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-rw-r--r--xlators/meta/src/tree.c176
1 files changed, 176 insertions, 0 deletions
diff --git a/xlators/meta/src/tree.c b/xlators/meta/src/tree.c
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+++ b/xlators/meta/src/tree.c
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+/*
+ Copyright (c) 2006, 2007, 2008 Z RESEARCH, Inc. <http://www.zresearch.com>
+ This file is part of GlusterFS.
+
+ GlusterFS is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published
+ by the Free Software Foundation; either version 3 of the License,
+ or (at your option) any later version.
+
+ GlusterFS 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
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see
+ <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include "config.h"
+#endif
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "glusterfs.h"
+#include "xlator.h"
+
+#include "meta.h"
+
+static int
+is_meta_path (const char *path)
+{
+ while (*path == '/')
+ path++;
+ if (!strncmp (path, ".meta", strlen (".meta")))
+ return 1;
+ return 0;
+}
+
+struct stat *
+new_stbuf (void)
+{
+ static int next_inode = 0;
+ struct stat *stbuf = CALLOC (1, sizeof (struct stat));
+
+ ERR_ABORT (stbuf);
+
+ stbuf->st_dev = 0;
+ stbuf->st_ino = next_inode++;
+ stbuf->st_mode = S_IRUSR | S_IRGRP | S_IROTH;
+ stbuf->st_nlink = 1;
+ stbuf->st_uid = 0;
+ stbuf->st_gid = 0;
+ stbuf->st_rdev = 0;
+ stbuf->st_size = 0;
+ stbuf->st_blksize = 0;
+ stbuf->st_blocks = 0;
+ stbuf->st_atime = time (NULL);
+ stbuf->st_atim.tv_nsec = 0;
+ stbuf->st_mtime = stbuf->st_atime;
+ stbuf->st_mtim.tv_nsec = 0;
+ stbuf->st_ctime = stbuf->st_ctime;
+ stbuf->st_ctim.tv_nsec = 0;
+
+ return stbuf;
+}
+
+/* find an entry among the siblings of an entry */
+static meta_dirent_t *
+find_entry (meta_dirent_t *node, const char *dir)
+{
+ meta_dirent_t *trav = node;
+ while (trav) {
+ if (!strcmp (trav->name, dir))
+ return trav;
+ trav = trav->next;
+ }
+ return NULL;
+}
+
+/*
+ * Return the meta_dirent_t corresponding to the pathname.
+ *
+ * If pathname does not exist in the meta tree, try to return
+ * its highest parent that does exist. The part of the
+ * pathname that is left over is returned in the value-result
+ * variable {remain}.
+ * For example, for "/.meta/xlators/brick1/view/foo/bar/baz",
+ * return the entry for "/.meta/xlators/brick1/view"
+ * and set remain to "/bar/baz"
+ */
+
+meta_dirent_t *
+lookup_meta_entry (meta_dirent_t *root, const char *path,
+ char **remain)
+{
+ char *_path = strdup (path);
+
+ if (!is_meta_path (path))
+ return NULL;
+
+ meta_dirent_t *trav = root;
+ char *dir = strtok (_path, "/");
+ dir = strtok (NULL, "/");
+
+ while (dir) {
+ meta_dirent_t *ntrav;
+ ntrav = find_entry (trav->children, dir);
+ if (!ntrav) {
+ /* we have reached bottom of the meta tree.
+ Unknown dragons lie further below */
+ if (remain) {
+ char *piece = dir;
+ while (piece) {
+ char *tmp = *remain;
+ if (*remain)
+ asprintf (remain, "/%s/%s", *remain, piece);
+ else
+ asprintf (remain, "/%s", piece);
+ if (tmp) free (tmp);
+ piece = strtok (NULL, "/");
+ }
+ }
+ return trav;
+ }
+ dir = strtok (NULL, "/");
+ trav = ntrav;
+ }
+
+ free (_path);
+ return trav;
+}
+
+meta_dirent_t *
+insert_meta_entry (meta_dirent_t *root, const char *path,
+ int type, struct stat *stbuf, struct xlator_fops *fops)
+{
+ if (!is_meta_path (path))
+ return NULL;
+ char *slashpos = strrchr (path, '/');
+ char *dir = strndup (path, slashpos - path);
+ meta_dirent_t *parent = lookup_meta_entry (root, dir, NULL);
+ if (!dir)
+ return NULL;
+
+ meta_dirent_t *new = CALLOC (1, sizeof (meta_dirent_t));
+ ERR_ABORT (new);
+ new->name = strdup (slashpos+1);
+ new->type = type;
+ new->parent = parent;
+ new->next = parent->children;
+ parent->children = new;
+ if (stbuf)
+ new->stbuf = stbuf;
+ else
+ new->stbuf = new_stbuf ();
+
+ new->stbuf->st_mode |= type;
+ new->fops = fops;
+ return new;
+}
+
+int main (void)
+{
+ meta_dirent_t *root = CALLOC (1, sizeof (meta_dirent_t));
+ ERR_ABORT (root);
+ root->name = strdup (".meta");
+
+ insert_meta_entry (root, "/.meta/version", S_IFREG, NULL, NULL);
+ return 0;
+}