addlen)*2;
+    newlen = (len+addlen);
+    if (newlen < SDS_MAX_PREALLOC)
+        newlen *= 2;
+    else
+        newlen += SDS_MAX_PREALLOC;

     newsh = zrealloc(sh, sizeof(struct sdshdr)+newlen+1);
     newsh = zrealloc(sh, sizeof(struct sdshdr)+newlen+1);

-#ifdef SDS_ABORT_ON_OOM
-    if (newsh == NULL) sdsOomAbort();
-#else

     if (newsh == NULL) return NULL;
     if (newsh == NULL) return NULL;

-#endif

 
     newsh->free = newlen - len;
     return newsh->buf;
 }
 
 
     newsh->free = newlen - len;
     return newsh->buf;
 }
 

-sds sdscatlen(sds s, void *t, size_t len) {
+/* 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. */
+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;
+}
+
+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 accordingly 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.
+ *
+ * Using sdsIncrLen() and sdsMakeRoomFor() it is possible to mount the
+ * following schema to cat bytes coming from the kerenl to the end of an
+ * sds string new things 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);
+ */
+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. */
+sds sdsgrowzero(sds s, size_t len) {
+    struct sdshdr *sh = (void*)(s-(sizeof(struct sdshdr)));
+    size_t totlen, curlen = sh->len;
+
+    if (len <= curlen) return s;
+    s = sdsMakeRoomFor(s,len-curlen);
+    if (s == NULL) return NULL;
+
+    /* Make sure added region doesn't contain garbage */
+    sh = (void*)(s-(sizeof(struct sdshdr)));
+    memset(s+curlen,0,(len-curlen+1)); /* also set trailing \0 byte */
+    totlen = sh->len+sh->free;
+    sh->len = len;
+    sh->free = totlen-sh->len;
+    return s;
+}
+
+sds sdscatlen(sds s, const void *t, size_t len) {

     struct sdshdr *sh;
     size_t curlen = sdslen(s);
 
     struct sdshdr *sh;
     size_t curlen = sdslen(s);
 


@@ -131,11 +193,15 @@ sds sdscatlen(sds s, void *t, size_t len) {
     return s;
 }
 
     return s;
 }
 

-sds sdscat(sds s, char *t) {
+sds sdscat(sds s, const char *t) {

     return sdscatlen(s, t, strlen(t));
 }
 
     return sdscatlen(s, t, strlen(t));
 }
 

-sds sdscpylen(sds s, char *t, size_t len) {
+sds sdscatsds(sds s, const sds t) {
+    return sdscatlen(s, t, sdslen(t));
+}
+
+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;
 
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     size_t totlen = sh->free+sh->len;
 


@@ -152,26 +218,21 @@ sds sdscpylen(sds s, char *t, size_t len) {
     return s;
 }
 
     return s;
 }
 

-sds sdscpy(sds s, char *t) {
+sds sdscpy(sds s, const char *t) {

     return sdscpylen(s, t, strlen(t));
 }
 
     return sdscpylen(s, t, strlen(t));
 }
 

-sds sdscatprintf(sds s, const char *fmt, ...) {
-    va_list ap;
+sds sdscatvprintf(sds s, const char *fmt, va_list ap) {
+    va_list cpy;

     char *buf, *t;
     size_t buflen = 16;
 
     while(1) {
         buf = zmalloc(buflen);
     char *buf, *t;
     size_t buflen = 16;
 
     while(1) {
         buf = zmalloc(buflen);

-#ifdef SDS_ABORT_ON_OOM
-        if (buf == NULL) sdsOomAbort();
-#else

         if (buf == NULL) return NULL;
         if (buf == NULL) return NULL;

-#endif

         buf[buflen-2] = '\0';
         buf[buflen-2] = '\0';

-        va_start(ap, fmt);
-        vsnprintf(buf, buflen, fmt, ap);
-        va_end(ap);
+        va_copy(cpy,ap);
+        vsnprintf(buf, buflen, fmt, cpy);

         if (buf[buflen-2] != '\0') {
             zfree(buf);
             buflen *= 2;
         if (buf[buflen-2] != '\0') {
             zfree(buf);
             buflen *= 2;


@@ -184,6 +245,15 @@ sds sdscatprintf(sds s, const char *fmt, ...) {
     return t;
 }
 
     return t;
 }
 

+sds sdscatprintf(sds s, const char *fmt, ...) {
+    va_list ap;
+    char *t;
+    va_start(ap, fmt);
+    t = sdscatvprintf(s,fmt,ap);
+    va_end(ap);
+    return t;
+}
+

 sds sdstrim(sds s, const char *cset) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     char *start, *end, *sp, *ep;
 sds sdstrim(sds s, const char *cset) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     char *start, *end, *sp, *ep;


@@ -216,13 +286,16 @@ sds sdsrange(sds s, int start, int end) {
     }
     newlen = (start > end) ? 0 : (end-start)+1;
     if (newlen != 0) {
     }
     newlen = (start > end) ? 0 : (end-start)+1;
     if (newlen != 0) {

-        if (start >= (signed)len) start = len-1;
-        if (end >= (signed)len) end = len-1;
-        newlen = (start > end) ? 0 : (end-start)+1;
+        if (start >= (signed)len) {
+            newlen = 0;
+        } else if (end >= (signed)len) {
+            end = len-1;
+            newlen = (start > end) ? 0 : (end-start)+1;
+        }

     } else {
         start = 0;
     }
     } else {
         start = 0;
     }

-    if (start != 0) memmove(sh->buf, sh->buf+start, newlen);
+    if (start && newlen) memmove(sh->buf, sh->buf+start, newlen);

     sh->buf[newlen] = 0;
     sh->free = sh->free+(sh->len-newlen);
     sh->len = newlen;
     sh->buf[newlen] = 0;
     sh->free = sh->free+(sh->len-newlen);
     sh->len = newlen;


@@ -241,7 +314,7 @@ void sdstoupper(sds s) {
     for (j = 0; j < len; j++) s[j] = toupper(s[j]);
 }
 
     for (j = 0; j < len; j++) s[j] = toupper(s[j]);
 }
 

-int sdscmp(sds s1, sds s2) {
+int sdscmp(const sds s1, const sds s2) {

     size_t l1, l2, minlen;
     int cmp;
 
     size_t l1, l2, minlen;
     int cmp;
 


@@ -269,14 +342,15 @@ int sdscmp(sds s1, sds s2) {
  * requires length arguments. sdssplit() is just the
  * same function but for zero-terminated strings.
  */
  * 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;
     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 = zmalloc(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;
     if (len == 0) {
         *count = 0;
         return tokens;


@@ -288,25 +362,13 @@ sds *sdssplitlen(char *s, int len, char *sep, int seplen, int *count) {
 
             slots *= 2;
             newtokens = zrealloc(tokens,sizeof(sds)*slots);
 
             slots *= 2;
             newtokens = zrealloc(tokens,sizeof(sds)*slots);

-            if (newtokens == NULL) {
-#ifdef SDS_ABORT_ON_OOM
-                sdsOomAbort();
-#else
-                goto cleanup;
-#endif
-            }
+            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);
             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 */
             elements++;
             start = j+seplen;
             j = j+seplen-1; /* skip the separator */


@@ -314,26 +376,19 @@ 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);
     }
     /* 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;
 
     elements++;
     *count = elements;
     return tokens;
 

-#ifndef SDS_ABORT_ON_OOM

 cleanup:
     {
         int i;
         for (i = 0; i < elements; i++) sdsfree(tokens[i]);
         zfree(tokens);
 cleanup:
     {
         int i;
         for (i = 0; i < elements; i++) sdsfree(tokens[i]);
         zfree(tokens);

+        *count = 0;

         return NULL;
     }
         return NULL;
     }

-#endif

 }
 
 void sdsfreesplitres(sds *tokens, int count) {
 }
 
 void sdsfreesplitres(sds *tokens, int count) {


@@ -358,7 +413,7 @@ sds sdsfromlonglong(long long value) {
     return sdsnewlen(p,32-(p-buf));
 }
 
     return sdsnewlen(p,32-(p-buf));
 }
 

-sds sdscatrepr(sds s, char *p, size_t len) {
+sds sdscatrepr(sds s, const char *p, size_t len) {

     s = sdscatlen(s,"\"",1);
     while(len--) {
         switch(*p) {
     s = sdscatlen(s,"\"",1);
     while(len--) {
         switch(*p) {


@@ -366,11 +421,11 @@ sds sdscatrepr(sds s, char *p, size_t len) {
         case '"':
             s = sdscatprintf(s,"\\%c",*p);
             break;
         case '"':
             s = sdscatprintf(s,"\\%c",*p);
             break;

-        case '\n': s = sdscatlen(s,"\\n",1); break;
-        case '\r': s = sdscatlen(s,"\\r",1); break;
-        case '\t': s = sdscatlen(s,"\\t",1); break;
-        case '\a': s = sdscatlen(s,"\\a",1); break;
-        case '\b': s = sdscatlen(s,"\\b",1); break;
+        case '\n': s = sdscatlen(s,"\\n",2); break;
+        case '\r': s = sdscatlen(s,"\\r",2); break;
+        case '\t': s = sdscatlen(s,"\\t",2); break;
+        case '\a': s = sdscatlen(s,"\\a",2); break;
+        case '\b': s = sdscatlen(s,"\\b",2); break;

         default:
             if (isprint(*p))
                 s = sdscatprintf(s,"%c",*p);
         default:
             if (isprint(*p))
                 s = sdscatprintf(s,"%c",*p);


@@ -383,6 +438,37 @@ sds sdscatrepr(sds s, char *p, size_t len) {
     return sdscatlen(s,"\"",1);
 }
 
     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:
  *
 /* Split a line into arguments, where every argument can be in the
  * following programming-language REPL-alike form:
  *


@@ -395,8 +481,8 @@ sds sdscatrepr(sds s, char *p, size_t len) {
  * Note that sdscatrepr() is able to convert back a string into
  * a quoted string in the same format sdssplitargs() is able to parse.
  */
  * Note that sdscatrepr() is able to convert back a string into
  * a quoted string in the same format sdssplitargs() is able to parse.
  */

-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;
 
     char *current = NULL;
     char **vector = NULL;
 


@@ -406,13 +492,24 @@ sds *sdssplitargs(char *line, int *argc) {
         while(*p && isspace(*p)) p++;
         if (*p) {
             /* get a token */
         while(*p && isspace(*p)) p++;
         if (*p) {
             /* get a token */

-            int inq=0; /* set to 1 if we are in "quotes" */
-            int done = 0;
+            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();
             while(!done) {
                 if (inq) {
 
             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++;
                         char c;
 
                         p++;


@@ -426,7 +523,28 @@ sds *sdssplitargs(char *line, int *argc) {
                         }
                         current = sdscatlen(current,&c,1);
                     } else if (*p == '"') {
                         }
                         current = sdscatlen(current,&c,1);
                     } else if (*p == '"') {

-                        done = 1;
+                        /* 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) {
+                        /* unterminated quotes */
+                        goto err;

                     } else {
                         current = sdscatlen(current,p,1);
                     }
                     } else {
                         current = sdscatlen(current,p,1);
                     }


@@ -442,6 +560,9 @@ sds *sdssplitargs(char *line, int *argc) {
                     case '"':
                         inq=1;
                         break;
                     case '"':
                         inq=1;
                         break;

+                    case '\'':
+                        insq=1;
+                        break;

                     default:
                         current = sdscatlen(current,p,1);
                         break;
                     default:
                         current = sdscatlen(current,p,1);
                         break;


@@ -458,4 +579,151 @@ sds *sdssplitargs(char *line, int *argc) {
             return vector;
         }
     }
             return vector;
         }
     }

+
+err:
+    while((*argc)--)
+        sdsfree(vector[*argc]);
+    zfree(vector);
+    if (current) sdsfree(current);
+    return NULL;
+}
+
+void sdssplitargs_free(sds *argv, int argc) {
+    int j;
+
+    for (j = 0 ;j < argc; j++) sdsfree(argv[j]);
+    zfree(argv);
+}
+
+/* Modify the string substituting all the occurrences of the set of
+ * characters specifed 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;
+}
+
+#ifdef SDS_TEST_MAIN
+#include <stdio.h>
+#include "testhelp.h"
+
+int main(void) {
+    {
+        struct sdshdr *sh;
+        sds x = sdsnew("foo"), y;
+
+        test_cond("Create a string and obtain the length",
+            sdslen(x) == 3 && memcmp(x,"foo\0",4) == 0)
+
+        sdsfree(x);
+        x = sdsnewlen("foo",2);
+        test_cond("Create a string with specified length",
+            sdslen(x) == 2 && memcmp(x,"fo\0",3) == 0)
+
+        x = sdscat(x,"bar");
+        test_cond("Strings concatenation",
+            sdslen(x) == 5 && memcmp(x,"fobar\0",6) == 0);
+
+        x = sdscpy(x,"a");
+        test_cond("sdscpy() against an originally longer string",
+            sdslen(x) == 1 && memcmp(x,"a\0",2) == 0)
+
+        x = sdscpy(x,"xyzxxxxxxxxxxyyyyyyyyyykkkkkkkkkk");
+        test_cond("sdscpy() against an originally shorter string",
+            sdslen(x) == 33 &&
+            memcmp(x,"xyzxxxxxxxxxxyyyyyyyyyykkkkkkkkkk\0",33) == 0)
+
+        sdsfree(x);
+        x = sdscatprintf(sdsempty(),"%d",123);
+        test_cond("sdscatprintf() seems working in the base case",
+            sdslen(x) == 3 && memcmp(x,"123\0",4) ==0)
+
+        sdsfree(x);
+        x = sdstrim(sdsnew("xxciaoyyy"),"xy");
+        test_cond("sdstrim() correctly trims characters",
+            sdslen(x) == 4 && memcmp(x,"ciao\0",5) == 0)
+
+        y = sdsrange(sdsdup(x),1,1);
+        test_cond("sdsrange(...,1,1)",
+            sdslen(y) == 1 && memcmp(y,"i\0",2) == 0)
+
+        sdsfree(y);
+        y = sdsrange(sdsdup(x),1,-1);
+        test_cond("sdsrange(...,1,-1)",
+            sdslen(y) == 3 && memcmp(y,"iao\0",4) == 0)
+
+        sdsfree(y);
+        y = sdsrange(sdsdup(x),-2,-1);
+        test_cond("sdsrange(...,-2,-1)",
+            sdslen(y) == 2 && memcmp(y,"ao\0",3) == 0)
+
+        sdsfree(y);
+        y = sdsrange(sdsdup(x),2,1);
+        test_cond("sdsrange(...,2,1)",
+            sdslen(y) == 0 && memcmp(y,"\0",1) == 0)
+
+        sdsfree(y);
+        y = sdsrange(sdsdup(x),1,100);
+        test_cond("sdsrange(...,1,100)",
+            sdslen(y) == 3 && memcmp(y,"iao\0",4) == 0)
+
+        sdsfree(y);
+        y = sdsrange(sdsdup(x),100,100);
+        test_cond("sdsrange(...,100,100)",
+            sdslen(y) == 0 && memcmp(y,"\0",1) == 0)
+
+        sdsfree(y);
+        sdsfree(x);
+        x = sdsnew("foo");
+        y = sdsnew("foa");
+        test_cond("sdscmp(foo,foa)", sdscmp(x,y) > 0)
+
+        sdsfree(y);
+        sdsfree(x);
+        x = sdsnew("bar");
+        y = sdsnew("bar");
+        test_cond("sdscmp(bar,bar)", sdscmp(x,y) == 0)
+
+        sdsfree(y);
+        sdsfree(x);
+        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