Refactoring write_packet_ack_nack_desc_egprs to prepare for CRBB support
Change-Id: Ie5c25b6ee30f2f1b613e923c234b03a6ffe12ae2
diff --git a/src/encoding.cpp b/src/encoding.cpp
index e5a8605..8fa4bf6 100644
--- a/src/encoding.cpp
+++ b/src/encoding.cpp
@@ -702,14 +702,17 @@
gprs_rlc_ul_window *window, bool is_final)
{
int urbb_len = 0;
- int crbb_len = 0;
int len;
bool bow = true;
bool eow = true;
int ssn = window->mod_sns(window->v_q() + 1);
int num_blocks = window->mod_sns(window->v_r() - window->v_q());
int esn_crbb = window->mod_sns(ssn - 1);
- int rest_bits = dest->data_len * 8 - wp;
+ /* Bit 0 at the end is mandatory Table 11.2.28.1 in 44.060 */
+ int rest_bits = dest->data_len * 8 - wp - 1;
+ int is_compressed = 0;
+ bool len_coded = true;
+ uint8_t i;
if (num_blocks > 0)
/* V(Q) is NACK and omitted -> SSN = V(Q) + 1 */
@@ -717,33 +720,31 @@
if (num_blocks > window->ws())
num_blocks = window->ws();
+ /* TODO Compression support */
+ if (is_compressed == 0) {
+ /* Union bit takes 1 bit */
+ /* Other fields in descr for uncompresed bitmap takes 15 bits*/
- if (num_blocks > rest_bits) {
- eow = false;
- urbb_len = rest_bits;
- /* TODO: use compression, start encoding bits and stop when the
- * space is exhausted. Use the first combination that encodes
- * all bits. If there is none, use the combination that encodes
- * the largest number of bits (e.g. by setting num_blocks to the
- * max and repeating the construction).
- */
- } else if (num_blocks > rest_bits - 9) {
- /* union bit and length field take 9 bits */
- eow = false;
- urbb_len = rest_bits - 9;
- /* TODO: use compression (see above) */
- } else
- urbb_len = num_blocks;
-
- if (urbb_len + crbb_len == rest_bits)
- len = -1;
- else if (crbb_len == 0)
+ if (num_blocks > rest_bits - 15 - 1) {
+ eow = false;
+ urbb_len = rest_bits - 15 - 1;
+ len_coded = false;
+ } else if (num_blocks == rest_bits - 15 - 1) {
+ urbb_len = rest_bits - 15 - 1;
+ len_coded = false;
+ /* Union bit takes 1 bit length field takes 8 bits*/
+ } else if (num_blocks > rest_bits - 15 - 9) {
+ eow = false;
+ urbb_len = rest_bits - 15 - 9;
+ } else
+ urbb_len = num_blocks;
len = urbb_len + 15;
- else
- len = urbb_len + crbb_len + 23;
+ } else {
+ /* TODO Compressed bitmap */
+ }
/* EGPRS Ack/Nack Description IE */
- if (len < 0) {
+ if (len_coded == false) {
bitvec_write_field(dest, wp, 0, 1); // 0: don't have length
} else {
bitvec_write_field(dest, wp, 1, 1); // 1: have length
@@ -754,17 +755,19 @@
bitvec_write_field(dest, wp, bow, 1); // BEGINNING_OF_WINDOW
bitvec_write_field(dest, wp, eow, 1); // END_OF_WINDOW
bitvec_write_field(dest, wp, ssn, 11); // STARTING_SEQUENCE_NUMBER
- bitvec_write_field(dest, wp, 0, 1); // 0: don't have CRBB
-
- /* TODO: Add CRBB support */
-
+ if (is_compressed) {
+ /* TODO Add CRBB support */
+ } else
+ bitvec_write_field(dest, wp, 0, 1); // CRBB_Exist
LOGP(DRLCMACUL, LOGL_DEBUG,
- " - EGPRS URBB, len = %d, SSN = %d, ESN_CRBB = %d, "
+ "EGPRS URBB, urbb len = %d, SSN = %d, ESN_CRBB = %d, "
+ "len present = %s,desc len = %d, "
"SNS = %d, WS = %d, V(Q) = %d, V(R) = %d%s%s\n",
- urbb_len, ssn, esn_crbb,
+ urbb_len, ssn, esn_crbb, len_coded ? "yes" : "No", len,
window->sns(), window->ws(), window->v_q(), window->v_r(),
bow ? ", BOW" : "", eow ? ", EOW" : "");
- for (int i = urbb_len; i > 0; i--) {
+
+ for (i = urbb_len; i > 0; i--) {
/* Set bit at the appropriate position (see 3GPP TS 04.60 12.3.1) */
bool is_ack = window->m_v_n.is_received(esn_crbb + i);
bitvec_write_field(dest, wp, is_ack, 1);