[rhythmbox] rhythmdb-import-job: check if symlink targets are already included

[Jonathan Matthew <jmatthew src gnome org>]

commit abff20dfb5c8fe474016203f3167f83d905bc70b
Author: Jonathan Matthew <jonathan d14n org>
Date:   Tue Mar 23 23:09:39 2021 +1000

    rhythmdb-import-job: check if symlink targets are already included
    
    If the target of a symlink we resolve is already included in the import
    job (equal to or a descendant of one of the imported URIs), adding it to
    the list of outstanding URIs will cause the import job to never finish,
    as the URI will only appear once, but there are two entries for it in
    the outstanding list.

 rhythmdb/rhythmdb-import-job.c | 52 +++++++++++++++++++++++++++++++++++++-----
 rhythmdb/rhythmdb-import-job.h |  1 +
 2 files changed, 47 insertions(+), 6 deletions(-)
---
diff --git a/rhythmdb/rhythmdb-import-job.c b/rhythmdb/rhythmdb-import-job.c
index 0b65da12e..08002e63c 100644
--- a/rhythmdb/rhythmdb-import-job.c
+++ b/rhythmdb/rhythmdb-import-job.c
@@ -89,6 +89,7 @@ struct _RhythmDBImportJobPrivate
        RhythmDBEntryType *error_type;
        GMutex          lock;
        GSList          *uri_list;
+       GSList          *next;
        gboolean        started;
        GCancellable    *cancel;
 
@@ -170,6 +171,38 @@ rhythmdb_import_job_add_uri (RhythmDBImportJob *job, const char *uri)
        g_mutex_unlock (&job->priv->lock);
 }
 
+/**
+ * rhythmdb_import_job_includes_uri:
+ * @job: a #RhythmDBImportJob
+ * @uri: a URI to check
+ *
+ * Checks if the specified URI is included in the import job.
+ *
+ * Return value: %TRUE if the import job includes the URI
+ */
+gboolean
+rhythmdb_import_job_includes_uri (RhythmDBImportJob *job, const char *uri)
+{
+       gboolean result = FALSE;
+       GSList *i;
+
+       g_mutex_lock (&job->priv->lock);
+       i = job->priv->uri_list;
+       while (i != NULL) {
+               const char *luri = i->data;
+               if ((g_strcmp0 (uri, luri) == 0) ||
+                   rb_uri_is_descendant (uri, luri)) {
+                       result = TRUE;
+                       break;
+               }
+
+               i = i->next;
+       }
+       g_mutex_unlock (&job->priv->lock);
+
+       return result;
+}
+
 /* must be called with lock held */
 static void
 maybe_start_more (RhythmDBImportJob *job)
@@ -331,7 +364,16 @@ uri_recurse_func (GFile *file, GFileInfo *info, RhythmDBImportJob *job)
                if (r != NULL) {
                        uri = g_file_get_uri (r);
                        g_object_unref (r);
+
+                       if (rhythmdb_import_job_includes_uri (job, uri)) {
+                               rb_debug ("symlink target %s already included", uri);
+                               g_free (uri);
+                               return TRUE;
+                       }
                } else {
+                       uri = g_file_get_uri (file);
+                       rb_debug ("unable to resolve symlink %s", uri);
+                       g_free (uri);
                        return FALSE;
                }
        } else {
@@ -386,14 +428,13 @@ static void
 next_uri (RhythmDBImportJob *job)
 {
        g_mutex_lock (&job->priv->lock);
-       if (job->priv->uri_list == NULL) {
+       if (job->priv->next == NULL) {
                rb_debug ("no more uris to scan");
                job->priv->scan_complete = TRUE;
                g_idle_add ((GSourceFunc)emit_scan_complete_idle, job);
        } else {
-               char *uri = job->priv->uri_list->data;
-               job->priv->uri_list = g_slist_delete_link (job->priv->uri_list,
-                                                          job->priv->uri_list);
+               const char *uri = job->priv->next->data;
+               job->priv->next = job->priv->next->next;
 
                rb_debug ("scanning uri %s", uri);
                rb_uri_handle_recursively_async (uri,
@@ -401,8 +442,6 @@ next_uri (RhythmDBImportJob *job)
                                                 (RBUriRecurseFunc) uri_recurse_func,
                                                 job,
                                                 (GDestroyNotify) next_uri);
-
-               g_free (uri);
        }
        g_mutex_unlock (&job->priv->lock);
 }
@@ -424,6 +463,7 @@ rhythmdb_import_job_start (RhythmDBImportJob *job)
        g_mutex_lock (&job->priv->lock);
        job->priv->started = TRUE;
        job->priv->uri_list = g_slist_reverse (job->priv->uri_list);
+       job->priv->next = job->priv->uri_list;
        g_mutex_unlock (&job->priv->lock);
        
        /* reference is released in emit_scan_complete_idle */
diff --git a/rhythmdb/rhythmdb-import-job.h b/rhythmdb/rhythmdb-import-job.h
index 72891f72d..aa8814f04 100644
--- a/rhythmdb/rhythmdb-import-job.h
+++ b/rhythmdb/rhythmdb-import-job.h
@@ -71,6 +71,7 @@ RhythmDBImportJob *rhythmdb_import_job_new            (RhythmDB *db,
                                                         RhythmDBEntryType *ignore_type,
                                                         RhythmDBEntryType *error_type);
 void           rhythmdb_import_job_add_uri             (RhythmDBImportJob *job, const char *uri);
+gboolean       rhythmdb_import_job_includes_uri        (RhythmDBImportJob *job, const char *uri);
 void           rhythmdb_import_job_start               (RhythmDBImportJob *job);
 void           rhythmdb_import_job_cancel              (RhythmDBImportJob *job);