3 files changed, 43 insertions, 0 deletions

diff --git a/include/grpc/byte_buffer.h b/include/grpc/byte_buffer.h
index 6d08474d8c..1b51569f24 100644
--- a/include/grpc/byte_buffer.h
+++ b/include/grpc/byte_buffer.h
@@ -103,6 +103,10 @@ void grpc_byte_buffer_reader_destroy(grpc_byte_buffer_reader *reader);
 int grpc_byte_buffer_reader_next(grpc_byte_buffer_reader *reader,
                                  gpr_slice *slice);
 
+/** Returns a RAW byte buffer instance from the output of \a reader. */
+grpc_byte_buffer *grpc_raw_byte_buffer_from_reader(
+    grpc_byte_buffer_reader *reader);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/core/surface/byte_buffer.c b/src/core/surface/byte_buffer.c
index 4817e00454..a930949f2d 100644
--- a/src/core/surface/byte_buffer.c
+++ b/src/core/surface/byte_buffer.c
@@ -55,6 +55,20 @@ grpc_byte_buffer *grpc_raw_compressed_byte_buffer_create(
   return bb;
 }
 
+grpc_byte_buffer *grpc_raw_byte_buffer_from_reader(
+    grpc_byte_buffer_reader *reader) {
+  grpc_byte_buffer *bb = malloc(sizeof(grpc_byte_buffer));
+  gpr_slice slice;
+  bb->type = GRPC_BB_RAW;
+  bb->data.raw.compression = GRPC_COMPRESS_NONE;
+  gpr_slice_buffer_init(&bb->data.raw.slice_buffer);
+
+  while (grpc_byte_buffer_reader_next(reader, &slice)) {
+    gpr_slice_buffer_add(&bb->data.raw.slice_buffer, slice);
+  }
+  return bb;
+}
+
 grpc_byte_buffer *grpc_byte_buffer_copy(grpc_byte_buffer *bb) {
   switch (bb->type) {
     case GRPC_BB_RAW:
diff --git a/test/core/surface/byte_buffer_reader_test.c b/test/core/surface/byte_buffer_reader_test.c
index 87a2cd7a43..2eb354a80a 100644
--- a/test/core/surface/byte_buffer_reader_test.c
+++ b/test/core/surface/byte_buffer_reader_test.c
@@ -160,6 +160,30 @@ static void test_read_deflate_compressed_slice(void) {
   read_compressed_slice(GRPC_COMPRESS_DEFLATE, INPUT_SIZE);
 }
 
+static void test_byte_buffer_from_reader(void) {
+  gpr_slice slice;
+  grpc_byte_buffer *buffer, *buffer_from_reader;
+  grpc_byte_buffer_reader reader;
+
+  LOG_TEST("test_byte_buffer_from_reader");
+  slice = gpr_slice_malloc(4);
+  memcpy(GPR_SLICE_START_PTR(slice), "test", 4);
+  buffer = grpc_raw_byte_buffer_create(&slice, 1);
+  gpr_slice_unref(slice);
+  grpc_byte_buffer_reader_init(&reader, buffer);
+
+  buffer_from_reader = grpc_raw_byte_buffer_from_reader(&reader);
+  GPR_ASSERT(buffer->type == buffer_from_reader->type);
+  GPR_ASSERT(buffer_from_reader->data.raw.compression == GRPC_COMPRESS_NONE);
+  GPR_ASSERT(buffer_from_reader->data.raw.slice_buffer.count == 1);
+  GPR_ASSERT(memcmp(GPR_SLICE_START_PTR(
+                        buffer_from_reader->data.raw.slice_buffer.slices[0]),
+                    "test", 4) == 0);
+
+  grpc_byte_buffer_destroy(buffer);
+  grpc_byte_buffer_destroy(buffer_from_reader);
+}
+
 int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
   test_read_one_slice();
@@ -167,6 +191,7 @@ int main(int argc, char **argv) {
   test_read_none_compressed_slice();
   test_read_gzip_compressed_slice();
   test_read_deflate_compressed_slice();
+  test_byte_buffer_from_reader();
 
   return 0;
 }