X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/726a39c15ff5d89f0d44a32cca8869cf0589f929..07ac2daaaa6c844cc3171c8f01ad5ad7e786e2ea:/src/sds.c?ds=sidebyside

diff --git a/src/sds.c b/src/sds.c
index 37c63b05..b6c2aaf3 100644
--- a/src/sds.c
+++ b/src/sds.c
@@ -36,11 +36,12 @@
 
 #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) {
@@ -78,11 +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));
 }
@@ -92,11 +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);
@@ -104,7 +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;
@@ -124,6 +128,37 @@ 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) {
@@ -161,6 +196,10 @@ sds sdscat(sds s, char *t) {
     return sdscatlen(s, t, strlen(t));
 }
 
+sds sdscatsds(sds s, sds t) {
+    return sdscatlen(s, t, sdslen(t));
+}
+
 sds sdscpylen(sds s, char *t, size_t len) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     size_t totlen = sh->free+sh->len;
@@ -308,15 +347,17 @@ 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) {
-        *count = 0;
-        return NULL;
-    }
+
     if (len == 0) {
         *count = 0;
         return tokens;
@@ -478,7 +519,8 @@ 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();
@@ -508,7 +550,23 @@ 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) {
@@ -529,6 +587,9 @@ sds *sdssplitargs(char *line, int *argc) {
                     case '"':
                         inq=1;
                         break;
+                    case '\'':
+                        insq=1;
+                        break;
                     default:
                         current = sdscatlen(current,p,1);
                         break;
@@ -561,12 +622,36 @@ void sdssplitargs_free(sds *argv, int argc) {
     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",
@@ -646,7 +731,26 @@ 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