lib/util: add strarray utility functions

Add some basic utilities for handling arrays of strings.

Signed-off-by: John Levon <john.levon@nutanix.com>
Change-Id: I2333f3e4605175b1717a7f289847ff2d48745e8d
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15274
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@nvidia.com>
Reviewed-by: Thanos Makatos <thanos.makatos@nutanix.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

include/spdk/string.h

@@ -236,6 +236,35 @@ long int spdk_strtol(const char *nptr, int base);
  */
 long long int spdk_strtoll(const char *nptr, int base);
 
+/**
+ * Build a NULL-terminated array of strings from the given string separated by
+ * the given chars in delim, as if split by strpbrk(). Empty items are pointers
+ * to an empty string.
+ *
+ * \param str Input string
+ * \param delim Separating delimiter set.
+ *
+ * \return the string array, or NULL on failure.
+ */
+char **spdk_strarray_from_string(const char *str, const char *delim);
+
+/**
+ * Duplicate a NULL-terminated array of strings. Returns NULL on failure.
+ * The array, and the strings, are allocated with the standard allocator (e.g.
+ * calloc()).
+ *
+ * \param strarray input array of strings.
+ */
+char **spdk_strarray_dup(const char **strarray);
+
+/**
+ * Free a NULL-terminated array of strings. The array and its strings must have
+ * been allocated with the standard allocator (calloc() etc.).
+ *
+ * \param strarray array of strings.
+ */
+void spdk_strarray_free(char **strarray);
+
 #ifdef __cplusplus
 }
 #endif

lib/util/Makefile

@@ -7,7 +7,7 @@ SPDK_ROOT_DIR := $(abspath $(CURDIR)/../..)
 include $(SPDK_ROOT_DIR)/mk/spdk.common.mk
 
 SO_VER := 5
-SO_MINOR := 1
+SO_MINOR := 2
 
 C_SRCS = base64.c bit_array.c cpuset.c crc16.c crc32.c crc32c.c crc32_ieee.c \
 	 dif.c fd.c file.c hexlify.c iov.c math.c pipe.c strerror_tls.c string.c uuid.c \

lib/util/spdk_util.map

@@ -123,6 +123,9 @@
 	spdk_mem_all_zero;
 	spdk_strtol;
 	spdk_strtoll;
+	spdk_strarray_from_string;
+	spdk_strarray_dup;
+	spdk_strarray_free;
 
 	# public functions in util.h
 	spdk_u32log2;

lib/util/string.c

@@ -446,3 +446,99 @@ spdk_strtoll(const char *nptr, int base)
 
 	return val;
 }
+
+void
+spdk_strarray_free(char **strarray)
+{
+	size_t i;
+
+	if (strarray == NULL) {
+		return;
+	}
+
+	for (i = 0; strarray[i] != NULL; i++) {
+		free(strarray[i]);
+	}
+	free(strarray);
+}
+
+char **
+spdk_strarray_from_string(const char *str, const char *delim)
+{
+	const char *c = str;
+	size_t count = 0;
+	char **result;
+	size_t i;
+
+	assert(str != NULL);
+	assert(delim != NULL);
+
+	/* Count number of entries. */
+	for (;;) {
+		const char *next = strpbrk(c, delim);
+
+		count++;
+
+		if (next == NULL) {
+			break;
+		}
+
+		c = next + 1;
+	}
+
+	/* Account for the terminating NULL entry. */
+	result = calloc(count + 1, sizeof(char *));
+	if (result == NULL) {
+		return NULL;
+	}
+
+	c = str;
+
+	for (i = 0; i < count; i++) {
+		const char *next = strpbrk(c, delim);
+
+		if (next == NULL) {
+			result[i] = strdup(c);
+		} else {
+			result[i] = strndup(c, next - c);
+		}
+
+		if (result[i] == NULL) {
+			spdk_strarray_free(result);
+			return NULL;
+		}
+
+		if (next != NULL) {
+			c = next + 1;
+		}
+	}
+
+	return result;
+}
+
+char **
+spdk_strarray_dup(const char **strarray)
+{
+	size_t count, i;
+	char **result;
+
+	assert(strarray != NULL);
+
+	for (count = 0; strarray[count] != NULL; count++)
+		;
+
+	result = calloc(count + 1, sizeof(char *));
+	if (result == NULL) {
+		return NULL;
+	}
+
+	for (i = 0; i < count; i++) {
+		result[i] = strdup(strarray[i]);
+		if (result[i] == NULL) {
+			spdk_strarray_free(result);
+			return NULL;
+		}
+	}
+
+	return result;
+}

test/unit/lib/util/string.c/string_ut.c

@@ -375,6 +375,67 @@ test_strtoll(void)
 	CU_ASSERT(val == 0);
 }
 
+static void
+test_strarray(void)
+{
+	char **r;
+	char **r2;
+
+	r = spdk_strarray_from_string("", ":");
+	CU_ASSERT(strcmp(r[0], "") == 0);
+	CU_ASSERT(r[1] == NULL);
+	spdk_strarray_free(r);
+
+	r = spdk_strarray_from_string(":", ":");
+	CU_ASSERT(strcmp(r[0], "") == 0);
+	CU_ASSERT(strcmp(r[1], "") == 0);
+	CU_ASSERT(r[2] == NULL);
+	spdk_strarray_free(r);
+
+	r = spdk_strarray_from_string("a", ":");
+	CU_ASSERT(strcmp(r[0], "a") == 0);
+	CU_ASSERT(r[1] == NULL);
+	spdk_strarray_free(r);
+
+	r = spdk_strarray_from_string("ab:", ":");
+	CU_ASSERT(strcmp(r[0], "ab") == 0);
+	CU_ASSERT(strcmp(r[1], "") == 0);
+	CU_ASSERT(r[2] == NULL);
+	spdk_strarray_free(r);
+
+	r = spdk_strarray_from_string(":ab", ":");
+	CU_ASSERT(strcmp(r[0], "") == 0);
+	CU_ASSERT(strcmp(r[1], "ab") == 0);
+	CU_ASSERT(r[2] == NULL);
+	spdk_strarray_free(r);
+
+	r = spdk_strarray_from_string("ab:c", ":");
+	CU_ASSERT(strcmp(r[0], "ab") == 0);
+	CU_ASSERT(strcmp(r[1], "c") == 0);
+	CU_ASSERT(r[2] == NULL);
+	spdk_strarray_free(r);
+
+	r = spdk_strarray_from_string(":ab.:c:", ":.");
+	CU_ASSERT(strcmp(r[0], "") == 0);
+	CU_ASSERT(strcmp(r[1], "ab") == 0);
+	CU_ASSERT(strcmp(r[2], "") == 0);
+	CU_ASSERT(strcmp(r[3], "c") == 0);
+	CU_ASSERT(strcmp(r[4], "") == 0);
+	CU_ASSERT(r[5] == NULL);
+	spdk_strarray_free(r);
+
+	r = spdk_strarray_from_string(":ab.:c:", ":.");
+	r2 = spdk_strarray_dup((const char **)r);
+	CU_ASSERT(strcmp(r2[0], "") == 0);
+	CU_ASSERT(strcmp(r2[1], "ab") == 0);
+	CU_ASSERT(strcmp(r2[2], "") == 0);
+	CU_ASSERT(strcmp(r2[3], "c") == 0);
+	CU_ASSERT(strcmp(r2[4], "") == 0);
+	CU_ASSERT(r2[5] == NULL);
+	spdk_strarray_free(r);
+	spdk_strarray_free(r2);
+}
+
 int
 main(int argc, char **argv)
 {
@@ -392,6 +453,7 @@ main(int argc, char **argv)
 	CU_ADD_TEST(suite, test_sprintf_append_realloc);
 	CU_ADD_TEST(suite, test_strtol);
 	CU_ADD_TEST(suite, test_strtoll);
+	CU_ADD_TEST(suite, test_strarray);
 
 	CU_basic_set_mode(CU_BRM_VERBOSE);