util: return the number of elements from strv_from_string

Signed-off-by: Yinon Burgansky <51504-Yinon@users.noreply.gitlab.freedesktop.org>

src/quirks.c

@@ -879,18 +879,15 @@ out:
 static bool
 parse_value_line(struct quirks_context *ctx, struct section *s, const char *line)
 {
-	char **strv;
-	const char *key, *value;
 	bool rc = false;
-
-	strv = strv_from_string(line, "=");
-	if (strv[0] == NULL || strv[1] == NULL || strv[2] != NULL) {
+	
+	size_t nelem;
+	char **strv = strv_from_string(line, "=", &nelem);
+	if (!strv || nelem != 2)
 		goto out;
-	}
 
-
-	key = strv[0];
-	value = strv[1];
+	const char *key = strv[0];
+	const char *value = strv[1];
 	if (strlen(key) == 0 || strlen(value) == 0)
 		goto out;
 

src/util-prop-parsers.c

@@ -176,32 +176,31 @@ parse_dimension_property(const char *prop, size_t *w, size_t *h)
 bool
 parse_calibration_property(const char *prop, float calibration_out[6])
 {
-	int idx;
-	char **strv;
-	float calibration[6];
-
 	if (!prop)
 		return false;
+	
+	bool rc = false;
 
-	strv = strv_from_string(prop, " ");
-	if (!strv)
-		return false;
+	size_t num_calibration;
+	char **strv = strv_from_string(prop, " ", &num_calibration);
+	if (!strv || num_calibration < 6)
+		goto out;
 
-	for (idx = 0; idx < 6; idx++) {
+	float calibration[6];
+	for (size_t idx = 0; idx < 6; idx++) {
 		double v;
-		if (strv[idx] == NULL || !safe_atod(strv[idx], &v)) {
-			strv_free(strv);
-			return false;
-		}
+		if (!safe_atod(strv[idx], &v))
+			goto out;
 
 		calibration[idx] = v;
 	}
 
-	strv_free(strv);
-
 	memcpy(calibration_out, calibration, sizeof(calibration));
+	rc = true;
 
-	return true;
+out:
+	strv_free(strv);
+	return rc;
 }
 
 bool
@@ -367,27 +366,19 @@ parse_evcode_string(const char *s, int *type_out, int *code_out)
 bool
 parse_evcode_property(const char *prop, struct input_event *events, size_t *nevents)
 {
-	char **strv = NULL;
 	bool rc = false;
-	size_t ncodes = 0;
-	size_t idx;
 	/* A randomly chosen max so we avoid crazy quirks */
 	struct input_event evs[32];
 
 	memset(evs, 0, sizeof evs);
 
-	strv = strv_from_string(prop, ";");
-	if (!strv)
-		goto out;
-
-	for (idx = 0; strv[idx]; idx++)
-		ncodes++;
-
-	if (ncodes == 0 || ncodes > ARRAY_LENGTH(evs))
+	size_t ncodes;
+	char **strv = strv_from_string(prop, ";", &ncodes);
+	if (!strv || ncodes == 0 || ncodes > ARRAY_LENGTH(evs))
 		goto out;
 
 	ncodes = min(*nevents, ncodes);
-	for (idx = 0; strv[idx]; idx++) {
+	for (size_t idx = 0; strv[idx]; idx++) {
 		char *s = strv[idx];
 
 		int type, code;
@@ -434,24 +425,16 @@ out:
 bool
 parse_input_prop_property(const char *prop, unsigned int *props_out, size_t *nprops)
 {
-	char **strv = NULL;
 	bool rc = false;
-	size_t count = 0;
-	size_t idx;
 	unsigned int props[INPUT_PROP_CNT]; /* doubling up on quirks is a bug */
 
-	strv = strv_from_string(prop, ";");
-	if (!strv)
-		goto out;
-
-	for (idx = 0; strv[idx]; idx++)
-		count++;
-
-	if (count == 0 || count > ARRAY_LENGTH(props))
+	size_t count;
+	char **strv = strv_from_string(prop, ";", &count);
+	if (!strv || count == 0 || count > ARRAY_LENGTH(props))
 		goto out;
 
 	count = min(*nprops, count);
-	for (idx = 0; strv[idx]; idx++) {
+	for (size_t idx = 0; strv[idx]; idx++) {
 		char *s = strv[idx];
 		unsigned int prop;
 

src/util-strings.c

@@ -91,47 +91,54 @@ strv_from_argv(int argc, char **argv)
 /**
  * Return a null-terminated string array with the tokens in the input
  * string, e.g. "one two\tthree" with a separator list of " \t" will return
- * an array [ "one", "two", "three", NULL ].
+ * an array [ "one", "two", "three", NULL ] and num elements 3.
  *
  * Use strv_free() to free the array.
  *
+ * Another example:
+ *   result = strv_from_string("+1-2++3--4++-+5-+-", "+-", &nelem)
+ *   result == [ "1", "2", "3", "4", "5", NULL ] and nelem == 5
+ * 
  * @param in Input string
  * @param separators List of separator characters
+ * @param num_elements Number of elements found in the input string
  *
  * @return A null-terminated string array or NULL on errors
  */
 char **
-strv_from_string(const char *in, const char *separators)
+strv_from_string(const char *in, const char *separators, size_t *num_elements)
 {
-	const char *s, *word;
-	char **strv = NULL;
-	int nelems = 0, idx;
-	size_t l;
-
 	assert(in != NULL);
 
-	s = in;
+	
+	const char *s = in;
+	size_t l, nelems = 0;
 	while (next_word(&s, &l, separators) != NULL)
-	       nelems++;
+		nelems++;
 
-	if (nelems == 0)
+	if (nelems == 0) {
+		*num_elements = 0;
 		return NULL;
+	}
 
-	nelems++; /* NULL-terminated */
-	strv = zalloc(nelems * sizeof *strv);
-
-	idx = 0;
+	size_t strv_len = nelems + 1; /* NULL-terminated */
+	char **strv = zalloc(strv_len * sizeof *strv);
 
+	size_t idx = 0;
+	const char *word;
 	s = in;
 	while ((word = next_word(&s, &l, separators)) != NULL) {
 		char *copy = strndup(word, l);
 		if (!copy) {
 			strv_free(strv);
+			*num_elements = 0;
 			return NULL;
 		}
 
 		strv[idx++] = copy;
 	}
+	
+	*num_elements = nelems;
 
 	return strv;
 }

src/util-strings.h

@@ -255,7 +255,7 @@ safe_atod(const char *str, double *val)
 }
 
 char **strv_from_argv(int argc, char **argv);
-char **strv_from_string(const char *in, const char *separator);
+char **strv_from_string(const char *in, const char *separator, size_t *num_elements);
 char *strv_join(char **strv, const char *joiner);
 
 static inline void
@@ -291,33 +291,26 @@ kv_double_from_string(const char *string,
 		      struct key_value_double **result_out)
 
 {
-	char **pairs;
-	char **pair;
 	struct key_value_double *result = NULL;
-	ssize_t npairs = 0;
-	unsigned int idx = 0;
 
 	if (!pair_separator || pair_separator[0] == '\0' ||
 	    !kv_separator || kv_separator[0] == '\0')
 		return -1;
 
-	pairs = strv_from_string(string, pair_separator);
-	if (!pairs)
-		return -1;
-
-	for (pair = pairs; *pair; pair++)
-		npairs++;
-
-	if (npairs == 0)
+	size_t npairs;
+	char **pairs = strv_from_string(string, pair_separator, &npairs);
+	if (!pairs || npairs == 0)
 		goto error;
 
 	result = zalloc(npairs * sizeof *result);
 
-	for (pair = pairs; *pair; pair++) {
-		char **kv = strv_from_string(*pair, kv_separator);
+	for (size_t idx = 0; idx < npairs; idx++) {
+		char *pair = pairs[idx];
+		size_t nelem;
+		char **kv = strv_from_string(pair, kv_separator, &nelem);
 		double k, v;
 
-		if (!kv || !kv[0] || !kv[1] || kv[2] ||
+		if (!kv || nelem != 2 ||
 		    !safe_atod(kv[0], &k) ||
 		    !safe_atod(kv[1], &v)) {
 			strv_free(kv);
@@ -326,7 +319,6 @@ kv_double_from_string(const char *string,
 
 		result[idx].key = k;
 		result[idx].value = v;
-		idx++;
 
 		strv_free(kv);
 	}

test/test-utils.c

@@ -1070,39 +1070,48 @@ START_TEST(strsplit_test)
 		const char *string;
 		const char *delim;
 		const char *results[10];
+		const size_t nresults;
 	} tests[] = {
-		{ "one two three", " ", { "one", "two", "three", NULL } },
-		{ "one", " ", { "one", NULL } },
-		{ "one two ", " ", { "one", "two", NULL } },
-		{ "one  two", " ", { "one", "two", NULL } },
-		{ " one two", " ", { "one", "two", NULL } },
-		{ "one", "\t \r", { "one", NULL } },
-		{ "one two three", " t", { "one", "wo", "hree", NULL } },
-		{ " one two three", "te", { " on", " ", "wo ", "hr", NULL } },
-		{ "one", "ne", { "o", NULL } },
-		{ "onene", "ne", { "o", NULL } },
-		{ NULL, NULL, { NULL }}
+		{ "one two three", " ", { "one", "two", "three", NULL }, 3 },
+		{ "one two\tthree", " \t", { "one", "two", "three", NULL }, 3 },
+		{ "one", " ", { "one", NULL }, 1 },
+		{ "one two ", " ", { "one", "two", NULL }, 2 },
+		{ "one  two", " ", { "one", "two", NULL }, 2 },
+		{ " one two", " ", { "one", "two", NULL }, 2 },
+		{ "one", "\t \r", { "one", NULL }, 1 },
+		{ "one two three", " t", { "one", "wo", "hree", NULL }, 3 },
+		{ " one two three", "te", { " on", " ", "wo ", "hr", NULL }, 4 },
+		{ "one", "ne", { "o", NULL }, 1 },
+		{ "onene", "ne", { "o", NULL }, 1 },
+		{ "+1-2++3--4++-+5-+-", "+-", { "1", "2", "3", "4", "5", NULL }, 5 },
+		/* special cases */
+		{ "", " ", { NULL }, 0 },
+		{ " ", " ", { NULL }, 0 },
+		{ "     ", " ", { NULL }, 0 },
+		{ "oneoneone", "one", { NULL} , 0 },
+		{ NULL, NULL, { NULL }, 0}
 	};
 	struct strsplit_test *t = tests;
 
 	while (t->string) {
-		char **strv;
-		int idx = 0;
-		strv = strv_from_string(t->string, t->delim);
-		while (t->results[idx]) {
+		size_t nelem;
+		char **strv = strv_from_string(t->string, t->delim, &nelem);
+
+		for (size_t idx = 0; idx < t->nresults; idx++)			
 			ck_assert_str_eq(t->results[idx], strv[idx]);
-			idx++;
-		}
-		ck_assert_ptr_eq(strv[idx], NULL);
+		
+		ck_assert_uint_eq(nelem, t->nresults);
+		
+		/* When there are no elements validate return value is Null,
+		   otherwise validate result array is Null terminated. */
+		if(t->nresults == 0)
+			ck_assert_ptr_null(strv);
+		else
+			ck_assert_ptr_null(strv[t->nresults]);
+
 		strv_free(strv);
 		t++;
 	}
-
-	/* Special cases */
-	ck_assert_ptr_eq(strv_from_string("", " "), NULL);
-	ck_assert_ptr_eq(strv_from_string(" ", " "), NULL);
-	ck_assert_ptr_eq(strv_from_string("     ", " "), NULL);
-	ck_assert_ptr_eq(strv_from_string("oneoneone", "one"), NULL);
 }
 END_TEST