[ostree] core: Add 'cat' builtin

[Colin Walters <walters src gnome org>]

commit eb7c3d01a30b3e6f7a2ba9bae30a796480bed891
Author: Colin Walters <walters verbum org>
Date:   Mon Mar 5 11:32:48 2012 -0500

    core: Add 'cat' builtin

 Makefile-ostree.am               |    1 +
 src/libostree/ostree-repo-file.c |   18 +++---
 src/ostree/main.c                |    1 +
 src/ostree/ot-builtin-cat.c      |  114 ++++++++++++++++++++++++++++++++++++++
 src/ostree/ot-builtins.h         |    1 +
 tests/t0000-basic.sh             |    7 ++-
 tests/t0001-archive.sh           |    7 ++-
 7 files changed, 139 insertions(+), 10 deletions(-)
---
diff --git a/Makefile-ostree.am b/Makefile-ostree.am
index 91aceb7..83333eb 100644
--- a/Makefile-ostree.am
+++ b/Makefile-ostree.am
@@ -21,6 +21,7 @@ bin_PROGRAMS += ostree
 
 ostree_SOURCES = src/ostree/main.c \
 	src/ostree/ot-builtins.h \
+	src/ostree/ot-builtin-cat.c \
 	src/ostree/ot-builtin-checkout.c \
 	src/ostree/ot-builtin-checksum.c \
 	src/ostree/ot-builtin-commit.c \
diff --git a/src/libostree/ostree-repo-file.c b/src/libostree/ostree-repo-file.c
index dd22d38..625067d 100644
--- a/src/libostree/ostree-repo-file.c
+++ b/src/libostree/ostree-repo-file.c
@@ -989,6 +989,7 @@ ostree_repo_file_read (GFile         *file,
   GFile *local_file = NULL;
   GFileInputStream *ret_stream = NULL;
   OstreeRepoFile *self = OSTREE_REPO_FILE (file);
+  const char *checksum;
 
   if (self->tree_contents)
     {
@@ -998,20 +999,21 @@ ostree_repo_file_read (GFile         *file,
       goto out;
     }
 
+  checksum = ostree_repo_file_get_checksum (self);
+
   if (ostree_repo_get_mode (self->repo) == OSTREE_REPO_MODE_ARCHIVE)
     {
-      g_set_error_literal (error, G_IO_ERROR,
-			   G_IO_ERROR_NOT_SUPPORTED,
-			   "Can't open archived file (yet)");
-      goto out;
+      local_file = ostree_repo_get_object_path (self->repo, checksum,
+                                                OSTREE_OBJECT_TYPE_ARCHIVED_FILE_CONTENT);
     }
   else
     {
-      local_file = ostree_repo_file_nontree_get_local (self);
-      ret_stream = g_file_read (local_file, cancellable, error);
-      if (!ret_stream)
-	goto out;
+      local_file = ostree_repo_get_file_object_path (self->repo, checksum);
     }
+
+  ret_stream = g_file_read (local_file, cancellable, error);
+  if (!ret_stream)
+    goto out;
   
   ret = TRUE;
  out:
diff --git a/src/ostree/main.c b/src/ostree/main.c
index d2e3eba..71a2efc 100644
--- a/src/ostree/main.c
+++ b/src/ostree/main.c
@@ -30,6 +30,7 @@
 #include "ot-builtins.h"
 
 static OstreeBuiltin builtins[] = {
+  { "cat", ostree_builtin_cat, 0 },
   { "checkout", ostree_builtin_checkout, 0 },
   { "checksum", ostree_builtin_checksum, OSTREE_BUILTIN_FLAG_NO_REPO },
   { "diff", ostree_builtin_diff, 0 },
diff --git a/src/ostree/ot-builtin-cat.c b/src/ostree/ot-builtin-cat.c
new file mode 100644
index 0000000..0096f3a
--- /dev/null
+++ b/src/ostree/ot-builtin-cat.c
@@ -0,0 +1,114 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2011 Colin Walters <walters verbum org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: Colin Walters <walters verbum org>
+ */
+
+#include "config.h"
+
+#include "ot-builtins.h"
+#include "ostree.h"
+#include "ostree-repo-file.h"
+
+#include <gio/gunixoutputstream.h>
+#include <glib/gi18n.h>
+
+static GOptionEntry options[] = {
+};
+
+static gboolean
+cat_one_file (GFile         *f,
+              GOutputStream *stdout_stream,
+              GCancellable  *cancellable,
+              GError       **error)
+{
+  gboolean ret = FALSE;
+  GInputStream *in = NULL;
+  
+  if (!ostree_repo_file_ensure_resolved ((OstreeRepoFile*)f, NULL))
+    g_assert_not_reached ();
+
+  in = (GInputStream*)g_file_read (f, cancellable, error);
+  if (!in)
+    goto out;
+
+  if (!g_output_stream_splice (stdout_stream, in, G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE,
+                               cancellable, error))
+    goto out;
+
+  ret = TRUE;
+ out:
+  g_clear_object (&in);
+  return ret;
+}
+
+gboolean
+ostree_builtin_cat (int argc, char **argv, GFile *repo_path, GError **error)
+{
+  GOptionContext *context;
+  gboolean ret = FALSE;
+  OstreeRepo *repo = NULL;
+  int i;
+  GCancellable *cancellable = NULL;
+  const char *rev;
+  GOutputStream *stdout_stream = NULL;
+  GFile *root = NULL;
+  GFile *f = NULL;
+
+  context = g_option_context_new ("COMMIT PATH [PATH...] - Concatenate contents of files");
+  g_option_context_add_main_entries (context, options, NULL);
+
+  if (!g_option_context_parse (context, &argc, &argv, error))
+    goto out;
+
+  repo = ostree_repo_new (repo_path);
+  if (!ostree_repo_check (repo, error))
+    goto out;
+
+  if (argc <= 2)
+    {
+      ot_util_usage_error (context, "An COMMIT and at least one PATH argument are required", error);
+      goto out;
+    }
+  rev = argv[1];
+
+  if (!ostree_repo_read_commit (repo, rev, &root, NULL, error))
+    goto out;
+
+  stdout_stream = g_unix_output_stream_new (1, FALSE);
+
+  for (i = 2; i < argc; i++)
+    {
+      g_clear_object (&f);
+      f = g_file_resolve_relative_path (root, argv[i]);
+
+      if (!cat_one_file (f, stdout_stream, cancellable, error))
+        goto out;
+    }
+ 
+  ret = TRUE;
+ out:
+  g_clear_object (&root);
+  g_clear_object (&f);
+  g_clear_object (&stdout_stream);
+  if (context)
+    g_option_context_free (context);
+  g_clear_object (&repo);
+  return ret;
+}
diff --git a/src/ostree/ot-builtins.h b/src/ostree/ot-builtins.h
index f35b7e2..befd203 100644
--- a/src/ostree/ot-builtins.h
+++ b/src/ostree/ot-builtins.h
@@ -27,6 +27,7 @@
 
 G_BEGIN_DECLS
 
+gboolean ostree_builtin_cat (int argc, char **argv, GFile *repo_path, GError **error);
 gboolean ostree_builtin_checkout (int argc, char **argv, GFile *repo_path, GError **error);
 gboolean ostree_builtin_checksum (int argc, char **argv, GFile *repo_path, GError **error);
 gboolean ostree_builtin_commit (int argc, char **argv, GFile *repo_path, GError **error);
diff --git a/tests/t0000-basic.sh b/tests/t0000-basic.sh
index c3cd7a5..bffed6f 100755
--- a/tests/t0000-basic.sh
+++ b/tests/t0000-basic.sh
@@ -19,7 +19,7 @@
 
 set -e
 
-echo "1..25"
+echo "1..26"
 
 . libtest.sh
 
@@ -185,3 +185,8 @@ echo "ok commit statoverridde"
 cd ${test_tmpdir}
 $OSTREE prune
 echo "ok prune didn't fail"
+
+cd ${test_tmpdir}
+$OSTREE cat test2 /yet/another/tree/green > greenfile-contents
+assert_file_has_content greenfile-contents "leaf"
+echo "ok cat-file"
diff --git a/tests/t0001-archive.sh b/tests/t0001-archive.sh
index 7849c1d..6bdc9aa 100755
--- a/tests/t0001-archive.sh
+++ b/tests/t0001-archive.sh
@@ -21,7 +21,7 @@ set -e
 
 . libtest.sh
 
-echo '1..9'
+echo '1..10'
 
 setup_test_repository "archive"
 echo "ok setup"
@@ -62,3 +62,8 @@ echo "ok uid0 ls"
 
 $OSTREE checkout -U test2-uid0 checkout-user-test2-uid0
 echo "ok user checkout from uid 0"
+
+cd ${test_tmpdir}
+$OSTREE cat test2 /baz/cow > cow-contents
+assert_file_has_content cow-contents "moo"
+echo "ok cat-file"