src/misc/messages.c

   1 /*****************************************************************************
   2  * messages.c: messages interface
   3  * This library provides an interface to the message queue to be used by other
   4  * modules, especially intf modules. See vlc_config.h for output configuration.
   5  *****************************************************************************
   6  * Copyright (C) 1998-2005 the VideoLAN team
   7  * $Id$
   8  *
   9  * Authors: Vincent Seguin <seguin@via.ecp.fr>
  10  *          Samuel Hocevar <sam@zoy.org>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 /*****************************************************************************
  28  * Preamble
  29  *****************************************************************************/
  30
  31 #ifdef HAVE_CONFIG_H
  32 # include "config.h"
  33 #endif
  34
  35 #include <vlc_common.h>
  36
  37 #include <stdarg.h>                                       /* va_list for BSD */
  38 #ifdef __APPLE__
  39 # include <xlocale.h>
  40 #elif defined(HAVE_LOCALE_H)
  41 # include <locale.h>
  42 #endif
  43 #include <errno.h>                                                  /* errno */
  44
  45 #ifdef WIN32
  46 #   include <vlc_network.h>          /* 'net_strerror' and 'WSAGetLastError' */
  47 #endif
  48
  49 #ifdef HAVE_UNISTD_H
  50 #   include <unistd.h>                                   /* close(), write() */
  51 #endif
  52
  53 #include <assert.h>
  54
  55 #include <vlc_charset.h>
  56 #include "../libvlc.h"
  57
  58 typedef struct
  59 {
  60     int i_code;
  61     char * psz_message;
  62 } msg_context_t;
  63
  64 static void cleanup_msg_context (void *data)
  65 {
  66     msg_context_t *ctx = data;
  67     free (ctx->psz_message);
  68     free (ctx);
  69 }
  70
  71 static vlc_threadvar_t msg_context;
  72 static uintptr_t banks = 0;
  73
  74 /*****************************************************************************
  75  * Local macros
  76  *****************************************************************************/
  77 #if defined(HAVE_VA_COPY)
  78 #   define vlc_va_copy(dest,src) va_copy(dest,src)
  79 #elif defined(HAVE___VA_COPY)
  80 #   define vlc_va_copy(dest,src) __va_copy(dest,src)
  81 #else
  82 #   define vlc_va_copy(dest,src) (dest)=(src)
  83 #endif
  84
  85 static inline msg_bank_t *libvlc_bank (libvlc_int_t *inst)
  86 {
  87     return (libvlc_priv (inst))->msg_bank;
  88 }
  89
  90 /*****************************************************************************
  91  * Local prototypes
  92  *****************************************************************************/
  93 static void PrintMsg ( vlc_object_t *, msg_item_t * );
  94
  95 static vlc_mutex_t msg_stack_lock = VLC_STATIC_MUTEX;
  96
  97 /**
  98  * Store all data required by messages interfaces.
  99  */
 100 struct msg_bank_t
 101 {
 102     /** Message queue lock */
 103     vlc_rwlock_t lock;
 104
 105     /* Subscribers */
 106     int i_sub;
 107     msg_subscription_t **pp_sub;
 108
 109     locale_t locale; /**< C locale for error messages */
 110     vlc_dictionary_t enabled_objects; ///< Enabled objects
 111     bool all_objects_enabled; ///< Should we print all objects?
 112 };
 113
 114 /**
 115  * Initialize messages queues
 116  * This function initializes all message queues
 117  */
 118 msg_bank_t *msg_Create (void)
 119 {
 120     msg_bank_t *bank = malloc (sizeof (*bank));
 121
 122     vlc_rwlock_init (&bank->lock);
 123     vlc_dictionary_init (&bank->enabled_objects, 0);
 124     bank->all_objects_enabled = true;
 125
 126     bank->i_sub = 0;
 127     bank->pp_sub = NULL;
 128
 129     /* C locale to get error messages in English in the logs */
 130     bank->locale = newlocale (LC_MESSAGES_MASK, "C", (locale_t)0);
 131
 132     vlc_mutex_lock( &msg_stack_lock );
 133     if( banks++ == 0 )
 134         vlc_threadvar_create( &msg_context, cleanup_msg_context );
 135     vlc_mutex_unlock( &msg_stack_lock );
 136     return bank;
 137 }
 138
 139 /**
 140  * Object Printing selection
 141  */
 142 static void const * kObjectPrintingEnabled = &kObjectPrintingEnabled;
 143 static void const * kObjectPrintingDisabled = &kObjectPrintingDisabled;
 144
 145 #undef msg_EnableObjectPrinting
 146 void msg_EnableObjectPrinting (vlc_object_t *obj, const char * psz_object)
 147 {
 148     msg_bank_t *bank = libvlc_bank (obj->p_libvlc);
 149
 150     vlc_rwlock_wrlock (&bank->lock);
 151     if( !strcmp(psz_object, "all") )
 152         bank->all_objects_enabled = true;
 153     else
 154         vlc_dictionary_insert (&bank->enabled_objects, psz_object,
 155                                (void *)kObjectPrintingEnabled);
 156     vlc_rwlock_unlock (&bank->lock);
 157 }
 158
 159 #undef msg_DisableObjectPrinting
 160 void msg_DisableObjectPrinting (vlc_object_t *obj, const char * psz_object)
 161 {
 162     msg_bank_t *bank = libvlc_bank (obj->p_libvlc);
 163
 164     vlc_rwlock_wrlock (&bank->lock);
 165     if( !strcmp(psz_object, "all") )
 166         bank->all_objects_enabled = false;
 167     else
 168         vlc_dictionary_insert (&bank->enabled_objects, psz_object,
 169                                (void *)kObjectPrintingDisabled);
 170     vlc_rwlock_unlock (&bank->lock);
 171 }
 172
 173 /**
 174  * Destroy the message queues
 175  *
 176  * This functions prints all messages remaining in the queues,
 177  * then frees all the allocated resources
 178  * No other messages interface functions should be called after this one.
 179  */
 180 void msg_Destroy (msg_bank_t *bank)
 181 {
 182     if (unlikely(bank->i_sub != 0))
 183         fputs ("stale interface subscribers (LibVLC might crash)\n", stderr);
 184
 185     vlc_mutex_lock( &msg_stack_lock );
 186     assert(banks > 0);
 187     if( --banks == 0 )
 188         vlc_threadvar_delete( &msg_context );
 189     vlc_mutex_unlock( &msg_stack_lock );
 190
 191     if (bank->locale != (locale_t)0)
 192        freelocale (bank->locale);
 193
 194     vlc_dictionary_clear (&bank->enabled_objects, NULL, NULL);
 195
 196     vlc_rwlock_destroy (&bank->lock);
 197     free (bank);
 198 }
 199
 200 struct msg_subscription_t
 201 {
 202     libvlc_int_t   *instance;
 203     msg_callback_t  func;
 204     msg_cb_data_t  *opaque;
 205 };
 206
 207 /**
 208  * Subscribe to the message queue.
 209  * Whenever a message is emitted, a callback will be called.
 210  * Callback invocation are serialized within a subscription.
 211  *
 212  * @param instance LibVLC instance to get messages from
 213  * @param cb callback function
 214  * @param opaque data for the callback function
 215  * @return a subscription pointer, or NULL in case of failure
 216  */
 217 msg_subscription_t *msg_Subscribe (libvlc_int_t *instance, msg_callback_t cb,
 218                                    msg_cb_data_t *opaque)
 219 {
 220     msg_subscription_t *sub = malloc (sizeof (*sub));
 221     if (sub == NULL)
 222         return NULL;
 223
 224     sub->instance = instance;
 225     sub->func = cb;
 226     sub->opaque = opaque;
 227
 228     msg_bank_t *bank = libvlc_bank (instance);
 229     vlc_rwlock_wrlock (&bank->lock);
 230     TAB_APPEND (bank->i_sub, bank->pp_sub, sub);
 231     vlc_rwlock_unlock (&bank->lock);
 232
 233     return sub;
 234 }
 235
 236 /**
 237  * Unsubscribe from the message queue.
 238  * This function waits for the message callback to return if needed.
 239  */
 240 void msg_Unsubscribe (msg_subscription_t *sub)
 241 {
 242     msg_bank_t *bank = libvlc_bank (sub->instance);
 243
 244     vlc_rwlock_wrlock (&bank->lock);
 245     TAB_REMOVE (bank->i_sub, bank->pp_sub, sub);
 246     vlc_rwlock_unlock (&bank->lock);
 247     free (sub);
 248 }
 249
 250 /*****************************************************************************
 251  * msg_*: print a message
 252  *****************************************************************************
 253  * These functions queue a message for later printing.
 254  *****************************************************************************/
 255 void msg_Generic( vlc_object_t *p_this, int i_type, const char *psz_module,
 256                     const char *psz_format, ... )
 257 {
 258     va_list args;
 259
 260     va_start( args, psz_format );
 261     msg_GenericVa (p_this, i_type, psz_module, psz_format, args);
 262     va_end( args );
 263 }
 264
 265 /**
 266  * Destroys a message.
 267  */
 268 static void msg_Free (gc_object_t *gc)
 269 {
 270     msg_item_t *msg = vlc_priv (gc, msg_item_t);
 271
 272     free (msg->psz_module);
 273     free (msg->psz_msg);
 274     free (msg->psz_header);
 275     free (msg);
 276 }
 277
 278 #undef msg_GenericVa
 279 /**
 280  * Add a message to a queue
 281  *
 282  * This function provides basic functionnalities to other msg_* functions.
 283  * It adds a message to a queue (after having printed all stored messages if it
 284  * is full). If the message can't be converted to string in memory, it issues
 285  * a warning.
 286  */
 287 void msg_GenericVa (vlc_object_t *p_this, int i_type,
 288                            const char *psz_module,
 289                            const char *psz_format, va_list _args)
 290 {
 291     size_t      i_header_size;             /* Size of the additionnal header */
 292     vlc_object_t *p_obj;
 293     char *       psz_str = NULL;                 /* formatted message string */
 294     char *       psz_header = NULL;
 295     va_list      args;
 296
 297     assert (p_this);
 298
 299     if( p_this->i_flags & OBJECT_FLAGS_QUIET ||
 300         (p_this->i_flags & OBJECT_FLAGS_NODBG && i_type == VLC_MSG_DBG) )
 301         return;
 302
 303     msg_bank_t *bank = libvlc_bank (p_this->p_libvlc);
 304     locale_t locale = uselocale (bank->locale);
 305
 306 #ifndef __GLIBC__
 307     /* Expand %m to strerror(errno) - only once */
 308     char buf[strlen( psz_format ) + 2001], *ptr;
 309     strcpy( buf, psz_format );
 310     ptr = (char*)buf;
 311     psz_format = (const char*) buf;
 312
 313     for( ;; )
 314     {
 315         ptr = strchr( ptr, '%' );
 316         if( ptr == NULL )
 317             break;
 318
 319         if( ptr[1] == 'm' )
 320         {
 321             char errbuf[2001];
 322             size_t errlen;
 323
 324 #ifndef WIN32
 325             strerror_r( errno, errbuf, 1001 );
 326 #else
 327             int sockerr = WSAGetLastError( );
 328             if( sockerr )
 329             {
 330                 strncpy( errbuf, net_strerror( sockerr ), 1001 );
 331                 WSASetLastError( sockerr );
 332             }
 333             if ((sockerr == 0)
 334              || (strcmp ("Unknown network stack error", errbuf) == 0))
 335                 strncpy( errbuf, strerror( errno ), 1001 );
 336 #endif
 337             errbuf[1000] = 0;
 338
 339             /* Escape '%' from the error string */
 340             for( char *percent = strchr( errbuf, '%' );
 341                  percent != NULL;
 342                  percent = strchr( percent + 2, '%' ) )
 343             {
 344                 memmove( percent + 1, percent, strlen( percent ) + 1 );
 345             }
 346
 347             errlen = strlen( errbuf );
 348             memmove( ptr + errlen, ptr + 2, strlen( ptr + 2 ) + 1 );
 349             memcpy( ptr, errbuf, errlen );
 350             break; /* Only once, so we don't overflow */
 351         }
 352
 353         /* Looks for conversion specifier... */
 354         do
 355             ptr++;
 356         while( *ptr && ( strchr( "diouxXeEfFgGaAcspn%", *ptr ) == NULL ) );
 357         if( *ptr )
 358             ptr++; /* ...and skip it */
 359     }
 360 #endif
 361
 362     /* Convert message to string  */
 363     vlc_va_copy( args, _args );
 364     if( vasprintf( &psz_str, psz_format, args ) == -1 )
 365         psz_str = NULL;
 366     va_end( args );
 367
 368     if( psz_str == NULL )
 369     {
 370         int canc = vlc_savecancel (); /* Do not print half of a message... */
 371 #ifdef __GLIBC__
 372         fprintf( stderr, "main warning: can't store message (%m): " );
 373 #else
 374         char psz_err[1001];
 375 #ifndef WIN32
 376         /* we're not using GLIBC, so we are sure that the error description
 377          * will be stored in the buffer we provide to strerror_r() */
 378         strerror_r( errno, psz_err, 1001 );
 379 #else
 380         strncpy( psz_err, strerror( errno ), 1001 );
 381 #endif
 382         psz_err[1000] = '\0';
 383         fprintf( stderr, "main warning: can't store message (%s): ", psz_err );
 384 #endif
 385         vlc_va_copy( args, _args );
 386         /* We should use utf8_vfprintf - but it calls malloc()... */
 387         vfprintf( stderr, psz_format, args );
 388         va_end( args );
 389         fputs( "\n", stderr );
 390         vlc_restorecancel (canc);
 391         uselocale (locale);
 392         return;
 393     }
 394     uselocale (locale);
 395
 396     msg_item_t * p_item = malloc (sizeof (*p_item));
 397     if (p_item == NULL)
 398         return; /* Uho! */
 399
 400     vlc_gc_init (p_item, msg_Free);
 401     p_item->psz_module = p_item->psz_msg = p_item->psz_header = NULL;
 402
 403
 404
 405     i_header_size = 0;
 406     p_obj = p_this;
 407     while( p_obj != NULL )
 408     {
 409         char *psz_old = NULL;
 410         if( p_obj->psz_header )
 411         {
 412             i_header_size += strlen( p_obj->psz_header ) + 4;
 413             if( psz_header )
 414             {
 415                 psz_old = strdup( psz_header );
 416                 psz_header = xrealloc( psz_header, i_header_size );
 417                 snprintf( psz_header, i_header_size , "[%s] %s",
 418                           p_obj->psz_header, psz_old );
 419             }
 420             else
 421             {
 422                 psz_header = xmalloc( i_header_size );
 423                 snprintf( psz_header, i_header_size, "[%s]",
 424                           p_obj->psz_header );
 425             }
 426         }
 427         free( psz_old );
 428         p_obj = p_obj->p_parent;
 429     }
 430
 431     /* Fill message information fields */
 432     p_item->i_type =        i_type;
 433     p_item->i_object_id =   (uintptr_t)p_this;
 434     p_item->psz_object_type = p_this->psz_object_type;
 435     p_item->psz_module =    strdup( psz_module );
 436     p_item->psz_msg =       psz_str;
 437     p_item->psz_header =    psz_header;
 438
 439     PrintMsg( p_this, p_item );
 440
 441     vlc_rwlock_rdlock (&bank->lock);
 442     for (int i = 0; i < bank->i_sub; i++)
 443     {
 444         msg_subscription_t *sub = bank->pp_sub[i];
 445         sub->func (sub->opaque, p_item, 0);
 446     }
 447     vlc_rwlock_unlock (&bank->lock);
 448     msg_Release (p_item);
 449 }
 450
 451 /*****************************************************************************
 452  * PrintMsg: output a standard message item to stderr
 453  *****************************************************************************
 454  * Print a message to stderr, with colour formatting if needed.
 455  *****************************************************************************/
 456 static void PrintMsg ( vlc_object_t * p_this, msg_item_t * p_item )
 457 {
 458 #   define COL(x)  "\033[" #x ";1m"
 459 #   define RED     COL(31)
 460 #   define GREEN   COL(32)
 461 #   define YELLOW  COL(33)
 462 #   define WHITE   COL(0)
 463 #   define GRAY    "\033[0m"
 464
 465     static const char ppsz_type[4][9] = { "", " error", " warning", " debug" };
 466     static const char ppsz_color[4][8] = { WHITE, RED, YELLOW, GRAY };
 467     const char *psz_object;
 468     libvlc_priv_t *priv = libvlc_priv (p_this->p_libvlc);
 469     msg_bank_t *bank = priv->msg_bank;
 470     int i_type = p_item->i_type;
 471
 472     switch( i_type )
 473     {
 474         case VLC_MSG_ERR:
 475             if( priv->i_verbose < 0 ) return;
 476             break;
 477         case VLC_MSG_INFO:
 478             if( priv->i_verbose < 0 ) return;
 479             break;
 480         case VLC_MSG_WARN:
 481             if( priv->i_verbose < 1 ) return;
 482             break;
 483         case VLC_MSG_DBG:
 484             if( priv->i_verbose < 2 ) return;
 485             break;
 486     }
 487
 488     psz_object = p_item->psz_object_type;
 489     void * val = vlc_dictionary_value_for_key (&bank->enabled_objects,
 490                                                p_item->psz_module);
 491     if( val == kObjectPrintingDisabled )
 492         return;
 493     if( val == kObjectPrintingEnabled )
 494         /* Allowed */;
 495     else
 496     {
 497         val = vlc_dictionary_value_for_key (&bank->enabled_objects,
 498                                             psz_object);
 499         if( val == kObjectPrintingDisabled )
 500             return;
 501         if( val == kObjectPrintingEnabled )
 502             /* Allowed */;
 503         else if( !bank->all_objects_enabled )
 504             return;
 505     }
 506
 507     int canc = vlc_savecancel ();
 508     /* Send the message to stderr */
 509     utf8_fprintf( stderr, "[%s%p%s] %s%s%s %s%s: %s%s%s\n",
 510                   priv->b_color ? GREEN : "",
 511                   (void *)p_item->i_object_id,
 512                   priv->b_color ? GRAY : "",
 513                   p_item->psz_header ? p_item->psz_header : "",
 514                   p_item->psz_header ? " " : "",
 515                   p_item->psz_module, psz_object,
 516                   ppsz_type[i_type],
 517                   priv->b_color ? ppsz_color[i_type] : "",
 518                   p_item->psz_msg,
 519                   priv->b_color ? GRAY : "" );
 520
 521 #ifdef WIN32
 522     fflush( stderr );
 523 #endif
 524     vlc_restorecancel (canc);
 525 }
 526
 527 static msg_context_t* GetContext(void)
 528 {
 529     msg_context_t *p_ctx = vlc_threadvar_get( msg_context );
 530     if( p_ctx == NULL )
 531     {
 532         p_ctx = malloc( sizeof( msg_context_t ) );
 533         if( !p_ctx )
 534             return NULL;
 535         p_ctx->psz_message = NULL;
 536         vlc_threadvar_set( msg_context, p_ctx );
 537     }
 538     return p_ctx;
 539 }
 540
 541 void msg_StackSet( int i_code, const char *psz_message, ... )
 542 {
 543     va_list ap;
 544     msg_context_t *p_ctx = GetContext();
 545
 546     if( p_ctx == NULL )
 547         return;
 548     free( p_ctx->psz_message );
 549
 550     va_start( ap, psz_message );
 551     if( vasprintf( &p_ctx->psz_message, psz_message, ap ) == -1 )
 552         p_ctx->psz_message = NULL;
 553     va_end( ap );
 554
 555     p_ctx->i_code = i_code;
 556 }
 557
 558 void msg_StackAdd( const char *psz_message, ... )
 559 {
 560     char *psz_tmp;
 561     va_list ap;
 562     msg_context_t *p_ctx = GetContext();
 563
 564     if( p_ctx == NULL )
 565         return;
 566
 567     va_start( ap, psz_message );
 568     if( vasprintf( &psz_tmp, psz_message, ap ) == -1 )
 569         psz_tmp = NULL;
 570     va_end( ap );
 571
 572     if( !p_ctx->psz_message )
 573         p_ctx->psz_message = psz_tmp;
 574     else
 575     {
 576         char *psz_new;
 577         if( asprintf( &psz_new, "%s: %s", psz_tmp, p_ctx->psz_message ) == -1 )
 578             psz_new = NULL;
 579
 580         free( p_ctx->psz_message );
 581         p_ctx->psz_message = psz_new;
 582         free( psz_tmp );
 583     }
 584 }
 585
 586 const char* msg_StackMsg( void )
 587 {
 588     msg_context_t *p_ctx = GetContext();
 589     assert( p_ctx );
 590     return p_ctx->psz_message;
 591 }