lib: Add `_ALLOW_NOENT` flag to internal variant mapping API

We have a lot of "allow_noent" type wrapper functions since
a common pattern is to allow files to not exist, but still
throw cleanly on other issues.

This is another instance of that, and cleans up duplicated error
handling code.

Part of this is prep for moving away from `GFile` consumers.

Closes: #319
Approved by: jlebon

diff --git a/src/libostree/ostree-repo-commit.c b/src/libostree/ostree-repo-commit.c
index b8f4824ad9e7d497e9dabb6b7401c3fe9bd7c3e8..6cb46ca987d9692ebdecda341af4b3f39aa38fec 100644 (file)
--- a/src/libostree/ostree-repo-commit.c
+++ b/src/libostree/ostree-repo-commit.c
@@ -2097,22 +2097,13 @@ ostree_repo_read_commit_detached_metadata (OstreeRepo      *self,
   g_autoptr(GFile) metadata_path =
     _ostree_repo_get_commit_metadata_loose_path (self, checksum);
   g_autoptr(GVariant) ret_metadata = NULL;
-  GError *temp_error = NULL;
   
   if (!ot_util_variant_map_at (AT_FDCWD, gs_file_get_path_cached (metadata_path),
                                G_VARIANT_TYPE ("a{sv}"),
-                               TRUE, &ret_metadata, &temp_error))
+                               OT_VARIANT_MAP_ALLOW_NOENT | OT_VARIANT_MAP_TRUSTED, &ret_metadata, error))
     {
-      if (g_error_matches (temp_error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
-        {
-          g_clear_error (&temp_error);
-        }
-      else
-        {
-          g_prefix_error (error, "Unable to read existing detached metadata: ");
-          g_propagate_error (error, temp_error);
-          goto out;
-        }
+      g_prefix_error (error, "Unable to read existing detached metadata: ");
+      goto out;
     }
 
   ret = TRUE;

diff --git a/src/libostree/ostree-repo-static-delta-core.c b/src/libostree/ostree-repo-static-delta-core.c
index 2b1338b54fcf08b28996db508f5412a4a3b2d762..de9e6c7a94c15e12c17c170c4d7f2ffdeef40e9c 100644 (file)
--- a/src/libostree/ostree-repo-static-delta-core.c
+++ b/src/libostree/ostree-repo-static-delta-core.c
@@ -842,7 +842,7 @@ _ostree_repo_static_delta_dump (OstreeRepo                    *self,
 
   if (!ot_util_variant_map_at (self->repo_dir_fd, superblock_path,
                                (GVariantType*)OSTREE_STATIC_DELTA_SUPERBLOCK_FORMAT,
-                               TRUE, &delta_superblock, error))
+                               OT_VARIANT_MAP_TRUSTED, &delta_superblock, error))
     goto out;
 
   g_print ("%s\n", g_variant_print (delta_superblock, 1));

diff --git a/src/libostree/ostree-repo.c b/src/libostree/ostree-repo.c
index 38dac761d7f30a062cdfff996c19735f07506925..2a26ffedd082ab8ae4d2a5288fb3d1eeece6f8bf 100644 (file)
--- a/src/libostree/ostree-repo.c
+++ b/src/libostree/ostree-repo.c
@@ -4620,7 +4620,6 @@ ostree_repo_add_gpg_signature_summary (OstreeRepo     *self,
   g_autoptr(GBytes) summary_data = NULL;
   g_autoptr(GFile) summary_file = NULL;
   g_autoptr(GFile) signature_path = NULL;
-  GError *temp_error = NULL;
   g_autoptr(GVariant) existing_signatures = NULL;
   g_autoptr(GVariant) new_metadata = NULL;
   g_autoptr(GVariant) normalized = NULL;
@@ -4634,18 +4633,8 @@ ostree_repo_add_gpg_signature_summary (OstreeRepo     *self,
 
   if (!ot_util_variant_map_at (AT_FDCWD, gs_file_get_path_cached (signature_path),
                                G_VARIANT_TYPE (OSTREE_SUMMARY_SIG_GVARIANT_STRING),
-                               TRUE, &existing_signatures, &temp_error))
-    {
-      if (g_error_matches (temp_error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
-        {
-          g_clear_error (&temp_error);
-        }
-      else
-        {
-          g_propagate_error (error, temp_error);
-          goto out;
-        }
-    }
+                               OT_VARIANT_MAP_ALLOW_NOENT, &existing_signatures, error))
+    goto out;
 
   for (i = 0; key_id[i]; i++)
     {

diff --git a/src/libotutil/ot-variant-utils.c b/src/libotutil/ot-variant-utils.c
index 26054459f8b277907436690c5b71ff76cb063c66..9d4a62d27d5336b3e14e4e24f94aa98e408fc502 100644 (file)
--- a/src/libotutil/ot-variant-utils.c
+++ b/src/libotutil/ot-variant-utils.c
@@ -121,18 +121,27 @@ gboolean
 ot_util_variant_map_at (int dfd,
                         const char *path,
                         const GVariantType *type,
-                        gboolean trusted,
+                        OtVariantMapFlags flags,
                         GVariant **out_variant,
                         GError  **error)
 {
   glnx_fd_close int fd = -1;
+  const gboolean trusted = (flags & OT_VARIANT_MAP_TRUSTED) > 0;
 
   fd = openat (dfd, path, O_RDONLY | O_CLOEXEC);
   if (fd < 0)
     {
-      glnx_set_error_from_errno (error);
-      g_prefix_error (error, "Opening %s: ", path);
-      return FALSE;
+      if (errno == ENOENT && (flags & OT_VARIANT_MAP_ALLOW_NOENT) > 0)
+        {
+          *out_variant = NULL;
+          return TRUE;
+        }
+      else
+        {
+          glnx_set_error_from_errno (error);
+          g_prefix_error (error, "Opening %s: ", path);
+          return FALSE;
+        }
     }
 
   return ot_util_variant_map_fd (fd, 0, type, trusted, out_variant, error);

diff --git a/src/libotutil/ot-variant-utils.h b/src/libotutil/ot-variant-utils.h
index f185b4fdb9e9dfdfa45a5de1685b82cb7f886629..8a33cf604d46fb9e63731cb88328d04c50d44bc9 100644 (file)
--- a/src/libotutil/ot-variant-utils.h
+++ b/src/libotutil/ot-variant-utils.h
@@ -42,10 +42,15 @@ gboolean ot_util_variant_save (GFile *dest,
                                GCancellable *cancellable,
                                GError  **error);
 
+typedef enum {
+  OT_VARIANT_MAP_TRUSTED = (1 << 0),
+  OT_VARIANT_MAP_ALLOW_NOENT = (1 << 1)
+} OtVariantMapFlags;
+
 gboolean ot_util_variant_map_at (int dfd,
                                  const char *path,
                                  const GVariantType *type,
-                                 gboolean trusted,
+                                 OtVariantMapFlags flags,
                                  GVariant **out_variant,
                                  GError  **error);