[ostree] core: checkout: Add --from-stdin option

[Colin Walters <walters src gnome org>]

commit a69e4452b464e56324454a69450bf3e76a5d3b0b
Author: Colin Walters <walters verbum org>
Date:   Fri Apr 6 15:11:11 2012 -0400

    core: checkout: Add --from-stdin option
    
    This allows checking out many branches in one go, useful in
    combination with the --union flag for ostbuild to combine a lot of
    components.

 src/ostree/ot-builtin-checkout.c |  258 +++++++++++++++++++++++++++-----------
 1 files changed, 182 insertions(+), 76 deletions(-)
---
diff --git a/src/ostree/ot-builtin-checkout.c b/src/ostree/ot-builtin-checkout.c
index a2a56b0..c7c0852 100644
--- a/src/ostree/ot-builtin-checkout.c
+++ b/src/ostree/ot-builtin-checkout.c
@@ -25,20 +25,24 @@
 #include "ot-builtins.h"
 #include "ostree.h"
 
+#include <gio/gunixinputstream.h>
+
 #include <glib/gi18n.h>
 
-static gboolean user_mode;
+static gboolean opt_user_mode;
 static gboolean opt_atomic_retarget;
 static gboolean opt_no_triggers;
-static char *subpath;
+static char *opt_subpath;
 static gboolean opt_union;
+static gboolean opt_from_stdin;
 
 static GOptionEntry options[] = {
-  { "user-mode", 'U', 0, G_OPTION_ARG_NONE, &user_mode, "Do not change file ownership or initialze extended attributes", NULL },
-  { "subpath", 0, 0, G_OPTION_ARG_STRING, &subpath, "Checkout sub-directory PATH", "PATH" },
+  { "user-mode", 'U', 0, G_OPTION_ARG_NONE, &opt_user_mode, "Do not change file ownership or initialze extended attributes", NULL },
+  { "subpath", 0, 0, G_OPTION_ARG_STRING, &opt_subpath, "Checkout sub-directory PATH", "PATH" },
   { "union", 0, 0, G_OPTION_ARG_NONE, &opt_union, "Keep existing directories, overwrite existing files", NULL },
   { "atomic-retarget", 0, 0, G_OPTION_ARG_NONE, &opt_atomic_retarget, "Make a symbolic link for destination, suffix with checksum", NULL },
   { "no-triggers", 0, 0, G_OPTION_ARG_NONE, &opt_no_triggers, "Don't run triggers", NULL },
+  { "from-stdin", 0, 0, G_OPTION_ARG_NONE, &opt_from_stdin, "Process many checkouts from standard input", NULL },
   { NULL }
 };
 
@@ -116,6 +120,110 @@ parse_commit_from_symlink (GFile        *symlink,
   return ret;
 }
 
+static gboolean
+process_one_checkout (OstreeRepo           *repo,
+                      const char           *resolved_commit,
+                      const char           *subpath,
+                      GFile                *target,
+                      GCancellable         *cancellable,
+                      GError              **error)
+{
+  gboolean ret = FALSE;
+  OstreeRepoFile *root = NULL;
+  OstreeRepoFile *subtree = NULL;
+  GFileInfo *file_info = NULL;
+  
+  root = (OstreeRepoFile*)ostree_repo_file_new_root (repo, resolved_commit);
+  if (!ostree_repo_file_ensure_resolved (root, error))
+    goto out;
+  
+  if (subpath)
+    subtree = (OstreeRepoFile*)g_file_resolve_relative_path ((GFile*)root, subpath);
+  else
+    subtree = g_object_ref (root);
+
+  file_info = g_file_query_info ((GFile*)subtree, OSTREE_GIO_FAST_QUERYINFO,
+                                 G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
+                                 cancellable, error);
+  if (!file_info)
+    goto out;
+
+  if (!ostree_repo_checkout_tree (repo, opt_user_mode ? OSTREE_REPO_CHECKOUT_MODE_USER : 0,
+                                  opt_union ? OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_FILES : 0,
+                                  target, subtree, file_info, cancellable, error))
+    goto out;
+                      
+  ret = TRUE;
+ out:
+  g_clear_object (&subtree);
+  g_clear_object (&root);
+  g_clear_object (&file_info);
+  return ret;
+}
+
+static gboolean
+process_many_checkouts (OstreeRepo         *repo,
+                        GFile              *target,
+                        GCancellable       *cancellable,
+                        GError            **error)
+{
+  gboolean ret = FALSE;
+  GInputStream *stdin_stream = NULL;
+  GDataInputStream *stdin_data = NULL;
+  char *revision = NULL;
+  char *subpath = NULL;
+  char *resolved_commit = NULL;
+  gsize len;
+  GError *temp_error = NULL;
+
+  stdin_stream = (GInputStream*)g_unix_input_stream_new (0, FALSE);
+  stdin_data = g_data_input_stream_new (stdin_stream);
+
+  while ((revision = g_data_input_stream_read_upto (stdin_data, "", 1, &len,
+                                                    cancellable, &temp_error)) != NULL)
+    {
+      if (revision[0] == '\0')
+        break;
+
+      /* Read the null byte */
+      (void) g_data_input_stream_read_byte (stdin_data, cancellable, NULL);
+      g_free (subpath);
+      subpath = g_data_input_stream_read_upto (stdin_data, "", 1, &len,
+                                               cancellable, &temp_error);
+      if (temp_error)
+        {
+          g_propagate_error (error, temp_error);
+          goto out;
+        }
+
+      /* Read the null byte */
+      (void) g_data_input_stream_read_byte (stdin_data, cancellable, NULL);
+
+      if (!ostree_repo_resolve_rev (repo, revision, FALSE, &resolved_commit, error))
+        goto out;
+
+      if (!process_one_checkout (repo, resolved_commit, subpath, target,
+                                 cancellable, error))
+        goto out;
+
+      g_free (revision);
+    }
+  if (temp_error)
+    {
+      g_propagate_error (error, temp_error);
+      goto out;
+    }
+
+  ret = TRUE;
+ out:
+  g_free (subpath);
+  g_free (revision);
+  g_free (resolved_commit);
+  g_clear_object (&stdin_stream);
+  g_clear_object (&stdin_data);
+  return ret;
+}
+
 gboolean
 ostree_builtin_checkout (int argc, char **argv, GFile *repo_path, GError **error)
 {
@@ -129,9 +237,6 @@ ostree_builtin_checkout (int argc, char **argv, GFile *repo_path, GError **error
   const char *destination;
   char *suffixed_destination = NULL;
   char *tmp_destination = NULL;
-  OstreeRepoFile *root = NULL;
-  OstreeRepoFile *subtree = NULL;
-  GFileInfo *file_info = NULL;
   GFileInfo *symlink_file_info = NULL;
   GFile *checkout_target = NULL;
   GFile *checkout_target_tmp = NULL;
@@ -157,93 +262,97 @@ ostree_builtin_checkout (int argc, char **argv, GFile *repo_path, GError **error
                            "COMMIT must be specified");
       goto out;
     }
-  
-  commit = argv[1];
-  if (argc < 3)
-    destination = commit;
-  else
-    destination = argv[2];
-
-  if (!ostree_repo_resolve_rev (repo, commit, FALSE, &resolved_commit, error))
-    goto out;
 
-  if (opt_atomic_retarget)
+  if (opt_from_stdin)
     {
-      GError *temp_error = NULL;
-
-      suffixed_destination = g_strconcat (destination, "-", resolved_commit, NULL);
-      checkout_target = ot_gfile_new_for_path (suffixed_destination);
-      tmp_destination = g_strconcat (suffixed_destination, ".tmp", NULL);
-      checkout_target_tmp = ot_gfile_new_for_path (tmp_destination);
-      symlink_target = ot_gfile_new_for_path (destination);
-
-      if (!parse_commit_from_symlink (symlink_target, &existing_commit,
-                                      cancellable, &temp_error))
+      if (opt_atomic_retarget)
         {
-          if (g_error_matches (temp_error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
-            {
-              skip_checkout = FALSE;
-              g_clear_error (&temp_error);
-            }
-          else
-            {
-              g_propagate_error (error, temp_error);
-              goto out;
-            }
+          g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                       "--atomic-retarget may not be used with --from-stdin");
+          goto out;
         }
-      else
+
+      destination = argv[1];
+      checkout_target = ot_gfile_new_for_path (destination);
+
+      if (!process_many_checkouts (repo, checkout_target, cancellable, error))
+        goto out;
+      
+      if (!opt_no_triggers)
         {
-          skip_checkout = strcmp (existing_commit, resolved_commit) == 0;
+          if (!ostree_run_triggers_in_root (checkout_target, cancellable, error))
+            goto out;
         }
     }
   else
     {
-      checkout_target = ot_gfile_new_for_path (destination);
-      skip_checkout = FALSE;
-    }
+      commit = argv[1];
+      if (argc < 3)
+        destination = commit;
+      else
+        destination = argv[2];
 
-  if (!skip_checkout)
-    {
-      root = (OstreeRepoFile*)ostree_repo_file_new_root (repo, resolved_commit);
-      if (!ostree_repo_file_ensure_resolved (root, error))
+      if (!ostree_repo_resolve_rev (repo, commit, FALSE, &resolved_commit, error))
         goto out;
 
-      if (subpath)
+      if (opt_atomic_retarget)
         {
-          subtree = (OstreeRepoFile*)g_file_resolve_relative_path ((GFile*)root, subpath);
+          GError *temp_error = NULL;
+
+          suffixed_destination = g_strconcat (destination, "-", resolved_commit, NULL);
+          checkout_target = ot_gfile_new_for_path (suffixed_destination);
+          tmp_destination = g_strconcat (suffixed_destination, ".tmp", NULL);
+          checkout_target_tmp = ot_gfile_new_for_path (tmp_destination);
+          symlink_target = ot_gfile_new_for_path (destination);
+
+          if (!parse_commit_from_symlink (symlink_target, &existing_commit,
+                                          cancellable, &temp_error))
+            {
+              if (g_error_matches (temp_error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
+                {
+                  skip_checkout = FALSE;
+                  g_clear_error (&temp_error);
+                }
+              else
+                {
+                  g_propagate_error (error, temp_error);
+                  goto out;
+                }
+            }
+          else
+            {
+              skip_checkout = strcmp (existing_commit, resolved_commit) == 0;
+            }
         }
       else
         {
-          subtree = g_object_ref (root);
+          checkout_target = ot_gfile_new_for_path (destination);
+          skip_checkout = FALSE;
         }
 
-      file_info = g_file_query_info ((GFile*)subtree, OSTREE_GIO_FAST_QUERYINFO,
-                                     G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
-                                     cancellable, error);
-      if (!file_info)
-        goto out;
-
-      if (!ostree_repo_checkout_tree (repo, user_mode ? OSTREE_REPO_CHECKOUT_MODE_USER : 0,
-                                      opt_union ? OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_FILES : 0,
-                                      checkout_target_tmp ? checkout_target_tmp : checkout_target,
-                                      subtree, file_info, cancellable, error))
-        goto out;
-
-      if (!opt_no_triggers)
+      if (!skip_checkout)
         {
-          if (!ostree_run_triggers_in_root (checkout_target_tmp ? checkout_target_tmp : checkout_target,
-                                            cancellable, error))
+          if (!process_one_checkout (repo, resolved_commit, opt_subpath,
+                                     checkout_target_tmp ? checkout_target_tmp : checkout_target,
+                                     cancellable, error))
             goto out;
-        }
 
-      if (opt_atomic_retarget)
-        {
-          if (!ot_gfile_rename (checkout_target_tmp, checkout_target, cancellable, error))
-            goto out;
-          if (!atomic_symlink_swap (symlink_target,
-                                    ot_gfile_get_basename_cached (checkout_target),
-                                    cancellable, error))
-            goto out;
+          if (!opt_no_triggers)
+            {
+              if (!ostree_run_triggers_in_root (checkout_target_tmp ? checkout_target_tmp : checkout_target,
+                                                cancellable, error))
+                goto out;
+            }
+
+          if (opt_atomic_retarget)
+            {
+              if (!ot_gfile_rename (checkout_target_tmp, checkout_target, cancellable, error))
+                goto out;
+              if (!atomic_symlink_swap (symlink_target,
+                                        ot_gfile_get_basename_cached (checkout_target),
+                                        cancellable, error))
+                goto out;
+            }
         }
     }
 
@@ -259,9 +368,6 @@ ostree_builtin_checkout (int argc, char **argv, GFile *repo_path, GError **error
   if (context)
     g_option_context_free (context);
   g_clear_object (&repo);
-  g_clear_object (&root);
-  g_clear_object (&subtree);
-  g_clear_object (&file_info);
   g_clear_object (&symlink_file_info);
   return ret;
 }