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sangamesh sajjan sangamesh.sajjan at radisys.comThis patch includes the changes for compression algorithm which
decompress the received CRBB bitmap and corresponding modification
of EPDAN handling
---
src/decoding.cpp | 30 ++++---------
src/decoding.h | 10 ++++-
src/egprs_rlc_compression.cpp | 96 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 113 insertions(+), 23 deletions(-)
diff --git a/src/decoding.cpp b/src/decoding.cpp
index f2b548c..4535d1b 100644
--- a/src/decoding.cpp
+++ b/src/decoding.cpp
@@ -536,7 +536,6 @@ int Decoding::decode_egprs_acknack_bits(const EGPRS_AckNack_Desc_t *desc,
bool have_bitmap;
int implicitly_acked_blocks;
int ssn = desc->STARTING_SEQUENCE_NUMBER;
- int rc;
if (desc->FINAL_ACK_INDICATION)
return handle_final_ack(bits, bsn_begin, bsn_end, window);
@@ -576,26 +575,15 @@ int Decoding::decode_egprs_acknack_bits(const EGPRS_AckNack_Desc_t *desc,
if (crbb_len > 0) {
int old_len = bits->cur_bit;
- struct bitvec crbb;
-
- crbb.data = (uint8_t *)desc->CRBB;
- crbb.data_len = sizeof(desc->CRBB);
- crbb.cur_bit = desc->CRBB_LENGTH;
-
- rc = osmo_t4_decode(&crbb, desc->CRBB_STARTING_COLOR_CODE,
- bits);
-
- if (rc < 0) {
- LOGP(DRLCMACUL, LOGL_NOTICE,
- "Failed to decode CRBB: "
- "length %d, data '%s'\n",
- desc->CRBB_LENGTH,
- osmo_hexdump(crbb.data, crbb.data_len));
- /* We don't know the SSN offset for the URBB,
- * return what we have so far and assume the
- * bitmap has stopped here */
- goto aborted;
- }
+
+ LOGP(DRLCMACDL, LOGL_DEBUG, "Compress bitmap exist,"
+ "CRBB LEN =%d and Starting color code =%d",
+ desc->CRBB_LENGTH, desc->CRBB_STARTING_COLOR_CODE);
+
+ decompress_crbb(desc->CRBB_LENGTH,
+ desc->CRBB_STARTING_COLOR_CODE,
+ desc->CRBB,
+ bits);
LOGP(DRLCMACDL, LOGL_DEBUG,
"CRBB len: %d, decoded len: %d, cc: %d, crbb: '%s'\n",
diff --git a/src/decoding.h b/src/decoding.h
index 58ecd18..5989907 100644
--- a/src/decoding.h
+++ b/src/decoding.h
@@ -60,6 +60,12 @@ public:
struct gprs_rlc_dl_window *window);
static int decode_gprs_acknack_bits(
const Ack_Nack_Description_t *desc,
- bitvec *bits, int *bsn_begin, int *bsn_end,
- gprs_rlc_dl_window *window);
+ bitvec * bits, int *bsn_begin, int *bsn_end,
+ gprs_rlc_dl_window * window);
+ static void decompress_crbb(
+ int8_t compress_bmap_len,
+ uint8_t clr_code_bit,
+ const uint8_t *orig_buf,
+ bitvec * dest
+ );
};
diff --git a/src/egprs_rlc_compression.cpp b/src/egprs_rlc_compression.cpp
index 4c17a17..2e4dc05 100644
--- a/src/egprs_rlc_compression.cpp
+++ b/src/egprs_rlc_compression.cpp
@@ -218,3 +218,99 @@ const char *zero_run_len_code_list[MAX_CDWDTBL_LEN] = {
"0000001110010",
"0000001110011"
};
+
+int search_runlen(
+ Node *root, /* root of Ones or Zeros tree */
+ const uint8_t *bmbuf, /* Received compressed bitmap buf */
+ uint8_t bit_pos, /* the start bit pos to read codeword */
+ uint8_t *len_codewd, /* length of codeword */
+ uint16_t *rlen /* run length of Ones or Zeros */
+ )
+{
+ Node *iter;
+ uint8_t dir;
+
+ iter = root;
+ *len_codewd = 0;
+
+ while (iter->run_length == 0) {
+ if ((iter->left == NULL) && (iter->right == NULL))
+ return -1;
+
+ /* get the bit value at the bitpos and put it in right most of dir */
+ dir = ((bmbuf[BITS_TO_BYTES(bit_pos)-1]
+ >>(7-(MOD8(bit_pos)))) & 0x01);
+ (bit_pos)++;
+ (*len_codewd)++;
+
+ if (((dir&0x01) == 0) && (iter->left != NULL))
+ iter = iter->left;
+
+ else if (((dir&0x01) == 1) && (iter->right != NULL))
+ iter = iter->right;
+ else
+ return -1;
+ }
+ (*rlen) = *(iter->run_length);
+
+ return 1;
+} /* search_runlen */
+
+void Decoding::decompress_crbb(
+ int8_t compress_bmap_len, /* compressed bitmap length */
+ uint8_t clr_code_bit, /* run length of Ones or Zeros */
+ const uint8_t *orig_crbb_buf, /* received block crbb bitmap */
+ bitvec * dest
+ )
+{
+
+ uint8_t bit_pos = 0;
+ uint8_t nbits = 0; /* number of bits of codeword */
+ uint16_t run_length = 0;
+ uint16_t cbmaplen = 0; /* compressed bitmap part after decompression */
+ unsigned wp = 0;
+
+ egprs_compress *compress = egprs_compress::instance();
+
+ while (compress_bmap_len >= 0) {
+ if (clr_code_bit == 1) {
+ search_runlen(compress->ones_list, orig_crbb_buf,
+ bit_pos, &nbits, &run_length);
+ /*If run length > 64, need makeup and terminating code*/
+ if (run_length < 64)
+ clr_code_bit = 0;
+ cbmaplen = cbmaplen + run_length;
+ /* put run length of Ones in uncompressed bitmap */
+ while (run_length != 0) {
+ if (run_length > 8) {
+ bitvec_write_field(dest, wp, 0xff, 8);
+ run_length = run_length - 8;
+ } else {
+ bitvec_write_field(dest, wp, 0xff,
+ run_length);
+ run_length = 0;
+ }
+ }
+ } else {
+ search_runlen(compress->zeros_list, orig_crbb_buf,
+ bit_pos, &nbits, &run_length);
+ /*If run length > 64, need makeup and terminating code*/
+ if (run_length < 64)
+ clr_code_bit = 1;
+ cbmaplen = cbmaplen + run_length;
+ /* put run length of Zeros in uncompressed bitmap */
+ while (run_length != 0) {
+ if (run_length > 8) {
+ bitvec_write_field(dest, wp, 0x00, 8);
+ run_length = run_length - 8;
+ } else {
+ bitvec_write_field(dest, wp, 0x00,
+ run_length);
+ run_length = 0;
+ }
+ }
+ }
+ bit_pos = bit_pos + nbits;
+ compress_bmap_len = compress_bmap_len - nbits;
+ }
+} /* Decompress_CRBB */
--
1.7.9.5