From f33a2f9a084f77ab58a5486723b97d06e1513912 Mon Sep 17 00:00:00 2001
From: Colin Walters <walters@verbum.org>
Date: Wed, 9 May 2012 23:20:36 -0400
Subject: [PATCH] core: pack: Keep loose objects which are referenced
 externally

By default, don't delete loose objects which have hard links.  This
has the natural semantics that if you delete all the checkouts, you
probably want it packed.

Conversely, if it has a hard link, we do want further checkouts to
share storage, even if we pack in between them.
---
 src/ostree/ot-builtin-pack.c | 90 +++++++++++++++++++++++++++---------
 1 file changed, 67 insertions(+), 23 deletions(-)

diff --git a/src/ostree/ot-builtin-pack.c b/src/ostree/ot-builtin-pack.c
index 9aaa1c7d..0c0d12b3 100644
--- a/src/ostree/ot-builtin-pack.c
+++ b/src/ostree/ot-builtin-pack.c
@@ -37,7 +37,8 @@
 static gboolean opt_analyze_only;
 static gboolean opt_metadata_only;
 static gboolean opt_reindex_only;
-static gboolean opt_keep_loose;
+static gboolean opt_delete_all_loose;
+static gboolean opt_keep_all_loose;
 static char* opt_pack_size;
 static char* opt_int_compression;
 static char* opt_ext_compression;
@@ -55,7 +56,8 @@ static GOptionEntry options[] = {
   { "metadata-only", 0, 0, G_OPTION_ARG_NONE, &opt_metadata_only, "Only pack metadata objects", NULL },
   { "analyze-only", 0, 0, G_OPTION_ARG_NONE, &opt_analyze_only, "Just analyze current state", NULL },
   { "reindex-only", 0, 0, G_OPTION_ARG_NONE, &opt_reindex_only, "Regenerate pack index", NULL },
-  { "keep-loose", 0, 0, G_OPTION_ARG_NONE, &opt_keep_loose, "Don't delete loose objects", NULL },
+  { "delete-all-loose", 0, 0, G_OPTION_ARG_NONE, &opt_delete_all_loose, "Delete all loose objects (default: delete unreferenced loose)", NULL },
+  { "keep-all-loose", 0, 0, G_OPTION_ARG_NONE, &opt_keep_all_loose, "Don't delete any loose objects (default: delete unreferenced loose)", NULL },
   { NULL }
 };
 
@@ -191,32 +193,74 @@ delete_loose_object (OtRepackData     *data,
                      GError          **error)
 {
   gboolean ret = FALSE;
+  gboolean do_delete = FALSE;
+  GError *temp_error = NULL;
   ot_lobj GFile *object_path = NULL;
   ot_lobj GFile *file_content_object_path = NULL;
-  ot_lvariant GVariant *archive_meta = NULL;
-  ot_lobj GFileInfo *file_info = NULL;
-  ot_lvariant GVariant *xattrs = NULL;
 
   object_path = ostree_repo_get_object_path (data->repo, checksum, objtype);
+
+  if (objtype == OSTREE_OBJECT_TYPE_FILE)
+    {
+      ot_lobj GFileInfo *file_info = NULL;
+
+      if (ostree_repo_get_mode (data->repo) == OSTREE_REPO_MODE_BARE)
+        {
+          file_info = g_file_query_info (object_path, OSTREE_GIO_FAST_QUERYINFO,
+                                         G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
+                                         cancellable, &temp_error);
+        }
+      else
+        {
+          ot_lobj GFile *content_object_path = NULL;
+        
+          content_object_path = ostree_repo_get_archive_content_path (data->repo, checksum);
+
+          file_info = g_file_query_info (content_object_path, OSTREE_GIO_FAST_QUERYINFO,
+                                         G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
+                                         cancellable, &temp_error);
+        }
   
-  if (!ot_gfile_unlink (object_path, cancellable, error))
-    {
-      g_prefix_error (error, "Failed to delete archived file metadata '%s'",
-                      ot_gfile_get_path_cached (object_path));
-      goto out;
+      if (!file_info)
+        {
+          if (!g_error_matches (temp_error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
+            {
+              g_propagate_error (error, temp_error);
+              goto out;
+            }
+          else
+            {
+              g_clear_error (&temp_error);
+            }
+        }
+          
+      do_delete = opt_delete_all_loose
+        || (file_info && g_file_info_get_attribute_uint32 (file_info, "unix::nlink") <= 1);
     }
+  else
+    do_delete = TRUE;
 
-  if (objtype == OSTREE_OBJECT_TYPE_FILE
-      && ostree_repo_get_mode (data->repo) == OSTREE_REPO_MODE_ARCHIVE)
+  if (do_delete)
     {
-      ot_lobj GFile *content_object_path = NULL;
+      if (!ot_gfile_unlink (object_path, cancellable, error))
+        {
+          g_prefix_error (error, "Failed to delete loose object '%s'",
+                          ot_gfile_get_path_cached (object_path));
+          goto out;
+        }
 
-      content_object_path = ostree_repo_get_archive_content_path (data->repo, checksum);
-
-      /* Ignoring errors for now; later should only be trying to
-       * delete files with content.
-       */
-      (void) ot_gfile_unlink (object_path, NULL, NULL);
+      if (objtype == OSTREE_OBJECT_TYPE_FILE
+          && ostree_repo_get_mode (data->repo) == OSTREE_REPO_MODE_ARCHIVE)
+        {
+          ot_lobj GFile *content_object_path = NULL;
+      
+          content_object_path = ostree_repo_get_archive_content_path (data->repo, checksum);
+      
+          /* Ignoring errors for now; later should only be trying to
+           * delete files with content.
+           */
+          (void) ot_gfile_unlink (content_object_path, NULL, NULL);
+        }
     }
 
   ret = TRUE;
@@ -475,7 +519,7 @@ create_pack_file (OtRepackData        *data,
 
   g_print ("Created pack file '%s' with %u objects\n", g_checksum_get_string (pack_checksum), objects->len);
 
-  if (!opt_keep_loose)
+  if (!opt_keep_all_loose)
     {
       for (i = 0; i < objects->len; i++)
         {
@@ -484,11 +528,11 @@ create_pack_file (OtRepackData        *data,
           guint32 objtype_u32;
           OstreeObjectType objtype;
           guint64 expected_objsize;
-
+      
           g_variant_get (object_data, "(&sut)", &checksum, &objtype_u32, &expected_objsize);
-          
+      
           objtype = (OstreeObjectType) objtype_u32;
-
+      
           if (!delete_loose_object (data, checksum, objtype, cancellable, error))
             goto out;
         }