Serializing a glib data type

[akappa]

Hi,
I want to serialize a glib data type (an hash), but I don't want to
access directly to the fields of the various structs, since it's an
opaque data type: there is one "more-or-less standard way to do it"
that it's more efficient than read all the fields with the iterator,
saves them on file and successively recreating the hash putting them
once per time?

Thanks in advice.

[Mark McIntyre]

On Sun, 19 Aug 2007 08:58:07 -0700, in comp.lang.c , akappa
<an******@gmail .comwrote:

>Hi,
I want to serialize a glib data type (an hash), but I don't want to
access directly to the fields of the various structs, since it's an
opaque data type: there is one "more-or-less standard way to do it"
that it's more efficient than read all the fields with the iterator,
saves them on file and successively recreating the hash putting them
once per time?

This sounds like an algorithm question. Try asking in
comp.programmin g? Alternatively, doesn't the data type provide some
accessor functions?
--
Mark McIntyre

"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it."
--Brian Kernighan

[Malcolm McLean]

"akappa" <an******@gmail .comwrote in message
news:11******** **************@ 50g2000hsm.goog legroups.com...

Hi,
I want to serialize a glib data type (an hash), but I don't want to
access directly to the fields of the various structs, since it's an
opaque data type: there is one "more-or-less standard way to do it"
that it's more efficient than read all the fields with the iterator,
saves them on file and successively recreating the hash putting them
once per time?

This is something that C doesn't do well. All objects ought to have
"serialise" methods built in at a fundamental level. In C of course you've
got the problem of what to do with shared pointers.
glib is open source, so by looking at the hash structure, you ought to be
able to write a serialise / deserialise pair that executes quite a bit
faster than rebuilding the table. However the objects in the table would
also need serialise methods.
glib might already have such methods, but I doubt it, because it adds so
much complexity to the basic hash interface.
--
Free games and programming goodies.
http://www.personal.leeds.ac.uk/~bgy1mm

[Flash Gordon]

akappa wrote, On 19/08/07 16:58:

Hi,
I want to serialize a glib data type (an hash), but I don't want to
access directly to the fields of the various structs, since it's an
opaque data type: there is one "more-or-less standard way to do it"
that it's more efficient than read all the fields with the iterator,
saves them on file and successively recreating the hash putting them
once per time?

C itself provides no mechanism to automatically do what you want. glib
might, but for that you need to ask where GLib is topical, such as one
of the gnome mailing lists http://mail.gnome.org/
--
Flash Gordon

[akappa]

At the first, thanks to all that have replied to my question :)

"Malcolm McLean" wrote:

glib is open source, so by looking at the hash structure, you ought to be
able to write a serialise / deserialise pair that executes quite a bit
faster than rebuilding the table.

You're of course right, but I don't want to °break° the datatype's
opaqueness:

The GHashTable struct is an opaque data structure to represent a Hash Table.
It should only be accessed via the following functions.

Unfortunately, glib (seems to) doesn't have no native way to
marshalling their owns data type...

BTW, I'm sorry to be a bit OT in this group, next time I should select
with much care the group :)

[CBFalconer]

akappa wrote:

>
I want to serialize a glib data type (an hash), but I don't want to
access directly to the fields of the various structs, since it's an
opaque data type: there is one "more-or-less standard way to do it"
that it's more efficient than read all the fields with the iterator,
saves them on file and successively recreating the hash putting them
once per time?

There is no iterator in the C language. Try comp.lang.c++.

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home .att.net>

--
Posted via a free Usenet account from http://www.teranews.com

[akappa]

On 19 Ago, 19:52, CBFalconer <cbfalco...@yah oo.comwrote:

There is no iterator in the C language. Try comp.lang.c++.

Yes, but I'm talking about the library's iterator:
http://developer.gnome.org/doc/API/2...-table-foreach

(note that C++'s boost have a marshalling framework: If I was coding
in C++, then I wouldn't have any problem with marshalling :P)

[Keith Thompson]

CBFalconer <cb********@yah oo.comwrites:

akappa wrote:

>I want to serialize a glib data type (an hash), but I don't want to
access directly to the fields of the various structs, since it's an
opaque data type: there is one "more-or-less standard way to do it"
that it's more efficient than read all the fields with the iterator,
saves them on file and successively recreating the hash putting them
once per time?

There is no iterator in the C language. Try comp.lang.c++.

C doesn't have linked lists or binary trees either, but they can be
built in standard C. He's not talking about a C++ iterator; he's
talking about an "interator" provided by glib, which is a C library.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[CBFalconer]

Keith Thompson wrote:

CBFalconer <cb********@yah oo.comwrites:

>akappa wrote:

>>I want to serialize a glib data type (an hash), but I don't want to
access directly to the fields of the various structs, since it's an
opaque data type: there is one "more-or-less standard way to do it"
that it's more efficient than read all the fields with the iterator,
saves them on file and successively recreating the hash putting them
once per time?

There is no iterator in the C language. Try comp.lang.c++.

C doesn't have linked lists or binary trees either, but they can be
built in standard C. He's not talking about a C++ iterator; he's
talking about an "interator" provided by glib, which is a C library.

OK, but GNU stuff is no more on-topic here than Windoze junk.

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home .att.net>

--
Posted via a free Usenet account from http://www.teranews.com

[CBFalconer]

akappa wrote:

On 19 Ago, 19:52, CBFalconer <cbfalco...@yah oo.comwrote:

>There is no iterator in the C language. Try comp.lang.c++.

Yes, but I'm talking about the library's iterator:
http://developer.gnome.org/doc/API/2...-table-foreach

(note that C++'s boost have a marshalling framework: If I was
coding in C++, then I wouldn't have any problem with marshalling

The 'library' is not defined in the C standard. Unless you post
the C-standard code involved here the question remains off-topic.

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home .att.net>

--
Posted via a free Usenet account from http://www.teranews.com