/* Initalize data compression */
int gprs_sndcp_dcomp_init(const void *ctx, struct gprs_sndcp_comp *comp_entity,
const struct gprs_sndcp_comp_field *comp_field)
{
/* Note: This function is automatically called from
* gprs_sndcp_comp.c when a new data compression
* entity is created by gprs_sndcp.c */
OSMO_ASSERT(comp_entity);
OSMO_ASSERT(comp_field);
if (comp_entity->compclass == SNDCP_XID_DATA_COMPRESSION
&& comp_entity->algo == V42BIS) {
OSMO_ASSERT(comp_field->v42bis_params);
comp_entity->state =
v42bis_init(ctx, NULL, comp_field->v42bis_params->p0,
comp_field->v42bis_params->p1,
comp_field->v42bis_params->p2,
&tx_v42bis_frame_handler, NULL,
V42BIS_MAX_OUTPUT_LENGTH,
&rx_v42bis_data_handler, NULL,
V42BIS_MAX_OUTPUT_LENGTH);
LOGP(DSNDCP, LOGL_INFO,
"V.42bis data compression initalized.\n");
return 0;
}
/* Just in case someone tries to initalize an unknown or unsupported
* data compresson. Since everything is checked during the SNDCP
* negotiation process, this should never happen! */
OSMO_ASSERT(false);
}
/* Perform a full reset of the V.42bis compression state */
static void v42bis_reset(v42bis_state_t *comp)
{
/* This function performs a complete reset of the V.42bis compression
* state by reinitalizing the state withe the previously negotiated
* parameters. */
int p0, p1, p2;
p0 = comp->decompress.v42bis_parm_p0 | comp->compress.v42bis_parm_p0;
p1 = comp->decompress.v42bis_parm_n2;
p2 = comp->decompress.v42bis_parm_n7;
DEBUGP(DSNDCP, "Resetting compression state: %p, p0=%d, p1=%d, p2=%d\n",
comp, p0, p1, p2);
v42bis_init(NULL, comp, p0, p1, p2, &tx_v42bis_frame_handler, NULL,
V42BIS_MAX_OUTPUT_LENGTH, &rx_v42bis_data_handler, NULL,
V42BIS_MAX_OUTPUT_LENGTH);
}
int main(int argc, char *argv[])
{
int len;
v42bis_state_t state_a;
v42bis_state_t state_b;
uint8_t buf[1024];
int in_fd;
int v42bis_fd;
int out_fd;
int do_compression;
int do_decompression;
time_t now;
do_compression = TRUE;
do_decompression = TRUE;
if (argc < 2)
{
fprintf(stderr, "Usage: %s <file>\n", argv[0]);
exit(2);
}
if (do_compression)
{
if ((in_fd = open(argv[1], O_RDONLY)) < 0)
{
fprintf(stderr, "Error opening file '%s'.\n", argv[1]);
exit(2);
}
if ((v42bis_fd = open(COMPRESSED_FILE_NAME, O_WRONLY | O_CREAT | O_TRUNC, 0666)) < 0)
{
fprintf(stderr, "Error opening file '%s'.\n", COMPRESSED_FILE_NAME);
exit(2);
}
time(&now);
v42bis_init(&state_a, 3, 512, 6, frame_handler, (void *) (intptr_t) v42bis_fd, 512, data_handler, NULL, 512);
v42bis_compression_control(&state_a, V42BIS_COMPRESSION_MODE_ALWAYS);
in_octets_to_date = 0;
out_octets_to_date = 0;
while ((len = read(in_fd, buf, 1024)) > 0)
{
if (v42bis_compress(&state_a, buf, len))
{
fprintf(stderr, "Bad return code from compression\n");
exit(2);
}
in_octets_to_date += len;
}
v42bis_compress_flush(&state_a);
printf("%d bytes compressed to %d bytes in %lds\n", in_octets_to_date, out_octets_to_date, time(NULL) - now);
close(in_fd);
close(v42bis_fd);
}
if (do_decompression)
{
/* Now open the files for the decompression. */
if ((v42bis_fd = open(COMPRESSED_FILE_NAME, O_RDONLY)) < 0)
{
fprintf(stderr, "Error opening file '%s'.\n", COMPRESSED_FILE_NAME);
exit(2);
}
if ((out_fd = open(OUTPUT_FILE_NAME, O_WRONLY | O_CREAT | O_TRUNC, 0666)) < 0)
{
fprintf(stderr, "Error opening file '%s'.\n", OUTPUT_FILE_NAME);
exit(2);
}
time(&now);
v42bis_init(&state_b, 3, 512, 6, frame_handler, (void *) (intptr_t) v42bis_fd, 512, data_handler, (void *) (intptr_t) out_fd, 512);
in_octets_to_date = 0;
out_octets_to_date = 0;
while ((len = read(v42bis_fd, buf, 1024)) > 0)
{
if (v42bis_decompress(&state_b, buf, len))
{
fprintf(stderr, "Bad return code from decompression\n");
exit(2);
}
in_octets_to_date += len;
}
v42bis_decompress_flush(&state_b);
printf("%d bytes decompressed to %d bytes in %lds\n", in_octets_to_date, out_octets_to_date, time(NULL) - now);
close(v42bis_fd);
close(out_fd);
}
return 0;
}
