session.c

   1 /*
   2  * This file is part of the libsigrokdecode project.
   3  *
   4  * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
   5  * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "libsigrokdecode.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
  22 #include "libsigrokdecode-internal.h"
  23 #include "config.h"
  24 #include <inttypes.h>
  25 #include <glib.h>
  26
  27 /**
  28  * @file
  29  *
  30  * Session handling.
  31  */
  32
  33 /**
  34  * @defgroup grp_session Session handling
  35  *
  36  * Starting and handling decoding sessions.
  37  *
  38  * @{
  39  */
  40
  41 /** @cond PRIVATE */
  42
  43 SRD_PRIV GSList *sessions = NULL;
  44 SRD_PRIV int max_session_id = -1;
  45
  46 /** @endcond */
  47
  48 /** @private */
  49 SRD_PRIV int session_is_valid(struct srd_session *sess)
  50 {
  51
  52         if (!sess || sess->session_id < 1)
  53                 return SRD_ERR;
  54
  55         return SRD_OK;
  56 }
  57
  58 /**
  59  * Create a decoding session.
  60  *
  61  * A session holds all decoder instances, their stack relationships and
  62  * output callbacks.
  63  *
  64  * @param sess A pointer which will hold a pointer to a newly
  65  *             initialized session on return.
  66  *
  67  * @return SRD_OK upon success, a (negative) error code otherwise.
  68  *
  69  * @since 0.3.0
  70  */
  71 SRD_API int srd_session_new(struct srd_session **sess)
  72 {
  73
  74         if (!sess) {
  75                 srd_err("Invalid session pointer.");
  76                 return SRD_ERR_ARG;
  77         }
  78
  79         if (!(*sess = g_try_malloc(sizeof(struct srd_session))))
  80                 return SRD_ERR_MALLOC;
  81         (*sess)->session_id = ++max_session_id;
  82         (*sess)->di_list = (*sess)->callbacks = NULL;
  83
  84         /* Keep a list of all sessions, so we can clean up as needed. */
  85         sessions = g_slist_append(sessions, *sess);
  86
  87         srd_dbg("Created session %d.", (*sess)->session_id);
  88
  89         return SRD_OK;
  90 }
  91
  92 /**
  93  * Start a decoding session.
  94  *
  95  * Decoders, instances and stack must have been prepared beforehand,
  96  * and all SRD_CONF parameters set.
  97  *
  98  * @param sess The session to start.
  99  *
 100  * @return SRD_OK upon success, a (negative) error code otherwise.
 101  *
 102  * @since 0.3.0
 103  */
 104 SRD_API int srd_session_start(struct srd_session *sess)
 105 {
 106         GSList *d;
 107         struct srd_decoder_inst *di;
 108         int ret;
 109
 110         if (session_is_valid(sess) != SRD_OK) {
 111                 srd_err("Invalid session pointer.");
 112                 return SRD_ERR;
 113         }
 114
 115         srd_dbg("Calling start() on all instances in session %d.", sess->session_id);
 116
 117         /* Run the start() method on all decoders receiving frontend data. */
 118         ret = SRD_OK;
 119         for (d = sess->di_list; d; d = d->next) {
 120                 di = d->data;
 121                 if ((ret = srd_inst_start(di)) != SRD_OK)
 122                         break;
 123         }
 124
 125         return ret;
 126 }
 127
 128 static int srd_inst_send_meta(struct srd_decoder_inst *di, int key,
 129                 GVariant *data)
 130 {
 131         PyObject *py_ret;
 132
 133         if (key != SRD_CONF_SAMPLERATE)
 134                 /* This is the only key we pass on to the decoder for now. */
 135                 return SRD_OK;
 136
 137         if (!PyObject_HasAttrString(di->py_inst, "metadata"))
 138                 /* This decoder doesn't want metadata, that's fine. */
 139                 return SRD_OK;
 140
 141         py_ret = PyObject_CallMethod(di->py_inst, "metadata", "lK",
 142                         (long)SRD_CONF_SAMPLERATE,
 143                         (unsigned long long)g_variant_get_uint64(data));
 144         Py_XDECREF(py_ret);
 145
 146         return SRD_OK;
 147 }
 148
 149 /**
 150  * Set a metadata configuration key in a session.
 151  *
 152  * @param sess The session to configure.
 153  * @param key The configuration key (SRD_CONF_*).
 154  * @param data The new value for the key, as a GVariant with GVariantType
 155  *             appropriate to that key. A floating reference can be passed
 156  *             in; its refcount will be sunk and unreferenced after use.
 157  *
 158  * @return SRD_OK upon success, a (negative) error code otherwise.
 159  *
 160  * @since 0.3.0
 161  */
 162 SRD_API int srd_session_metadata_set(struct srd_session *sess, int key,
 163                 GVariant *data)
 164 {
 165         GSList *l;
 166         int ret;
 167
 168         if (session_is_valid(sess) != SRD_OK) {
 169                 srd_err("Invalid session.");
 170                 return SRD_ERR_ARG;
 171         }
 172
 173         if (!key) {
 174                 srd_err("Invalid key.");
 175                 return SRD_ERR_ARG;
 176         }
 177
 178         if (!data) {
 179                 srd_err("Invalid value.");
 180                 return SRD_ERR_ARG;
 181         }
 182
 183         /* Hardcoded to samplerate/uint64 for now. */
 184
 185         if (key != SRD_CONF_SAMPLERATE) {
 186                 srd_err("Unknown config key %d.", key);
 187                 return SRD_ERR_ARG;
 188         }
 189         if (!g_variant_is_of_type(data, G_VARIANT_TYPE_UINT64)) {
 190                 srd_err("Invalid value type: expected uint64, got %s",
 191                                 g_variant_get_type_string(data));
 192                 return SRD_ERR_ARG;
 193         }
 194
 195         srd_dbg("Setting session %d samplerate to %"PRIu64".",
 196                         sess->session_id, g_variant_get_uint64(data));
 197
 198         ret = SRD_OK;
 199         for (l = sess->di_list; l; l = l->next) {
 200                 if ((ret = srd_inst_send_meta(l->data, key, data)) != SRD_OK)
 201                         break;
 202         }
 203
 204         g_variant_unref(data);
 205
 206         return ret;
 207 }
 208
 209 /**
 210  * Send a chunk of logic sample data to a running decoder session.
 211  *
 212  * If no channel map has been set up, the logic samples must be arranged
 213  * in channel order, in the least amount of space possible. The default
 214  * channel set consists of all required channels + all optional channels.
 215  *
 216  * The size of a sample in inbuf is the unit size passed to
 217  * srd_inst_channel_set_all(). If no channel map has been configured, it is
 218  * the minimum number of bytes needed to store the default channels.
 219  *
 220  * @param sess The session to use.
 221  * @param start_samplenum The sample number of the first sample in this chunk.
 222  * @param end_samplenum The sample number of the last sample in this chunk.
 223  * @param inbuf Pointer to sample data.
 224  * @param inbuflen Length in bytes of the buffer.
 225  *
 226  * @return SRD_OK upon success, a (negative) error code otherwise.
 227  *
 228  * @since 0.3.0
 229  */
 230 SRD_API int srd_session_send(struct srd_session *sess,
 231                 uint64_t start_samplenum, uint64_t end_samplenum,
 232                 const uint8_t *inbuf, uint64_t inbuflen)
 233 {
 234         GSList *d;
 235         int ret;
 236
 237         if (session_is_valid(sess) != SRD_OK) {
 238                 srd_err("Invalid session.");
 239                 return SRD_ERR_ARG;
 240         }
 241
 242         srd_dbg("Calling decode() on all instances with starting sample "
 243                         "number %" PRIu64 ", %" PRIu64 " bytes at 0x%p",
 244                         start_samplenum, inbuflen, inbuf);
 245
 246         for (d = sess->di_list; d; d = d->next) {
 247                 if ((ret = srd_inst_decode(d->data, start_samplenum,
 248                                 end_samplenum, inbuf, inbuflen)) != SRD_OK)
 249                         return ret;
 250         }
 251
 252         return SRD_OK;
 253 }
 254
 255 /**
 256  * Destroy a decoding session.
 257  *
 258  * All decoder instances and output callbacks are properly released.
 259  *
 260  * @param sess The session to be destroyed.
 261  *
 262  * @return SRD_OK upon success, a (negative) error code otherwise.
 263  *
 264  * @since 0.3.0
 265  */
 266 SRD_API int srd_session_destroy(struct srd_session *sess)
 267 {
 268         int session_id;
 269
 270         if (!sess) {
 271                 srd_err("Invalid session.");
 272                 return SRD_ERR_ARG;
 273         }
 274
 275         session_id = sess->session_id;
 276         if (sess->di_list)
 277                 srd_inst_free_all(sess, NULL);
 278         if (sess->callbacks)
 279                 g_slist_free_full(sess->callbacks, g_free);
 280         sessions = g_slist_remove(sessions, sess);
 281         g_free(sess);
 282
 283         srd_dbg("Destroyed session %d.", session_id);
 284
 285         return SRD_OK;
 286 }
 287
 288 /**
 289  * Register/add a decoder output callback function.
 290  *
 291  * The function will be called when a protocol decoder sends output back
 292  * to the PD controller (except for Python objects, which only go up the
 293  * stack).
 294  *
 295  * @param sess The output session in which to register the callback.
 296  * @param output_type The output type this callback will receive. Only one
 297  *                    callback per output type can be registered.
 298  * @param cb The function to call. Must not be NULL.
 299  * @param cb_data Private data for the callback function. Can be NULL.
 300  *
 301  * @since 0.3.0
 302  */
 303 SRD_API int srd_pd_output_callback_add(struct srd_session *sess,
 304                 int output_type, srd_pd_output_callback cb, void *cb_data)
 305 {
 306         struct srd_pd_callback *pd_cb;
 307
 308         if (session_is_valid(sess) != SRD_OK) {
 309                 srd_err("Invalid session.");
 310                 return SRD_ERR_ARG;
 311         }
 312
 313         srd_dbg("Registering new callback for output type %d.", output_type);
 314
 315         if (!(pd_cb = g_try_malloc(sizeof(struct srd_pd_callback)))) {
 316                 srd_err("Failed to g_malloc() struct srd_pd_callback.");
 317                 return SRD_ERR_MALLOC;
 318         }
 319
 320         pd_cb->output_type = output_type;
 321         pd_cb->cb = cb;
 322         pd_cb->cb_data = cb_data;
 323         sess->callbacks = g_slist_append(sess->callbacks, pd_cb);
 324
 325         return SRD_OK;
 326 }
 327
 328 /** @private */
 329 SRD_PRIV struct srd_pd_callback *srd_pd_output_callback_find(
 330                 struct srd_session *sess, int output_type)
 331 {
 332         GSList *l;
 333         struct srd_pd_callback *tmp, *pd_cb;
 334
 335         if (session_is_valid(sess) != SRD_OK) {
 336                 srd_err("Invalid session.");
 337                 return NULL;
 338         }
 339
 340         pd_cb = NULL;
 341         for (l = sess->callbacks; l; l = l->next) {
 342                 tmp = l->data;
 343                 if (tmp->output_type == output_type) {
 344                         pd_cb = tmp;
 345                         break;
 346                 }
 347         }
 348
 349         return pd_cb;
 350 }
 351
 352 /** @} */