/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- *
 *
 * Author:
 *  Michael Zucchi <notzed@ximian.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU Lesser General Public
 * License as published by the Free Software Foundation.
 *
 * This program 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 program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 * USA
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <errno.h>
#include <pthread.h>
#include <stdio.h>
#include <string.h>

#include <glib.h>
#include <glib/gstdio.h>

#include "camel-file-utils.h"
#include "camel-list-utils.h"
#include "camel-object.h"

#define d(x)
#define b(x)			/* object bag */
#define h(x)			/* hooks */

/* I just mashed the keyboard for these... */
#define CAMEL_OBJECT_MAGIC		 0x77A344ED
#define CAMEL_OBJECT_CLASS_MAGIC	 0xEE26A997
#define CAMEL_INTERFACE_MAGIC	 0xBCE137A7
#define CAMEL_OBJECT_FINALISED_MAGIC       0x84AC365F
#define CAMEL_OBJECT_CLASS_FINALISED_MAGIC 0x7621ABCD
#define CAMEL_INTERFACE_FINALISED_MAGIC    0x7CB2FE71

/* ** Quickie type system ************************************************* */

/* A 'locked' hooklist, that is only allocated on demand */
typedef struct _CamelHookList {
	GStaticRecMutex lock;

	guint depth:30;	/* recursive event depth */
	guint flags:2;	/* flags, see below */

	guint list_length;
	struct _CamelHookPair *list;
} CamelHookList;

#define CAMEL_HOOK_PAIR_REMOVED (1<<0)

/* a 'hook pair', actually a hook tuple, we just store all hooked events in the same list,
   and just comapre as we go, rather than storing separate lists for each hook type

   the name field just points directly to the key field in the class's preplist hashtable.
   This way we can just use a direct pointer compare when scanning it, and also saves
   copying the string */
typedef struct _CamelHookPair
{
	struct _CamelHookPair *next; /* next MUST be the first member */

	guint id:30;
	guint flags:2;	/* removed, etc */

	const gchar *name;	/* points to the key field in the classes preplist, static memory */
	union {
		CamelObjectEventHookFunc event;
		CamelObjectEventPrepFunc prep;
		gchar *filename;
	} func;
	gpointer data;
} CamelHookPair;

struct _CamelObjectBagKey {
	struct _CamelObjectBagKey *next;

	gpointer key;		/* the key reserved */
	gint waiters;		/* count of threads waiting for key */
	pthread_t owner;	/* the thread that has reserved the bag for a new entry */
	gint have_owner;
	GCond *cond;
};

struct _CamelObjectBag {
	GHashTable *object_table; /* object by key */
	GHashTable *key_table;	/* key by object */
	GEqualFunc equal_key;
	CamelCopyFunc copy_key;
	GFreeFunc free_key;

	struct _CamelObjectBagKey *reserved;
};

/* used to tag a bag hookpair */
static const gchar bag_name[] = "object:bag";

/* meta-data stuff */
static void co_metadata_free(CamelObject *obj, CamelObjectMeta *meta);
static CamelObjectMeta *co_metadata_get(CamelObject *obj);
static CamelHookPair *co_metadata_pair(CamelObject *obj, gint create);

static const gchar meta_name[] = "object:meta";
#define CAMEL_OBJECT_STATE_FILE_MAGIC "CLMD"

/* interface stuff */
static const gchar interface_name[] = "object:interface";

/* ********************************************************************** */

static CamelHookList *camel_object_get_hooks(CamelObject *o);
static void camel_object_free_hooks(CamelObject *o);
static void camel_object_bag_remove_unlocked(CamelObjectBag *inbag, CamelObject *o, CamelHookList *hooks);

#define camel_object_unget_hooks(o) \
	(g_static_rec_mutex_unlock(&CAMEL_OBJECT(o)->hooks->lock))

/* ********************************************************************** */

/* type-lock must be recursive, for atomically creating classes */
static GStaticRecMutex type_lock = G_STATIC_REC_MUTEX_INIT;
/* ref-lock must be global :-(  for object bags to work */
static GMutex *ref_lock;

static GHashTable *type_table;

/* fundamental types are accessed via global */
CamelType camel_object_type = CAMEL_INVALID_TYPE;
CamelType camel_interface_type = CAMEL_INVALID_TYPE;

#define P_LOCK(l) (pthread_mutex_lock(&l))
#define P_UNLOCK(l) (pthread_mutex_unlock(&l))
#define CLASS_LOCK(k) (g_mutex_lock((((CamelObjectClass *)k)->lock)))
#define CLASS_UNLOCK(k) (g_mutex_unlock((((CamelObjectClass *)k)->lock)))
#define REF_LOCK() (g_mutex_lock(ref_lock))
#define REF_UNLOCK() (g_mutex_unlock(ref_lock))
#define TYPE_LOCK() (g_static_rec_mutex_lock(&type_lock))
#define TYPE_UNLOCK() (g_static_rec_mutex_unlock(&type_lock))

static struct _CamelHookPair *
pair_alloc(void)
{
	static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
	static guint next_id = 1;
	CamelHookPair *pair;

	pair = g_slice_new (CamelHookPair);

	g_static_mutex_lock (&mutex);
	pair->id = next_id++;
	if (next_id == 0)
		next_id = 1;
	g_static_mutex_unlock (&mutex);

	return pair;
}

static void
pair_free(CamelHookPair *pair)
{
	g_slice_free (CamelHookPair, pair);
}

static struct _CamelHookList *
hooks_alloc(void)
{
	return g_slice_new0 (CamelHookList);
}

static void
hooks_free(CamelHookList *hooks)
{
	g_slice_free (CamelHookList, hooks);
}

/* not checked locked, who cares, only required for people that want to redefine root objects */
void
camel_type_init(void)
{
	static gint init = FALSE;

	if (init)
		return;

	init = TRUE;
	type_table = g_hash_table_new(NULL, NULL);
	ref_lock = g_mutex_new();
}

/* ************************************************************************ */

/* CamelObject base methods */

/* Should this return the object to the caller? */
static void
cobject_init(CamelObject *o, CamelObjectClass *klass)
{
	o->klass = klass;
	o->magic = CAMEL_OBJECT_MAGIC;
	o->ref_count = 1;
	o->flags = 0;
}

static void
cobject_finalise(CamelObject *o)
{
	/*printf("%p: finalise %s\n", o, o->klass->name);*/

	if (o->ref_count == 0)
		return;

	camel_object_free_hooks(o);

	o->magic = CAMEL_OBJECT_FINALISED_MAGIC;
	o->klass = NULL;
}

static gint
cobject_getv(CamelObject *o, CamelException *ex, CamelArgGetV *args)
{
	gint i;
	guint32 tag;

	for (i=0;i<args->argc;i++) {
		CamelArgGet *arg = &args->argv[i];

		tag = arg->tag;

		switch (tag & CAMEL_ARG_TAG) {
		case CAMEL_OBJECT_ARG_DESCRIPTION:
			*arg->ca_str = (gchar *)o->klass->name;
			break;
		case CAMEL_OBJECT_ARG_METADATA:
			*arg->ca_ptr = co_metadata_get(o);
			break;
		case CAMEL_OBJECT_ARG_STATE_FILE: {
			CamelHookPair *pair = co_metadata_pair(o, FALSE);

			if (pair) {
				*arg->ca_str = g_strdup(pair->func.filename);
				camel_object_unget_hooks(o);
			}
			break; }
		}
	}

	/* could have flags or stuff here? */
	return 0;
}

static gint
cobject_setv(CamelObject *o, CamelException *ex, CamelArgV *args)
{
	gint i;
	guint32 tag;

	for (i=0;i<args->argc;i++) {
		CamelArg *arg = &args->argv[i];

		tag = arg->tag;

		switch (tag & CAMEL_ARG_TAG) {
		case CAMEL_OBJECT_ARG_STATE_FILE: {
			CamelHookPair *pair;

			/* We store the filename on the meta-data hook-pair */
			pair = co_metadata_pair(o, TRUE);
			g_free(pair->func.filename);
			pair->func.filename = g_strdup(arg->ca_str);
			camel_object_unget_hooks(o);
			break; }
		}
	}

	/* could have flags or stuff here? */
	return 0;
}

static void
cobject_free(CamelObject *o, guint32 tag, gpointer value)
{
	switch (tag & CAMEL_ARG_TAG) {
	case CAMEL_OBJECT_ARG_METADATA:
		co_metadata_free(o, value);
		break;
	case CAMEL_OBJECT_ARG_STATE_FILE:
		g_free(value);
		break;
	case CAMEL_OBJECT_ARG_PERSISTENT_PROPERTIES:
		g_slist_free((GSList *)value);
		break;
	}
}

static gchar *
cobject_meta_get(CamelObject *obj, const gchar * name)
{
	CamelHookPair *pair;
	CamelObjectMeta *meta;
	gchar *res = NULL;

	g_return_val_if_fail(CAMEL_IS_OBJECT (obj), NULL);
	g_return_val_if_fail(name != NULL, NULL);

	pair = co_metadata_pair(obj, FALSE);
	if (pair) {
		meta = pair->data;
		while (meta) {
			if (!strcmp(meta->name, name)) {
				res = g_strdup(meta->value);
				break;
			}
			meta = meta->next;
		}
		camel_object_unget_hooks(obj);
	}

	return res;
}

static gboolean
cobject_meta_set(CamelObject *obj, const gchar * name, const gchar *value)
{
	CamelHookPair *pair;
	gint changed = FALSE;
	CamelObjectMeta *meta, *metap;

	g_return_val_if_fail(CAMEL_IS_OBJECT (obj), FALSE);
	g_return_val_if_fail(name != NULL, FALSE);

	if (obj->hooks == NULL && value == NULL)
		return FALSE;

	pair = co_metadata_pair(obj, TRUE);
	meta = pair->data;
	metap = (CamelObjectMeta *)&pair->data;
	while (meta) {
		if (!strcmp(meta->name, name))
			break;
		metap = meta;
		meta = meta->next;
	}

	/* TODO: The camelobjectmeta structure is identical to
	   CamelTag, they could be merged or share common code */
	if (meta == NULL) {
		if (value == NULL)
			goto done;
		meta = g_malloc(sizeof(*meta) + strlen(name));
		meta->next = pair->data;
		pair->data = meta;
		strcpy(meta->name, name);
		meta->value = g_strdup(value);
		changed = TRUE;
	} else if (value == NULL) {
		metap->next = meta->next;
		g_free(meta->value);
		g_free(meta);
		changed = TRUE;
	} else if (strcmp(meta->value, value) != 0) {
		g_free(meta->value);
		meta->value = g_strdup(value);
		changed = TRUE;
	}

done:
	camel_object_unget_hooks(obj);

	return changed;
}

/* State file for CamelObject data.  Any later versions should only append data.

   version:uint32

   Version 0 of the file:

   version:uint32 = 0
   count:uint32				-- count of meta-data items
   ( name:string value:string ) *count		-- meta-data items

   Version 1 of the file adds:
   count:uint32					-- count of persistent properties
   ( tag:uing32 value:tagtype ) *count		-- persistent properties

*/

static gint
cobject_state_read(CamelObject *obj, FILE *fp)
{
	guint32 i, count, version;

	/* NB: for later versions, just check the version is 1 .. known version */
	if (camel_file_util_decode_uint32(fp, &version) == -1
	    || version > 1
	    || camel_file_util_decode_uint32(fp, &count) == -1)
		return -1;

	for (i=0;i<count;i++) {
		gchar *name = NULL, *value = NULL;

		if (camel_file_util_decode_string(fp, &name) == 0
		    && camel_file_util_decode_string(fp, &value) == 0) {
			camel_object_meta_set(obj, name, value);
			g_free(name);
			g_free(value);
		} else {
			g_free(name);
			g_free(value);

			return -1;
		}
	}

	if (version > 0) {
		CamelArgV *argv;

		if (camel_file_util_decode_uint32(fp, &count) == -1
			|| count == 0 || count > 1024) {
			/* maybe it was just version 0 afterall */
			return 0;
		}

		count = MIN(count, CAMEL_ARGV_MAX);

		/* we batch up the properties and set them in one go */
		argv = g_try_malloc(sizeof(CamelArgV) -
			((CAMEL_ARGV_MAX - count) * sizeof(CamelArg)));
		if (argv == NULL)
			return -1;

		argv->argc = 0;
		for (i=0;i<count;i++) {
			if (camel_file_util_decode_uint32(fp, &argv->argv[argv->argc].tag) == -1)
				goto cleanup;

			/* so far,only do strings and ints, doubles could be added,
			   object's would require a serialisation interface */

			switch (argv->argv[argv->argc].tag & CAMEL_ARG_TYPE) {
			case CAMEL_ARG_INT:
			case CAMEL_ARG_BOO:
				if (camel_file_util_decode_uint32(fp, (guint32 *) &argv->argv[argv->argc].ca_int) == -1)
					goto cleanup;
				break;
			case CAMEL_ARG_STR:
				if (camel_file_util_decode_string(fp, &argv->argv[argv->argc].ca_str) == -1)
					goto cleanup;
				break;
			default:
				goto cleanup;
			}

			argv->argc++;
		}

		camel_object_setv(obj, NULL, argv);
	cleanup:
		for (i=0;i<argv->argc;i++) {
			if ((argv->argv[i].tag & CAMEL_ARG_TYPE) == CAMEL_ARG_STR)
				g_free(argv->argv[i].ca_str);
		}
		g_free(argv);
	}

	return 0;
}

/* TODO: should pass exception around */
static gint
cobject_state_write(CamelObject *obj, FILE *fp)
{
	gint32 count, i;
	CamelObjectMeta *meta = NULL, *scan;
	gint res = -1;
	GSList *props = NULL, *l;
	CamelArgGetV *arggetv = NULL;
	CamelArgV *argv = NULL;

	camel_object_get(obj, NULL, CAMEL_OBJECT_METADATA, &meta, NULL);

	count = 0;
	scan = meta;
	while (scan) {
		count++;
		scan = scan->next;
	}

	/* current version is 1 */
	if (camel_file_util_encode_uint32(fp, 1) == -1
	    || camel_file_util_encode_uint32(fp, count) == -1)
		goto abort;

	scan = meta;
	while (scan) {
		if (camel_file_util_encode_string(fp, scan->name) == -1
		    || camel_file_util_encode_string(fp, scan->value) == -1)
			goto abort;
		scan = scan->next;
	}

	camel_object_get(obj, NULL, CAMEL_OBJECT_PERSISTENT_PROPERTIES, &props, NULL);

	/* we build an arggetv to query the object atomically,
	   we also need an argv to store the results - bit messy */

	count = g_slist_length(props);
	count = MIN(count, CAMEL_ARGV_MAX);

	arggetv = g_malloc0(sizeof(CamelArgGetV) -
		((CAMEL_ARGV_MAX - count) * sizeof(CamelArgGet)));
	argv = g_malloc0(sizeof(CamelArgV) -
		((CAMEL_ARGV_MAX - count) * sizeof(CamelArg)));
	l = props;
	i = 0;
	while (l) {
		CamelProperty *prop = l->data;

		argv->argv[i].tag = prop->tag;
		arggetv->argv[i].tag = prop->tag;
		arggetv->argv[i].ca_ptr = &argv->argv[i].ca_ptr;

		i++;
		l = l->next;
	}
	arggetv->argc = i;
	argv->argc = i;

	camel_object_getv(obj, NULL, arggetv);

	if (camel_file_util_encode_uint32(fp, count) == -1)
		goto abort;

	for (i=0;i<argv->argc;i++) {
		CamelArg *arg = &argv->argv[i];

		if (camel_file_util_encode_uint32(fp, arg->tag) == -1)
			goto abort;

		switch (arg->tag & CAMEL_ARG_TYPE) {
		case CAMEL_ARG_INT:
		case CAMEL_ARG_BOO:
			if (camel_file_util_encode_uint32(fp, arg->ca_int) == -1)
				goto abort;
			break;
		case CAMEL_ARG_STR:
			if (camel_file_util_encode_string(fp, arg->ca_str) == -1)
				goto abort;
			break;
		}
	}

	res = 0;
abort:
	for (i=0;i<argv->argc;i++) {
		CamelArg *arg = &argv->argv[i];

		if ((argv->argv[i].tag & CAMEL_ARG_TYPE) == CAMEL_ARG_STR)
			camel_object_free(obj, arg->tag, arg->ca_str);
	}

	g_free(argv);
	g_free(arggetv);

	if (props)
		camel_object_free(obj, CAMEL_OBJECT_PERSISTENT_PROPERTIES, props);

	if (meta)
		camel_object_free(obj, CAMEL_OBJECT_METADATA, meta);

	return res;
}

static void
cobject_class_init(CamelObjectClass *klass)
{
	klass->magic = CAMEL_OBJECT_CLASS_MAGIC;

	klass->getv = cobject_getv;
	klass->setv = cobject_setv;
	klass->free = cobject_free;

	klass->meta_get = cobject_meta_get;
	klass->meta_set = cobject_meta_set;
	klass->state_read = cobject_state_read;
	klass->state_write = cobject_state_write;

	camel_object_class_add_event(klass, "finalize", NULL);
	camel_object_class_add_event(klass, "meta_changed", NULL);
}

static void
cobject_class_finalise(CamelObjectClass * klass)
{
	klass->magic = CAMEL_OBJECT_CLASS_FINALISED_MAGIC;

	g_free(klass);
}

/* CamelInterface base methods */

G_GNUC_NORETURN static void
cinterface_init(CamelObject *o, CamelObjectClass *klass)
{
	g_error("Cannot instantiate interfaces, trying to instantiate '%s'", klass->name);
}

static gint
cinterface_getv(CamelObject *o, CamelException *ex, CamelArgGetV *args)
{
	return 0;
}

static gint
cinterface_setv(CamelObject *o, CamelException *ex, CamelArgV *args)
{
	return 0;
}

static void
cinterface_free(CamelObject *o, guint32 tag, gpointer value)
{
	/* NOOP */
}

static void
cinterface_class_init(CamelObjectClass *klass)
{
	klass->magic = CAMEL_INTERFACE_MAGIC;

	/* just setup dummy callbacks, properties could be part of the interface but we support none */
	klass->getv = cinterface_getv;
	klass->setv = cinterface_setv;
	klass->free = cinterface_free;

	/* TODO: ok, these are cruft hanging around an interface, but it saves having to define two different class bases */
	klass->meta_get = NULL;
	klass->meta_set = NULL;
	klass->state_read = NULL;
	klass->state_write = NULL;
}

static void
cinterface_class_finalise(CamelObjectClass * klass)
{
	klass->magic = CAMEL_INTERFACE_FINALISED_MAGIC;
	g_free(klass);
}

/* this function must be called for any other in the object system */
CamelType
camel_object_get_type(void)
{
	if (camel_object_type == CAMEL_INVALID_TYPE) {
		camel_type_init();

		camel_object_type = camel_type_register(NULL, "CamelObject", /*, 0, 0*/
							sizeof(CamelObject), sizeof(CamelObjectClass),
							cobject_class_init, cobject_class_finalise,
							cobject_init, cobject_finalise);

		camel_interface_type = camel_type_register(NULL, "CamelInterface",
							   0, sizeof(CamelInterface),
							   cinterface_class_init, cinterface_class_finalise,
							   cinterface_init, NULL);

	}

	return camel_object_type;
}

static void
camel_type_class_init(CamelObjectClass *klass, CamelObjectClass *type)
{
	if (type->parent)
		camel_type_class_init(klass, type->parent);

	if (type->klass_init)
		type->klass_init(klass);
}

static CamelType
co_type_register(CamelType parent, const gchar * name,
		 /*guint ver, guint rev,*/
		 gsize object_size, gsize klass_size,
		 CamelObjectClassInitFunc class_init,
		 CamelObjectClassFinalizeFunc class_finalise,
		 CamelObjectInitFunc object_init,
		 CamelObjectFinalizeFunc object_finalise)
{
	CamelObjectClass *klass;
	/*int offset;
	  gsize size;*/

	TYPE_LOCK();

	camel_type_init(); /* has a static boolean itself */

	/* Have to check creation, it might've happened in another thread before we got here */
	klass = g_hash_table_lookup(type_table, name);
	if (klass != NULL) {
		if (klass->klass_size != klass_size || klass->object_size != object_size
		    || klass->klass_init != class_init || klass->klass_finalise != class_finalise
		    || klass->init != object_init || klass->finalise != object_finalise) {
			g_warning("camel_type_register: Trying to re-register class '%s'", name);
			klass = NULL;
		}
		TYPE_UNLOCK();
		return klass;
	}

	/* this is for objects with no parent as part of their struct ('interfaces'?) */
	/*offset = parent?parent->klass_size:0;
	offset = (offset + 3) & (~3);

	size = offset + klass_size;

	klass = g_slice_alloc0(size);

	klass->klass_size = size;
	klass->klass_data = offset;

	offset = parent?parent->object_size:0;
	offset = (offset + 3) & (~3);

	klass->object_size = offset + object_size;
	klass->object_data = offset;*/

	if (parent
	    && klass_size < parent->klass_size) {
		g_warning("camel_type_register: '%s' has smaller class size than parent '%s'", name, parent->name);
		TYPE_UNLOCK();
		return NULL;
	}

	klass = g_slice_alloc0 (klass_size);
	klass->klass_size = klass_size;
	klass->object_size = object_size;
	klass->lock = g_mutex_new();
	klass->hooks = NULL;

	klass->parent = parent;
	if (parent) {
		klass->next = parent->child;
		parent->child = klass;
	}
	klass->name = name;

	/*klass->version = ver;
	  klass->revision = rev;*/

	klass->klass_init = class_init;
	klass->klass_finalise = class_finalise;

	klass->init = object_init;
	klass->finalise = object_finalise;

	/* setup before class init, incase class init func uses the type or looks it up ? */
	g_hash_table_insert(type_table, (gpointer)name, klass);

	camel_type_class_init(klass, klass);

	TYPE_UNLOCK();

	return klass;
}

CamelType
camel_type_register(CamelType parent, const gchar * name,
		    /*guint ver, guint rev,*/
		    gsize object_size, gsize klass_size,
		    CamelObjectClassInitFunc class_init,
		    CamelObjectClassFinalizeFunc class_finalise,
		    CamelObjectInitFunc object_init,
		    CamelObjectFinalizeFunc object_finalise)
{
	if (parent != NULL && parent->magic != CAMEL_OBJECT_CLASS_MAGIC) {
		g_warning("camel_type_register: invalid junk parent class for '%s'", name);
		return NULL;
	}

	return co_type_register(parent, name, object_size, klass_size, class_init, class_finalise, object_init, object_finalise);
}

CamelType
camel_interface_register(CamelType parent, const gchar *name,
			 gsize class_size,
			 CamelObjectClassInitFunc class_init,
			 CamelObjectClassFinalizeFunc class_finalise)
{
	if (parent != NULL && parent->magic != CAMEL_INTERFACE_MAGIC) {
		g_warning("camel_interface_register: invalid junk parent class for '%s'", name);
		return NULL;
	}

	return camel_type_register(parent, name, 0, class_size, class_init, class_finalise, NULL, NULL);
}

static void
camel_object_init(CamelObject *o, CamelObjectClass *klass, CamelType type)
{
	if (type->parent)
		camel_object_init(o, klass, type->parent);

	if (type->init)
		type->init(o, klass);
}

CamelObject *
camel_object_new(CamelType type)
{
	CamelObject *o;

	if (type == NULL)
		return NULL;

	if (type->magic != CAMEL_OBJECT_CLASS_MAGIC)
		return NULL;

	CLASS_LOCK(type);

	o = g_slice_alloc0 (type->object_size);

#ifdef CAMEL_OBJECT_TRACK_INSTANCES
	if (type->instances)
		type->instances->prev = o;
	o->next = type->instances;
	o->prev = NULL;
	type->instances = o;
#endif

	CLASS_UNLOCK(type);

	camel_object_init(o, type, type);

	d(printf("%p: new %s()\n", o, o->klass->name));

	return o;
}

void
camel_object_ref(gpointer vo)
{
	register CamelObject *o = vo;

	g_return_if_fail(CAMEL_IS_OBJECT(o));

	REF_LOCK();

	o->ref_count++;
	d(printf("%p: ref %s(%d)\n", o, o->klass->name, o->ref_count));

	REF_UNLOCK();
}

void
camel_object_unref(gpointer vo)
{
	register CamelObject *o = vo;
	register CamelObjectClass *klass, *k;
	CamelHookList *hooks = NULL;

	g_return_if_fail(CAMEL_IS_OBJECT(o));

	klass = o->klass;

	if (o->hooks)
		hooks = camel_object_get_hooks(o);

	REF_LOCK();

	o->ref_count--;

	d(printf("%p: unref %s(%d)\n", o, o->klass->name, o->ref_count));

	if (o->ref_count > 0
	    || (o->flags & CAMEL_OBJECT_DESTROY)) {
		REF_UNLOCK();
		if (hooks)
			camel_object_unget_hooks(o);
		return;
	}

	o->flags |= CAMEL_OBJECT_DESTROY;

	if (hooks)
		camel_object_bag_remove_unlocked(NULL, o, hooks);

	REF_UNLOCK();

	if (hooks)
		camel_object_unget_hooks(o);

	camel_object_trigger_event(o, "finalize", NULL);

	k = klass;
	while (k) {
		if (k->finalise)
			k->finalise(o);
		k = k->parent;
	}

	o->magic = CAMEL_OBJECT_FINALISED_MAGIC;

	CLASS_LOCK(klass);
#ifdef CAMEL_OBJECT_TRACK_INSTANCES
	if (o->prev)
		o->prev->next = o->next;
	else
		klass->instances = o->next;
	if (o->next)
		o->next->prev = o->prev;
#endif
	g_slice_free1 (klass->object_size, o);
	CLASS_UNLOCK(klass);
}

const gchar *
camel_type_to_name(CamelType type)
{
	if (type == NULL)
		return "(NULL class)";

	if (type->magic == CAMEL_OBJECT_CLASS_MAGIC)
		return type->name;

	if (type->magic == CAMEL_INTERFACE_MAGIC)
		return type->name;

	return "(Junk class)";
}

CamelType camel_name_to_type(const gchar *name)
{
	/* TODO: Load a class off disk (!) */

	return g_hash_table_lookup(type_table, name);
}

static gchar *
desc_data(CamelObject *o, guint32 ok)
{
	gchar *what;

	if (o == NULL)
		what = g_strdup("NULL OBJECT");
	else if (o->magic == ok)
		what = NULL;
	else if (o->magic == CAMEL_OBJECT_MAGIC)
		what = g_strdup_printf("CLASS '%s'", ((CamelObjectClass *)o)->name);
	else if (o->magic == CAMEL_OBJECT_CLASS_MAGIC)
		what = g_strdup_printf("CLASS '%s'", ((CamelObjectClass *)o)->name);
	else if (o->magic == CAMEL_INTERFACE_MAGIC)
		what = g_strdup_printf("INTERFACE '%s'", ((CamelObjectClass *)o)->name);
	else if (o->magic == CAMEL_OBJECT_FINALISED_MAGIC)
		what = g_strdup_printf("finalised OBJECT");
	else if (o->magic == CAMEL_OBJECT_CLASS_FINALISED_MAGIC)
		what = g_strdup_printf("finalised CLASS");
	else if (o->magic == CAMEL_INTERFACE_FINALISED_MAGIC)
		what = g_strdup_printf("finalised INTERFACE");
	else
		what = g_strdup_printf("junk data");

	return what;
}

#define check_magic(o, ctype, omagic) \
	( ((CamelObject *)(o))->magic == (omagic) \
	&& (ctype)->magic == CAMEL_OBJECT_CLASS_MAGIC) \
	? 1 : check_magic_fail(o, ctype, omagic)

static gboolean
check_magic_fail(gpointer o, CamelType ctype, guint32 omagic)
{
	gchar *what, *to;

	what = desc_data(o, omagic);
	to = desc_data((CamelObject *)ctype, CAMEL_OBJECT_CLASS_MAGIC);

	if (what || to) {
		if (what == NULL) {
			if (omagic == CAMEL_OBJECT_MAGIC)
				what = g_strdup_printf("OBJECT '%s'", ((CamelObject *)o)->klass->name);
			else
				what = g_strdup_printf("OBJECT '%s'", ((CamelObjectClass *)o)->name);
		}
		if (to == NULL)
			to = g_strdup_printf("OBJECT '%s'", ctype->name);
		g_warning("Trying to check %s is %s", what, to);
		g_free(what);
		g_free(to);

		return FALSE;
	}

	return TRUE;
}

gboolean
camel_object_is(CamelObject *o, CamelType ctype)
{
	CamelObjectClass *k;

	g_return_val_if_fail(o != NULL, FALSE);
	g_return_val_if_fail(check_magic(o, ctype, CAMEL_OBJECT_MAGIC), FALSE);

	k = o->klass;
	while (k) {
		if (k == ctype)
			return TRUE;
		k = k->parent;
	}

	return FALSE;
}

gboolean
camel_object_class_is(CamelObjectClass *k, CamelType ctype)
{
	g_return_val_if_fail(k != NULL, FALSE);
	g_return_val_if_fail(check_magic(k, ctype, CAMEL_OBJECT_CLASS_MAGIC), FALSE);

	while (k) {
		if (k == ctype)
			return TRUE;
		k = k->parent;
	}

	return FALSE;
}

gboolean
camel_interface_is(CamelObjectClass *k, CamelType ctype)
{
	g_return_val_if_fail(k != NULL, FALSE);
	g_return_val_if_fail(check_magic(k, ctype, CAMEL_INTERFACE_MAGIC), FALSE);

	while (k) {
		if (k == ctype)
			return TRUE;
		k = k->parent;
	}

	return FALSE;
}

CamelObject *
camel_object_cast(CamelObject *o, CamelType ctype)
{
	CamelObjectClass *k;

        g_return_val_if_fail(o != NULL, NULL);
	g_return_val_if_fail(check_magic(o, ctype, CAMEL_OBJECT_MAGIC), NULL);

	k = o->klass;
	while (k) {
		if (k == ctype)
			return o;
		k = k->parent;
	}

	g_warning("Object %p (class '%s') doesn't have '%s' in its hierarchy", (gpointer) o, o->klass->name, ctype->name);

	return NULL;
}

CamelObjectClass *
camel_object_class_cast(CamelObjectClass *k, CamelType ctype)
{
	CamelObjectClass *r = k;

	g_return_val_if_fail(check_magic(k, ctype, CAMEL_OBJECT_CLASS_MAGIC), NULL);

	while (k) {
		if (k == ctype)
			return r;
		k = k->parent;
	}

	g_warning("Class '%s' doesn't have '%s' in its hierarchy", r->name, ctype->name);

	return NULL;
}

CamelObjectClass *
camel_interface_cast(CamelObjectClass *k, CamelType ctype)
{
	CamelObjectClass *r = k;

	g_return_val_if_fail(check_magic(k, ctype, CAMEL_INTERFACE_MAGIC), NULL);

	while (k) {
		if (k == ctype)
			return r;
		k = k->parent;
	}

	g_warning("Interface '%s' doesn't have '%s' in its hierarchy", r->name, ctype->name);

	return NULL;
}

static CamelHookPair *
co_find_pair(CamelObjectClass *klass, const gchar *name)
{
	CamelHookPair *hook;

	hook = klass->hooks;
	while (hook) {
		if (strcmp(hook->name, name) == 0)
			return hook;
		hook = hook->next;
	}

	return NULL;
}

static CamelHookPair *
co_find_pair_ptr(CamelObjectClass *klass, const gchar *name)
{
	CamelHookPair *hook;

	hook = klass->hooks;
	while (hook) {
		if (hook->name == name)
			return hook;
		hook = hook->next;
	}

	return NULL;
}

/* class functions */
void
camel_object_class_add_event(CamelObjectClass *klass, const gchar *name, CamelObjectEventPrepFunc prep)
{
	CamelHookPair *pair;

	g_return_if_fail (name);

	pair = co_find_pair(klass, name);
	if (pair) {
		g_warning("camel_object_class_add_event: '%s' is already declared for '%s'",
			  name, klass->name);
		return;
	}

	if (klass->magic == CAMEL_INTERFACE_MAGIC && prep != NULL) {
		g_warning("camel_object_class_add_event: '%s', CamelInterface '%s' may not have an event prep function - ignored",
			  name, klass->name);
		prep = NULL;
	}

	pair = pair_alloc();
	pair->name = name;
	pair->func.prep = prep;
	pair->flags = 0;

	pair->next = klass->hooks;
	klass->hooks = pair;
}

void
camel_object_class_add_interface(CamelObjectClass *klass, CamelType itype)
{
	CamelHookPair *pair;
	CamelType iscan;
	GPtrArray *interfaces;
	gint i;

	if (!camel_interface_is(itype, camel_interface_type)) {
		g_warning("Cannot add an interface not derived from CamelInterface on class '%s'", klass->name);
		return;
	}

	if (camel_object_class_is(klass, camel_interface_type)) {
		g_warning("Cannot add an interface onto a class derived from CamelInterface");
		return;
	}

	/* we store it on the class hooks so we don't have to add any extra space to the class */
	pair = co_find_pair_ptr(klass, interface_name);
	if (pair == NULL) {
		pair = pair_alloc();
		pair->data = g_ptr_array_new();
		pair->next = klass->hooks;
		klass->hooks = pair;
	}

	/* We just check that this type isn't added/derived anywhere else */
	interfaces = pair->data;
	iscan = itype;
	while (iscan && iscan != camel_interface_type) {
		for (i=0;i<interfaces->len;i++) {
			if (camel_interface_is((CamelType)interfaces->pdata[i], iscan)) {
				g_warning("Cannot add an interface twice '%s' on class '%s'\n", itype->name, klass->name);
				return;
			}
		}
		iscan = iscan->parent;
	}

	if (iscan == camel_interface_type)
		g_ptr_array_add(interfaces, itype);
}

/* free hook data */
static void
camel_object_free_hooks(CamelObject *o)
{
	CamelHookPair *pair, *next;

	if (o->hooks) {
		g_assert(o->hooks->depth == 0);
		g_assert((o->hooks->flags & CAMEL_HOOK_PAIR_REMOVED) == 0);

		pair = o->hooks->list;
		while (pair) {
			next = pair->next;

			if (pair->name == meta_name) {
				co_metadata_free(o, pair->data);
				g_free(pair->func.filename);
			}

			pair_free(pair);
			pair = next;
		}
		g_static_rec_mutex_free(&o->hooks->lock);
		hooks_free(o->hooks);
		o->hooks = NULL;
	}
}

/* return (allocate if required) the object's hook list, locking at the same time */
static CamelHookList *
camel_object_get_hooks(CamelObject *o)
{
	static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
	CamelHookList *hooks;

	/* if we have it, we dont have to do any other locking,
	   otherwise use a global lock to setup the object's hook data */
	if (o->hooks == NULL) {
		pthread_mutex_lock(&lock);
		if (o->hooks == NULL) {
			hooks = hooks_alloc();
			g_static_rec_mutex_init(&hooks->lock);
			hooks->flags = 0;
			hooks->depth = 0;
			hooks->list_length = 0;
			hooks->list = NULL;
			o->hooks = hooks;
		}
		pthread_mutex_unlock(&lock);
	}

	g_static_rec_mutex_lock(&o->hooks->lock);

	return o->hooks;
}

guint
camel_object_hook_event(gpointer vo, const gchar * name, CamelObjectEventHookFunc func, gpointer data)
{
	CamelObject *obj = vo;
	CamelHookPair *pair, *hook;
	CamelHookList *hooks;
	gint id;

	g_return_val_if_fail(CAMEL_IS_OBJECT (obj), 0);
	g_return_val_if_fail(name != NULL, 0);
	g_return_val_if_fail(func != NULL, 0);

	hook = co_find_pair(obj->klass, name);

	/* Check all interfaces on this object for events defined on them */
	if (hook == NULL) {
		pair = co_find_pair_ptr(obj->klass, interface_name);
		if (pair) {
			GPtrArray *interfaces = pair->data;
			gint i;

			for (i=0;i<interfaces->len;i++) {
				hook = co_find_pair(interfaces->pdata[i], name);
				if (hook)
					goto setup;
			}
		}

		g_warning("camel_object_hook_event: trying to hook event '%s' in class '%s' with no defined events.",
			  name, obj->klass->name);

		return 0;
	}
setup:
	/* setup hook pair */
	pair = pair_alloc();
	pair->name = hook->name;	/* effectively static! */
	pair->func.event = func;
	pair->data = data;
	pair->flags = 0;
	id = pair->id;

	/* get the hook list object, locked, link in new event hook, unlock */
	hooks = camel_object_get_hooks(obj);
	pair->next = hooks->list;
	hooks->list = pair;
	hooks->list_length++;
	camel_object_unget_hooks(obj);

	h(printf("%p hook event '%s' %p %p = %d\n", vo, name, func, data, id));

	return id;
}

void
camel_object_remove_event(gpointer vo, guint id)
{
	CamelObject *obj = vo;
	CamelHookList *hooks;
	CamelHookPair *pair, *parent;

	g_return_if_fail (CAMEL_IS_OBJECT (obj));
	g_return_if_fail (id != 0);

	if (obj->hooks == NULL) {
		g_warning("camel_object_unhook_event: trying to unhook '%u' from an instance of '%s' with no hooks",
			  id, obj->klass->name);
		return;
	}

	h(printf("%p remove event %d\n", vo, id));

	/* scan hooks for this event, remove it, or flag it if we're busy */
	hooks = camel_object_get_hooks(obj);
	parent = (CamelHookPair *)&hooks->list;
	pair = parent->next;
	while (pair) {
		if (pair->id == id
		    && (pair->flags & CAMEL_HOOK_PAIR_REMOVED) == 0) {
			if (hooks->depth > 0) {
				pair->flags |= CAMEL_HOOK_PAIR_REMOVED;
				hooks->flags |= CAMEL_HOOK_PAIR_REMOVED;
			} else {
				parent->next = pair->next;
				pair_free(pair);
				hooks->list_length--;
			}
			camel_object_unget_hooks(obj);
			return;
		}
		parent = pair;
		pair = pair->next;
	}
	camel_object_unget_hooks(obj);

	g_warning("camel_object_unhook_event: cannot find hook id %u in instance of '%s'",
		  id, obj->klass->name);
}

void
camel_object_unhook_event(gpointer vo, const gchar * name, CamelObjectEventHookFunc func, gpointer data)
{
	CamelObject *obj = vo;
	CamelHookList *hooks;
	CamelHookPair *pair, *parent;

	g_return_if_fail (CAMEL_IS_OBJECT (obj));
	g_return_if_fail (name != NULL);
	g_return_if_fail (func != NULL);

	if (obj->hooks == NULL) {
		g_warning("camel_object_unhook_event: trying to unhook '%s' from an instance of '%s' with no hooks",
			  name, obj->klass->name);
		return;
	}

	h(printf("%p unhook event '%s' %p %p\n", vo, name, func, data));

	/* scan hooks for this event, remove it, or flag it if we're busy */
	hooks = camel_object_get_hooks(obj);
	parent = (CamelHookPair *)&hooks->list;
	pair = parent->next;
	while (pair) {
		if (pair->func.event == func
		    && pair->data == data
		    && strcmp(pair->name, name) == 0
		    && (pair->flags & CAMEL_HOOK_PAIR_REMOVED) == 0) {
			if (hooks->depth > 0) {
				pair->flags |= CAMEL_HOOK_PAIR_REMOVED;
				hooks->flags |= CAMEL_HOOK_PAIR_REMOVED;
			} else {
				parent->next = pair->next;
				pair_free(pair);
				hooks->list_length--;
			}
			camel_object_unget_hooks(obj);
			return;
		}
		parent = pair;
		pair = pair->next;
	}
	camel_object_unget_hooks(obj);

	g_warning("camel_object_unhook_event: cannot find hook/data pair %p/%p in an instance of '%s' attached to '%s'",
		  (gpointer) func, data, obj->klass->name, name);
}

void
camel_object_trigger_event(gpointer vo, const gchar * name, gpointer event_data)
{
	CamelObject *obj = vo;
	CamelHookList *hooks;
	CamelHookPair *pair, **pairs, *parent, *hook;
	gint i, size;
	const gchar *prepname;

	g_return_if_fail (CAMEL_IS_OBJECT (obj));
	g_return_if_fail (name);

	hook = co_find_pair(obj->klass, name);
	if (hook)
		goto trigger;

	if (obj->hooks == NULL)
		return;

	/* interface events can't have prep functions */
	pair = co_find_pair_ptr(obj->klass, interface_name);
	if (pair) {
		GPtrArray *interfaces = pair->data;

		for (i=0;i<interfaces->len;i++) {
			hook = co_find_pair(interfaces->pdata[i], name);
			if (hook)
				goto trigger_interface;
		}
	}

	g_warning("camel_object_trigger_event: trying to trigger unknown event '%s' in class '%s'",
		  name, obj->klass->name);

	return;

trigger:
	/* try prep function, if false, then quit */
	if (hook->func.prep != NULL && !hook->func.prep(obj, event_data))
		return;

	/* also, no hooks, dont bother going further */
	if (obj->hooks == NULL)
		return;

trigger_interface:
	/* lock the object for hook emission */
	camel_object_ref(obj);
	hooks = camel_object_get_hooks(obj);

	if (hooks->list) {
		/* first, copy the items in the list, and say we're in an event */
		hooks->depth++;
		pair = hooks->list;
		size = 0;
		pairs = alloca(sizeof(pairs[0]) * hooks->list_length);
		prepname = hook->name;
		while (pair) {
			if (pair->name == prepname)
				pairs[size++] = pair;
			pair = pair->next;
		}

		/* now execute the events we have, if they haven't been removed during our calls */
		for (i=size-1;i>=0;i--) {
			pair = pairs[i];
			if ((pair->flags & CAMEL_HOOK_PAIR_REMOVED) == 0)
				(pair->func.event) (obj, event_data, pair->data);
		}
		hooks->depth--;

		/* and if we're out of any events, then clean up any pending removes */
		if (hooks->depth == 0 && (hooks->flags & CAMEL_HOOK_PAIR_REMOVED)) {
			parent = (CamelHookPair *)&hooks->list;
			pair = parent->next;
			while (pair) {
				if (pair->flags & CAMEL_HOOK_PAIR_REMOVED) {
					parent->next = pair->next;
					pair_free(pair);
					hooks->list_length--;
				} else {
					parent = pair;
				}
				pair = parent->next;
			}
			hooks->flags &= ~CAMEL_HOOK_PAIR_REMOVED;
		}
	}

	camel_object_unget_hooks(obj);
	camel_object_unref(obj);
}

gpointer
camel_object_get_interface(gpointer vo, CamelType itype)
{
	CamelObject *obj = vo;
	CamelHookPair *pair;

	g_return_val_if_fail(CAMEL_IS_OBJECT (obj), NULL);
	g_return_val_if_fail(camel_interface_is(itype, camel_interface_type), NULL);

	pair = co_find_pair_ptr(obj->klass, interface_name);
	if (pair) {
		GPtrArray *interfaces = pair->data;
		gint i;

		for (i=0;i<interfaces->len;i++) {
			if (camel_interface_is((CamelType)interfaces->pdata[i], itype))
				return (CamelType)interfaces->pdata[i];
		}
	}

	g_warning("Object %p class %s doesn't contain interface %s\n", vo, obj->klass->name, itype->name);

	return NULL;
}

/* get/set arg methods */
gint camel_object_set(gpointer vo, CamelException *ex, ...)
{
	CamelArgV args;
	CamelObject *o = vo;
	CamelObjectClass *klass = o->klass;
	gint ret = 0;

	g_return_val_if_fail(CAMEL_IS_OBJECT(o), -1);

	camel_argv_start(&args, ex);

	while (camel_argv_build(&args) && ret == 0)
		ret = klass->setv(o, ex, &args);
	if (ret == 0)
		ret = klass->setv(o, ex, &args);

	camel_argv_end(&args);

	return ret;
}

gint camel_object_setv(gpointer vo, CamelException *ex, CamelArgV *args)
{
	g_return_val_if_fail(CAMEL_IS_OBJECT(vo), -1);

	return ((CamelObject *)vo)->klass->setv(vo, ex, args);
}

gint camel_object_get(gpointer vo, CamelException *ex, ...)
{
	CamelObject *o = vo;
	CamelArgGetV args;
	CamelObjectClass *klass = o->klass;
	gint ret = 0;

	g_return_val_if_fail(CAMEL_IS_OBJECT(o), -1);

	camel_argv_start(&args, ex);

	while (camel_arggetv_build(&args) && ret == 0)
		ret = klass->getv(o, ex, &args);
	if (ret == 0)
		ret = klass->getv(o, ex, &args);

	camel_argv_end(&args);

	return ret;
}

gpointer camel_object_get_ptr(gpointer vo, CamelException *ex, gint tag)
{
	CamelObject *o = vo;
	CamelArgGetV args;
	CamelObjectClass *klass = o->klass;
	gint ret = 0;
	gpointer val = NULL;

	g_return_val_if_fail(CAMEL_IS_OBJECT(o), NULL);
	g_return_val_if_fail((tag & CAMEL_ARG_TYPE) == CAMEL_ARG_OBJ
			     || (tag & CAMEL_ARG_TYPE) == CAMEL_ARG_STR
			     || (tag & CAMEL_ARG_TYPE) == CAMEL_ARG_PTR, NULL);

	/* woefully inefficient, *shrug */
	args.argc = 1;
	args.argv[0].tag = tag;
	args.argv[0].ca_ptr = &val;

	ret = klass->getv(o, ex, &args);
	if (ret != 0)
		return NULL;
	else
		return val;
}

gint camel_object_get_int(gpointer vo, CamelException *ex, gint tag)
{
	CamelObject *o = vo;
	CamelArgGetV args;
	CamelObjectClass *klass = o->klass;
	gint ret = 0;
	gint val = 0;

	g_return_val_if_fail(CAMEL_IS_OBJECT(o), 0);
	g_return_val_if_fail((tag & CAMEL_ARG_TYPE) == CAMEL_ARG_INT
			     || (tag & CAMEL_ARG_TYPE) == CAMEL_ARG_BOO, 0);

	/* woefully inefficient, *shrug */
	args.argc = 1;
	args.argv[0].tag = tag;
	args.argv[0].ca_int = &val;

	ret = klass->getv(o, ex, &args);
	if (ret != 0)
		return 0;
	else
		return val;
}

gint camel_object_getv(gpointer vo, CamelException *ex, CamelArgGetV *args)
{
	g_return_val_if_fail(CAMEL_IS_OBJECT(vo), -1);

	return ((CamelObject *)vo)->klass->getv(vo, ex, args);
}

/* NB: If this doesn't return NULL, then you must unget_hooks when done */
static CamelHookPair *
co_metadata_pair(CamelObject *obj, gint create)
{
	CamelHookPair *pair;
	CamelHookList *hooks;

	if (obj->hooks == NULL && !create)
		return NULL;

	hooks = camel_object_get_hooks(obj);
	pair = hooks->list;
	while (pair) {
		if (pair->name == meta_name)
			return pair;

		pair = pair->next;
	}

	if (create) {
		pair = pair_alloc();
		pair->name = meta_name;
		pair->data = NULL;
		pair->flags = 0;
		pair->func.filename = NULL;
		pair->next = hooks->list;
		hooks->list = pair;
		hooks->list_length++;
	} else {
		camel_object_unget_hooks(obj);
	}

	return pair;
}

static CamelObjectMeta *
co_metadata_get(CamelObject *obj)
{
	CamelHookPair *pair;
	CamelObjectMeta *meta = NULL, *metaout = NULL, *metalast = NULL;

	pair = co_metadata_pair(obj, FALSE);
	if (pair) {
		meta = pair->data;

		while (meta) {
			CamelObjectMeta *m;

			m = g_malloc(sizeof(*m) + strlen(meta->name));
			m->next = NULL;
			strcpy(m->name, meta->name);
			m->value = g_strdup(meta->value);
			if (metaout == NULL)
				metalast = metaout = m;
			else {
				metalast->next = m;
				metalast = m;
			}
			meta = meta->next;
		}

		camel_object_unget_hooks(obj);
	}

	return metaout;
}

static void
co_metadata_free(CamelObject *obj, CamelObjectMeta *meta)
{
	while (meta) {
		CamelObjectMeta *metan = meta->next;

		g_free(meta->value);
		g_free(meta);
		meta = metan;
	}
}

/**
 * camel_object_meta_get:
 * @vo:
 * @name:
 *
 * Get a meta-data on an object.
 *
 * Returns: NULL if the meta-data is not set.
 **/
gchar *
camel_object_meta_get(gpointer vo, const gchar * name)
{
	CamelObject *obj = vo;

	g_return_val_if_fail(CAMEL_IS_OBJECT (obj), NULL);
	g_return_val_if_fail(name != NULL, NULL);

	return obj->klass->meta_get(obj, name);
}

/**
 * camel_object_meta_set:
 * @vo:
 * @name: Name of meta-data.  Should be prefixed with class of setter.
 * @value: Value to set.  If NULL, then the meta-data is removed.
 *
 * Set a meta-data item on an object.  If the object supports persistent
 * data, then the meta-data will be persistent across sessions.
 *
 * If the meta-data changes, is added, or removed, then a
 * "meta_changed" event will be triggered with the name of the changed
 * data.
 *
 * Return Value: TRUE if the setting caused a change to the object's
 * metadata.
 **/
gboolean
camel_object_meta_set(gpointer vo, const gchar * name, const gchar *value)
{
	CamelObject *obj = vo;

	g_return_val_if_fail(CAMEL_IS_OBJECT (obj), FALSE);
	g_return_val_if_fail(name != NULL, FALSE);

	if (obj->klass->meta_set(obj, name, value)) {
		camel_object_trigger_event(obj, "meta_changed", (gpointer)name);
		return TRUE;
	}

	return FALSE;
}

/**
 * camel_object_state_read:
 * @vo:
 *
 * Read persistent object state from object_set(CAMEL_OBJECT_STATE_FILE).
 *
 * Returns: -1 on error.
 **/
gint camel_object_state_read(gpointer vo)
{
	CamelObject *obj = vo;
	gint res = -1;
	gchar *file;
	FILE *fp;
	gchar magic[4];

	camel_object_get(vo, NULL, CAMEL_OBJECT_STATE_FILE, &file, NULL);
	if (file == NULL)
		return 0;

	fp = g_fopen(file, "rb");
	if (fp != NULL) {
		if (fread(magic, 4, 1, fp) == 1
		    && memcmp(magic, CAMEL_OBJECT_STATE_FILE_MAGIC, 4) == 0)
			res = obj->klass->state_read(obj, fp);
		else
			res = -1;
		fclose(fp);
	}

	camel_object_free(vo, CAMEL_OBJECT_STATE_FILE, file);

	return res;
}

/**
 * camel_object_state_write:
 * @vo:
 *
 * Write persistent state to the file as set by object_set(CAMEL_OBJECT_STATE_FILE).
 *
 * Returns: -1 on error.
 **/
gint camel_object_state_write(gpointer vo)
{
	CamelObject *obj = vo;
	gint res = -1;
	gchar *file, *savename, *dirname;
	FILE *fp;

	camel_object_get(vo, NULL, CAMEL_OBJECT_STATE_FILE, &file, NULL);
	if (file == NULL)
		return 0;

	savename = camel_file_util_savename(file);
	dirname = g_path_get_dirname(savename);
	g_mkdir_with_parents(dirname, 0700);
	g_free(dirname);
	fp = g_fopen(savename, "wb");
	if (fp != NULL) {
		if (fwrite(CAMEL_OBJECT_STATE_FILE_MAGIC, 4, 1, fp) == 1
		    && obj->klass->state_write(obj, fp) == 0) {
			if (fclose(fp) == 0) {
				res = 0;
				g_rename(savename, file);
			}
		} else {
			fclose(fp);
		}
	} else {
		g_warning("Could not save object state file to '%s': %s", savename, g_strerror(errno));
	}

	g_free(savename);
	camel_object_free(vo, CAMEL_OBJECT_STATE_FILE, file);

	return res;
}

/* free an arg object, you can only free objects 1 at a time */
void camel_object_free(gpointer vo, guint32 tag, gpointer value)
{
	g_return_if_fail(CAMEL_IS_OBJECT(vo));

	/* We could also handle freeing of args differently

	   Add a 'const' bit to the arg type field,
	   specifying that the object should not be freed.

	   And, add free handlers for any pointer objects which are
	   not const.  The free handlers would be hookpairs off of the
	   class.

	   Then we handle the basic types OBJ,STR here, and pass PTR
	   types to their appropriate handler, without having to pass
	   through the invocation heirarchy of the free method.

	   This would also let us copy and do other things with args
	   we can't do, but i can't see a use for that yet ...  */

	((CamelObject *)vo)->klass->free(vo, tag, value);
}

static void
object_class_dump_tree_rec(CamelType root, gint depth)
{
	gchar *p;
#ifdef CAMEL_OBJECT_TRACK_INSTANCES
	struct _CamelObject *o;
#endif

	p = alloca(depth*2+1);
	memset(p, ' ', depth*2);
	p[depth*2] = 0;

	while (root) {
		CLASS_LOCK(root);
		printf("%sClass: %s\n", p, root->name);
		/*printf("%sVersion: %u.%u\n", p, root->version, root->revision);*/
		if (root->hooks) {
			CamelHookPair *pair = root->hooks;

			while (pair) {
				printf("%s  event '%s' prep %p\n", p, pair->name, (gpointer) pair->func.prep);
				pair = pair->next;
			}
		}

#ifdef CAMEL_OBJECT_TRACK_INSTANCES
		o = root->instances;
		while (o) {
			printf("%s instance %p [%d]\n", p, (gpointer) o, o->ref_count);
			/* todo: should lock hooks while it scans them */
			if (o->hooks) {
				CamelHookPair *pair = o->hooks->list;

				while (pair) {
					printf("%s  hook '%s' func %p data %p\n", p, pair->name, (gpointer) pair->func.event, (gpointer) pair->data);
					pair = pair->next;
				}
			}
			o = o->next;
		}
#endif
		CLASS_UNLOCK(root);

		if (root->child)
			object_class_dump_tree_rec(root->child, depth+1);

		root = root->next;
	}
}

void
camel_object_class_dump_tree(CamelType root)
{
	object_class_dump_tree_rec(root, 0);
}

/**
 * camel_object_bag_new:
 * @hash:
 * @equal:
 * @keycopy:
 * @keyfree:
 *
 * Allocate a new object bag.  Object bag's are key'd hash tables of
 * camel-objects which can be updated atomically using transaction
 * semantics.
 *
 * Returns:
 **/
CamelObjectBag *
camel_object_bag_new(GHashFunc hash, GEqualFunc equal, CamelCopyFunc keycopy, GFreeFunc keyfree)
{
	CamelObjectBag *bag;

	bag = g_malloc(sizeof(*bag));
	bag->object_table = g_hash_table_new(hash, equal);
	bag->equal_key = equal;
	bag->copy_key = keycopy;
	bag->free_key = keyfree;
	bag->key_table = g_hash_table_new(NULL, NULL);
	bag->reserved = NULL;

	return bag;
}

static void
save_object(gpointer key, CamelObject *o, GPtrArray *objects)
{
	g_ptr_array_add(objects, o);
}

void
camel_object_bag_destroy(CamelObjectBag *bag)
{
	GPtrArray *objects = g_ptr_array_new();
	gint i;

	g_assert(bag->reserved == NULL);

	g_hash_table_foreach(bag->object_table, (GHFunc)save_object, objects);
	for (i=0;i<objects->len;i++)
		camel_object_bag_remove(bag, objects->pdata[i]);

	g_ptr_array_free(objects, TRUE);
	g_hash_table_destroy(bag->object_table);
	g_hash_table_destroy(bag->key_table);
	g_free(bag);
}

/* must be called with ref_lock held */
static void
co_bag_unreserve(CamelObjectBag *bag, gconstpointer key)
{
	struct _CamelObjectBagKey *res, *resp;

	resp = (struct _CamelObjectBagKey *)&bag->reserved;
	res = resp->next;
	while (res) {
		if (bag->equal_key(res->key, key))
			break;
		resp = res;
		res = res->next;
	}

	g_assert(res != NULL);
	g_assert(res->have_owner && pthread_equal(res->owner, pthread_self()));

	if (res->waiters > 0) {
		b(printf("unreserve bag '%s', waking waiters\n", (gchar *)key));
		res->have_owner = FALSE;
		g_cond_signal(res->cond);
	} else {
		b(printf("unreserve bag '%s', no waiters, freeing reservation\n", (gchar *)key));
		resp->next = res->next;
		bag->free_key(res->key);
		g_cond_free(res->cond);
		g_free(res);
	}
}

/**
 * camel_object_bag_add:
 * @bag:
 * @key:
 * @vo:
 *
 * Add an object @vo to the object bag @bag.  The @key MUST have
 * previously been reserved using camel_object_bag_reserve().
 **/
void
camel_object_bag_add(CamelObjectBag *bag, gconstpointer key, gpointer vo)
{
	CamelObject *o = vo;
	CamelHookList *hooks;
	CamelHookPair *pair;
	gpointer k;

	hooks = camel_object_get_hooks(o);
	REF_LOCK();

	pair = hooks->list;
	while (pair) {
		if (pair->name == bag_name && pair->data == bag) {
			REF_UNLOCK();
			camel_object_unget_hooks(o);
			return;
		}
		pair = pair->next;
	}

	pair = pair_alloc();
	pair->name = bag_name;
	pair->data = bag;
	pair->flags = 0;
	pair->func.event = NULL;

	pair->next = hooks->list;
	hooks->list = pair;
	hooks->list_length++;

	k = bag->copy_key(key);
	g_hash_table_insert(bag->object_table, k, vo);
	g_hash_table_insert(bag->key_table, vo, k);

	co_bag_unreserve(bag, key);

	REF_UNLOCK();
	camel_object_unget_hooks(o);
}

/**
 * camel_object_bag_get:
 * @bag:
 * @key:
 *
 * Lookup an object by @key.  If the key is currently reserved, then
 * wait until the key has been committed before continuing.
 *
 * Returns: NULL if the object corresponding to @key is not
 * in the bag.  Otherwise a ref'd object pointer which the caller owns
 * the ref to.
 **/
gpointer
camel_object_bag_get(CamelObjectBag *bag, gconstpointer key)
{
	CamelObject *o;

	REF_LOCK();

	o = g_hash_table_lookup(bag->object_table, key);
	if (o) {
		b(printf("object bag get '%s' = %p\n", (gchar *)key, o));

		/* we use the same lock as the refcount */
		o->ref_count++;
	} else {
		struct _CamelObjectBagKey *res = bag->reserved;

		/* check if this name is reserved currently, if so wait till its finished */
		while (res) {
			if (bag->equal_key(res->key, key))
				break;
			res = res->next;
		}

		if (res) {
			b(printf("object bag get '%s', reserved, waiting\n", (gchar *)key));

			res->waiters++;
			g_assert(!res->have_owner || !pthread_equal(res->owner, pthread_self()));
			g_cond_wait(res->cond, ref_lock);
			res->waiters--;

			/* re-check if it slipped in */
			o = g_hash_table_lookup(bag->object_table, key);
			if (o)
				o->ref_count++;

			b(printf("object bag get '%s', finished waiting, got %p\n", (gchar *)key, o));

			/* we don't actually reserve it */
			res->owner = pthread_self();
			res->have_owner = TRUE;
			co_bag_unreserve(bag, key);
		}
	}

	REF_UNLOCK();

	return o;
}

/**
 * camel_object_bag_peek:
 * @bag:
 * @key:
 *
 * Lookup the object @key in @bag, ignoring any reservations.  If it
 * isn't committed, then it isn't considered.  This should only be
 * used where reliable transactional-based state is not required.
 *
 * Unlike other 'peek' operations, the object is still reffed if
 * found.
 *
 * Returns: A referenced object, or NULL if @key is not
 * present in the bag.
 **/
gpointer
camel_object_bag_peek(CamelObjectBag *bag, gconstpointer key)
{
	CamelObject *o;

	REF_LOCK();

	o = g_hash_table_lookup(bag->object_table, key);
	if (o) {
		/* we use the same lock as the refcount */
		o->ref_count++;
	}

	REF_UNLOCK();

	return o;
}

/**
 * camel_object_bag_reserve:
 * @bag:
 * @key:
 *
 * Reserve a key in the object bag.  If the key is already reserved in
 * another thread, then wait until the reservation has been committed.
 *
 * After reserving a key, you either get a reffed pointer to the
 * object corresponding to the key, similar to object_bag_get, or you
 * get NULL, signifying that you then MIST call either object_bag_add
 * or object_bag_abort.
 *
 * You may reserve multiple keys from the same thread, but they should
 * always be reserved in the same order, to avoid deadlocks.
 *
 * Returns:
 **/
gpointer
camel_object_bag_reserve(CamelObjectBag *bag, gconstpointer key)
{
	CamelObject *o;

	REF_LOCK();

	o = g_hash_table_lookup(bag->object_table, key);
	if (o) {
		o->ref_count++;
	} else {
		struct _CamelObjectBagKey *res = bag->reserved;

		while (res) {
			if (bag->equal_key(res->key, key))
				break;
			res = res->next;
		}

		if (res) {
			b(printf("bag reserve %s, already reserved, waiting\n", (gchar *)key));
			g_assert(!res->have_owner || !pthread_equal(res->owner, pthread_self()));
			res->waiters++;
			g_cond_wait(res->cond, ref_lock);
			res->waiters--;
			/* incase its slipped in while we were waiting */
			o = g_hash_table_lookup(bag->object_table, key);
			if (o) {
				b(printf("finished wait, someone else created '%s' = %p\n", (gchar *)key, o));
				o->ref_count++;
				/* in which case we dont need to reserve the bag either */
				res->owner = pthread_self();
				res->have_owner = TRUE;
				co_bag_unreserve(bag, key);
			} else {
				b(printf("finished wait, now owner of '%s'\n", (gchar *)key));
				res->owner = pthread_self();
				res->have_owner = TRUE;
			}
		} else {
			b(printf("bag reserve %s, no key, reserving\n", (gchar *)key));
			res = g_malloc(sizeof(*res));
			res->waiters = 0;
			res->key = bag->copy_key(key);
			res->cond = g_cond_new();
			res->owner = pthread_self();
			res->have_owner = TRUE;
			res->next = bag->reserved;
			bag->reserved = res;
		}
	}

	REF_UNLOCK();

	return o;
}

/**
 * camel_object_bag_abort:
 * @bag:
 * @key:
 *
 * Abort a key reservation.
 **/
void
camel_object_bag_abort(CamelObjectBag *bag, gconstpointer key)
{
	REF_LOCK();

	co_bag_unreserve(bag, key);

	REF_UNLOCK();
}

/**
 * camel_object_bag_rekey:
 * @bag:
 * @o:
 * @newkey:
 *
 * Re-key an object, atomically.  The key for object @o is set to
 * @newkey, in an atomic manner.
 *
 * It is an api (fatal) error if @o is not currently in the bag.
 **/
void
camel_object_bag_rekey(CamelObjectBag *bag, gpointer o, gconstpointer newkey)
{
	gpointer oldkey;

	REF_LOCK();

	if (g_hash_table_lookup_extended(bag->key_table, o, NULL, &oldkey)) {
		g_hash_table_remove(bag->object_table, oldkey);
		g_hash_table_remove(bag->key_table, o);
		bag->free_key(oldkey);
		oldkey = bag->copy_key(newkey);
		g_hash_table_insert(bag->object_table, oldkey, o);
		g_hash_table_insert(bag->key_table, o, oldkey);
	} else {
		abort();
	}

	REF_UNLOCK();
}

static void
save_bag(gpointer key, CamelObject *o, GPtrArray *list)
{
	/* we have the refcount lock already */
	o->ref_count++;
	g_ptr_array_add(list, o);
}

/* get a list of all objects in the bag, ref'd
   ignores any reserved keys */
GPtrArray *
camel_object_bag_list(CamelObjectBag *bag)
{
	GPtrArray *list;

	list = g_ptr_array_new();

	REF_LOCK();
	g_hash_table_foreach(bag->object_table, (GHFunc)save_bag, list);
	REF_UNLOCK();

	return list;
}

/* if bag is NULL, remove all bags from object */
static void
camel_object_bag_remove_unlocked(CamelObjectBag *inbag, CamelObject *o, CamelHookList *hooks)
{
	CamelHookPair *pair, *parent;
	gpointer oldkey;
	CamelObjectBag *bag;

	parent = (CamelHookPair *)&hooks->list;
	pair = parent->next;
	while (pair) {
		if (pair->name == bag_name
		    && (inbag == NULL || inbag == pair->data)) {
			bag = pair->data;
			/* lookup object in table? */
			oldkey = g_hash_table_lookup(bag->key_table, o);
			if (oldkey) {
				g_hash_table_remove(bag->key_table, o);
				g_hash_table_remove(bag->object_table, oldkey);
				bag->free_key(oldkey);
			}
			parent->next = pair->next;
			pair_free(pair);
			hooks->list_length--;
		} else {
			parent = pair;
		}
		pair = parent->next;
	}
}

void
camel_object_bag_remove(CamelObjectBag *inbag, gpointer vo)
{
	CamelObject *o = vo;
	CamelHookList *hooks;

	if (o->hooks == NULL)
		return;

	hooks = camel_object_get_hooks(o);
	REF_LOCK();

	camel_object_bag_remove_unlocked(inbag, o, hooks);

	REF_UNLOCK();
	camel_object_unget_hooks(o);
}

/* ********************************************************************** */

gpointer camel_iterator_new(CamelIteratorVTable *klass, gsize size)
{
	CamelIterator *it;

	g_assert(size >= sizeof(CamelIterator));

	it = g_malloc0(size);
	it->klass = klass;

	return it;
}

gconstpointer camel_iterator_next(gpointer it, CamelException *ex)
{
	g_assert(it);
	return ((CamelIterator *)it)->klass->next(it, ex);
}

void camel_iterator_reset(gpointer it)
{
	g_assert(it);
	((CamelIterator *)it)->klass->reset(it);
}

gint camel_iterator_length(gpointer it)
{
	g_assert(it);
	g_return_val_if_fail(((CamelIterator *)it)->klass->length != NULL, 0);

	return ((CamelIterator *)it)->klass->length(it);
}

void camel_iterator_free(gpointer it)
{
	if (it) {
		if (((CamelIterator *)it)->klass->free)
			((CamelIterator *)it)->klass->free(it);
		g_free(it);
	}
}