#include <errno.h>
+#ifdef DEBUG_FILEDATA
+gint global_file_data_count = 0;
+#endif
+
static GHashTable *file_data_pool = NULL;
static GHashTable *file_data_planned_change_hash = NULL;
}
fd = g_new0(FileData, 1);
+#ifdef DEBUG_FILEDATA
+ global_file_data_count++;
+ DEBUG_2("file data count++: %d", global_file_data_count);
+#endif
fd->size = st->st_size;
fd->date = st->st_mtime;
{
g_assert(fd->magick == FD_MAGICK);
g_assert(fd->ref == 0);
+ g_assert(!fd->locked);
+
+#ifdef DEBUG_FILEDATA
+ global_file_data_count--;
+ DEBUG_2("file data count--: %d", global_file_data_count);
+#endif
metadata_cache_free(fd);
g_hash_table_remove(file_data_pool, fd->original_path);
g_free(fd);
}
+/**
+ * \brief Checks if the FileData is referenced
+ *
+ * Checks the refcount and whether the FileData is locked.
+ */
+static gboolean file_data_check_has_ref(FileData *fd)
+{
+ return fd->ref > 0 || fd->locked;
+}
+
+/**
+ * \brief Consider freeing a FileData.
+ *
+ * This function will free a FileData and its children provided that neither its parent nor it has
+ * a positive refcount, and provided that neither is locked.
+ */
+static void file_data_consider_free(FileData *fd)
+{
+ GList *work;
+ FileData *parent = fd->parent ? fd->parent : fd;
+
+ g_assert(fd->magick == FD_MAGICK);
+ if (file_data_check_has_ref(fd)) return;
+ if (file_data_check_has_ref(parent)) return;
+
+ work = parent->sidecar_files;
+ while (work)
+ {
+ FileData *sfd = work->data;
+ if (file_data_check_has_ref(sfd)) return;
+ work = work->next;
+ }
+
+ /* Neither the parent nor the siblings are referenced, so we can free everything */
+ DEBUG_2("file_data_consider_free: deleting '%s', parent '%s'",
+ fd->path, fd->parent ? parent->path : "-");
+
+ work = parent->sidecar_files;
+ while (work)
+ {
+ FileData *sfd = work->data;
+ file_data_free(sfd);
+ work = work->next;
+ }
+
+ g_list_free(parent->sidecar_files);
+ parent->sidecar_files = NULL;
+
+ file_data_free(parent);
+}
+
#ifdef DEBUG_FILEDATA
void file_data_unref_debug(const gchar *file, gint line, FileData *fd)
#else
fd->ref--;
#ifdef DEBUG_FILEDATA
- DEBUG_2("file_data_unref fd=%p (%d): '%s' @ %s:%d", fd, fd->ref, fd->path, file, line);
+ DEBUG_2("file_data_unref fd=%p (%d:%d): '%s' @ %s:%d", fd, fd->ref, fd->locked, fd->path,
+ file, line);
#else
- DEBUG_2("file_data_unref fd=%p (%d): '%s'", fd, fd->ref, fd->path);
+ DEBUG_2("file_data_unref fd=%p (%d:%d): '%s'", fd, fd->ref, fd->locked, fd->path);
#endif
- if (fd->ref == 0)
- {
- GList *work;
- FileData *parent = fd->parent ? fd->parent : fd;
- if (parent->ref > 0) return;
+ // Free FileData if it's no longer ref'd
+ file_data_consider_free(fd);
+}
- work = parent->sidecar_files;
- while (work)
- {
- FileData *sfd = work->data;
- if (sfd->ref > 0) return;
- work = work->next;
- }
+/**
+ * \brief Lock the FileData in memory.
+ *
+ * This allows the caller to prevent a FileData from being freed, even after its refcount is zero.
+ * This is intended to be used in cases where a FileData _should_ stay in memory as an optimization,
+ * even if the code would continue to function properly even if the FileData were freed. Code that
+ * _requires_ the FileData to remain in memory should continue to use file_data_(un)ref.
+ * <p />
+ * Note: This differs from file_data_ref in that the behavior is reentrant -- after N calls to
+ * file_data_lock, a single call to file_data_unlock will unlock the FileData.
+ */
+void file_data_lock(FileData *fd)
+{
+ if (fd == NULL) return;
+ if (fd->magick != FD_MAGICK) DEBUG_0("fd magick mismatch fd=%p", fd);
- /* none of parent/children is referenced, we can free everything */
+ g_assert(fd->magick == FD_MAGICK);
+ fd->locked = TRUE;
- DEBUG_2("file_data_unref: deleting '%s', parent '%s'", fd->path, fd->parent ? parent->path : "-");
+ DEBUG_2("file_data_ref fd=%p (%d): '%s'", fd, fd->ref, fd->path);
+}
- work = parent->sidecar_files;
- while (work)
- {
- FileData *sfd = work->data;
- file_data_free(sfd);
- work = work->next;
- }
+/**
+ * \brief Reset the maintain-FileData-in-memory lock
+ *
+ * This again allows the FileData to be freed when its refcount drops to zero. Automatically frees
+ * the FileData if its refcount is already zero (which will happen if the lock is the only thing
+ * keeping it from being freed.
+ */
+void file_data_unlock(FileData *fd)
+{
+ if (fd == NULL) return;
+ if (fd->magick != FD_MAGICK) DEBUG_0("fd magick mismatch fd=%p", fd);
- g_list_free(parent->sidecar_files);
- parent->sidecar_files = NULL;
+ g_assert(fd->magick == FD_MAGICK);
+ fd->locked = FALSE;
- file_data_free(parent);
+ // Free FileData if it's no longer ref'd
+ file_data_consider_free(fd);
+}
+
+/**
+ * \brief Lock all of the FileDatas in the provided list
+ *
+ * \see file_data_lock(FileData)
+ */
+void file_data_lock_list(GList *list)
+{
+ GList *work;
+
+ work = list;
+ while (work)
+ {
+ FileData *fd = work->data;
+ work = work->next;
+ file_data_lock(fd);
}
}
+/**
+ * \brief Unlock all of the FileDatas in the provided list
+ *
+ * \see file_data_unlock(FileData)
+ */
+void file_data_unlock_list(GList *list)
+{
+ GList *work;
+ work = list;
+ while (work)
+ {
+ FileData *fd = work->data;
+ work = work->next;
+ file_data_unlock(fd);
+ }
+}
/*
*-----------------------------------------------------------------------------