+++ /dev/null
-/* Blue Sky: File Systems in the Cloud
- *
- * Copyright (C) 2009 The Regents of the University of California
- * Written by Michael Vrable <mvrable@cs.ucsd.edu>
- *
- * TODO: Licensing
- */
-
-#include <stdint.h>
-#include <glib.h>
-
-#include "bluesky.h"
-
-/* Core filesystem: handling of directories. */
-
-void bluesky_dirent_destroy(gpointer data)
-{
- BlueSkyDirent *dirent = (BlueSkyDirent *)data;
- g_free(dirent->name);
- g_free(dirent);
-}
-
-gint bluesky_dirent_compare(gconstpointer a, gconstpointer b,
- gpointer unused)
-{
- uint32_t hash1 = ((const BlueSkyDirent *)a)->cookie;
- uint32_t hash2 = ((const BlueSkyDirent *)b)->cookie;
-
- if (hash1 < hash2)
- return -1;
- else if (hash1 > hash2)
- return 1;
- else
- return 0;
-}
-
-/* Perform a lookup for a file name within a directory. Returns the inode
- * number if found, or 0 if not (0 is never a valid inode number). Should be
- * called with the inode lock already held. */
-uint64_t bluesky_directory_lookup(BlueSkyInode *inode, gchar *name)
-{
- g_return_val_if_fail(inode->type == BLUESKY_DIRECTORY, 0);
- g_return_val_if_fail(inode->dirhash != NULL, 0);
-
- BlueSkyDirent *d = g_hash_table_lookup(inode->dirhash, name);
- if (d == NULL)
- return 0;
- else
- return d->inum;
-}
-
-/* Insert a new entry into a directory. Should be called with the inode lock
- * already held. */
-gboolean bluesky_directory_insert(BlueSkyInode *dir, gchar *name, uint64_t inum)
-{
- g_return_val_if_fail(dir->type == BLUESKY_DIRECTORY, FALSE);
-
- /* Check that no entry with the given name already exists. */
- if (g_hash_table_lookup(dir->dirhash, name) != NULL)
- return FALSE;
-
- BlueSkyDirent *d = g_new(BlueSkyDirent, 1);
- d->name = g_strdup(name);
- d->inum = inum;
-
- GSequence *dirents = dir->dirents;
-
- /* Pick an unused cookie value for the directory at random. Restrict
- * ourselves to positive 32-bit values (even if treated as signed), and
- * keep the first four slots free. */
- while (1) {
- do {
- d->cookie = g_random_int() & 0x7fffffff;
- } while (d->cookie < 4);
-
- /* If the directory is empty, we can't possibly have a collision, so
- * just go with the first key chosen. */
- if (g_sequence_get_length(dirents) == 0)
- break;
-
- /* Otherwise, try looking up the generated cookie. If we do not find a
- * match, we can use this cookie value, otherwise we need to generate a
- * new one and try again. Because of the check above for an empty
- * directory, we know that the lookup will return something so no need
- * to worry about NULL. */
- GSequenceIter *i = g_sequence_search(dir->dirents, d,
- bluesky_dirent_compare, NULL);
- i = g_sequence_iter_prev(i);
- if (((BlueSkyDirent *)g_sequence_get(i))->cookie != d->cookie)
- break;
- }
-
- /* Add the directory entry to both indices. */
- g_sequence_insert_sorted(dirents, d, bluesky_dirent_compare, NULL);
- g_hash_table_insert(dir->dirhash, d->name, d);
-
- bluesky_inode_update_ctime(dir, 1);
-
- return TRUE;
-}
-
-/* Remove an from a directory. Should be called with the inode lock already
- * held. */
-gboolean bluesky_directory_remove(BlueSkyInode *dir, gchar *name)
-{
- g_return_val_if_fail(dir->type == BLUESKY_DIRECTORY, FALSE);
-
- BlueSkyDirent *d = g_hash_table_lookup(dir->dirhash, name);
- if (d == NULL) {
- return FALSE;
- }
-
- g_hash_table_remove(dir->dirhash, name);
-
- GSequenceIter *i = g_sequence_search(dir->dirents, d,
- bluesky_dirent_compare, NULL);
- i = g_sequence_iter_prev(i);
-
- /* Assertion check, this ought to succeed */
- g_return_val_if_fail(g_sequence_get(i) == d, FALSE);
-
- g_sequence_remove(i);
-
- bluesky_dirent_destroy(d);
-
- bluesky_inode_update_ctime(dir, 1);
-
- return TRUE;
-}
-
-/* Dump the contents of a directory to stdout. Debugging only. */
-void bluesky_directory_dump(BlueSkyInode *dir)
-{
- g_print("Directory dump:\n");
-
- GSequenceIter *i = g_sequence_get_begin_iter(dir->dirents);
-
- while (!g_sequence_iter_is_end(i)) {
- BlueSkyDirent *d = g_sequence_get(i);
- g_print(" 0x%08x [inum=%lld] %s\n", d->cookie, d->inum, d->name);
- i = g_sequence_iter_next(i);
- }
-}