[easytag] Do not maintain an open handle on Ogg files

[David King <davidk src gnome org>]

commit e5c640ca3f259f1b74e716723345521987a7bd68
Author: David King <amigadave amigadave com>
Date:   Wed Nov 9 17:29:34 2016 +0000

    Do not maintain an open handle on Ogg files
    
    Only keep a file open for reading long enough to read the necessary
    items from the file. Remove the file input stream from EtOggState, as
    it is no longer preserved across function calls.

 src/tags/vcedit.c |   92 +++++++++++++++++++++--------------------------------
 1 files changed, 36 insertions(+), 56 deletions(-)
---
diff --git a/src/tags/vcedit.c b/src/tags/vcedit.c
index cf43428..a40762d 100644
--- a/src/tags/vcedit.c
+++ b/src/tags/vcedit.c
@@ -35,7 +35,6 @@
 struct _EtOggState
 {
     /*< private >*/
-    GFileInputStream *in;
 #ifdef ENABLE_SPEEX
     SpeexHeader *si;
 #endif
@@ -126,11 +125,6 @@ vcedit_clear_internals (EtOggState *state)
     }
 #endif /* ENABLE_OPUS */
 
-    if (state->in)
-    {
-        g_object_unref (state->in);
-    }
-
     memset (state, 0, sizeof (*state));
 }
 
@@ -245,6 +239,7 @@ _blocksize (EtOggState *s,
 
 static gboolean
 _fetch_next_packet (EtOggState *s,
+                    GInputStream *istream,
                     ogg_packet *p,
                     ogg_page *page,
                     GError **error)
@@ -274,8 +269,8 @@ _fetch_next_packet (EtOggState *s,
         while (ogg_sync_pageout (s->oy, page) <= 0)
         {
             buffer = ogg_sync_buffer (s->oy, CHUNKSIZE);
-            bytes = g_input_stream_read (G_INPUT_STREAM (s->in), buffer,
-                                         CHUNKSIZE, NULL, error);
+            bytes = g_input_stream_read (istream, buffer, CHUNKSIZE, NULL,
+                                         error);
             ogg_sync_wrote (s->oy, bytes);
 
             if(bytes == 0)
@@ -308,7 +303,7 @@ _fetch_next_packet (EtOggState *s,
 
         g_assert (error == NULL || *error == NULL);
         ogg_stream_pagein (s->os, page);
-        return _fetch_next_packet (s, p, page, error);
+        return _fetch_next_packet (s, istream, p, page, error);
     }
 }
 
@@ -407,14 +402,13 @@ vcedit_open (EtOggState *state,
         return FALSE;
     }
 
-    state->in = istream;
     state->oy = g_slice_new (ogg_sync_state);
     ogg_sync_init (state->oy);
 
     while(1)
     {
         buffer = ogg_sync_buffer (state->oy, CHUNKSIZE);
-        bytes = g_input_stream_read (G_INPUT_STREAM (state->in), buffer,
+        bytes = g_input_stream_read (G_INPUT_STREAM (istream), buffer,
                                      CHUNKSIZE, NULL, error);
         if (bytes == -1)
         {
@@ -654,7 +648,7 @@ vcedit_open (EtOggState *state,
         }
 
         buffer = ogg_sync_buffer (state->oy, CHUNKSIZE);
-        bytes = g_input_stream_read (G_INPUT_STREAM (state->in), buffer,
+        bytes = g_input_stream_read (G_INPUT_STREAM (istream), buffer,
                                      CHUNKSIZE, NULL, error);
 
         if (bytes == -1)
@@ -676,11 +670,14 @@ vcedit_open (EtOggState *state,
 
     /* Headers are done! */
     g_assert (error == NULL || *error == NULL);
+    /* TODO: Handle error during stream close. */
+    g_object_unref (istream);
 
     return TRUE;
 
 err:
     g_assert (error == NULL || *error != NULL);
+    g_object_unref (istream);
     vcedit_clear_internals (state);
     return FALSE;
 }
@@ -702,6 +699,7 @@ vcedit_write (EtOggState *state,
     char *buffer;
     int bytes;
     int needflush = 0, needout = 0;
+    GFileInputStream *istream;
     GOutputStream *ostream;
     gchar *buf;
     gsize size;
@@ -709,11 +707,22 @@ vcedit_write (EtOggState *state,
 
     g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
 
-    fileinfo = g_file_query_info (file, G_FILE_ATTRIBUTE_STANDARD_SIZE,
-                                  G_FILE_QUERY_INFO_NONE, NULL, error);
+    istream = g_file_read (file, NULL, error);
+
+    if (!istream)
+    {
+        g_assert (error == NULL || *error != NULL);
+        return FALSE;
+    }
+
+    fileinfo = g_file_input_stream_query_info (istream,
+                                               G_FILE_ATTRIBUTE_STANDARD_SIZE,
+                                               NULL, error);
+
     if (!fileinfo)
     {
         g_assert (error == NULL || *error != NULL);
+        g_object_unref (istream);
         return FALSE;
     }
 
@@ -774,7 +783,8 @@ vcedit_write (EtOggState *state,
         }
     }
 
-    while (_fetch_next_packet (state, &op, &ogin, error))
+    while (_fetch_next_packet (state, G_INPUT_STREAM (istream), &op, &ogin,
+                               error))
     {
         if (needflush)
         {
@@ -950,7 +960,7 @@ vcedit_write (EtOggState *state,
     {
         /* We copy the rest of the stream (other logical streams)
          * through, a page at a time. */
-        while(1)
+        while (1)
         {
             result = ogg_sync_pageout (state->oy, &ogout);
 
@@ -989,7 +999,7 @@ vcedit_write (EtOggState *state,
 
         buffer = ogg_sync_buffer (state->oy, CHUNKSIZE);
 
-        bytes = g_input_stream_read (G_INPUT_STREAM (state->in), buffer,
+        bytes = g_input_stream_read (G_INPUT_STREAM (istream), buffer,
                                      CHUNKSIZE, NULL, error);
 
         if (bytes == -1)
@@ -1007,11 +1017,19 @@ vcedit_write (EtOggState *state,
         }
     }
 
-
 cleanup:
     ogg_stream_clear (&streamout);
     ogg_packet_clear (&header_comments);
 
+    if (!g_input_stream_close (G_INPUT_STREAM (istream), NULL, error))
+    {
+        /* Ignore the _close() failure, and try the write anyway. */
+        g_warning ("Error closing Ogg file for reading: %s",
+                   (*error)->message);
+        g_clear_error (error);
+    }
+
+    g_object_unref (istream);
     g_free (state->mainbuf);
     g_free (state->bookbuf);
     state->mainbuf = state->bookbuf = NULL;
@@ -1045,41 +1063,13 @@ cleanup:
     buf = g_memory_output_stream_steal_data (G_MEMORY_OUTPUT_STREAM (ostream));
     size = g_memory_output_stream_get_data_size (G_MEMORY_OUTPUT_STREAM (ostream));
 
-    /* At least on Windows, writing to a file with an open-for-reading stream
-     * fails, so close the input stream before writing to the file. */
-    if (!g_input_stream_close (G_INPUT_STREAM (state->in), NULL, error))
-    {
-        /* Ignore the _close() failure, and try the write anyway. */
-        g_warning ("Error closing Ogg file for reading: %s",
-                   (*error)->message);
-        g_clear_error (error);
-    }
-
-    g_object_unref (state->in);
-    state->in = NULL;
-
     /* Write the in-memory data back out to the original file. */
     if (!g_file_replace_contents (file, buf, size, NULL, FALSE,
                                   G_FILE_CREATE_NONE, NULL, NULL, error))
     {
-        GError *tmp_error = NULL;
-
         g_object_unref (ostream);
         g_free (buf);
 
-        /* Re-open the file for reading, to keep the internal state
-         * consistent. */
-        state->in = g_file_read (file, NULL, &tmp_error);
-
-        if (!state->in)
-        {
-            g_warning ("Error opening Ogg file for reading after write failure: %s",
-                       tmp_error->message);
-            g_clear_error (&tmp_error);
-            g_assert (error == NULL || *error != NULL);
-            return FALSE;
-        }
-
         g_assert (error == NULL || *error != NULL);
         return FALSE;
     }
@@ -1087,16 +1077,6 @@ cleanup:
     g_free (buf);
     g_object_unref (ostream);
 
-    /* Re-open the file, now that the write has completed. */
-    state->in = g_file_read (file, NULL, error);
-
-    if (!state->in)
-    {
-        g_assert (error == NULL || *error != NULL);
-        return FALSE;
-    }
-
-
     return TRUE;
 }