X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/5171777bf112a6a930c4750949037ce741f3bf28..2c2b20853724d86eaa6c51308f11645cc576dc1c:/src/sds.c

diff --git a/src/sds.c b/src/sds.c
index 2f3ffedc..c3a0ccb9 100644
--- a/src/sds.c
+++ b/src/sds.c
@@ -26,15 +26,22 @@
  * 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.
+ *
+ * History:
+ *
+ * - 22 March 2011: History section created on top of sds.c
+ * - 22 March 2011: Fixed a problem with "\xab" escapes convertion in
+ *                  function sdssplitargs().
  */
 
 #define SDS_ABORT_ON_OOM
 
-#include "sds.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
+#include <assert.h>
+#include "sds.h"
 #include "zmalloc.h"
 
 static void sdsOomAbort(void) {
@@ -45,7 +52,11 @@ static void sdsOomAbort(void) {
 sds sdsnewlen(const void *init, size_t initlen) {
     struct sdshdr *sh;
 
-    sh = zmalloc(sizeof(struct sdshdr)+initlen+1);
+    if (init) {
+        sh = zmalloc(sizeof(struct sdshdr)+initlen+1);
+    } else {
+        sh = zcalloc(sizeof(struct sdshdr)+initlen+1);
+    }
 #ifdef SDS_ABORT_ON_OOM
     if (sh == NULL) sdsOomAbort();
 #else
@@ -53,10 +64,8 @@ sds sdsnewlen(const void *init, size_t initlen) {
 #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;
 }
@@ -70,11 +79,6 @@ sds sdsnew(const char *init) {
     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));
 }
@@ -84,11 +88,6 @@ void sdsfree(sds s) {
     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);
@@ -96,7 +95,20 @@ void sdsupdatelen(sds s) {
     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;
@@ -116,6 +128,56 @@ static sds sdsMakeRoomFor(sds s, size_t addlen) {
     return newsh->buf;
 }
 
+/* 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, void *t, size_t len) {
     struct sdshdr *sh;
     size_t curlen = sdslen(s);
@@ -223,13 +285,16 @@ sds sdsrange(sds s, int start, int end) {
     }
     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;
     }
-    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;
@@ -278,12 +343,17 @@ int sdscmp(sds s1, sds s2) {
  */
 sds *sdssplitlen(char *s, int len, char *sep, int seplen, int *count) {
     int elements = 0, slots = 5, start = 0, j;
+    sds *tokens;
+
+    if (seplen < 1 || len < 0) return NULL;
 
-    sds *tokens = zmalloc(sizeof(sds)*slots);
+    tokens = zmalloc(sizeof(sds)*slots);
 #ifdef SDS_ABORT_ON_OOM
     if (tokens == NULL) sdsOomAbort();
+#else
+    if (tokens == NULL) return NULL;
 #endif
-    if (seplen < 1 || len < 0 || tokens == NULL) return NULL;
+
     if (len == 0) {
         *count = 0;
         return tokens;
@@ -338,6 +408,7 @@ cleanup:
         int i;
         for (i = 0; i < elements; i++) sdsfree(tokens[i]);
         zfree(tokens);
+        *count = 0;
         return NULL;
     }
 #endif
@@ -373,11 +444,11 @@ sds sdscatrepr(sds s, char *p, size_t len) {
         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);
@@ -390,6 +461,37 @@ sds sdscatrepr(sds s, char *p, size_t len) {
     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:
  *
@@ -413,13 +515,24 @@ 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();
             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++;
@@ -433,7 +546,23 @@ 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) {
@@ -454,6 +583,9 @@ sds *sdssplitargs(char *line, int *argc) {
                     case '"':
                         inq=1;
                         break;
+                    case '\'':
+                        insq=1;
+                        break;
                     default:
                         current = sdscatlen(current,p,1);
                         break;
@@ -478,3 +610,143 @@ err:
     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, char *from, 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