modules/access/concat.c

   1 /*****************************************************************************
   2  * concat.c: Concatenated inputs
   3  *****************************************************************************
   4  * Copyright (C) 2015 Rémi Denis-Courmont
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include "config.h"
  23 #endif
  24
  25 #include <assert.h>
  26 #include <stdint.h>
  27
  28 #include <vlc_common.h>
  29 #include <vlc_plugin.h>
  30 #include <vlc_access.h>
  31
  32 struct access_entry
  33 {
  34     struct access_entry *next;
  35     char mrl[1];
  36 };
  37
  38 typedef struct
  39 {
  40     stream_t *access;
  41     struct access_entry *next;
  42     struct access_entry *first;
  43     bool can_seek;
  44     bool can_seek_fast;
  45     bool can_pause;
  46     bool can_control_pace;
  47     uint64_t size;
  48     vlc_tick_t caching;
  49 } access_sys_t;
  50
  51 static stream_t *GetAccess(stream_t *access)
  52 {
  53     access_sys_t *sys = access->p_sys;
  54     stream_t *a = sys->access;
  55
  56     if (a != NULL)
  57     {
  58         if (!vlc_stream_Eof(a))
  59             return a;
  60
  61         vlc_stream_Delete(a);
  62         sys->access = NULL;
  63     }
  64
  65     if (sys->next == NULL)
  66         return NULL;
  67
  68     a = vlc_access_NewMRL(VLC_OBJECT(access), sys->next->mrl);
  69     if (a == NULL)
  70         return NULL;
  71
  72     sys->access = a;
  73     sys->next = sys->next->next;
  74     return a;
  75 }
  76
  77 static ssize_t Read(stream_t *access, void *buf, size_t len)
  78 {
  79     stream_t *a = GetAccess(access);
  80     if (a == NULL)
  81         return 0;
  82
  83     /* NOTE: Since we recreate the underlying access, the access method can
  84      * change. We need to check it. For instance, a path could point to a
  85      * regular file during Open() yet point to a directory here and now. */
  86     if (unlikely(a->pf_read == NULL))
  87         return 0;
  88
  89     return vlc_stream_ReadPartial(a, buf, len);
  90 }
  91
  92 static block_t *Block(stream_t *access, bool *restrict eof)
  93 {
  94     stream_t *a = GetAccess(access);
  95     if (a == NULL)
  96     {
  97         *eof = true;
  98         return NULL;
  99     }
 100
 101     return vlc_stream_ReadBlock(a);
 102 }
 103
 104 static int Seek(stream_t *access, uint64_t position)
 105 {
 106     access_sys_t *sys = access->p_sys;
 107
 108     if (sys->access != NULL)
 109     {
 110         vlc_stream_Delete(sys->access);
 111         sys->access = NULL;
 112     }
 113
 114     sys->next = sys->first;
 115
 116     for (uint64_t offset = 0;;)
 117     {
 118         stream_t *a = GetAccess(access);
 119         if (a == NULL)
 120             break;
 121
 122         bool can_seek;
 123         vlc_stream_Control(a, STREAM_CAN_SEEK, &can_seek);
 124         if (!can_seek)
 125             break;
 126
 127         uint64_t size;
 128
 129         if (vlc_stream_GetSize(a, &size))
 130             break;
 131         if (position - offset < size)
 132         {
 133             if (vlc_stream_Seek(a, position - offset))
 134                 break;
 135             return VLC_SUCCESS;
 136         }
 137
 138         offset += size;
 139         vlc_stream_Delete(a);
 140         sys->access = NULL;
 141     }
 142
 143     return VLC_EGENERIC;
 144 }
 145
 146 static int Control(stream_t *access, int query, va_list args)
 147 {
 148     access_sys_t *sys = access->p_sys;
 149
 150     switch (query)
 151     {
 152         case STREAM_CAN_SEEK:
 153             *va_arg(args, bool *) = sys->can_seek;
 154             break;
 155         case STREAM_CAN_FASTSEEK:
 156             *va_arg(args, bool *) = sys->can_seek_fast;
 157             break;
 158         case STREAM_CAN_PAUSE:
 159             *va_arg(args, bool *) = sys->can_pause;
 160             break;
 161         case STREAM_CAN_CONTROL_PACE:
 162             *va_arg(args, bool *) = sys->can_control_pace;
 163             break;
 164         case STREAM_GET_SIZE:
 165             if (sys->size == UINT64_MAX)
 166                 return VLC_EGENERIC;
 167             *va_arg(args, uint64_t *) = sys->size;
 168             break;
 169         case STREAM_GET_PTS_DELAY:
 170             *va_arg(args, vlc_tick_t *) = sys->caching;
 171             break;
 172
 173         case STREAM_GET_SIGNAL:
 174         case STREAM_SET_PAUSE_STATE:
 175             return vlc_stream_vaControl(sys->access, query, args);
 176
 177         default:
 178             return VLC_EGENERIC;
 179     }
 180     return VLC_SUCCESS;
 181 }
 182
 183 static int Open(vlc_object_t *obj)
 184 {
 185     stream_t *access = (stream_t *)obj;
 186
 187     char *list = var_CreateGetNonEmptyString(access, "concat-list");
 188     if (list == NULL)
 189         return VLC_EGENERIC;
 190
 191     access_sys_t *sys = vlc_obj_malloc(obj, sizeof (*sys));
 192     if (unlikely(sys == NULL))
 193     {
 194         free(list);
 195         return VLC_ENOMEM;
 196     }
 197
 198     var_SetString(access, "concat-list", ""); /* prevent recursion */
 199
 200     bool read_cb = true;
 201
 202     sys->access = NULL;
 203     sys->can_seek = true;
 204     sys->can_seek_fast = true;
 205     sys->can_pause = true;
 206     sys->can_control_pace = true;
 207     sys->size = 0;
 208     sys->caching = 0;
 209
 210     struct access_entry **pp = &sys->first;
 211
 212     for (char *buf, *mrl = strtok_r(list, ",", &buf);
 213          mrl != NULL;
 214          mrl = strtok_r(NULL, ",", &buf))
 215     {
 216         size_t mlen = strlen(mrl);
 217         struct access_entry *e = malloc(sizeof (*e) + mlen);
 218         if (unlikely(e == NULL))
 219             break;
 220
 221         stream_t *a = vlc_access_NewMRL(obj, mrl);
 222         if (a == NULL)
 223         {
 224             msg_Err(access, "cannot concatenate location %s", mrl);
 225             free(e);
 226             continue;
 227         }
 228
 229         if (a->pf_read == NULL)
 230         {
 231             if (a->pf_block == NULL)
 232             {
 233                 msg_Err(access, "cannot concatenate directory %s", mrl);
 234                 vlc_stream_Delete(a);
 235                 free(e);
 236                 continue;
 237             }
 238             read_cb = false;
 239         }
 240
 241         *pp = e;
 242         e->next = NULL;
 243         memcpy(e->mrl, mrl, mlen + 1);
 244
 245         if (sys->can_seek)
 246             vlc_stream_Control(a, STREAM_CAN_SEEK, &sys->can_seek);
 247         if (sys->can_seek_fast)
 248             vlc_stream_Control(a, STREAM_CAN_FASTSEEK, &sys->can_seek_fast);
 249         if (sys->can_pause)
 250             vlc_stream_Control(a, STREAM_CAN_PAUSE, &sys->can_pause);
 251         if (sys->can_control_pace)
 252             vlc_stream_Control(a, STREAM_CAN_CONTROL_PACE,
 253                                &sys->can_control_pace);
 254         if (sys->size != UINT64_MAX)
 255         {
 256             uint64_t size;
 257
 258             if (vlc_stream_GetSize(a, &size))
 259                 sys->size = UINT64_MAX;
 260             else
 261                 sys->size += size;
 262         }
 263
 264         vlc_tick_t caching;
 265         vlc_stream_Control(a, STREAM_GET_PTS_DELAY, &caching);
 266         if (caching > sys->caching)
 267             sys->caching = caching;
 268
 269         vlc_stream_Delete(a);
 270         pp = &e->next;
 271     }
 272
 273     free(list);
 274     *pp = NULL;
 275     sys->next = sys->first;
 276
 277     access->pf_read = read_cb ? Read : NULL;
 278     access->pf_block = read_cb ? NULL : Block;
 279     access->pf_seek = Seek;
 280     access->pf_control = Control;
 281     access->p_sys = sys;
 282
 283     return VLC_SUCCESS;
 284 }
 285
 286 static void Close(vlc_object_t *obj)
 287 {
 288     stream_t *access = (stream_t *)obj;
 289     access_sys_t *sys = access->p_sys;
 290
 291     if (sys->access != NULL)
 292         vlc_stream_Delete(sys->access);
 293
 294     for (struct access_entry *e = sys->first, *next; e != NULL; e = next)
 295     {
 296         next = e->next;
 297         free(e);
 298     }
 299
 300     var_Destroy(access, "concat-list");
 301 }
 302
 303 #define INPUT_LIST_TEXT N_("Inputs list")
 304 #define INPUT_LIST_LONGTEXT N_( \
 305     "Comma-separated list of input URLs to concatenate.")
 306
 307 vlc_module_begin()
 308     set_shortname(N_("Concatenation"))
 309     set_description(N_("Concatenated inputs"))
 310     set_category(CAT_INPUT)
 311     set_subcategory(SUBCAT_INPUT_ACCESS)
 312     add_string("concat-list", NULL, INPUT_LIST_TEXT, INPUT_LIST_LONGTEXT, true)
 313     set_capability("access", 0)
 314     set_callbacks(Open, Close)
 315     add_shortcut("concast", "list")
 316 vlc_module_end()