From eefb5b5634e341396fb535f4eeac1323bf716ed0 Mon Sep 17 00:00:00 2001
From: Fred Sundvik <fsundvik@gmail.com>
Date: Sun, 14 Feb 2016 14:25:54 +0200
Subject: Mutiple frame handling for byte stuffer
Also handles unexpected data.
---
serial_link/protocol/byte_stuffer.c | 12 +++++++-
serial_link/tests/byte_stuffer_tests.c | 53 +++++++++++++++++++++++++++++++++-
2 files changed, 63 insertions(+), 2 deletions(-)
diff --git a/serial_link/protocol/byte_stuffer.c b/serial_link/protocol/byte_stuffer.c
index 7ce01a96a..e578f88dc 100644
--- a/serial_link/protocol/byte_stuffer.c
+++ b/serial_link/protocol/byte_stuffer.c
@@ -41,6 +41,7 @@ void init_byte_stuffer_state(byte_stuffer_state_t* state) {
}
void recv_byte(byte_stuffer_state_t* state, uint8_t data) {
+ // Start of a new frame
if (state->next_zero == 0) {
state->next_zero = data;
state->data_pos = 0;
@@ -49,10 +50,19 @@ void recv_byte(byte_stuffer_state_t* state, uint8_t data) {
state->next_zero--;
if (data == 0) {
- recv_frame(state->data, state->data_pos);
+ if (state->next_zero == 0) {
+ // The frame is completed
+ recv_frame(state->data, state->data_pos);
+ }
+ else {
+ // The frame is invalid, so reset
+ state->next_zero = 0;
+ state->data_pos = 0;
+ }
}
else {
if (state->next_zero == 0) {
+ // Special case for zeroes
state->next_zero = data;
state->data[state->data_pos++] = 0;
}
diff --git a/serial_link/tests/byte_stuffer_tests.c b/serial_link/tests/byte_stuffer_tests.c
index 2fc7a0b26..74a349b1f 100644
--- a/serial_link/tests/byte_stuffer_tests.c
+++ b/serial_link/tests/byte_stuffer_tests.c
@@ -72,7 +72,7 @@ Ensure(ByteStuffer, receives_three_bytes_valid_frame) {
when(size, is_equal_to(3)),
when(data, is_equal_to_contents_of(expected, 3))
);
- recv_byte(&state, 5);
+ recv_byte(&state, 4);
recv_byte(&state, 0x37);
recv_byte(&state, 0x99);
recv_byte(&state, 0xFF);
@@ -103,3 +103,54 @@ Ensure(ByteStuffer, receives_valid_frame_with_zeroes) {
recv_byte(&state, 1);
recv_byte(&state, 0);
}
+
+Ensure(ByteStuffer, receives_two_valid_frames) {
+ uint8_t expected1[] = {5, 0};
+ uint8_t expected2[] = {3};
+ expect(recv_frame,
+ when(size, is_equal_to(2)),
+ when(data, is_equal_to_contents_of(expected1, 2))
+ );
+ expect(recv_frame,
+ when(size, is_equal_to(1)),
+ when(data, is_equal_to_contents_of(expected2, 1))
+ );
+ recv_byte(&state, 2);
+ recv_byte(&state, 5);
+ recv_byte(&state, 1);
+ recv_byte(&state, 0);
+ recv_byte(&state, 2);
+ recv_byte(&state, 3);
+ recv_byte(&state, 0);
+}
+
+Ensure(ByteStuffer, receives_valid_frame_after_unexpected_zero) {
+ uint8_t expected[] = {5, 7};
+ expect(recv_frame,
+ when(size, is_equal_to(2)),
+ when(data, is_equal_to_contents_of(expected, 2))
+ );
+ recv_byte(&state, 3);
+ recv_byte(&state, 1);
+ recv_byte(&state, 0);
+ recv_byte(&state, 3);
+ recv_byte(&state, 5);
+ recv_byte(&state, 7);
+ recv_byte(&state, 0);
+}
+
+Ensure(ByteStuffer, receives_valid_frame_after_unexpected_non_zero) {
+ uint8_t expected[] = {5, 7};
+ expect(recv_frame,
+ when(size, is_equal_to(2)),
+ when(data, is_equal_to_contents_of(expected, 2))
+ );
+ recv_byte(&state, 2);
+ recv_byte(&state, 9);
+ recv_byte(&state, 4); // This should have been zero
+ recv_byte(&state, 0);
+ recv_byte(&state, 3);
+ recv_byte(&state, 5);
+ recv_byte(&state, 7);
+ recv_byte(&state, 0);
+}
--
cgit v1.2.3