session.c

   1 /*
   2  * This file is part of the sigrok-cli project.
   3  *
   4  * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "sigrok-cli.h"
  21 #include <glib.h>
  22 #include <glib/gstdio.h>
  23 #include <string.h>
  24 #include <stdlib.h>
  25
  26 static int default_output_format = FALSE;
  27 static uint64_t limit_samples = 0;
  28 static uint64_t limit_frames = 0;
  29
  30 #ifdef HAVE_SRD
  31 extern struct srd_session *srd_sess;
  32 #endif
  33
  34 static int set_limit_time(const struct sr_dev_inst *sdi)
  35 {
  36         GVariant *gvar;
  37         uint64_t time_msec;
  38         uint64_t samplerate;
  39
  40         if (!(time_msec = sr_parse_timestring(opt_time))) {
  41                 g_critical("Invalid time '%s'", opt_time);
  42                 return SR_ERR;
  43         }
  44
  45         if (sr_dev_has_option(sdi, SR_CONF_LIMIT_MSEC)) {
  46                 gvar = g_variant_new_uint64(time_msec);
  47                 if (sr_config_set(sdi, NULL, SR_CONF_LIMIT_MSEC, gvar) != SR_OK) {
  48                         g_critical("Failed to configure time limit.");
  49                         return SR_ERR;
  50                 }
  51         } else if (sr_dev_has_option(sdi, SR_CONF_SAMPLERATE)) {
  52                 /* Convert to samples based on the samplerate.  */
  53                 sr_config_get(sdi->driver, sdi, NULL, SR_CONF_SAMPLERATE, &gvar);
  54                 samplerate = g_variant_get_uint64(gvar);
  55                 g_variant_unref(gvar);
  56                 limit_samples = (samplerate) * time_msec / (uint64_t)1000;
  57                 if (limit_samples == 0) {
  58                         g_critical("Not enough time at this samplerate.");
  59                         return SR_ERR;
  60                 }
  61                 gvar = g_variant_new_uint64(limit_samples);
  62                 if (sr_config_set(sdi, NULL, SR_CONF_LIMIT_SAMPLES, gvar) != SR_OK) {
  63                         g_critical("Failed to configure time-based sample limit.");
  64                         return SR_ERR;
  65                 }
  66         } else {
  67                 g_critical("This device does not support time limits.");
  68                 return SR_ERR;
  69         }
  70
  71         return SR_OK;
  72 }
  73
  74 GHashTable *generic_arg_to_opt(const struct sr_option *opts, GHashTable *genargs)
  75 {
  76         GHashTable *hash;
  77         GVariant *gvar;
  78         const struct sr_option *opt;
  79         char *s;
  80
  81         hash = g_hash_table_new_full(g_str_hash, g_str_equal, g_free,
  82                         (GDestroyNotify)g_variant_unref);
  83         for (opt = opts; opt->id && opt->def; opt++) {
  84                 if (!(s = g_hash_table_lookup(genargs, opt->id)))
  85                         continue;
  86                 if (g_variant_is_of_type(opt->def, G_VARIANT_TYPE_UINT32)) {
  87                         gvar = g_variant_new_uint32(strtoul(s, NULL, 10));
  88                         g_hash_table_insert(hash, g_strdup(opt->id),
  89                                         g_variant_ref_sink(gvar));
  90                 } else if (g_variant_is_of_type(opt->def, G_VARIANT_TYPE_DOUBLE)) {
  91                         gvar = g_variant_new_double(strtod(s, NULL));
  92                         g_hash_table_insert(hash, g_strdup(opt->id),
  93                                         g_variant_ref_sink(gvar));
  94                 } else {
  95                         g_critical("Don't know GVariant type for option '%s'!", opt->id);
  96                  }
  97         }
  98
  99         return hash;
 100 }
 101
 102 const struct sr_output *setup_output_format(const struct sr_dev_inst *sdi)
 103 {
 104         const struct sr_output_module *omod;
 105         const struct sr_option *opts;
 106         const struct sr_output *o;
 107         GHashTable *fmtargs, *fmtopts;
 108         char *fmtspec;
 109
 110         if (opt_output_format && !strcmp(opt_output_format, "sigrok")) {
 111                 /* Doesn't really exist as an output module - this is
 112                  * the session save mode. */
 113                 g_free(opt_output_format);
 114                 opt_output_format = NULL;
 115         }
 116
 117         if (!opt_output_format) {
 118                 opt_output_format = DEFAULT_OUTPUT_FORMAT;
 119                 /* we'll need to remember this so when saving to a file
 120                  * later, sigrok session format will be used.
 121                  */
 122                 default_output_format = TRUE;
 123         }
 124
 125         fmtargs = parse_generic_arg(opt_output_format, TRUE);
 126         fmtspec = g_hash_table_lookup(fmtargs, "sigrok_key");
 127         if (!fmtspec)
 128                 g_critical("Invalid output format.");
 129         if (!(omod = sr_output_find(fmtspec)))
 130                 g_critical("Unknown output format '%s'.", fmtspec);
 131         g_hash_table_remove(fmtargs, "sigrok_key");
 132         if ((opts = sr_output_options_get(omod))) {
 133                 fmtopts = generic_arg_to_opt(opts, fmtargs);
 134                 sr_output_options_free(omod);
 135         } else
 136                 fmtopts = NULL;
 137         o = sr_output_new(omod, fmtopts, sdi);
 138         if (fmtopts)
 139                 g_hash_table_destroy(fmtopts);
 140         g_hash_table_destroy(fmtargs);
 141
 142         return o;
 143 }
 144
 145 void datafeed_in(const struct sr_dev_inst *sdi,
 146                 const struct sr_datafeed_packet *packet, void *cb_data)
 147 {
 148         const struct sr_datafeed_meta *meta;
 149         const struct sr_datafeed_logic *logic;
 150         const struct sr_datafeed_analog *analog;
 151         struct sr_session *session;
 152         struct sr_config *src;
 153         struct sr_channel *ch;
 154         static const struct sr_output *o = NULL;
 155         static const struct sr_output *oa = NULL;
 156         static uint64_t rcvd_samples_logic = 0;
 157         static uint64_t rcvd_samples_analog = 0;
 158         static uint64_t samplerate = 0;
 159         static int triggered = 0;
 160         static FILE *outfile = NULL;
 161         GSList *l;
 162         GString *out;
 163         GVariant *gvar;
 164         uint64_t end_sample;
 165         uint64_t input_len;
 166         int i;
 167         char **channels;
 168
 169         /* If the first packet to come in isn't a header, don't even try. */
 170         if (packet->type != SR_DF_HEADER && o == NULL)
 171                 return;
 172
 173         session = cb_data;
 174         switch (packet->type) {
 175         case SR_DF_HEADER:
 176                 g_debug("cli: Received SR_DF_HEADER.");
 177                 o = setup_output_format(sdi);
 178
 179                 /* Set up backup analog output module. */
 180                 oa = sr_output_new(sr_output_find("analog"), NULL, sdi);
 181
 182                 /* Prepare non-stdout output. */
 183                 outfile = stdout;
 184                 if (opt_output_file) {
 185                         if (default_output_format) {
 186                                 outfile = NULL;
 187                         } else {
 188                                 /* saving to a file in whatever format was set
 189                                  * with --format, so all we need is a filehandle */
 190                                 outfile = g_fopen(opt_output_file, "wb");
 191                         }
 192                 }
 193                 rcvd_samples_logic = rcvd_samples_analog = 0;
 194
 195                 if (sr_config_get(sdi->driver, sdi, NULL, SR_CONF_SAMPLERATE,
 196                                 &gvar) == SR_OK) {
 197                         samplerate = g_variant_get_uint64(gvar);
 198                         g_variant_unref(gvar);
 199                 }
 200
 201 #ifdef HAVE_SRD
 202                 if (opt_pds) {
 203                         if (samplerate) {
 204                                 if (srd_session_metadata_set(srd_sess, SRD_CONF_SAMPLERATE,
 205                                                 g_variant_new_uint64(samplerate)) != SRD_OK) {
 206                                         g_critical("Failed to configure decode session.");
 207                                         break;
 208                                 }
 209                         }
 210                         if (srd_session_start(srd_sess) != SRD_OK) {
 211                                 g_critical("Failed to start decode session.");
 212                                 break;
 213                         }
 214                 }
 215 #endif
 216                 break;
 217
 218         case SR_DF_META:
 219                 g_debug("cli: Received SR_DF_META.");
 220                 meta = packet->payload;
 221                 for (l = meta->config; l; l = l->next) {
 222                         src = l->data;
 223                         switch (src->key) {
 224                         case SR_CONF_SAMPLERATE:
 225                                 samplerate = g_variant_get_uint64(src->data);
 226                                 g_debug("cli: Got samplerate %"PRIu64" Hz.", samplerate);
 227 #ifdef HAVE_SRD
 228                                 if (opt_pds) {
 229                                         if (srd_session_metadata_set(srd_sess, SRD_CONF_SAMPLERATE,
 230                                                         g_variant_new_uint64(samplerate)) != SRD_OK) {
 231                                                 g_critical("Failed to pass samplerate to decoder.");
 232                                         }
 233                                 }
 234 #endif
 235                                 break;
 236                         case SR_CONF_SAMPLE_INTERVAL:
 237                                 samplerate = g_variant_get_uint64(src->data);
 238                                 g_debug("cli: Got sample interval %"PRIu64" ms.", samplerate);
 239                                 break;
 240                         default:
 241                                 /* Unknown metadata is not an error. */
 242                                 break;
 243                         }
 244                 }
 245                 break;
 246
 247         case SR_DF_TRIGGER:
 248                 g_debug("cli: Received SR_DF_TRIGGER.");
 249                 triggered = 1;
 250                 break;
 251
 252         case SR_DF_LOGIC:
 253                 logic = packet->payload;
 254                 g_message("cli: Received SR_DF_LOGIC (%"PRIu64" bytes, unitsize = %d).",
 255                                 logic->length, logic->unitsize);
 256                 if (logic->length == 0)
 257                         break;
 258
 259                 /* Don't store any samples until triggered. */
 260                 if (opt_wait_trigger && !triggered)
 261                         break;
 262
 263                 if (limit_samples && rcvd_samples_logic >= limit_samples)
 264                         break;
 265
 266                 end_sample = rcvd_samples_logic + logic->length / logic->unitsize;
 267                 /* Cut off last packet according to the sample limit. */
 268                 if (limit_samples && end_sample > limit_samples)
 269                         end_sample = limit_samples;
 270                 input_len = (end_sample - rcvd_samples_logic) * logic->unitsize;
 271
 272                 if (opt_output_file && default_output_format) {
 273                         /* Saving to a session file. */
 274                         if (rcvd_samples_logic == 0) {
 275                                 /* First packet with logic data, init session file. */
 276                                 channels = g_malloc(sizeof(char *) * g_slist_length(sdi->channels));
 277                                 for (i = 0, l = sdi->channels; l; l = l->next) {
 278                                         ch = l->data;
 279                                         if (ch->enabled && ch->type == SR_CHANNEL_LOGIC)
 280                                                 channels[i++] = ch->name;
 281                                 }
 282                                 channels[i] = NULL;
 283                                 sr_session_save_init(session, opt_output_file,
 284                                                 samplerate, channels);
 285                                 g_free(channels);
 286                         }
 287                         save_chunk_logic(session, logic->data, input_len, logic->unitsize);
 288                 } else {
 289                         if (opt_pds) {
 290 #ifdef HAVE_SRD
 291                                 if (srd_session_send(srd_sess, rcvd_samples_logic, end_sample,
 292                                                 logic->data, input_len) != SRD_OK)
 293                                         sr_session_stop(session);
 294 #endif
 295                         }
 296                 }
 297
 298                 rcvd_samples_logic = end_sample;
 299                 break;
 300
 301         case SR_DF_ANALOG:
 302                 analog = packet->payload;
 303                 g_message("cli: Received SR_DF_ANALOG (%d samples).", analog->num_samples);
 304                 if (analog->num_samples == 0)
 305                         break;
 306
 307                 if (limit_samples && rcvd_samples_analog >= limit_samples)
 308                         break;
 309
 310                 rcvd_samples_analog += analog->num_samples;
 311                 break;
 312
 313         case SR_DF_FRAME_BEGIN:
 314                 g_debug("cli: Received SR_DF_FRAME_BEGIN.");
 315                 break;
 316
 317         case SR_DF_FRAME_END:
 318                 g_debug("cli: Received SR_DF_FRAME_END.");
 319                 break;
 320
 321         default:
 322                 break;
 323         }
 324
 325         if (o && outfile && !opt_pds) {
 326                 if (sr_output_send(o, packet, &out) == SR_OK) {
 327                         if (!out || (out->len == 0 && default_output_format
 328                                         && packet->type == SR_DF_ANALOG)) {
 329                                 /* The user didn't specify an output module,
 330                                  * but needs to see this analog data. */
 331                                 sr_output_send(oa, packet, &out);
 332                         }
 333                         if (out && out->len > 0) {
 334                                 fwrite(out->str, 1, out->len, outfile);
 335                                 fflush(outfile);
 336                         }
 337                         if (out)
 338                                 g_string_free(out, TRUE);
 339                 }
 340         }
 341
 342         /* SR_DF_END needs to be handled after the output module's receive()
 343          * is called, so it can properly clean up that module. */
 344         if (packet->type == SR_DF_END) {
 345                 g_debug("cli: Received SR_DF_END.");
 346
 347                 if (o)
 348                         sr_output_free(o);
 349                 o = NULL;
 350
 351                 sr_output_free(oa);
 352                 oa = NULL;
 353
 354                 if (outfile && outfile != stdout)
 355                         fclose(outfile);
 356
 357                 if (opt_output_file && default_output_format)
 358                         /* Flush whatever is left out to the session file. */
 359                         save_chunk_logic(session, NULL, 0, 0);
 360
 361                 if (limit_samples) {
 362                         if (rcvd_samples_logic > 0 && rcvd_samples_logic < limit_samples)
 363                                 g_warning("Device only sent %" PRIu64 " samples.",
 364                                            rcvd_samples_logic);
 365                         else if (rcvd_samples_analog > 0 && rcvd_samples_analog < limit_samples)
 366                                 g_warning("Device only sent %" PRIu64 " samples.",
 367                                            rcvd_samples_analog);
 368                 }
 369         }
 370
 371 }
 372
 373 int opt_to_gvar(char *key, char *value, struct sr_config *src)
 374 {
 375         const struct sr_config_info *srci;
 376         double tmp_double, dlow, dhigh;
 377         uint64_t tmp_u64, p, q, low, high;
 378         GVariant *rational[2], *range[2];
 379         gboolean tmp_bool;
 380         int ret;
 381
 382         if (!(srci = sr_config_info_name_get(key))) {
 383                 g_critical("Unknown device option '%s'.", (char *) key);
 384                 return -1;
 385         }
 386         src->key = srci->key;
 387
 388         if ((value == NULL) &&
 389                 (srci->datatype != SR_T_BOOL)) {
 390                 g_critical("Option '%s' needs a value.", (char *)key);
 391                 return -1;
 392         }
 393
 394         ret = 0;
 395         switch (srci->datatype) {
 396         case SR_T_UINT64:
 397                 ret = sr_parse_sizestring(value, &tmp_u64);
 398                 if (ret != 0)
 399                         break;
 400                 src->data = g_variant_new_uint64(tmp_u64);
 401                 break;
 402         case SR_T_INT32:
 403                 ret = sr_parse_sizestring(value, &tmp_u64);
 404                 if (ret != 0)
 405                         break;
 406                 src->data = g_variant_new_int32(tmp_u64);
 407                 break;
 408         case SR_T_STRING:
 409                 src->data = g_variant_new_string(value);
 410                 break;
 411         case SR_T_BOOL:
 412                 if (!value)
 413                         tmp_bool = TRUE;
 414                 else
 415                         tmp_bool = sr_parse_boolstring(value);
 416                 src->data = g_variant_new_boolean(tmp_bool);
 417                 break;
 418         case SR_T_FLOAT:
 419                 tmp_double = strtof(value, NULL);
 420                 src->data = g_variant_new_double(tmp_double);
 421                 break;
 422         case SR_T_RATIONAL_PERIOD:
 423                 if ((ret = sr_parse_period(value, &p, &q)) != SR_OK)
 424                         break;
 425                 rational[0] = g_variant_new_uint64(p);
 426                 rational[1] = g_variant_new_uint64(q);
 427                 src->data = g_variant_new_tuple(rational, 2);
 428                 break;
 429         case SR_T_RATIONAL_VOLT:
 430                 if ((ret = sr_parse_voltage(value, &p, &q)) != SR_OK)
 431                         break;
 432                 rational[0] = g_variant_new_uint64(p);
 433                 rational[1] = g_variant_new_uint64(q);
 434                 src->data = g_variant_new_tuple(rational, 2);
 435                 break;
 436         case SR_T_UINT64_RANGE:
 437                 if (sscanf(value, "%"PRIu64"-%"PRIu64, &low, &high) != 2) {
 438                         ret = -1;
 439                         break;
 440                 } else {
 441                         range[0] = g_variant_new_uint64(low);
 442                         range[1] = g_variant_new_uint64(high);
 443                         src->data = g_variant_new_tuple(range, 2);
 444                 }
 445                 break;
 446         case SR_T_DOUBLE_RANGE:
 447                 if (sscanf(value, "%lf-%lf", &dlow, &dhigh) != 2) {
 448                         ret = -1;
 449                         break;
 450                 } else {
 451                         range[0] = g_variant_new_double(dlow);
 452                         range[1] = g_variant_new_double(dhigh);
 453                         src->data = g_variant_new_tuple(range, 2);
 454                 }
 455                 break;
 456         default:
 457                 ret = -1;
 458         }
 459
 460         return ret;
 461 }
 462
 463 int set_dev_options(struct sr_dev_inst *sdi, GHashTable *args)
 464 {
 465         struct sr_config src;
 466         struct sr_channel_group *cg;
 467         GHashTableIter iter;
 468         gpointer key, value;
 469         int ret;
 470
 471         g_hash_table_iter_init(&iter, args);
 472         while (g_hash_table_iter_next(&iter, &key, &value)) {
 473                 if ((ret = opt_to_gvar(key, value, &src)) != 0)
 474                         return ret;
 475                 cg = select_channel_group(sdi);
 476                 ret = sr_config_set(sdi, cg, src.key, src.data);
 477                 if (ret != SR_OK) {
 478                         g_critical("Failed to set device option '%s'.", (char *)key);
 479                         return ret;
 480                 }
 481         }
 482
 483         return SR_OK;
 484 }
 485
 486 void run_session(void)
 487 {
 488         GSList *devices;
 489         GHashTable *devargs;
 490         GVariant *gvar;
 491         struct sr_session *session;
 492         struct sr_trigger *trigger;
 493         struct sr_dev_inst *sdi;
 494         uint64_t min_samples, max_samples;
 495
 496         devices = device_scan();
 497         if (!devices) {
 498                 g_critical("No devices found.");
 499                 return;
 500         }
 501         if (g_slist_length(devices) > 1) {
 502                 g_critical("sigrok-cli only supports one device for capturing.");
 503                 g_slist_free(devices);
 504                 return;
 505         }
 506         sdi = devices->data;
 507         g_slist_free(devices);
 508
 509         sr_session_new(&session);
 510         sr_session_datafeed_callback_add(session, datafeed_in, NULL);
 511
 512         if (sr_dev_open(sdi) != SR_OK) {
 513                 g_critical("Failed to open device.");
 514                 return;
 515         }
 516
 517         if (sr_session_dev_add(session, sdi) != SR_OK) {
 518                 g_critical("Failed to add device to session.");
 519                 sr_session_destroy(session);
 520                 return;
 521         }
 522
 523         if (opt_config) {
 524                 if ((devargs = parse_generic_arg(opt_config, FALSE))) {
 525                         if (set_dev_options(sdi, devargs) != SR_OK)
 526                                 return;
 527                         g_hash_table_destroy(devargs);
 528                 }
 529         }
 530
 531         if (select_channels(sdi) != SR_OK) {
 532                 g_critical("Failed to set channels.");
 533                 sr_session_destroy(session);
 534                 return;
 535         }
 536
 537         if (opt_triggers) {
 538                 if (!parse_triggerstring(sdi, opt_triggers, &trigger)) {
 539                         sr_session_destroy(session);
 540                         return;
 541                 }
 542                 if (sr_session_trigger_set(session, trigger) != SR_OK) {
 543                         sr_session_destroy(session);
 544                         return;
 545                 }
 546         }
 547
 548         if (opt_continuous) {
 549                 if (!sr_dev_has_option(sdi, SR_CONF_CONTINUOUS)) {
 550                         g_critical("This device does not support continuous sampling.");
 551                         sr_session_destroy(session);
 552                         return;
 553                 }
 554         }
 555
 556         if (opt_time) {
 557                 if (set_limit_time(sdi) != SR_OK) {
 558                         sr_session_destroy(session);
 559                         return;
 560                 }
 561         }
 562
 563         if (opt_samples) {
 564                 if ((sr_parse_sizestring(opt_samples, &limit_samples) != SR_OK)) {
 565                         g_critical("Invalid sample limit '%s'.", opt_samples);
 566                         sr_session_destroy(session);
 567                         return;
 568                 }
 569                 if (sr_config_list(sdi->driver, sdi, NULL,
 570                                 SR_CONF_LIMIT_SAMPLES, &gvar) == SR_OK) {
 571                         /* The device has no compression, or compression is turned
 572                          * off, and publishes its sample memory size. */
 573                         g_variant_get(gvar, "(tt)", &min_samples, &max_samples);
 574                         g_variant_unref(gvar);
 575                         if (limit_samples < min_samples) {
 576                                 g_critical("The device stores at least %"PRIu64
 577                                                 " samples with the current settings.", min_samples);
 578                         }
 579                         if (limit_samples > max_samples) {
 580                                 g_critical("The device can store only %"PRIu64
 581                                                 " samples with the current settings.", max_samples);
 582                         }
 583                 }
 584                 gvar = g_variant_new_uint64(limit_samples);
 585                 if (sr_config_set(sdi, NULL, SR_CONF_LIMIT_SAMPLES, gvar) != SR_OK) {
 586                         g_critical("Failed to configure sample limit.");
 587                         sr_session_destroy(session);
 588                         return;
 589                 }
 590         }
 591
 592         if (opt_frames) {
 593                 if ((sr_parse_sizestring(opt_frames, &limit_frames) != SR_OK)) {
 594                         g_critical("Invalid sample limit '%s'.", opt_samples);
 595                         sr_session_destroy(session);
 596                         return;
 597                 }
 598                 gvar = g_variant_new_uint64(limit_frames);
 599                 if (sr_config_set(sdi, NULL, SR_CONF_LIMIT_FRAMES, gvar) != SR_OK) {
 600                         g_critical("Failed to configure frame limit.");
 601                         sr_session_destroy(session);
 602                         return;
 603                 }
 604         }
 605
 606         if (sr_session_start(session) != SR_OK) {
 607                 g_critical("Failed to start session.");
 608                 sr_session_destroy(session);
 609                 return;
 610         }
 611
 612         if (opt_continuous)
 613                 add_anykey(session);
 614
 615         sr_session_run(session);
 616
 617         if (opt_continuous)
 618                 clear_anykey();
 619
 620         sr_session_datafeed_callback_remove_all(session);
 621         sr_session_destroy(session);
 622
 623 }
 624
 625 void save_chunk_logic(struct sr_session *session, uint8_t *data,
 626                 uint64_t data_len, int unitsize)
 627 {
 628         static uint8_t *buf = NULL;
 629         static int buf_len = 0;
 630         static int last_unitsize = 0;
 631         int max;
 632
 633         if (!buf)
 634                 buf = g_malloc(SAVE_CHUNK_SIZE);
 635
 636         while (data_len > SAVE_CHUNK_SIZE) {
 637                 save_chunk_logic(session, data, SAVE_CHUNK_SIZE, unitsize);
 638                 data += SAVE_CHUNK_SIZE;
 639                 data_len -= SAVE_CHUNK_SIZE;
 640         }
 641
 642         if (buf_len + data_len > SAVE_CHUNK_SIZE) {
 643                 max = (SAVE_CHUNK_SIZE - buf_len) / unitsize * unitsize;
 644                 memcpy(buf + buf_len, data, max);
 645                 sr_session_append(session, opt_output_file, buf, unitsize,
 646                                 (buf_len + max) / unitsize);
 647                 memcpy(buf, data + max, data_len - max);
 648                 buf_len = data_len - max;
 649         } else if (data_len == 0 && last_unitsize != 0) {
 650                 /* End of data, flush the buffer out. */
 651                 sr_session_append(session, opt_output_file, buf, last_unitsize,
 652                                 buf_len / last_unitsize);
 653         } else {
 654                 /* Buffer chunk. */
 655                 memcpy(buf + buf_len, data, data_len);
 656                 buf_len += data_len;
 657         }
 658         last_unitsize = unitsize;
 659
 660 }