json_helper: get the size of the read buffer

modules/misc/webservices/acoustid.c

@@ -74,9 +74,10 @@ static void parse_recordings( vlc_object_t *p_obj, const json_value *node, acous
     }
 }
 
-static bool ParseJson( vlc_object_t *p_obj, const void *p_buffer, acoustid_results_t *p_results )
+static bool ParseJson( vlc_object_t *p_obj, const void *p_buffer, size_t i_buffer,
+                       acoustid_results_t *p_results )
 {
-    json_value *root = json_parse_document( p_obj, p_buffer );
+    json_value *root = json_parse_document( p_obj, p_buffer, i_buffer );
     if( !root )
         return false;
 
@@ -153,12 +154,13 @@ int acoustid_lookup_fingerprint( const acoustid_config_t *p_cfg, acoustid_finger
     }
 
     msg_Dbg( p_cfg->p_obj, "Querying AcoustID from %s", psz_url );
-    void *p_buffer = json_retrieve_document( p_cfg->p_obj, psz_url );
+    size_t i_buffer;
+    void *p_buffer = json_retrieve_document( p_cfg->p_obj, psz_url, &i_buffer );
     free( psz_url );
     if( !p_buffer )
         return VLC_EGENERIC;
 
-    if ( ParseJson( p_cfg->p_obj, p_buffer, & p_data->results ) )
+    if ( ParseJson( p_cfg->p_obj, p_buffer, i_buffer, & p_data->results ) )
         msg_Dbg( p_cfg->p_obj, "results count == %d", p_data->results.count );
     else
         msg_Dbg( p_cfg->p_obj, "No results" );

modules/misc/webservices/json_helper.h

@@ -54,7 +54,7 @@ char * json_dupstring(const json_value *node, const char *key)
 }
 
 static inline
-json_value * json_parse_document(vlc_object_t *p_obj, const char *psz_buffer)
+json_value * json_parse_document(vlc_object_t *p_obj, const char *psz_buffer, size_t i_buffer)
 {
     json_settings settings;
     char psz_error[128];
@@ -79,7 +79,7 @@ error:
 }
 
 static inline
-void * json_retrieve_document(vlc_object_t *p_obj, const char *psz_url)
+void * json_retrieve_document(vlc_object_t *p_obj, const char *psz_url, size_t *buf_size)
 {
     bool saved_no_interact = p_obj->no_interact;
     p_obj->no_interact = true;
@@ -95,29 +95,29 @@ void * json_retrieve_document(vlc_object_t *p_obj, const char *psz_url)
 
     /* read answer */
     char *p_buffer = NULL;
-    int i_ret = 0;
+    *buf_size = 0;
     for(;;)
     {
         int i_read = 65536;
 
-        if(i_ret >= INT_MAX - i_read)
+        if(*buf_size >= (SIZE_MAX - i_read - 1))
             break;
 
-        p_buffer = realloc_or_free(p_buffer, 1 + i_ret + i_read);
+        p_buffer = realloc_or_free(p_buffer, 1 + *buf_size + i_read);
         if(unlikely(p_buffer == NULL))
         {
             vlc_stream_Delete(p_stream);
             return NULL;
         }
 
-        i_read = vlc_stream_Read(p_stream, &p_buffer[i_ret], i_read);
+        i_read = vlc_stream_Read(p_stream, &p_buffer[*buf_size], i_read);
         if(i_read <= 0)
             break;
 
-        i_ret += i_read;
+        *buf_size += i_read;
     }
     vlc_stream_Delete(p_stream);
-    p_buffer[i_ret] = 0;
+    p_buffer[*buf_size++] = '\0';
 
     return p_buffer;
 }

modules/misc/webservices/musicbrainz.c

@@ -47,14 +47,15 @@ static musicbrainz_lookup_t * musicbrainz_lookup_new(void)
 static musicbrainz_lookup_t * musicbrainz_lookup(vlc_object_t *p_obj, const char *psz_url)
 {
     msg_Dbg(p_obj, "Querying MB for %s", psz_url);
-    void *p_buffer = json_retrieve_document(p_obj, psz_url);
+    size_t i_buffer;
+    void *p_buffer = json_retrieve_document(p_obj, psz_url, &i_buffer);
     if(!p_buffer)
         return NULL;
 
     musicbrainz_lookup_t *p_lookup = musicbrainz_lookup_new();
     if(p_lookup)
     {
-        p_lookup->root = json_parse_document(p_obj, p_buffer);
+        p_lookup->root = json_parse_document(p_obj, p_buffer, i_buffer);
         if (!p_lookup->root)
             msg_Dbg(p_obj, "No results");
     }