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 /*****************************************************************************
  59  * Local macros
  60  *****************************************************************************/
  61 #if defined(HAVE_VA_COPY)
  62 #   define vlc_va_copy(dest,src) va_copy(dest,src)
  63 #elif defined(HAVE___VA_COPY)
  64 #   define vlc_va_copy(dest,src) __va_copy(dest,src)
  65 #else
  66 #   define vlc_va_copy(dest,src) (dest)=(src)
  67 #endif
  68
  69 static inline msg_bank_t *libvlc_bank (libvlc_int_t *inst)
  70 {
  71     return (libvlc_priv (inst))->msg_bank;
  72 }
  73
  74 /*****************************************************************************
  75  * Local prototypes
  76  *****************************************************************************/
  77 static void PrintMsg ( vlc_object_t *, const msg_item_t * );
  78
  79 /**
  80  * Store all data required by messages interfaces.
  81  */
  82 struct msg_bank_t
  83 {
  84     /** Message queue lock */
  85     vlc_rwlock_t lock;
  86
  87     /* Subscribers */
  88     int i_sub;
  89     msg_subscription_t **pp_sub;
  90
  91     locale_t locale; /**< C locale for error messages */
  92     vlc_dictionary_t enabled_objects; ///< Enabled objects
  93     bool all_objects_enabled; ///< Should we print all objects?
  94 };
  95
  96 /**
  97  * Initialize messages queues
  98  * This function initializes all message queues
  99  */
 100 msg_bank_t *msg_Create (void)
 101 {
 102     msg_bank_t *bank = malloc (sizeof (*bank));
 103
 104     vlc_rwlock_init (&bank->lock);
 105     vlc_dictionary_init (&bank->enabled_objects, 0);
 106     bank->all_objects_enabled = true;
 107
 108     bank->i_sub = 0;
 109     bank->pp_sub = NULL;
 110
 111     /* C locale to get error messages in English in the logs */
 112     bank->locale = newlocale (LC_MESSAGES_MASK, "C", (locale_t)0);
 113     return bank;
 114 }
 115
 116 /**
 117  * Object Printing selection
 118  */
 119 static void const * kObjectPrintingEnabled = &kObjectPrintingEnabled;
 120 static void const * kObjectPrintingDisabled = &kObjectPrintingDisabled;
 121
 122
 123 #undef msg_EnableObjectPrinting
 124 void msg_EnableObjectPrinting (vlc_object_t *obj, const char * psz_object)
 125 {
 126     msg_bank_t *bank = libvlc_bank (obj->p_libvlc);
 127
 128     vlc_rwlock_wrlock (&bank->lock);
 129     if( !strcmp(psz_object, "all") )
 130         bank->all_objects_enabled = true;
 131     else
 132         vlc_dictionary_insert (&bank->enabled_objects, psz_object,
 133                                (void *)kObjectPrintingEnabled);
 134     vlc_rwlock_unlock (&bank->lock);
 135 }
 136
 137 #undef msg_DisableObjectPrinting
 138 void msg_DisableObjectPrinting (vlc_object_t *obj, const char * psz_object)
 139 {
 140     msg_bank_t *bank = libvlc_bank (obj->p_libvlc);
 141
 142     vlc_rwlock_wrlock (&bank->lock);
 143     if( !strcmp(psz_object, "all") )
 144         bank->all_objects_enabled = false;
 145     else
 146         vlc_dictionary_insert (&bank->enabled_objects, psz_object,
 147                                (void *)kObjectPrintingDisabled);
 148     vlc_rwlock_unlock (&bank->lock);
 149 }
 150
 151 /**
 152  * Destroy the message queues
 153  *
 154  * This functions prints all messages remaining in the queues,
 155  * then frees all the allocated resources
 156  * No other messages interface functions should be called after this one.
 157  */
 158 void msg_Destroy (msg_bank_t *bank)
 159 {
 160     if (unlikely(bank->i_sub != 0))
 161         fputs ("stale interface subscribers (LibVLC might crash)\n", stderr);
 162
 163     if (bank->locale != (locale_t)0)
 164        freelocale (bank->locale);
 165
 166     vlc_dictionary_clear (&bank->enabled_objects, NULL, NULL);
 167
 168     vlc_rwlock_destroy (&bank->lock);
 169     free (bank);
 170 }
 171
 172 struct msg_subscription_t
 173 {
 174     libvlc_int_t   *instance;
 175     msg_callback_t  func;
 176     msg_cb_data_t  *opaque;
 177     int             verbosity;
 178 };
 179
 180 /**
 181  * Subscribe to the message queue.
 182  * Whenever a message is emitted, a callback will be called.
 183  * Callback invocation are serialized within a subscription.
 184  *
 185  * @param instance LibVLC instance to get messages from
 186  * @param cb callback function
 187  * @param opaque data for the callback function
 188  * @return a subscription pointer, or NULL in case of failure
 189  */
 190 msg_subscription_t *msg_Subscribe (libvlc_int_t *instance, msg_callback_t cb,
 191                                    msg_cb_data_t *opaque)
 192 {
 193     msg_subscription_t *sub = malloc (sizeof (*sub));
 194     if (sub == NULL)
 195         return NULL;
 196
 197     sub->instance = instance;
 198     sub->func = cb;
 199     sub->opaque = opaque;
 200     sub->verbosity = 2; /* by default, give all the messages */
 201
 202     msg_bank_t *bank = libvlc_bank (instance);
 203     vlc_rwlock_wrlock (&bank->lock);
 204     TAB_APPEND (bank->i_sub, bank->pp_sub, sub);
 205     vlc_rwlock_unlock (&bank->lock);
 206
 207     return sub;
 208 }
 209
 210 /**
 211  * Unsubscribe from the message queue.
 212  * This function waits for the message callback to return if needed.
 213  */
 214 void msg_Unsubscribe (msg_subscription_t *sub)
 215 {
 216     msg_bank_t *bank = libvlc_bank (sub->instance);
 217
 218     vlc_rwlock_wrlock (&bank->lock);
 219     TAB_REMOVE (bank->i_sub, bank->pp_sub, sub);
 220     vlc_rwlock_unlock (&bank->lock);
 221     free (sub);
 222 }
 223
 224 void msg_SubscriptionSetVerbosity( msg_subscription_t *sub, const int i_verbosity )
 225 {
 226     if( i_verbosity < 0 || i_verbosity > 2 ) return;
 227
 228     msg_bank_t *bank = libvlc_bank ( sub->instance );
 229
 230     vlc_rwlock_wrlock (&bank->lock);
 231
 232     sub->verbosity = i_verbosity;
 233
 234     vlc_rwlock_unlock (&bank->lock);
 235 }
 236 /*****************************************************************************
 237  * msg_*: print a message
 238  *****************************************************************************
 239  * These functions queue a message for later printing.
 240  *****************************************************************************/
 241 void msg_Generic( vlc_object_t *p_this, int i_type, const char *psz_module,
 242                     const char *psz_format, ... )
 243 {
 244     va_list args;
 245
 246     va_start( args, psz_format );
 247     msg_GenericVa (p_this, i_type, psz_module, psz_format, args);
 248     va_end( args );
 249 }
 250
 251 #undef msg_GenericVa
 252 /**
 253  * Add a message to a queue
 254  *
 255  * This function provides basic functionnalities to other msg_* functions.
 256  * It adds a message to a queue (after having printed all stored messages if it
 257  * is full). If the message can't be converted to string in memory, it issues
 258  * a warning.
 259  */
 260 void msg_GenericVa (vlc_object_t *p_this, int i_type,
 261                            const char *psz_module,
 262                            const char *psz_format, va_list _args)
 263 {
 264     char *       psz_str = NULL;                 /* formatted message string */
 265     va_list      args;
 266
 267     assert (p_this);
 268
 269     if( p_this->i_flags & OBJECT_FLAGS_QUIET ||
 270         (p_this->i_flags & OBJECT_FLAGS_NODBG && i_type == VLC_MSG_DBG) )
 271         return;
 272
 273     msg_bank_t *bank = libvlc_bank (p_this->p_libvlc);
 274     locale_t locale = uselocale (bank->locale);
 275
 276 #ifndef __GLIBC__
 277     /* Expand %m to strerror(errno) - only once */
 278     char buf[strlen( psz_format ) + 2001], *ptr;
 279     strcpy( buf, psz_format );
 280     ptr = (char*)buf;
 281     psz_format = (const char*) buf;
 282
 283     for( ;; )
 284     {
 285         ptr = strchr( ptr, '%' );
 286         if( ptr == NULL )
 287             break;
 288
 289         if( ptr[1] == 'm' )
 290         {
 291             char errbuf[2001];
 292             size_t errlen;
 293
 294 #ifndef WIN32
 295             strerror_r( errno, errbuf, 1001 );
 296 #else
 297             int sockerr = WSAGetLastError( );
 298             if( sockerr )
 299             {
 300                 strncpy( errbuf, net_strerror( sockerr ), 1001 );
 301                 WSASetLastError( sockerr );
 302             }
 303             if ((sockerr == 0)
 304              || (strcmp ("Unknown network stack error", errbuf) == 0))
 305                 strncpy( errbuf, strerror( errno ), 1001 );
 306 #endif
 307             errbuf[1000] = 0;
 308
 309             /* Escape '%' from the error string */
 310             for( char *percent = strchr( errbuf, '%' );
 311                  percent != NULL;
 312                  percent = strchr( percent + 2, '%' ) )
 313             {
 314                 memmove( percent + 1, percent, strlen( percent ) + 1 );
 315             }
 316
 317             errlen = strlen( errbuf );
 318             memmove( ptr + errlen, ptr + 2, strlen( ptr + 2 ) + 1 );
 319             memcpy( ptr, errbuf, errlen );
 320             break; /* Only once, so we don't overflow */
 321         }
 322
 323         /* Looks for conversion specifier... */
 324         do
 325             ptr++;
 326         while( *ptr && ( strchr( "diouxXeEfFgGaAcspn%", *ptr ) == NULL ) );
 327         if( *ptr )
 328             ptr++; /* ...and skip it */
 329     }
 330 #endif
 331
 332     /* Convert message to string  */
 333     vlc_va_copy( args, _args );
 334     if( vasprintf( &psz_str, psz_format, args ) == -1 )
 335         psz_str = NULL;
 336     va_end( args );
 337
 338     if( psz_str == NULL )
 339     {
 340         int canc = vlc_savecancel (); /* Do not print half of a message... */
 341 #ifdef __GLIBC__
 342         fprintf( stderr, "main warning: can't store message (%m): " );
 343 #else
 344         char psz_err[1001];
 345 #ifndef WIN32
 346         /* we're not using GLIBC, so we are sure that the error description
 347          * will be stored in the buffer we provide to strerror_r() */
 348         strerror_r( errno, psz_err, 1001 );
 349 #else
 350         strncpy( psz_err, strerror( errno ), 1001 );
 351 #endif
 352         psz_err[1000] = '\0';
 353         fprintf( stderr, "main warning: can't store message (%s): ", psz_err );
 354 #endif
 355         vlc_va_copy( args, _args );
 356         /* We should use utf8_vfprintf - but it calls malloc()... */
 357         vfprintf( stderr, psz_format, args );
 358         va_end( args );
 359         fputs( "\n", stderr );
 360         vlc_restorecancel (canc);
 361         uselocale (locale);
 362         return;
 363     }
 364     uselocale (locale);
 365
 366     /* Fill message information fields */
 367     msg_item_t msg;
 368
 369     msg.i_type = i_type;
 370     msg.i_object_id = (uintptr_t)p_this;
 371     msg.psz_object_type = p_this->psz_object_type;
 372     msg.psz_module = psz_module;
 373     msg.psz_msg = psz_str;
 374     msg.psz_header = NULL;
 375
 376     for (vlc_object_t *o = p_this; o != NULL; o = o->p_parent)
 377         if (o->psz_header != NULL)
 378         {
 379             msg.psz_header = o->psz_header;
 380             break;
 381         }
 382
 383     PrintMsg( p_this, &msg );
 384
 385     vlc_rwlock_rdlock (&bank->lock);
 386     for (int i = 0; i < bank->i_sub; i++)
 387     {
 388         msg_subscription_t *sub = bank->pp_sub[i];
 389         libvlc_priv_t *priv = libvlc_priv( sub->instance );
 390         msg_bank_t *bank = priv->msg_bank;
 391         void *val = vlc_dictionary_value_for_key( &bank->enabled_objects,
 392                                                   msg.psz_module );
 393         if( val == kObjectPrintingDisabled ) continue;
 394         if( val != kObjectPrintingEnabled  ) /*if not allowed */
 395         {
 396             val = vlc_dictionary_value_for_key( &bank->enabled_objects,
 397                                                 msg.psz_object_type );
 398             if( val == kObjectPrintingDisabled ) continue;
 399             if( val == kObjectPrintingEnabled  ); /* Allowed */
 400             else if( !bank->all_objects_enabled ) continue;
 401         }
 402         switch( msg.i_type )
 403         {
 404             case VLC_MSG_INFO:
 405             case VLC_MSG_ERR:
 406                 if( sub->verbosity < 0 ) continue;
 407                 break;
 408             case VLC_MSG_WARN:
 409                 if( sub->verbosity < 1 ) continue;
 410                 break;
 411             case VLC_MSG_DBG:
 412                 if( sub->verbosity < 2 ) continue;
 413                 break;
 414         }
 415
 416         sub->func (sub->opaque, &msg);
 417     }
 418     vlc_rwlock_unlock (&bank->lock);
 419     free (msg.psz_msg);
 420 }
 421
 422 /*****************************************************************************
 423  * PrintMsg: output a standard message item to stderr
 424  *****************************************************************************
 425  * Print a message to stderr, with colour formatting if needed.
 426  *****************************************************************************/
 427 static void PrintMsg ( vlc_object_t *p_this, const msg_item_t *p_item )
 428 {
 429 #   define COL(x,y)  "\033[" #x ";" #y "m"
 430 #   define RED     COL(31,1)
 431 #   define GREEN   COL(32,1)
 432 #   define YELLOW  COL(0,33)
 433 #   define WHITE   COL(0,1)
 434 #   define GRAY    "\033[0m"
 435     static const char msgtype[4][9] = { "", " error", " warning", " debug" };
 436     static const char msgcolor[4][8] = { WHITE, RED, YELLOW, GRAY };
 437
 438     libvlc_priv_t *priv = libvlc_priv (p_this->p_libvlc);
 439     int type = p_item->i_type;
 440
 441     if (priv->i_verbose < 0 || priv->i_verbose < (type - VLC_MSG_ERR))
 442         return;
 443
 444     const char *objtype = p_item->psz_object_type;
 445     msg_bank_t *bank = priv->msg_bank;
 446     void * val = vlc_dictionary_value_for_key (&bank->enabled_objects,
 447                                                p_item->psz_module);
 448     if( val == kObjectPrintingDisabled )
 449         return;
 450     if( val == kObjectPrintingEnabled )
 451         /* Allowed */;
 452     else
 453     {
 454         val = vlc_dictionary_value_for_key (&bank->enabled_objects,
 455                                             objtype);
 456         if( val == kObjectPrintingDisabled )
 457             return;
 458         if( val == kObjectPrintingEnabled )
 459             /* Allowed */;
 460         else if( !bank->all_objects_enabled )
 461             return;
 462     }
 463
 464     /* Send the message to stderr */
 465     FILE *stream = stderr;
 466     int canc = vlc_savecancel ();
 467
 468     flockfile (stream);
 469     fprintf (stream, priv->b_color ? "["GREEN"%p"GRAY"] " : "[%p] ",
 470             (void *)p_item->i_object_id);
 471     if (p_item->psz_header != NULL)
 472         utf8_fprintf (stream, "[%s] ", p_item->psz_header);
 473     utf8_fprintf (stream, "%s %s%s: ", p_item->psz_module, objtype,
 474                   msgtype[type]);
 475     if (priv->b_color)
 476         fputs (msgcolor[type], stream);
 477     fputs (p_item->psz_msg, stream);
 478     if (priv->b_color)
 479         fputs (GRAY, stream);
 480     putc_unlocked ('\n', stream);
 481 #if defined (WIN32) || defined (__OS2__)
 482     fflush (stream);
 483 #endif
 484     funlockfile (stream);
 485     vlc_restorecancel (canc);
 486 }