glib/gvdb-builder.c
Michael Catanzaro 16fb81cd7e Add some g_return checks to gvdb_table_write_contents()
I'm not auditing all the public functions in this file for precondition
checks, but since I'm adding an async version of this function, it
makes sense to ensure there are matching checks for the sync version.
2019-06-21 10:04:49 -05:00

625 lines
16 KiB
C

/*
* 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 2.1 of the License, 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, see <http://www.gnu.org/licenses/>.
*
* Author: Ryan Lortie <desrt@desrt.ca>
*/
#include "gvdb-builder.h"
#include "gvdb-format.h"
#include <glib.h>
#include <fcntl.h>
#if !defined(G_OS_WIN32) || !defined(_MSC_VER)
#include <unistd.h>
#endif
#include <string.h>
struct _GvdbItem
{
gchar *key;
guint32 hash_value;
guint32_le assigned_index;
GvdbItem *parent;
GvdbItem *sibling;
GvdbItem *next;
/* one of:
* this:
*/
GVariant *value;
/* this: */
GHashTable *table;
/* or this: */
GvdbItem *child;
};
static void
gvdb_item_free (gpointer data)
{
GvdbItem *item = data;
g_free (item->key);
if (item->value)
g_variant_unref (item->value);
if (item->table)
g_hash_table_unref (item->table);
g_slice_free (GvdbItem, item);
}
GHashTable *
gvdb_hash_table_new (GHashTable *parent,
const gchar *name_in_parent)
{
GHashTable *table;
table = g_hash_table_new_full (g_str_hash, g_str_equal,
g_free, gvdb_item_free);
if (parent)
{
GvdbItem *item;
item = gvdb_hash_table_insert (parent, name_in_parent);
gvdb_item_set_hash_table (item, table);
}
return table;
}
static guint32
djb_hash (const gchar *key)
{
guint32 hash_value = 5381;
while (*key)
hash_value = hash_value * 33 + *(signed char *)key++;
return hash_value;
}
GvdbItem *
gvdb_hash_table_insert (GHashTable *table,
const gchar *key)
{
GvdbItem *item;
item = g_slice_new0 (GvdbItem);
item->key = g_strdup (key);
item->hash_value = djb_hash (key);
g_hash_table_insert (table, g_strdup (key), item);
return item;
}
void
gvdb_hash_table_insert_string (GHashTable *table,
const gchar *key,
const gchar *value)
{
GvdbItem *item;
item = gvdb_hash_table_insert (table, key);
gvdb_item_set_value (item, g_variant_new_string (value));
}
void
gvdb_item_set_value (GvdbItem *item,
GVariant *value)
{
g_return_if_fail (!item->value && !item->table && !item->child);
item->value = g_variant_ref_sink (value);
}
void
gvdb_item_set_hash_table (GvdbItem *item,
GHashTable *table)
{
g_return_if_fail (!item->value && !item->table && !item->child);
item->table = g_hash_table_ref (table);
}
void
gvdb_item_set_parent (GvdbItem *item,
GvdbItem *parent)
{
GvdbItem **node;
g_return_if_fail (g_str_has_prefix (item->key, parent->key));
g_return_if_fail (!parent->value && !parent->table);
g_return_if_fail (!item->parent && !item->sibling);
for (node = &parent->child; *node; node = &(*node)->sibling)
if (strcmp ((*node)->key, item->key) > 0)
break;
item->parent = parent;
item->sibling = *node;
*node = item;
}
typedef struct
{
GvdbItem **buckets;
gint n_buckets;
} HashTable;
static HashTable *
hash_table_new (gint n_buckets)
{
HashTable *table;
table = g_slice_new (HashTable);
table->buckets = g_new0 (GvdbItem *, n_buckets);
table->n_buckets = n_buckets;
return table;
}
static void
hash_table_free (HashTable *table)
{
g_free (table->buckets);
g_slice_free (HashTable, table);
}
static void
hash_table_insert (gpointer key,
gpointer value,
gpointer data)
{
guint32 hash_value, bucket;
HashTable *table = data;
GvdbItem *item = value;
hash_value = djb_hash (key);
bucket = hash_value % table->n_buckets;
item->next = table->buckets[bucket];
table->buckets[bucket] = item;
}
static guint32_le
item_to_index (GvdbItem *item)
{
if (item != NULL)
return item->assigned_index;
return guint32_to_le (-1u);
}
typedef struct
{
GQueue *chunks;
guint64 offset;
gboolean byteswap;
} FileBuilder;
typedef struct
{
gsize offset;
gsize size;
gpointer data;
} FileChunk;
static gpointer
file_builder_allocate (FileBuilder *fb,
guint alignment,
gsize size,
struct gvdb_pointer *pointer)
{
FileChunk *chunk;
if (size == 0)
return NULL;
fb->offset += (-fb->offset) & (alignment - 1);
chunk = g_slice_new (FileChunk);
chunk->offset = fb->offset;
chunk->size = size;
chunk->data = g_malloc (size);
pointer->start = guint32_to_le (fb->offset);
fb->offset += size;
pointer->end = guint32_to_le (fb->offset);
g_queue_push_tail (fb->chunks, chunk);
return chunk->data;
}
static void
file_builder_add_value (FileBuilder *fb,
GVariant *value,
struct gvdb_pointer *pointer)
{
GVariant *variant, *normal;
gpointer data;
gsize size;
if (fb->byteswap)
{
value = g_variant_byteswap (value);
variant = g_variant_new_variant (value);
g_variant_unref (value);
}
else
variant = g_variant_new_variant (value);
normal = g_variant_get_normal_form (variant);
g_variant_unref (variant);
size = g_variant_get_size (normal);
data = file_builder_allocate (fb, 8, size, pointer);
g_variant_store (normal, data);
g_variant_unref (normal);
}
static void
file_builder_add_string (FileBuilder *fb,
const gchar *string,
guint32_le *start,
guint16_le *size)
{
FileChunk *chunk;
gsize length;
length = strlen (string);
chunk = g_slice_new (FileChunk);
chunk->offset = fb->offset;
chunk->size = length;
chunk->data = g_malloc (length);
if (length != 0)
memcpy (chunk->data, string, length);
*start = guint32_to_le (fb->offset);
*size = guint16_to_le (length);
fb->offset += length;
g_queue_push_tail (fb->chunks, chunk);
}
static void
file_builder_allocate_for_hash (FileBuilder *fb,
gsize n_buckets,
gsize n_items,
guint bloom_shift,
gsize n_bloom_words,
guint32_le **bloom_filter,
guint32_le **hash_buckets,
struct gvdb_hash_item **hash_items,
struct gvdb_pointer *pointer)
{
guint32_le bloom_hdr, table_hdr;
guchar *data;
gsize size;
g_assert (n_bloom_words < (1u << 27));
bloom_hdr = guint32_to_le (bloom_shift << 27 | n_bloom_words);
table_hdr = guint32_to_le (n_buckets);
size = sizeof bloom_hdr + sizeof table_hdr +
n_bloom_words * sizeof (guint32_le) +
n_buckets * sizeof (guint32_le) +
n_items * sizeof (struct gvdb_hash_item);
data = file_builder_allocate (fb, 4, size, pointer);
#define chunk(s) (size -= (s), data += (s), data - (s))
memcpy (chunk (sizeof bloom_hdr), &bloom_hdr, sizeof bloom_hdr);
memcpy (chunk (sizeof table_hdr), &table_hdr, sizeof table_hdr);
*bloom_filter = (guint32_le *) chunk (n_bloom_words * sizeof (guint32_le));
*hash_buckets = (guint32_le *) chunk (n_buckets * sizeof (guint32_le));
*hash_items = (struct gvdb_hash_item *) chunk (n_items *
sizeof (struct gvdb_hash_item));
g_assert (size == 0);
#undef chunk
memset (*bloom_filter, 0, n_bloom_words * sizeof (guint32_le));
/* NOTE - the code to actually fill in the bloom filter here is missing.
* Patches welcome!
*
* http://en.wikipedia.org/wiki/Bloom_filter
* http://0pointer.de/blog/projects/bloom.html
*/
}
static void
file_builder_add_hash (FileBuilder *fb,
GHashTable *table,
struct gvdb_pointer *pointer)
{
guint32_le *buckets, *bloom_filter;
struct gvdb_hash_item *items;
HashTable *mytable;
GvdbItem *item;
guint32 index;
gint bucket;
mytable = hash_table_new (g_hash_table_size (table));
g_hash_table_foreach (table, hash_table_insert, mytable);
index = 0;
for (bucket = 0; bucket < mytable->n_buckets; bucket++)
for (item = mytable->buckets[bucket]; item; item = item->next)
item->assigned_index = guint32_to_le (index++);
file_builder_allocate_for_hash (fb, mytable->n_buckets, index, 5, 0,
&bloom_filter, &buckets, &items, pointer);
index = 0;
for (bucket = 0; bucket < mytable->n_buckets; bucket++)
{
buckets[bucket] = guint32_to_le (index);
for (item = mytable->buckets[bucket]; item; item = item->next)
{
struct gvdb_hash_item *entry = items++;
const gchar *basename;
g_assert (index == guint32_from_le (item->assigned_index));
entry->hash_value = guint32_to_le (item->hash_value);
entry->parent = item_to_index (item->parent);
entry->unused = 0;
if (item->parent != NULL)
basename = item->key + strlen (item->parent->key);
else
basename = item->key;
file_builder_add_string (fb, basename,
&entry->key_start,
&entry->key_size);
if (item->value != NULL)
{
g_assert (item->child == NULL && item->table == NULL);
file_builder_add_value (fb, item->value, &entry->value.pointer);
entry->type = 'v';
}
if (item->child != NULL)
{
guint32 children = 0, i = 0;
guint32_le *offsets;
GvdbItem *child;
g_assert (item->table == NULL);
for (child = item->child; child; child = child->sibling)
children++;
offsets = file_builder_allocate (fb, 4, 4 * children,
&entry->value.pointer);
entry->type = 'L';
for (child = item->child; child; child = child->sibling)
offsets[i++] = child->assigned_index;
g_assert (children == i);
}
if (item->table != NULL)
{
entry->type = 'H';
file_builder_add_hash (fb, item->table, &entry->value.pointer);
}
index++;
}
}
hash_table_free (mytable);
}
static FileBuilder *
file_builder_new (gboolean byteswap)
{
FileBuilder *builder;
builder = g_slice_new (FileBuilder);
builder->chunks = g_queue_new ();
builder->offset = sizeof (struct gvdb_header);
builder->byteswap = byteswap;
return builder;
}
static GString *
file_builder_serialise (FileBuilder *fb,
struct gvdb_pointer root)
{
struct gvdb_header header = { { 0, }, };
GString *result;
if (fb->byteswap)
{
header.signature[0] = GVDB_SWAPPED_SIGNATURE0;
header.signature[1] = GVDB_SWAPPED_SIGNATURE1;
}
else
{
header.signature[0] = GVDB_SIGNATURE0;
header.signature[1] = GVDB_SIGNATURE1;
}
result = g_string_new (NULL);
header.root = root;
g_string_append_len (result, (gpointer) &header, sizeof header);
while (!g_queue_is_empty (fb->chunks))
{
FileChunk *chunk = g_queue_pop_head (fb->chunks);
if (result->len != chunk->offset)
{
gchar zero[8] = { 0, };
g_assert (chunk->offset > result->len);
g_assert (chunk->offset - result->len < 8);
g_string_append_len (result, zero, chunk->offset - result->len);
g_assert (result->len == chunk->offset);
}
g_string_append_len (result, chunk->data, chunk->size);
g_free (chunk->data);
g_slice_free (FileChunk, chunk);
}
g_queue_free (fb->chunks);
g_slice_free (FileBuilder, fb);
return result;
}
gboolean
gvdb_table_write_contents (GHashTable *table,
const gchar *filename,
gboolean byteswap,
GError **error)
{
struct gvdb_pointer root;
gboolean status;
FileBuilder *fb;
GString *str;
g_return_val_if_fail (table != NULL, FALSE);
g_return_val_if_fail (filename != NULL, FALSE);
g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
fb = file_builder_new (byteswap);
file_builder_add_hash (fb, table, &root);
str = file_builder_serialise (fb, root);
status = g_file_set_contents (filename, str->str, str->len, error);
g_string_free (str, TRUE);
return status;
}
typedef struct {
GBytes *contents; /* (owned) */
GFile *file; /* (owned) */
} WriteContentsData;
static WriteContentsData *
write_contents_data_new (GBytes *contents,
GFile *file)
{
WriteContentsData *data;
data = g_slice_new (WriteContentsData);
data->contents = g_bytes_ref (contents);
data->file = g_object_ref (file);
return data;
}
static void
write_contents_data_free (WriteContentsData *data)
{
g_bytes_unref (data->contents);
g_object_unref (data->file);
g_slice_free (WriteContentsData, data);
}
static void
replace_contents_cb (GObject *source_object,
GAsyncResult *result,
gpointer user_data)
{
GTask *task = user_data;
WriteContentsData *data = g_task_get_task_data (task);
GError *error = NULL;
g_return_if_fail (g_task_get_source_tag (task) == gvdb_table_write_contents_async);
if (!g_file_replace_contents_finish (data->file, result, NULL, &error))
g_task_return_error (task, g_steal_pointer (&error));
else
g_task_return_boolean (task, TRUE);
g_object_unref (task);
}
void
gvdb_table_write_contents_async (GHashTable *table,
const gchar *filename,
gboolean byteswap,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
struct gvdb_pointer root;
FileBuilder *fb;
WriteContentsData *data;
GString *str;
GBytes *bytes;
GFile *file;
GTask *task;
g_return_if_fail (table != NULL);
g_return_if_fail (filename != NULL);
g_return_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable));
fb = file_builder_new (byteswap);
file_builder_add_hash (fb, table, &root);
str = file_builder_serialise (fb, root);
bytes = g_string_free_to_bytes (str);
file = g_file_new_for_path (filename);
data = write_contents_data_new (bytes, file);
task = g_task_new (NULL, cancellable, callback, user_data);
g_task_set_task_data (task, data, (GDestroyNotify)write_contents_data_free);
g_task_set_source_tag (task, gvdb_table_write_contents_async);
g_file_replace_contents_async (file, str->str, str->len,
NULL, FALSE,
G_FILE_CREATE_PRIVATE | G_FILE_CREATE_REPLACE_DESTINATION,
cancellable, replace_contents_cb, g_steal_pointer (&task));
g_bytes_unref (bytes);
g_object_unref (file);
}
gboolean
gvdb_table_write_contents_finish (GHashTable *table,
GAsyncResult *result,
GError **error)
{
g_return_val_if_fail (table != NULL, FALSE);
g_return_val_if_fail (g_task_is_valid (result, NULL), FALSE);
g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
return g_task_propagate_boolean (G_TASK (result), error);
}