util: string: Return element count from virStringSplit

To allow using the array manipulation macros on the arrays returned by
virStringSplit we need to know the count of the elements in the array.
Modify virStringSplit to return this value, rename it and add a helper
with the old name so that we don't need to update all the code.

src/libvirt_private.syms

@@ -1908,6 +1908,7 @@ virStringSearch;
 virStringSortCompare;
 virStringSortRevCompare;
 virStringSplit;
+virStringSplitCount;
 virStrncpy;
 virStrndup;
 virStrToDouble;

src/util/virstring.c

@@ -43,13 +43,15 @@ VIR_LOG_INIT("util.string");
  */
 
 /**
- * virStringSplit:
+ * virStringSplitCount:
  * @string: a string to split
  * @delim: a string which specifies the places at which to split
  *     the string. The delimiter is not included in any of the resulting
  *     strings, unless @max_tokens is reached.
  * @max_tokens: the maximum number of pieces to split @string into.
  *     If this is 0, the string is split completely.
+ * @tokcount: If provided, the value is set to the count of pieces the string
+ *            was split to excluding the terminating NULL element.
  *
  * Splits a string into a maximum of @max_tokens pieces, using the given
  * @delim. If @max_tokens is reached, the remainder of @string is
@@ -65,9 +67,11 @@ VIR_LOG_INIT("util.string");
  * Return value: a newly-allocated NULL-terminated array of strings. Use
  *    virStringFreeList() to free it.
  */
-char **virStringSplit(const char *string,
-                      const char *delim,
-                      size_t max_tokens)
+char **
+virStringSplitCount(const char *string,
+                    const char *delim,
+                    size_t max_tokens,
+                    size_t *tokcount)
 {
     char **tokens = NULL;
     size_t ntokens = 0;
@@ -109,6 +113,9 @@ char **virStringSplit(const char *string,
         goto error;
     tokens[ntokens++] = NULL;
 
+    if (tokcount)
+        *tokcount = ntokens - 1;
+
     return tokens;
 
  error:
@@ -119,6 +126,15 @@ char **virStringSplit(const char *string,
 }
 
 
+char **
+virStringSplit(const char *string,
+               const char *delim,
+               size_t max_tokens)
+{
+    return virStringSplitCount(string, delim, max_tokens, NULL);
+}
+
+
 /**
  * virStringJoin:
  * @strings: a NULL-terminated array of strings to join

src/util/virstring.h

@@ -26,6 +26,12 @@
 
 # include "internal.h"
 
+char **virStringSplitCount(const char *string,
+                           const char *delim,
+                           size_t max_tokens,
+                           size_t *tokcount)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+
 char **virStringSplit(const char *string,
                       const char *delim,
                       size_t max_tokens)

tests/virstringtest.c

@@ -53,11 +53,14 @@ static int testSplit(const void *args)
 {
     const struct testSplitData *data = args;
     char **got;
+    size_t ntokens;
+    size_t exptokens = 0;
     char **tmp1;
     const char **tmp2;
     int ret = -1;
 
-    if (!(got = virStringSplit(data->string, data->delim, data->max_tokens))) {
+    if (!(got = virStringSplitCount(data->string, data->delim,
+                                    data->max_tokens, &ntokens))) {
         VIR_DEBUG("Got no tokens at all");
         return -1;
     }
@@ -71,6 +74,7 @@ static int testSplit(const void *args)
         }
         tmp1++;
         tmp2++;
+        exptokens++;
     }
     if (*tmp1) {
         virFilePrintf(stderr, "Too many pieces returned\n");
@@ -81,6 +85,14 @@ static int testSplit(const void *args)
         goto cleanup;
     }
 
+    if (ntokens != exptokens) {
+        virFilePrintf(stderr,
+                      "Returned token count (%zu) doesn't match "
+                      "expected count (%zu)",
+                      ntokens, exptokens);
+        goto cleanup;
+    }
+
     ret = 0;
  cleanup:
     virStringFreeList(got);