modules/misc/webservices/acoustid.c

   1 /*****************************************************************************
   2  * acoustid.c: AcoustId webservice parser
   3  *****************************************************************************
   4  * Copyright (C) 2012 VLC authors and VideoLAN
   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 <vlc_common.h>
  26 #include <vlc_stream.h>
  27 #include <limits.h>
  28 #include <vlc_memory.h>
  29
  30 #include <vlc/vlc.h>
  31 #include "acoustid.h"
  32 #include "json.h"
  33
  34 /*****************************************************************************
  35  * Requests lifecycle
  36  *****************************************************************************/
  37 void free_acoustid_result_t( acoustid_result_t * r )
  38 {
  39     free( r->psz_id );
  40     for ( unsigned int i=0; i<r->recordings.count; i++ )
  41     {
  42         free( r->recordings.p_recordings[ i ].psz_artist );
  43         free( r->recordings.p_recordings[ i ].psz_title );
  44     }
  45     free( r->recordings.p_recordings );
  46 }
  47
  48 static json_value * jsongetbyname( json_value *object, const char *psz_name )
  49 {
  50     if ( object->type != json_object ) return NULL;
  51     for ( unsigned int i=0; i < object->u.object.length; i++ )
  52         if ( strcmp( object->u.object.values[i].name, psz_name ) == 0 )
  53             return object->u.object.values[i].value;
  54     return NULL;
  55 }
  56
  57 static void parse_artists( json_value *node, musicbrainz_recording_t *record )
  58 {
  59     /* take only main */
  60     if ( !node || node->type != json_array || node->u.array.length < 1 ) return;
  61     json_value *artistnode = node->u.array.values[ 0 ];
  62     json_value *value = jsongetbyname( artistnode, "name" );
  63     if ( value && value->type == json_string )
  64         record->psz_artist = strdup( value->u.string.ptr );
  65 }
  66
  67 static void parse_recordings( vlc_object_t *p_obj, json_value *node, acoustid_result_t *p_result )
  68 {
  69     if ( !node || node->type != json_array ) return;
  70     p_result->recordings.p_recordings = calloc( node->u.array.length, sizeof(musicbrainz_recording_t) );
  71     if ( ! p_result->recordings.p_recordings ) return;
  72     p_result->recordings.count = node->u.array.length;
  73
  74     for( unsigned int i=0; i<node->u.array.length; i++ )
  75     {
  76         musicbrainz_recording_t *record = & p_result->recordings.p_recordings[ i ];
  77         json_value *recordnode = node->u.array.values[ i ];
  78         if ( !recordnode || recordnode->type != json_object ) break;
  79         json_value *value = jsongetbyname( recordnode, "title" );
  80         if ( value && value->type == json_string )
  81             record->psz_title = strdup( value->u.string.ptr );
  82         value = jsongetbyname( recordnode, "id" );
  83         if ( value && value->type == json_string )
  84         {
  85             size_t i_len = strlen( value->u.string.ptr );
  86             i_len = __MIN( i_len, MB_ID_SIZE );
  87             memcpy( record->s_musicbrainz_id, value->u.string.ptr, i_len );
  88         }
  89         parse_artists( jsongetbyname( recordnode, "artists" ), record );
  90         msg_Dbg( p_obj, "recording %d title %s %36s %s", i, record->psz_title, record->s_musicbrainz_id, record->psz_artist );
  91     }
  92 }
  93
  94 static bool ParseJson( vlc_object_t *p_obj, char *psz_buffer, acoustid_results_t *p_results )
  95 {
  96     json_settings settings;
  97     char psz_error[128];
  98     memset (&settings, 0, sizeof (json_settings));
  99     json_value *root = json_parse_ex( &settings, psz_buffer, psz_error );
 100     if ( root == NULL )
 101     {
 102         msg_Warn( p_obj, "Can't parse json data: %s", psz_error );
 103         goto error;
 104     }
 105     if ( root->type != json_object )
 106     {
 107         msg_Warn( p_obj, "wrong json root node" );
 108         goto error;
 109     }
 110     json_value *node = jsongetbyname( root, "status" );
 111     if ( !node || node->type != json_string )
 112     {
 113         msg_Warn( p_obj, "status node not found or invalid" );
 114         goto error;
 115     }
 116     if ( strcmp( node->u.string.ptr, "ok" ) != 0 )
 117     {
 118         msg_Warn( p_obj, "Bad request status" );
 119         goto error;
 120     }
 121     node = jsongetbyname( root, "results" );
 122     if ( !node || node->type != json_array )
 123     {
 124         msg_Warn( p_obj, "Bad results array or no results" );
 125         goto error;
 126     }
 127     p_results->p_results = calloc( node->u.array.length, sizeof(acoustid_result_t) );
 128     if ( ! p_results->p_results ) goto error;
 129     p_results->count = node->u.array.length;
 130     for( unsigned int i=0; i<node->u.array.length; i++ )
 131     {
 132         json_value *resultnode = node->u.array.values[i];
 133         if ( resultnode && resultnode->type == json_object )
 134         {
 135             acoustid_result_t *p_result = & p_results->p_results[i];
 136             json_value *value = jsongetbyname( resultnode, "score" );
 137             if ( value && value->type == json_double )
 138                 p_result->d_score = value->u.dbl;
 139             value = jsongetbyname( resultnode, "id" );
 140             if ( value && value->type == json_string )
 141                 p_result->psz_id = strdup( value->u.string.ptr );
 142             parse_recordings( p_obj, jsongetbyname( resultnode, "recordings" ), p_result );
 143         }
 144     }
 145     json_value_free( root );
 146     return true;
 147
 148 error:
 149     if ( root ) json_value_free( root );
 150     return false;
 151 }
 152
 153 int DoAcoustIdWebRequest( vlc_object_t *p_obj, acoustid_fingerprint_t *p_data )
 154 {
 155     if ( !p_data->psz_fingerprint ) return VLC_SUCCESS;
 156
 157     char *psz_url;
 158     if( unlikely(asprintf( &psz_url, "https://fingerprint.videolan.org/"
 159                            "acoustid.php?meta=recordings+tracks+usermeta+"
 160                            "releases&duration=%d&fingerprint=%s",
 161                            p_data->i_duration, p_data->psz_fingerprint ) < 1 ) )
 162          return VLC_EGENERIC;
 163
 164     msg_Dbg( p_obj, "Querying AcoustID from %s", psz_url );
 165     int i_saved_flags = p_obj->obj.flags;
 166     p_obj->obj.flags |= OBJECT_FLAGS_NOINTERACT;
 167
 168     stream_t *p_stream = vlc_stream_NewURL( p_obj, psz_url );
 169
 170     free( psz_url );
 171     p_obj->obj.flags = i_saved_flags;
 172     if ( p_stream == NULL )
 173         return VLC_EGENERIC;
 174
 175     stream_t *p_chain = vlc_stream_FilterNew( p_stream, "inflate" );
 176     if( p_chain )
 177         p_stream = p_chain;
 178
 179     /* read answer */
 180     char *p_buffer = NULL;
 181     int i_ret = 0;
 182     for( ;; )
 183     {
 184         int i_read = 65536;
 185
 186         if( i_ret >= INT_MAX - i_read )
 187             break;
 188
 189         p_buffer = realloc_or_free( p_buffer, 1 + i_ret + i_read );
 190         if( unlikely(p_buffer == NULL) )
 191         {
 192             vlc_stream_Delete( p_stream );
 193             return VLC_ENOMEM;
 194         }
 195
 196         i_read = vlc_stream_Read( p_stream, &p_buffer[i_ret], i_read );
 197         if( i_read <= 0 )
 198             break;
 199
 200         i_ret += i_read;
 201     }
 202     vlc_stream_Delete( p_stream );
 203     p_buffer[i_ret] = 0;
 204
 205     if ( ParseJson( p_obj, p_buffer, & p_data->results ) )
 206         msg_Dbg( p_obj, "results count == %d", p_data->results.count );
 207     else
 208         msg_Dbg( p_obj, "No results" );
 209
 210     return VLC_SUCCESS;
 211 }