Introduce struct razor_root.

This object encapsulates the directory layout and locking protocol for
a razor install root.

diff --git a/main.c b/main.c
index 45ef898..6f27f41 100644 (file)
--- a/main.c
+++ b/main.c
@@ -563,6 +563,159 @@ command_import_rpms(int argc, const char *argv[])
        return 0;
 }
 
+/* The image data struct encapsulates filesystem conventions and the
+ * locking protocol.  FIXME: Should this be razor_root?*/
+struct razor_root {
+       struct razor_set *system;
+       int fd;
+       char path[PATH_MAX];
+       char new_path[PATH_MAX];
+};
+
+#define RAZOR_ROOT_OPEN_WRITE 0x01
+
+int
+razor_root_create(const char *root);
+struct razor_root *
+razor_root_open(const char *root, int flags);
+struct razor_transaction *
+razor_root_create_transaction(struct razor_root *image,
+                             struct razor_set *upstream);
+int
+razor_root_close(struct razor_root *image);
+void
+razor_root_update(struct razor_root *image, struct razor_set *next);
+int
+razor_root_commit(struct razor_root *image);
+
+int
+razor_root_create(const char *root)
+{      
+       struct stat buf;
+       struct razor_set *set;
+       char path[PATH_MAX];
+
+       if (stat(root, &buf) < 0) {
+               if (mkdir(root, 0777) < 0) {
+                       fprintf(stderr,
+                               "could not create install root \"%s\"\n",
+                               root);
+                       return -1;
+               }
+               fprintf(stderr, "created install root \"%s\"\n", root);
+       } else if (!S_ISDIR(buf.st_mode)) {
+               fprintf(stderr,
+                       "install root \"%s\" exists, but is not a directory\n",
+                       root);
+               return -1;
+       }
+
+       snprintf(path, sizeof path, "%s/%s",
+                razor_root_path, system_repo_filename);
+       if (razor_create_dir(root, path) < 0) {
+               fprintf(stderr, "could not create %s%s\n",
+                       root, razor_root_path);
+               return -1;
+       }
+
+       set = razor_set_create();
+       snprintf(path, sizeof path, "%s%s/%s",
+                root, razor_root_path, system_repo_filename);
+       if (stat(root, &buf) == 0) {
+               fprintf(stderr,
+                       "a razor install root is already initialized\n");
+               return -1;
+       }
+       if (razor_set_write(set, path) < 0) {
+               fprintf(stderr, "could not write initial package set\n");
+               return -1;
+       }
+       razor_set_destroy(set);
+
+       return 0;
+}
+
+struct razor_root *
+razor_root_open(const char *root, int flags)
+{
+       struct razor_root *image;
+
+       image = malloc(sizeof *image);
+       if (image == NULL)
+               return NULL;
+
+       /* Create the new next repo file up front to ensure exclusive
+        * access. */
+       snprintf(image->new_path, sizeof image->new_path,
+                "%s%s/%s", root, root, next_repo_filename);
+       image->fd = open(image->new_path,
+                        O_CREAT | O_WRONLY | O_TRUNC | O_EXCL, 0666);
+       if (image->fd < 0) {
+               fprintf(stderr, "failed to get lock file, "
+                       "maybe previous operation crashed?\n");
+
+               /* FIXME: Use fcntl advisory locking on the system
+                * package set file to figure out whether previous
+                * operation crashed or is still in progress. */
+
+               free(image);
+               return NULL;
+       }
+
+       snprintf(image->path, sizeof image->path,
+                "%s%s/%s", root, razor_root_path, system_repo_filename);
+       image->system = razor_set_open(image->path);
+       if (image->system == NULL) {
+               unlink(image->new_path);
+               close(image->fd);
+               free(image);
+               return NULL;
+       }
+
+       return image;
+}
+
+struct razor_transaction *
+razor_root_create_transaction(struct razor_root *image,
+                             struct razor_set *upstream)
+{
+       /* FIXME: This should take a number of upstream repos. */
+       return razor_transaction_create(image->system, upstream);
+}
+
+int
+razor_root_close(struct razor_root *image)
+{
+       unlink(image->new_path);
+       close(image->fd);
+       free(image);
+
+       return 0;
+}
+
+void
+razor_root_update(struct razor_root *image, struct razor_set *next)
+{
+       razor_set_write_to_fd(next, image->fd);
+
+       /* Sync the new repo file so the new package set is on disk
+        * before we start upgrading. */
+       fsync(image->fd);
+       printf("wrote %s\n", image->new_path);
+}
+
+int
+razor_root_commit(struct razor_root *image)
+{
+       /* Make it so. */
+       rename(image->new_path, image->path);
+       printf("renamed %s to %s\n", image->new_path, image->path);
+       close(image->fd);
+       free(image);
+
+       return 0;
+}
+
 static void
 download_package(const char *name,
                 const char *old_version,
@@ -634,45 +787,24 @@ install_package(const char *name,
 static int
 command_install(int argc, const char *argv[])
 {
-       struct razor_set *system, *upstream, *next;
+       struct razor_root *root;
+       struct razor_set *upstream, *next;
        struct razor_transaction *trans;
-       char path[PATH_MAX], new_path[PATH_MAX];
-       int i = 0, errors, fd, dependencies = 1;
+       int i = 0, errors, dependencies = 1;
 
        if (i < argc && strcmp(argv[i], "--no-dependencies") == 0) {
                dependencies = 0;
                i++;
        }
 
-       /* Create the new next repo file up front to ensure exclusive
-        * access. */
-       snprintf(new_path, sizeof new_path,
-                "%s%s/%s", root, razor_root_path, next_repo_filename);
-       fd = open(new_path, O_CREAT | O_WRONLY | O_TRUNC | O_EXCL, 0666);
-       if (fd < 0) {
-               fprintf(stderr, "failed to get lock file, "
-                       "maybe previous operation crashed?\n");
-
-               /* FIXME: Use fcntl advisory locking to figure out
-                * whether previous operation crashed or is still in
-                * progress. */
-
-               return -1;
-       }
-
+       root = razor_root_open(razor_root_path, RAZOR_ROOT_OPEN_WRITE);
        upstream = razor_set_open(rawhide_repo_filename);
-       snprintf(path, sizeof path,
-                "%s%s/%s", root, razor_root_path, system_repo_filename);
-       system = razor_set_open(path);
-       if (system == NULL || upstream == NULL) {
-               unlink(new_path);
-               return 1;
-       }
-       trans = razor_transaction_create(system, upstream);
+       trans = razor_root_create_transaction(root, upstream);
+
        for (; i < argc; i++) {
                if (mark_packages_for_update(trans, upstream, argv[i]) == 0) {
                        fprintf(stderr, "no package matched %s\n", argv[i]);
-                       unlink(new_path);
+                       razor_root_close(root);
                        return 1;
                }
        }
@@ -680,83 +812,42 @@ command_install(int argc, const char *argv[])
        if (dependencies) {
                errors = razor_transaction_resolve(trans);
                if (errors) {
-                       unlink(new_path);
+                       razor_root_close(root);
                        return 1;
                }
        }
 
        next = razor_transaction_finish(trans);
 
-       razor_set_write_to_fd(next, fd);
-       printf("wrote %s\n", new_path);
+       razor_root_update(root, next);
 
        if (mkdir("rpms", 0777) && errno != EEXIST) {
                fprintf(stderr, "failed to create rpms directory.\n");
+               razor_root_close(root);
                return 1;
        }
 
-       razor_set_diff(system, next, download_package, &errors);
+       razor_set_diff(root->system, next, download_package, &errors);
        if (errors > 0) {
                fprintf(stderr, "failed to download %d packages\n", errors);
-               unlink(new_path);
+               razor_root_close(root);
                 return 1;
         }
 
        /* FIXME: We need to figure out the right install order here,
         * so the post and pre scripts can run. */
-       razor_set_diff(system, next, install_package, (void *) root);
+       razor_set_diff(root->system, next, install_package, (void *) root);
 
        razor_set_destroy(next);
-       razor_set_destroy(system);
        razor_set_destroy(upstream);
 
-       /* Make it so. */
-       rename(new_path, path);
-       printf("renamed %s to %s\n", new_path, path);
-
-       return 0;
+       return razor_root_commit(root);
 }
 
 static int
 command_init(int argc, const char *argv[])
 {
-       struct stat buf;
-       struct razor_set *set;
-       char path[PATH_MAX];
-
-       if (stat(root, &buf) < 0) {
-               if (mkdir(root, 0777) < 0) {
-                       fprintf(stderr,
-                               "could not create install root \"%s\"\n",
-                               root);
-                       return -1;
-               }
-               fprintf(stderr, "created install root \"%s\"\n", root);
-       } else if (!S_ISDIR(buf.st_mode)) {
-               fprintf(stderr,
-                       "install root \"%s\" exists, but is not a directory\n",
-                       root);
-               return -1;
-       }
-
-       snprintf(path, sizeof path, "%s/%s",
-                razor_root_path, system_repo_filename);
-       if (razor_create_dir(root, path) < 0) {
-               fprintf(stderr, "could not create %s%s\n",
-                       root, razor_root_path);
-               return -1;
-       }
-
-       set = razor_set_create();
-       snprintf(path, sizeof path, "%s%s/%s",
-                root, razor_root_path, system_repo_filename);
-       if (razor_set_write(set, path) < 0) {
-               fprintf(stderr, "could not write initial package set\n");
-               return -1;
-       }
-       razor_set_destroy(set);
-
-       return 0;
+       return razor_root_create(root);
 }
 
 static int