Added gpr_strsplit (with tests)

src/core/support/string.c

@@ -38,6 +38,7 @@
 #include <string.h>
 
 #include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
 #include <grpc/support/port_platform.h>
 #include <grpc/support/useful.h>
 
@@ -187,6 +188,27 @@ char *gpr_strjoin_sep(const char **strs, size_t nstrs, const char *sep,
   return out;
 }
 
+static void do_nothing(void *ignored) {}
+gpr_slice_buffer *gpr_strsplit(const char *str, const char *sep) {
+  const size_t sep_len = strlen(sep);
+  const char *splitpoint = str;
+  gpr_slice_buffer *parts;
+
+  GPR_ASSERT(sep_len > 0);
+
+  parts = gpr_malloc(sizeof(gpr_slice_buffer));
+  gpr_slice_buffer_init(parts);
+
+  for (; (splitpoint = strstr(str, sep)) != NULL; splitpoint += sep_len) {
+    gpr_slice_buffer_add(
+        parts, gpr_slice_new((void *)str, splitpoint - str, do_nothing));
+    str += (splitpoint - str + sep_len);
+  }
+  gpr_slice_buffer_add(parts,
+                       gpr_slice_new((void *)str, strlen(str), do_nothing));
+  return parts;
+}
+
 void gpr_strvec_init(gpr_strvec *sv) {
   memset(sv, 0, sizeof(*sv));
 }

src/core/support/string.h

@@ -37,6 +37,7 @@
 #include <stddef.h>
 
 #include <grpc/support/port_platform.h>
+#include <grpc/support/slice_buffer.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -78,6 +79,9 @@ char *gpr_strjoin(const char **strs, size_t nstrs, size_t *total_length);
 char *gpr_strjoin_sep(const char **strs, size_t nstrs, const char *sep,
                       size_t *total_length);
 
+/** Split \a str at separator \a sep. */
+gpr_slice_buffer *gpr_strsplit(const char *str, const char *sep);
+
 /* A vector of strings... for building up a final string one piece at a time */
 typedef struct {
   char **strs;

test/core/support/string_test.c

@@ -192,6 +192,58 @@ static void test_strjoin_sep(void) {
   gpr_free(joined);
 }
 
+static void test_strsplit(void) {
+  gpr_slice_buffer* parts;
+  LOG_TEST_NAME("test_strsplit");
+
+  parts = gpr_strsplit("one, two, three, four", ", ");
+  GPR_ASSERT(4 == parts->count);
+  GPR_ASSERT(0 == gpr_slice_str_cmp(parts->slices[0], "one"));
+  GPR_ASSERT(0 == gpr_slice_str_cmp(parts->slices[1], "two"));
+  GPR_ASSERT(0 == gpr_slice_str_cmp(parts->slices[2], "three"));
+  GPR_ASSERT(0 == gpr_slice_str_cmp(parts->slices[3], "four"));
+  gpr_slice_buffer_destroy(parts);
+  gpr_free(parts);
+
+  /* separator not present in string */
+  parts = gpr_strsplit("one two three four", ", ");
+  GPR_ASSERT(1 == parts->count);
+  GPR_ASSERT(0 == gpr_slice_str_cmp(parts->slices[0], "one two three four"));
+  gpr_slice_buffer_destroy(parts);
+  gpr_free(parts);
+
+  /* separator at the end */
+  parts = gpr_strsplit("foo,", ",");
+  GPR_ASSERT(2 == parts->count);
+  GPR_ASSERT(0 == gpr_slice_str_cmp(parts->slices[0], "foo"));
+  GPR_ASSERT(0 == gpr_slice_str_cmp(parts->slices[1], ""));
+  gpr_slice_buffer_destroy(parts);
+  gpr_free(parts);
+
+  /* separator at the beginning */
+  parts = gpr_strsplit(",foo", ",");
+  GPR_ASSERT(2 == parts->count);
+  GPR_ASSERT(0 == gpr_slice_str_cmp(parts->slices[0], ""));
+  GPR_ASSERT(0 == gpr_slice_str_cmp(parts->slices[1], "foo"));
+  gpr_slice_buffer_destroy(parts);
+  gpr_free(parts);
+
+  /* standalone separator */
+  parts = gpr_strsplit(",", ",");
+  GPR_ASSERT(2 == parts->count);
+  GPR_ASSERT(0 == gpr_slice_str_cmp(parts->slices[0], ""));
+  GPR_ASSERT(0 == gpr_slice_str_cmp(parts->slices[1], ""));
+  gpr_slice_buffer_destroy(parts);
+  gpr_free(parts);
+
+  /* empty input */
+  parts = gpr_strsplit("", ",");
+  GPR_ASSERT(1 == parts->count);
+  GPR_ASSERT(0 == gpr_slice_str_cmp(parts->slices[0], ""));
+  gpr_slice_buffer_destroy(parts);
+  gpr_free(parts);
+}
+
 int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
   test_strdup();
@@ -200,5 +252,6 @@ int main(int argc, char **argv) {
   test_asprintf();
   test_strjoin();
   test_strjoin_sep();
+  test_strsplit();
   return 0;
 }