Bump AWS_EVENT_STREAM_MAX_MESSAGE_SIZE to 256MB (#122)

Author: waahm7

include/aws/event-stream/event_stream.h

@@ -16,8 +16,10 @@
 AWS_PUSH_SANE_WARNING_LEVEL
 
 #define AWS_C_EVENT_STREAM_PACKAGE_ID 4
-/* max message size is 16MB */
-#define AWS_EVENT_STREAM_MAX_MESSAGE_SIZE (16 * 1024 * 1024)
+/* max message size is technically unbounded on the client side, and validated on the server side but we don't want to
+ * allocate large buffers in case of bugs. 256 MB is a reasonably large buffer size limit. Current service-
+ * side max is 24 MB, likely to increase in future. */
+#define AWS_EVENT_STREAM_MAX_MESSAGE_SIZE (256 * 1024 * 1024)
 
 /* max header size is 128kb */
 #define AWS_EVENT_STREAM_MAX_HEADERS_SIZE (128 * 1024)

tests/CMakeLists.txt

@@ -28,7 +28,7 @@ add_test_case(test_streaming_decoder_incoming_multiple_messages)
 add_test_case(test_channel_handler_single_valid_messages_parse)
 add_test_case(test_channel_handler_multiple_valid_messages_parse)
 add_test_case(test_channel_handler_corrupted_crc_fails)
-add_test_case(test_channel_handler_msg_too_large_fails)
+add_test_case(test_channel_handler_large_msg_success)
 add_test_case(test_channel_handler_write_message)
 
 add_net_test_case(test_event_stream_rpc_server_connection_setup_and_teardown)

tests/channel_handler_test.c

@@ -384,7 +384,7 @@ AWS_TEST_CASE_FIXTURE(
     &s_test_data)
 
 /* send various valid messages in serial to make sure the happy path of message parsing is correct. */
-static int s_test_channel_handler_msg_too_large_fails(struct aws_allocator *allocator, void *ctx) {
+static int s_test_channel_handler_large_msg_success(struct aws_allocator *allocator, void *ctx) {
     (void)allocator;
 
     struct test_data *test_data = ctx;
@@ -395,7 +395,8 @@ static int s_test_channel_handler_msg_too_large_fails(struct aws_allocator *allo
     test_data->received_fn = s_test_on_single_message;
     test_data->user_data = &message_test_data;
 
-    /* message is 1 byte too large */
+    /* message length is 16MB + 1 byte. We used to have our stream message limit set at 16MB. Now this test validates
+     * that we can send messages > 16MB */
     uint8_t empty_message[] = {
         0x01,
         0x00,
@@ -417,15 +418,14 @@ static int s_test_channel_handler_msg_too_large_fails(struct aws_allocator *allo
 
     struct aws_byte_cursor empty_message_cursor = aws_byte_cursor_from_array(empty_message, sizeof(empty_message));
     ASSERT_SUCCESS(testing_channel_push_read_data(&s_test_data.testing_channel, empty_message_cursor));
-    ASSERT_UINT_EQUALS(AWS_ERROR_EVENT_STREAM_MESSAGE_FIELD_SIZE_EXCEEDED, message_test_data.last_error_code);
-
+    ASSERT_UINT_EQUALS(AWS_OP_SUCCESS, message_test_data.last_error_code);
     return AWS_OP_SUCCESS;
 }
 
 AWS_TEST_CASE_FIXTURE(
-    test_channel_handler_msg_too_large_fails,
+    test_channel_handler_large_msg_success,
     s_fixture_setup,
-    s_test_channel_handler_msg_too_large_fails,
+    s_test_channel_handler_large_msg_success,
     s_fixture_shutdown,
     &s_test_data)