[evince/wip/chpe/load-fd: 845/845] tiff: Implement loading from file descriptor

[Christian Persch <chpe src gnome org>]

commit 498ed6166a72fb2be621e76f1a3c2a524ce20ce0
Author: Christian Persch <chpe src gnome org>
Date:   Thu Nov 18 00:03:14 2021 +0100

    tiff: Implement loading from file descriptor
    
    FIXME: Implement save when source is FD.

 backend/tiff/tiff-document.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
---
diff --git a/backend/tiff/tiff-document.c b/backend/tiff/tiff-document.c
index 6dd6d88b0..c6a817e4a 100644
--- a/backend/tiff/tiff-document.c
+++ b/backend/tiff/tiff-document.c
@@ -135,6 +135,35 @@ tiff_document_load (EvDocument  *document,
        return TRUE;
 }
 
+static gboolean
+tiff_document_load_fd (EvDocument          *document,
+                       int                  fd,
+                       EvDocumentLoadFlags  flags,
+                       GCancellable        *cancellable,
+                       GError             **error)
+{
+        TiffDocument *tiff_document = TIFF_DOCUMENT (document);
+        TIFF *tiff;
+
+        push_handlers ();
+        tiff = TIFFFdOpen (fd, "document.tiff" /* fake filename */, "r");
+        pop_handlers ();
+
+        if (!tiff) {
+                g_set_error_literal (error,
+                                     EV_DOCUMENT_ERROR,
+                                     EV_DOCUMENT_ERROR_INVALID,
+                                     _("Invalid document"));
+                return FALSE;
+        }
+
+
+        tiff_document->tiff = tiff;
+        g_clear_pointer (&tiff_document->uri, g_free);
+
+        return TRUE;
+}
+
 static gboolean
 tiff_document_save (EvDocument  *document,
                    const char  *uri,
@@ -142,6 +171,13 @@ tiff_document_save (EvDocument  *document,
 {
        TiffDocument *tiff_document = TIFF_DOCUMENT (document);
 
+        /* FIXME: create an output stream for the uri, then splice the source fd to it */
+        if (tiff_document->uri == NULL) {
+                g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                                     "Cannot save document from FD");
+                return FALSE;
+        }
+
        return ev_xfer_uri_simple (tiff_document->uri, uri, error);
 }
 
@@ -451,6 +487,7 @@ tiff_document_class_init (TiffDocumentClass *klass)
        gobject_class->finalize = tiff_document_finalize;
 
        ev_document_class->load = tiff_document_load;
+       ev_document_class->load_fd = tiff_document_load_fd;
        ev_document_class->save = tiff_document_save;
        ev_document_class->get_n_pages = tiff_document_get_n_pages;
        ev_document_class->get_page_size = tiff_document_get_page_size;