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diff --git a/endless/gvdb/gvdb-reader.c b/endless/gvdb/gvdb-reader.c
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+/*
+ * Copyright © 2010 Codethink Limited
+ *
+ * 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 licence, 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: Allison Lortie <desrt@desrt.ca>
+ */
+
+#include "gvdb-reader.h"
+#include "gvdb-format.h"
+
+#include <string.h>
+
+struct _GvdbTable {
+ GBytes *bytes;
+
+ const gchar *data;
+ gsize size;
+
+ gboolean byteswapped;
+ gboolean trusted;
+
+ const guint32_le *bloom_words;
+ guint32 n_bloom_words;
+ guint bloom_shift;
+
+ const guint32_le *hash_buckets;
+ guint32 n_buckets;
+
+ struct gvdb_hash_item *hash_items;
+ guint32 n_hash_items;
+};
+
+static const gchar *
+gvdb_table_item_get_key (GvdbTable *file,
+ const struct gvdb_hash_item *item,
+ gsize *size)
+{
+ guint32 start, end;
+
+ start = guint32_from_le (item->key_start);
+ *size = guint16_from_le (item->key_size);
+ end = start + *size;
+
+ if G_UNLIKELY (start > end || end > file->size)
+ return NULL;
+
+ return file->data + start;
+}
+
+static gconstpointer
+gvdb_table_dereference (GvdbTable *file,
+ const struct gvdb_pointer *pointer,
+ gint alignment,
+ gsize *size)
+{
+ guint32 start, end;
+
+ start = guint32_from_le (pointer->start);
+ end = guint32_from_le (pointer->end);
+
+ if G_UNLIKELY (start > end || end > file->size || start & (alignment - 1))
+ return NULL;
+
+ *size = end - start;
+
+ return file->data + start;
+}
+
+static void
+gvdb_table_setup_root (GvdbTable *file,
+ const struct gvdb_pointer *pointer)
+{
+ const struct gvdb_hash_header *header;
+ guint32 n_bloom_words;
+ guint32 n_buckets;
+ gsize size;
+
+ header = gvdb_table_dereference (file, pointer, 4, &size);
+
+ if G_UNLIKELY (header == NULL || size < sizeof *header)
+ return;
+
+ size -= sizeof *header;
+
+ n_bloom_words = guint32_from_le (header->n_bloom_words);
+ n_buckets = guint32_from_le (header->n_buckets);
+ n_bloom_words &= (1u << 27) - 1;
+
+ if G_UNLIKELY (n_bloom_words * sizeof (guint32_le) > size)
+ return;
+
+ file->bloom_words = (gpointer) (header + 1);
+ size -= n_bloom_words * sizeof (guint32_le);
+ file->n_bloom_words = n_bloom_words;
+
+ if G_UNLIKELY (n_buckets > G_MAXUINT / sizeof (guint32_le) ||
+ n_buckets * sizeof (guint32_le) > size)
+ return;
+
+ file->hash_buckets = file->bloom_words + file->n_bloom_words;
+ size -= n_buckets * sizeof (guint32_le);
+ file->n_buckets = n_buckets;
+
+ if G_UNLIKELY (size % sizeof (struct gvdb_hash_item))
+ return;
+
+ file->hash_items = (gpointer) (file->hash_buckets + n_buckets);
+ file->n_hash_items = size / sizeof (struct gvdb_hash_item);
+}
+
+/**
+ * gvdb_table_new_from_bytes:
+ * @bytes: the #GBytes with the data
+ * @trusted: if the contents of @bytes are trusted
+ * @error: %NULL, or a pointer to a %NULL #GError
+ * @returns: a new #GvdbTable
+ *
+ * Creates a new #GvdbTable from the contents of @bytes.
+ *
+ * This call can fail if the header contained in @bytes is invalid.
+ *
+ * You should call gvdb_table_free() on the return result when you no
+ * longer require it.
+ **/
+GvdbTable *
+gvdb_table_new_from_bytes (GBytes *bytes,
+ gboolean trusted,
+ GError **error)
+{
+ const struct gvdb_header *header;
+ GvdbTable *file;
+
+ file = g_slice_new0 (GvdbTable);
+ file->bytes = g_bytes_ref (bytes);
+ file->data = g_bytes_get_data (bytes, &file->size);
+ file->trusted = trusted;
+
+ if (file->size < sizeof (struct gvdb_header))
+ goto invalid;
+
+ header = (gpointer) file->data;
+
+ if (header->signature[0] == GVDB_SIGNATURE0 &&
+ header->signature[1] == GVDB_SIGNATURE1 &&
+ guint32_from_le (header->version) == 0)
+ file->byteswapped = FALSE;
+
+ else if (header->signature[0] == GVDB_SWAPPED_SIGNATURE0 &&
+ header->signature[1] == GVDB_SWAPPED_SIGNATURE1 &&
+ guint32_from_le (header->version) == 0)
+ file->byteswapped = TRUE;
+
+ else
+ goto invalid;
+
+ gvdb_table_setup_root (file, &header->root);
+
+ return file;
+
+invalid:
+ g_set_error_literal (error, G_FILE_ERROR, G_FILE_ERROR_INVAL, "invalid gvdb header");
+
+ g_bytes_unref (file->bytes);
+
+ g_slice_free (GvdbTable, file);
+
+ return NULL;
+}
+
+/**
+ * gvdb_table_new:
+ * @filename: a filename
+ * @trusted: if the contents of @bytes are trusted
+ * @error: %NULL, or a pointer to a %NULL #GError
+ * @returns: a new #GvdbTable
+ *
+ * Creates a new #GvdbTable using the #GMappedFile for @filename as the
+ * #GBytes.
+ **/
+GvdbTable *
+gvdb_table_new (const gchar *filename,
+ gboolean trusted,
+ GError **error)
+{
+ GMappedFile *mapped;
+ GvdbTable *table;
+ GBytes *bytes;
+
+ mapped = g_mapped_file_new (filename, FALSE, error);
+ if (!mapped)
+ return NULL;
+
+ bytes = g_mapped_file_get_bytes (mapped);
+ table = gvdb_table_new_from_bytes (bytes, trusted, error);
+ g_mapped_file_unref (mapped);
+ g_bytes_unref (bytes);
+
+ g_prefix_error (error, "%s: ", filename);
+
+ return table;
+}
+
+static gboolean
+gvdb_table_bloom_filter (GvdbTable *file,
+ guint32 hash_value)
+{
+ guint32 word, mask;
+
+ if (file->n_bloom_words == 0)
+ return TRUE;
+
+ word = (hash_value / 32) % file->n_bloom_words;
+ mask = 1 << (hash_value & 31);
+ mask |= 1 << ((hash_value >> file->bloom_shift) & 31);
+
+ return (guint32_from_le (file->bloom_words[word]) & mask) == mask;
+}
+
+static gboolean
+gvdb_table_check_name (GvdbTable *file,
+ struct gvdb_hash_item *item,
+ const gchar *key,
+ guint key_length)
+{
+ const gchar *this_key;
+ gsize this_size;
+ guint32 parent;
+
+ this_key = gvdb_table_item_get_key (file, item, &this_size);
+
+ if G_UNLIKELY (this_key == NULL || this_size > key_length)
+ return FALSE;
+
+ key_length -= this_size;
+
+ if G_UNLIKELY (memcmp (this_key, key + key_length, this_size) != 0)
+ return FALSE;
+
+ parent = guint32_from_le (item->parent);
+ if (key_length == 0 && parent == 0xffffffffu)
+ return TRUE;
+
+ if G_LIKELY (parent < file->n_hash_items && this_size > 0)
+ return gvdb_table_check_name (file,
+ &file->hash_items[parent],
+ key, key_length);
+
+ return FALSE;
+}
+
+static const struct gvdb_hash_item *
+gvdb_table_lookup (GvdbTable *file,
+ const gchar *key,
+ gchar type)
+{
+ guint32 hash_value = 5381;
+ guint key_length;
+ guint32 bucket;
+ guint32 lastno;
+ guint32 itemno;
+
+ if G_UNLIKELY (file->n_buckets == 0 || file->n_hash_items == 0)
+ return NULL;
+
+ for (key_length = 0; key[key_length]; key_length++)
+ hash_value = (hash_value * 33) + ((signed char *) key)[key_length];
+
+ if (!gvdb_table_bloom_filter (file, hash_value))
+ return NULL;
+
+ bucket = hash_value % file->n_buckets;
+ itemno = guint32_from_le (file->hash_buckets[bucket]);
+
+ if (bucket == file->n_buckets - 1 ||
+ (lastno = guint32_from_le(file->hash_buckets[bucket + 1])) > file->n_hash_items)
+ lastno = file->n_hash_items;
+
+ while G_LIKELY (itemno < lastno)
+ {
+ struct gvdb_hash_item *item = &file->hash_items[itemno];
+
+ if (hash_value == guint32_from_le (item->hash_value))
+ if G_LIKELY (gvdb_table_check_name (file, item, key, key_length))
+ if G_LIKELY (item->type == type)
+ return item;
+
+ itemno++;
+ }
+
+ return NULL;
+}
+
+static gboolean
+gvdb_table_list_from_item (GvdbTable *table,
+ const struct gvdb_hash_item *item,
+ const guint32_le **list,
+ guint *length)
+{
+ gsize size;
+
+ *list = gvdb_table_dereference (table, &item->value.pointer, 4, &size);
+
+ if G_LIKELY (*list == NULL || size % 4)
+ return FALSE;
+
+ *length = size / 4;
+
+ return TRUE;
+}
+
+/**
+ * gvdb_table_get_names:
+ * @table: a #GvdbTable
+ * @length: the number of items returned, or %NULL
+ *
+ * Gets a list of all names contained in @table.
+ *
+ * No call to gvdb_table_get_table(), gvdb_table_list() or
+ * gvdb_table_get_value() will succeed unless it is for one of the
+ * names returned by this function.
+ *
+ * Note that some names that are returned may still fail for all of the
+ * above calls in the case of the corrupted file. Note also that the
+ * returned strings may not be utf8.
+ *
+ * Returns: a %NULL-terminated list of strings, of length @length
+ **/
+gchar **
+gvdb_table_get_names (GvdbTable *table,
+ gint *length)
+{
+ gchar **names;
+ guint n_names;
+ guint filled;
+ guint total;
+ guint i;
+
+ /* We generally proceed by iterating over the list of items in the
+ * hash table (in order of appearance) recording them into an array.
+ *
+ * Each item has a parent item (except root items). The parent item
+ * forms part of the name of the item. We could go fetching the
+ * parent item chain at the point that we encounter each item but then
+ * we would need to implement some sort of recursion along with checks
+ * for self-referential items.
+ *
+ * Instead, we do a number of passes. Each pass will build up one
+ * level of names (starting from the root). We continue to do passes
+ * until no more items are left. The first pass will only add root
+ * items and each further pass will only add items whose direct parent
+ * is an item added in the immediately previous pass. It's also
+ * possible that items get filled if they follow their parent within a
+ * particular pass.
+ *
+ * At most we will have a number of passes equal to the depth of the
+ * tree. Self-referential items will never be filled in (since their
+ * parent will have never been filled in). We continue until we have
+ * a pass that fills in no additional items.
+ *
+ * This takes an O(n) algorithm and turns it into O(n*m) where m is
+ * the depth of the tree, but in all sane cases the tree won't be very
+ * deep and the constant factor of this algorithm is lower (and the
+ * complexity of coding it, as well).
+ */
+
+ n_names = table->n_hash_items;
+ names = g_new0 (gchar *, n_names + 1);
+
+ /* 'names' starts out all-NULL. On each pass we record the number
+ * of items changed from NULL to non-NULL in 'filled' so we know if we
+ * should repeat the loop. 'total' counts the total number of items
+ * filled. If 'total' ends up equal to 'n_names' then we know that
+ * 'names' has been completely filled.
+ */
+
+ total = 0;
+ do
+ {
+ /* Loop until we have filled no more entries */
+ filled = 0;
+
+ for (i = 0; i < n_names; i++)
+ {
+ const struct gvdb_hash_item *item = &table->hash_items[i];
+ const gchar *name;
+ gsize name_length;
+ guint32 parent;
+
+ /* already got it on a previous pass */
+ if (names[i] != NULL)
+ continue;
+
+ parent = guint32_from_le (item->parent);
+
+ if (parent == 0xffffffffu)
+ {
+ /* it's a root item */
+ name = gvdb_table_item_get_key (table, item, &name_length);
+
+ if (name != NULL)
+ {
+ names[i] = g_strndup (name, name_length);
+ filled++;
+ }
+ }
+
+ else if (parent < n_names && names[parent] != NULL)
+ {
+ /* It's a non-root item whose parent was filled in already.
+ *
+ * Calculate the name of this item by combining it with
+ * its parent name.
+ */
+ name = gvdb_table_item_get_key (table, item, &name_length);
+
+ if (name != NULL)
+ {
+ const gchar *parent_name = names[parent];
+ gsize parent_length;
+ gchar *fullname;
+
+ parent_length = strlen (parent_name);
+ fullname = g_malloc (parent_length + name_length + 1);
+ memcpy (fullname, parent_name, parent_length);
+ memcpy (fullname + parent_length, name, name_length);
+ fullname[parent_length + name_length] = '\0';
+ names[i] = fullname;
+ filled++;
+ }
+ }
+ }
+
+ total += filled;
+ }
+ while (filled && total < n_names);
+
+ /* If the table was corrupted then 'names' may have holes in it.
+ * Collapse those.
+ */
+ if G_UNLIKELY (total != n_names)
+ {
+ GPtrArray *fixed_names;
+
+ fixed_names = g_ptr_array_new ();
+ for (i = 0; i < n_names; i++)
+ if (names[i] != NULL)
+ g_ptr_array_add (fixed_names, names[i]);
+
+ g_free (names);
+ n_names = fixed_names->len;
+ g_ptr_array_add (fixed_names, NULL);
+ names = (gchar **) g_ptr_array_free (fixed_names, FALSE);
+ }
+
+ if (length)
+ *length = n_names;
+
+ return names;
+}
+
+/**
+ * gvdb_table_list:
+ * @file: a #GvdbTable
+ * @key: a string
+ * @returns: a %NULL-terminated string array
+ *
+ * List all of the keys that appear below @key. The nesting of keys
+ * within the hash file is defined by the program that created the hash
+ * file. One thing is constant: each item in the returned array can be
+ * concatenated to @key to obtain the full name of that key.
+ *
+ * It is not possible to tell from this function if a given key is
+ * itself a path, a value, or another hash table; you are expected to
+ * know this for yourself.
+ *
+ * You should call g_strfreev() on the return result when you no longer
+ * require it.
+ **/
+gchar **
+gvdb_table_list (GvdbTable *file,
+ const gchar *key)
+{
+ const struct gvdb_hash_item *item;
+ const guint32_le *list;
+ gchar **strv;
+ guint length;
+ guint i;
+
+ if ((item = gvdb_table_lookup (file, key, 'L')) == NULL)
+ return NULL;
+
+ if (!gvdb_table_list_from_item (file, item, &list, &length))
+ return NULL;
+
+ strv = g_new (gchar *, length + 1);
+ for (i = 0; i < length; i++)
+ {
+ guint32 itemno = guint32_from_le (list[i]);
+
+ if (itemno < file->n_hash_items)
+ {
+ const struct gvdb_hash_item *item;
+ const gchar *string;
+ gsize strsize;
+
+ item = file->hash_items + itemno;
+
+ string = gvdb_table_item_get_key (file, item, &strsize);
+
+ if (string != NULL)
+ strv[i] = g_strndup (string, strsize);
+ else
+ strv[i] = g_malloc0 (1);
+ }
+ else
+ strv[i] = g_malloc0 (1);
+ }
+
+ strv[i] = NULL;
+
+ return strv;
+}
+
+/**
+ * gvdb_table_has_value:
+ * @file: a #GvdbTable
+ * @key: a string
+ * @returns: %TRUE if @key is in the table
+ *
+ * Checks for a value named @key in @file.
+ *
+ * Note: this function does not consider non-value nodes (other hash
+ * tables, for example).
+ **/
+gboolean
+gvdb_table_has_value (GvdbTable *file,
+ const gchar *key)
+{
+ static const struct gvdb_hash_item *item;
+ gsize size;
+
+ item = gvdb_table_lookup (file, key, 'v');
+
+ if (item == NULL)
+ return FALSE;
+
+ return gvdb_table_dereference (file, &item->value.pointer, 8, &size) != NULL;
+}
+
+static GVariant *
+gvdb_table_value_from_item (GvdbTable *table,
+ const struct gvdb_hash_item *item)
+{
+ GVariant *variant, *value;
+ gconstpointer data;
+ GBytes *bytes;
+ gsize size;
+
+ data = gvdb_table_dereference (table, &item->value.pointer, 8, &size);
+
+ if G_UNLIKELY (data == NULL)
+ return NULL;
+
+ bytes = g_bytes_new_from_bytes (table->bytes, ((gchar *) data) - table->data, size);
+ variant = g_variant_new_from_bytes (G_VARIANT_TYPE_VARIANT, bytes, table->trusted);
+ value = g_variant_get_variant (variant);
+ g_variant_unref (variant);
+ g_bytes_unref (bytes);
+
+ return value;
+}
+
+/**
+ * gvdb_table_get_value:
+ * @file: a #GvdbTable
+ * @key: a string
+ * @returns: a #GVariant, or %NULL
+ *
+ * Looks up a value named @key in @file.
+ *
+ * If the value is not found then %NULL is returned. Otherwise, a new
+ * #GVariant instance is returned. The #GVariant does not depend on the
+ * continued existence of @file.
+ *
+ * You should call g_variant_unref() on the return result when you no
+ * longer require it.
+ **/
+GVariant *
+gvdb_table_get_value (GvdbTable *file,
+ const gchar *key)
+{
+ const struct gvdb_hash_item *item;
+ GVariant *value;
+
+ if ((item = gvdb_table_lookup (file, key, 'v')) == NULL)
+ return NULL;
+
+ value = gvdb_table_value_from_item (file, item);
+
+ if (value && file->byteswapped)
+ {
+ GVariant *tmp;
+
+ tmp = g_variant_byteswap (value);
+ g_variant_unref (value);
+ value = tmp;
+ }
+
+ return value;
+}
+
+/**
+ * gvdb_table_get_raw_value:
+ * @table: a #GvdbTable
+ * @key: a string
+ * @returns: a #GVariant, or %NULL
+ *
+ * Looks up a value named @key in @file.
+ *
+ * This call is equivalent to gvdb_table_get_value() except that it
+ * never byteswaps the value.
+ **/
+GVariant *
+gvdb_table_get_raw_value (GvdbTable *table,
+ const gchar *key)
+{
+ const struct gvdb_hash_item *item;
+
+ if ((item = gvdb_table_lookup (table, key, 'v')) == NULL)
+ return NULL;
+
+ return gvdb_table_value_from_item (table, item);
+}
+
+/**
+ * gvdb_table_get_table:
+ * @file: a #GvdbTable
+ * @key: a string
+ * @returns: a new #GvdbTable, or %NULL
+ *
+ * Looks up the hash table named @key in @file.
+ *
+ * The toplevel hash table in a #GvdbTable can contain reference to
+ * child hash tables (and those can contain further references...).
+ *
+ * If @key is not found in @file then %NULL is returned. Otherwise, a
+ * new #GvdbTable is returned, referring to the child hashtable as
+ * contained in the file. This newly-created #GvdbTable does not depend
+ * on the continued existence of @file.
+ *
+ * You should call gvdb_table_free() on the return result when you no
+ * longer require it.
+ **/
+GvdbTable *
+gvdb_table_get_table (GvdbTable *file,
+ const gchar *key)
+{
+ const struct gvdb_hash_item *item;
+ GvdbTable *new;
+
+ item = gvdb_table_lookup (file, key, 'H');
+
+ if (item == NULL)
+ return NULL;
+
+ new = g_slice_new0 (GvdbTable);
+ new->bytes = g_bytes_ref (file->bytes);
+ new->byteswapped = file->byteswapped;
+ new->trusted = file->trusted;
+ new->data = file->data;
+ new->size = file->size;
+
+ gvdb_table_setup_root (new, &item->value.pointer);
+
+ return new;
+}
+
+/**
+ * gvdb_table_free:
+ * @file: a #GvdbTable
+ *
+ * Frees @file.
+ **/
+void
+gvdb_table_free (GvdbTable *file)
+{
+ g_bytes_unref (file->bytes);
+ g_slice_free (GvdbTable, file);
+}
+
+/**
+ * gvdb_table_is_valid:
+ * @table: a #GvdbTable
+ * @returns: %TRUE if @table is still valid
+ *
+ * Checks if the table is still valid.
+ *
+ * An on-disk GVDB can be marked as invalid. This happens when the file
+ * has been replaced. The appropriate action is typically to reopen the
+ * file.
+ **/
+gboolean
+gvdb_table_is_valid (GvdbTable *table)
+{
+ return !!*table->data;
+}