/*
* Copyright © 2008 Ryan Lortie
* 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 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, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Author: Ryan Lortie <desrt@desrt.ca>
*/
#include "config.h"
#include "gvarianttypeinfo.h"
#include <glib/gtestutils.h>
#include <glib/gthread.h>
#include <glib/gslice.h>
#include <glib/ghash.h>
/* < private >
* GVariantTypeInfo:
*
* This structure contains the necessary information to facilitate the
* serialisation and fast deserialisation of a given type of GVariant
* value. A GVariant instance holds a pointer to one of these
* structures to provide for efficient operation.
*
* The GVariantTypeInfo structures for all of the base types, plus the
* "variant" type are stored in a read-only static array.
*
* For container types, a hash table and reference counting is used to
* ensure that only one of these structures exists for any given type.
* In general, a container GVariantTypeInfo will exist for a given type
* only if one or more GVariant instances of that type exist or if
* another GVariantTypeInfo has that type as a subtype. For example, if
* a process contains a single GVariant instance with type "(asv)", then
* container GVariantTypeInfo structures will exist for "(asv)" and
* for "as" (note that "s" and "v" always exist in the static array).
*
* The trickiest part of GVariantTypeInfo (and in fact, the major reason
* for its existence) is the storage of somewhat magical constants that
* allow for O(1) lookups of items in tuples. This is described below.
*
* 'container_class' is set to 'a' or 'r' if the GVariantTypeInfo is
* contained inside of an ArrayInfo or TupleInfo, respectively. This
* allows the storage of the necessary additional information.
*
* 'fixed_size' is set to the fixed size of the type, if applicable, or
* 0 otherwise (since no type has a fixed size of 0).
*
* 'alignment' is set to one less than the alignment requirement for
* this type. This makes many operations much more convenient.
*/
struct _GVariantTypeInfo
{
gsize fixed_size;
guchar alignment;
guchar container_class;
};
/* Container types are reference counted. They also need to have their
* type string stored explicitly since it is not merely a single letter.
*/
typedef struct
{
GVariantTypeInfo info;
gchar *type_string;
gint ref_count;
} ContainerInfo;
/* For 'array' and 'maybe' types, we store some extra information on the
* end of the GVariantTypeInfo struct -- the element type (ie: "s" for
* "as"). The container GVariantTypeInfo structure holds a reference to
* the element typeinfo.
*/
typedef struct
{
ContainerInfo container;
GVariantTypeInfo *element;
} ArrayInfo;
/* For 'tuple' and 'dict entry' types, we store extra information for
* each member -- its type and how to find it inside the serialised data
* in O(1) time using 4 variables -- 'i', 'a', 'b', and 'c'. See the
* comment on GVariantMemberInfo in gvarianttypeinfo.h.
*/
typedef struct
{
ContainerInfo container;
GVariantMemberInfo *members;
gsize n_members;
} TupleInfo;
/* Hard-code the base types in a constant array */
static const GVariantTypeInfo g_variant_type_info_basic_table[24] = {
#define fixed_aligned(x) x, x - 1
#define not_a_type 0,
#define unaligned 0, 0
#define aligned(x) 0, x - 1
/* 'b' */ { fixed_aligned(1) }, /* boolean */
/* 'c' */ { not_a_type },
/* 'd' */ { fixed_aligned(8) }, /* double */
/* 'e' */ { not_a_type },
/* 'f' */ { not_a_type },
/* 'g' */ { unaligned }, /* signature string */
/* 'h' */ { fixed_aligned(4) }, /* file handle (int32) */
/* 'i' */ { fixed_aligned(4) }, /* int32 */
/* 'j' */ { not_a_type },
/* 'k' */ { not_a_type },
/* 'l' */ { not_a_type },
/* 'm' */ { not_a_type },
/* 'n' */ { fixed_aligned(2) }, /* int16 */
/* 'o' */ { unaligned }, /* object path string */
/* 'p' */ { not_a_type },
/* 'q' */ { fixed_aligned(2) }, /* uint16 */
/* 'r' */ { not_a_type },
/* 's' */ { unaligned }, /* string */
/* 't' */ { fixed_aligned(8) }, /* uint64 */
/* 'u' */ { fixed_aligned(4) }, /* uint32 */
/* 'v' */ { aligned(8) }, /* variant */
/* 'w' */ { not_a_type },
/* 'x' */ { fixed_aligned(8) }, /* int64 */
/* 'y' */ { fixed_aligned(1) }, /* byte */
#undef fixed_aligned
#undef not_a_type
#undef unaligned
#undef aligned
};
/* We need to have type strings to return for the base types. We store
* those in another array. Since all base type strings are single
* characters this is easy. By not storing pointers to strings into the
* GVariantTypeInfo itself, we save a bunch of relocations.
*/
static const char g_variant_type_info_basic_chars[24][2] = {
"b", " ", "d", " ", " ", "g", "h", "i", " ", " ", " ", " ",
"n", "o", " ", "q", " ", "s", "t", "u", "v", " ", "x", "y"
};
/* sanity checks to make debugging easier */
static void
g_variant_type_info_check (const GVariantTypeInfo *info,
char container_class)
{
g_assert (!container_class || info->container_class == container_class);
/* alignment can only be one of these */
g_assert (info->alignment == 0 || info->alignment == 1 ||
info->alignment == 3 || info->alignment == 7);
if (info->container_class)
{
ContainerInfo *container = (ContainerInfo *) info;
/* extra checks for containers */
g_assert_cmpint (container->ref_count, >, 0);
g_assert (container->type_string != NULL);
}
else
{
gint index;
/* if not a container, then ensure that it is a valid member of
* the basic types table
*/
index = info - g_variant_type_info_basic_table;
g_assert (G_N_ELEMENTS (g_variant_type_info_basic_table) == 24);
g_assert (G_N_ELEMENTS (g_variant_type_info_basic_chars) == 24);
g_assert (0 <= index && index < 24);
g_assert (g_variant_type_info_basic_chars[index][0] != ' ');
}
}
/* < private >
* g_variant_type_info_get_type_string:
* @info: a #GVariantTypeInfo
*
* Gets the type string for @info. The string is nul-terminated.
*/
const gchar *
g_variant_type_info_get_type_string (GVariantTypeInfo *info)
{
g_variant_type_info_check (info, 0);
if (info->container_class)
{
ContainerInfo *container = (ContainerInfo *) info;
/* containers have their type string stored inside them */
return container->type_string;
}
else
{
gint index;
/* look up the type string in the base type array. the call to
* g_variant_type_info_check() above already ensured validity.
*/
index = info - g_variant_type_info_basic_table;
return g_variant_type_info_basic_chars[index];
}
}
/* < private >
* g_variant_type_info_query:
* @info: a #GVariantTypeInfo
* @alignment: (allow-none): the location to store the alignment, or %NULL
* @fixed_size: (allow-none): the location to store the fixed size, or %NULL
*
* Queries @info to determine the alignment requirements and fixed size
* (if any) of the type.
*
* @fixed_size, if non-%NULL is set to the fixed size of the type, or 0
* to indicate that the type is a variable-sized type. No type has a
* fixed size of 0.
*
* @alignment, if non-%NULL, is set to one less than the required
* alignment of the type. For example, for a 32bit integer, @alignment
* would be set to 3. This allows you to round an integer up to the
* proper alignment by performing the following efficient calculation:
*
* offset += ((-offset) & alignment);
*/
void
g_variant_type_info_query (GVariantTypeInfo *info,
guint *alignment,
gsize *fixed_size)
{
g_variant_type_info_check (info, 0);
if (alignment)
*alignment = info->alignment;
if (fixed_size)
*fixed_size = info->fixed_size;
}
/* == array == */
#define GV_ARRAY_INFO_CLASS 'a'
static ArrayInfo *
GV_ARRAY_INFO (GVariantTypeInfo *info)
{
g_variant_type_info_check (info, GV_ARRAY_INFO_CLASS);
return (ArrayInfo *) info;
}
static void
array_info_free (GVariantTypeInfo *info)
{
ArrayInfo *array_info;
g_assert (info->container_class == GV_ARRAY_INFO_CLASS);
array_info = (ArrayInfo *) info;
g_variant_type_info_unref (array_info->element);
g_slice_free (ArrayInfo, array_info);
}
static ContainerInfo *
array_info_new (const GVariantType *type)
{
ArrayInfo *info;
info = g_slice_new (ArrayInfo);
info->container.info.container_class = GV_ARRAY_INFO_CLASS;
info->element = g_variant_type_info_get (g_variant_type_element (type));
info->container.info.alignment = info->element->alignment;
info->container.info.fixed_size = 0;
return (ContainerInfo *) info;
}
/* < private >
* g_variant_type_info_element:
* @info: a #GVariantTypeInfo for an array or maybe type
*
* Returns the element type for the array or maybe type. A reference is
* not added, so the caller must add their own.
*/
GVariantTypeInfo *
g_variant_type_info_element (GVariantTypeInfo *info)
{
return GV_ARRAY_INFO (info)->element;
}
/* < private >
* g_variant_type_query_element:
* @info: a #GVariantTypeInfo for an array or maybe type
* @alignment: (allow-none): the location to store the alignment, or %NULL
* @fixed_size: (allow-none): the location to store the fixed size, or %NULL
*
* Returns the alignment requires and fixed size (if any) for the
* element type of the array. This call is a convenience wrapper around
* g_variant_type_info_element() and g_variant_type_info_query().
*/
void
g_variant_type_info_query_element (GVariantTypeInfo *info,
guint *alignment,
gsize *fixed_size)
{
g_variant_type_info_query (GV_ARRAY_INFO (info)->element,
alignment, fixed_size);
}
/* == tuple == */
#define GV_TUPLE_INFO_CLASS 'r'
static TupleInfo *
GV_TUPLE_INFO (GVariantTypeInfo *info)
{
g_variant_type_info_check (info, GV_TUPLE_INFO_CLASS);
return (TupleInfo *) info;
}
static void
tuple_info_free (GVariantTypeInfo *info)
{
TupleInfo *tuple_info;
gint i;
g_assert (info->container_class == GV_TUPLE_INFO_CLASS);
tuple_info = (TupleInfo *) info;
for (i = 0; i < tuple_info->n_members; i++)
g_variant_type_info_unref (tuple_info->members[i].type_info);
g_slice_free1 (sizeof (GVariantMemberInfo) * tuple_info->n_members,
tuple_info->members);
g_slice_free (TupleInfo, tuple_info);
}
static void
tuple_allocate_members (const GVariantType *type,
GVariantMemberInfo **members,
gsize *n_members)
{
const GVariantType *item_type;
gsize i = 0;
*n_members = g_variant_type_n_items (type);
*members = g_slice_alloc (sizeof (GVariantMemberInfo) * *n_members);
item_type = g_variant_type_first (type);
while (item_type)
{
GVariantMemberInfo *member = &(*members)[i++];
member->type_info = g_variant_type_info_get (item_type);
item_type = g_variant_type_next (item_type);
if (member->type_info->fixed_size)
member->ending_type = G_VARIANT_MEMBER_ENDING_FIXED;
else if (item_type == NULL)
member->ending_type = G_VARIANT_MEMBER_ENDING_LAST;
else
member->ending_type = G_VARIANT_MEMBER_ENDING_OFFSET;
}
g_assert (i == *n_members);
}
/* this is g_variant_type_info_query for a given member of the tuple.
* before the access is done, it is ensured that the item is within
* range and %FALSE is returned if not.
*/
static gboolean
tuple_get_item (TupleInfo *info,
GVariantMemberInfo *item,
gsize *d,
gsize *e)
{
if (&info->members[info->n_members] == item)
return FALSE;
*d = item->type_info->alignment;
*e = item->type_info->fixed_size;
return TRUE;
}
/* Read the documentation for #GVariantMemberInfo in gvarianttype.h
* before attempting to understand this.
*
* This function adds one set of "magic constant" values (for one item
* in the tuple) to the table.
*
* The algorithm in tuple_generate_table() calculates values of 'a', 'b'
* and 'c' for each item, such that the procedure for finding the item
* is to start at the end of the previous variable-sized item, add 'a',
* then round up to the nearest multiple of 'b', then then add 'c'.
* Note that 'b' is stored in the usual "one less than" form. ie:
*
* start = ROUND_UP(prev_end + a, (b + 1)) + c;
*
* We tweak these values a little to allow for a slightly easier
* computation and more compact storage.
*/
static void
tuple_table_append (GVariantMemberInfo **items,
gsize i,
gsize a,
gsize b,
gsize c)
{
GVariantMemberInfo *item = (*items)++;
/* We can shift multiples of the alignment size from 'c' into 'a'.
* As long as we're shifting whole multiples, it won't affect the
* result. This means that we can take the "aligned" portion off of
* 'c' and add it into 'a'.
*
* Imagine (for sake of clarity) that ROUND_10 rounds up to the
* nearest 10. It is clear that:
*
* ROUND_10(a) + c == ROUND_10(a + 10*(c / 10)) + (c % 10)
*
* ie: remove the 10s portion of 'c' and add it onto 'a'.
*
* To put some numbers on it, imagine we start with a = 34 and c = 27:
*
* ROUND_10(34) + 27 = 40 + 27 = 67
*
* but also, we can split 27 up into 20 and 7 and do this:
*
* ROUND_10(34 + 20) + 7 = ROUND_10(54) + 7 = 60 + 7 = 67
* ^^ ^
* without affecting the result. We do that here.
*
* This reduction in the size of 'c' means that we can store it in a
* gchar instead of a gsize. Due to how the structure is packed, this
* ends up saving us 'two pointer sizes' per item in each tuple when
* allocating using GSlice.
*/
a += ~b & c; /* take the "aligned" part of 'c' and add to 'a' */
c &= b; /* chop 'c' to contain only the unaligned part */
/* Finally, we made one last adjustment. Recall:
*
* start = ROUND_UP(prev_end + a, (b + 1)) + c;
*
* Forgetting the '+ c' for the moment:
*
* ROUND_UP(prev_end + a, (b + 1));
*
* we can do a "round up" operation by adding 1 less than the amount
* to round up to, then rounding down. ie:
*
* #define ROUND_UP(x, y) ROUND_DOWN(x + (y-1), y)
*
* Of course, for rounding down to a power of two, we can just mask
* out the appropriate number of low order bits:
*
* #define ROUND_DOWN(x, y) (x & ~(y - 1))
*
* Which gives us
*
* #define ROUND_UP(x, y) (x + (y - 1) & ~(y - 1))
*
* but recall that our alignment value 'b' is already "one less".
* This means that to round 'prev_end + a' up to 'b' we can just do:
*
* ((prev_end + a) + b) & ~b
*
* Associativity, and putting the 'c' back on:
*
* (prev_end + (a + b)) & ~b + c
*
* Now, since (a + b) is constant, we can just add 'b' to 'a' now and
* store that as the number to add to prev_end. Then we use ~b as the
* number to take a bitwise 'and' with. Finally, 'c' is added on.
*
* Note, however, that all the low order bits of the 'aligned' value
* are masked out and that all of the high order bits of 'c' have been
* "moved" to 'a' (in the previous step). This means that there are
* no overlapping bits in the addition -- so we can do a bitwise 'or'
* equivalently.
*
* This means that we can now compute the start address of a given
* item in the tuple using the algorithm given in the documentation
* for #GVariantMemberInfo:
*
* item_start = ((prev_end + a) & b) | c;
*/
item->i = i;
item->a = a + b;
item->b = ~b;
item->c = c;
}
static gsize
tuple_align (gsize offset,
guint alignment)
{
return offset + ((-offset) & alignment);
}
/* This function is the heart of the algorithm for calculating 'i', 'a',
* 'b' and 'c' for each item in the tuple.
*
* Imagine we want to find the start of the "i" in the type "(su(qx)ni)".
* That's a string followed by a uint32, then a tuple containing a
* uint16 and a int64, then an int16, then our "i". In order to get to
* our "i" we:
*
* Start at the end of the string, align to 4 (for the uint32), add 4.
* Align to 8, add 16 (for the tuple). Align to 2, add 2 (for the
* int16). Then we're there. It turns out that, given 3 simple rules,
* we can flatten this iteration into one addition, one alignment, then
* one more addition.
*
* The loop below plays through each item in the tuple, querying its
* alignment and fixed_size into 'd' and 'e', respectively. At all
* times the variables 'a', 'b', and 'c' are maintained such that in
* order to get to the current point, you add 'a', align to 'b' then add
* 'c'. 'b' is kept in "one less than" form. For each item, the proper
* alignment is applied to find the values of 'a', 'b' and 'c' to get to
* the start of that item. Those values are recorded into the table.
* The fixed size of the item (if applicable) is then added on.
*
* These 3 rules are how 'a', 'b' and 'c' are modified for alignment and
* addition of fixed size. They have been proven correct but are
* presented here, without proof:
*
* 1) in order to "align to 'd'" where 'd' is less than or equal to the
* largest level of alignment seen so far ('b'), you align 'c' to
* 'd'.
* 2) in order to "align to 'd'" where 'd' is greater than the largest
* level of alignment seen so far, you add 'c' aligned to 'b' to the
* value of 'a', set 'b' to 'd' (ie: increase the 'largest alignment
* seen') and reset 'c' to 0.
* 3) in order to "add 'e'", just add 'e' to 'c'.
*/
static void
tuple_generate_table (TupleInfo *info)
{
GVariantMemberInfo *items = info->members;
gsize i = -1, a = 0, b = 0, c = 0, d, e;
/* iterate over each item in the tuple.
* 'd' will be the alignment of the item (in one-less form)
* 'e' will be the fixed size (or 0 for variable-size items)
*/
while (tuple_get_item (info, items, &d, &e))
{
/* align to 'd' */
if (d <= b)
c = tuple_align (c, d); /* rule 1 */
else
a += tuple_align (c, b), b = d, c = 0; /* rule 2 */
/* the start of the item is at this point (ie: right after we
* have aligned for it). store this information in the table.
*/
tuple_table_append (&items, i, a, b, c);
/* "move past" the item by adding in its size. */
if (e == 0)
/* variable size:
*
* we'll have an offset stored to mark the end of this item, so
* just bump the offset index to give us a new starting point
* and reset all the counters.
*/
i++, a = b = c = 0;
else
/* fixed size */
c += e; /* rule 3 */
}
}
static void
tuple_set_base_info (TupleInfo *info)
{
GVariantTypeInfo *base = &info->container.info;
if (info->n_members > 0)
{
GVariantMemberInfo *m;
/* the alignment requirement of the tuple is the alignment
* requirement of its largest item.
*/
base->alignment = 0;
for (m = info->members; m < &info->members[info->n_members]; m++)
/* can find the max of a list of "one less than" powers of two
* by 'or'ing them
*/
base->alignment |= m->type_info->alignment;
m--; /* take 'm' back to the last item */
/* the structure only has a fixed size if no variable-size
* offsets are stored and the last item is fixed-sized too (since
* an offset is never stored for the last item).
*/
if (m->i == -1 && m->type_info->fixed_size)
/* in that case, the fixed size can be found by finding the
* start of the last item (in the usual way) and adding its
* fixed size.
*
* if a tuple has a fixed size then it is always a multiple of
* the alignment requirement (to make packing into arrays
* easier) so we round up to that here.
*/
base->fixed_size =
tuple_align (((m->a & m->b) | m->c) + m->type_info->fixed_size,
base->alignment);
else
/* else, the tuple is not fixed size */
base->fixed_size = 0;
}
else
{
/* the empty tuple: '()'.
*
* has a size of 1 and an no alignment requirement.
*
* It has a size of 1 (not 0) for two practical reasons:
*
* 1) So we can determine how many of them are in an array
* without dividing by zero or without other tricks.
*
* 2) Even if we had some trick to know the number of items in
* the array (as GVariant did at one time) this would open a
* potential denial of service attack: an attacker could send
* you an extremely small array (in terms of number of bytes)
* containing trillions of zero-sized items. If you iterated
* over this array you would effectively infinite-loop your
* program. By forcing a size of at least one, we bound the
* amount of computation done in response to a message to a
* reasonable function of the size of that message.
*/
base->alignment = 0;
base->fixed_size = 1;
}
}
static ContainerInfo *
tuple_info_new (const GVariantType *type)
{
TupleInfo *info;
info = g_slice_new (TupleInfo);
info->container.info.container_class = GV_TUPLE_INFO_CLASS;
tuple_allocate_members (type, &info->members, &info->n_members);
tuple_generate_table (info);
tuple_set_base_info (info);
return (ContainerInfo *) info;
}
/* < private >
* g_variant_type_info_n_members:
* @info: a #GVariantTypeInfo for a tuple or dictionary entry type
*
* Returns the number of members in a tuple or dictionary entry type.
* For a dictionary entry this will always be 2.
*/
gsize
g_variant_type_info_n_members (GVariantTypeInfo *info)
{
return GV_TUPLE_INFO (info)->n_members;
}
/* < private >
* g_variant_type_info_member_info:
* @info: a #GVariantTypeInfo for a tuple or dictionary entry type
* @index: the member to fetch information for
*
* Returns the #GVariantMemberInfo for a given member. See
* documentation for that structure for why you would want this
* information.
*
* @index must refer to a valid child (ie: strictly less than
* g_variant_type_info_n_members() returns).
*/
const GVariantMemberInfo *
g_variant_type_info_member_info (GVariantTypeInfo *info,
gsize index)
{
TupleInfo *tuple_info = GV_TUPLE_INFO (info);
if (index < tuple_info->n_members)
return &tuple_info->members[index];
return NULL;
}
/* == new/ref/unref == */
static GRecMutex g_variant_type_info_lock;
static GHashTable *g_variant_type_info_table;
/* < private >
* g_variant_type_info_get:
* @type: a #GVariantType
*
* Returns a reference to a #GVariantTypeInfo for @type.
*
* If an info structure already exists for this type, a new reference is
* returned. If not, the required calculations are performed and a new
* info structure is returned.
*
* It is appropriate to call g_variant_type_info_unref() on the return
* value.
*/
GVariantTypeInfo *
g_variant_type_info_get (const GVariantType *type)
{
char type_char;
type_char = g_variant_type_peek_string (type)[0];
if (type_char == G_VARIANT_TYPE_INFO_CHAR_MAYBE ||
type_char == G_VARIANT_TYPE_INFO_CHAR_ARRAY ||
type_char == G_VARIANT_TYPE_INFO_CHAR_TUPLE ||
type_char == G_VARIANT_TYPE_INFO_CHAR_DICT_ENTRY)
{
GVariantTypeInfo *info;
gchar *type_string;
type_string = g_variant_type_dup_string (type);
g_rec_mutex_lock (&g_variant_type_info_lock);
if (g_variant_type_info_table == NULL)
g_variant_type_info_table = g_hash_table_new (g_str_hash,
g_str_equal);
info = g_hash_table_lookup (g_variant_type_info_table, type_string);
if (info == NULL)
{
ContainerInfo *container;
if (type_char == G_VARIANT_TYPE_INFO_CHAR_MAYBE ||
type_char == G_VARIANT_TYPE_INFO_CHAR_ARRAY)
{
container = array_info_new (type);
}
else /* tuple or dict entry */
{
container = tuple_info_new (type);
}
info = (GVariantTypeInfo *) container;
container->type_string = type_string;
container->ref_count = 1;
g_hash_table_insert (g_variant_type_info_table, type_string, info);
type_string = NULL;
}
else
g_variant_type_info_ref (info);
g_rec_mutex_unlock (&g_variant_type_info_lock);
g_variant_type_info_check (info, 0);
g_free (type_string);
return info;
}
else
{
const GVariantTypeInfo *info;
int index;
index = type_char - 'b';
g_assert (G_N_ELEMENTS (g_variant_type_info_basic_table) == 24);
g_assert_cmpint (0, <=, index);
g_assert_cmpint (index, <, 24);
info = g_variant_type_info_basic_table + index;
g_variant_type_info_check (info, 0);
return (GVariantTypeInfo *) info;
}
}
/* < private >
* g_variant_type_info_ref:
* @info: a #GVariantTypeInfo
*
* Adds a reference to @info.
*/
GVariantTypeInfo *
g_variant_type_info_ref (GVariantTypeInfo *info)
{
g_variant_type_info_check (info, 0);
if (info->container_class)
{
ContainerInfo *container = (ContainerInfo *) info;
g_assert_cmpint (container->ref_count, >, 0);
g_atomic_int_inc (&container->ref_count);
}
return info;
}
/* < private >
* g_variant_type_info_unref:
* @info: a #GVariantTypeInfo
*
* Releases a reference held on @info. This may result in @info being
* freed.
*/
void
g_variant_type_info_unref (GVariantTypeInfo *info)
{
g_variant_type_info_check (info, 0);
if (info->container_class)
{
ContainerInfo *container = (ContainerInfo *) info;
g_rec_mutex_lock (&g_variant_type_info_lock);
if (g_atomic_int_dec_and_test (&container->ref_count))
{
g_hash_table_remove (g_variant_type_info_table,
container->type_string);
if (g_hash_table_size (g_variant_type_info_table) == 0)
{
g_hash_table_unref (g_variant_type_info_table);
g_variant_type_info_table = NULL;
}
g_rec_mutex_unlock (&g_variant_type_info_lock);
g_free (container->type_string);
if (info->container_class == GV_ARRAY_INFO_CLASS)
array_info_free (info);
else if (info->container_class == GV_TUPLE_INFO_CLASS)
tuple_info_free (info);
else
g_assert_not_reached ();
}
else
g_rec_mutex_unlock (&g_variant_type_info_lock);
}
}
void
g_variant_type_info_assert_no_infos (void)
{
g_assert (g_variant_type_info_table == NULL);
}