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[lttv.git] / lttv / lttv / hook.c

/* This file is part of the Linux Trace Toolkit viewer
 * Copyright (C) 2003-2004 Michel Dagenais
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License Version 2 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 General Public License for more details.
 *
 * You should have received a copy of the GNU 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 <lttv/hook.h>
#include <stdio.h>

typedef struct _LttvHookClosure {
	LttvHook      hook;
	void         *hook_data;
	LttvHookPrio  prio;
	guint         ref_count;
} LttvHookClosure;

gint lttv_hooks_prio_compare(LttvHookClosure *a, LttvHookClosure *b)
{
	gint ret=0;
	if(a->prio < b->prio) ret = -1;
	else if(a->prio > b->prio) ret = 1;
	return ret;
}


LttvHooks *lttv_hooks_new(void)
{
	return g_array_new(FALSE, FALSE, sizeof(LttvHookClosure));
}


void lttv_hooks_destroy(LttvHooks *h) 
{
	g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "lttv_hooks_destroy()");
	g_array_free(h, TRUE);
}


void lttv_hooks_add(LttvHooks *h, LttvHook f, void *hook_data, LttvHookPrio p) 
{
	LttvHookClosure *c, new_c;
	guint i;

	if(unlikely(h == NULL))g_error("Null hook added");

	new_c.hook = f;
	new_c.hook_data = hook_data;
	new_c.prio = p;
	new_c.ref_count = 1;

	/* Preliminary check for duplication */
	/* only hook and hook data is checked */
	for(i = 0; i < h->len; i++) {
		c = &g_array_index(h, LttvHookClosure, i);
		if(new_c.hook == c->hook && new_c.hook_data == c->hook_data) {
			g_assert(new_c.prio == c->prio);
			c->ref_count++;
			return;
		}
	}


	for(i = 0; i < h->len; i++) {
		c = &g_array_index(h, LttvHookClosure, i);
		if(new_c.prio < c->prio) {
			g_array_insert_val(h,i,new_c);
			return;
		}
	}
	if(i == h->len)
		g_array_append_val(h,new_c);
}

/* lttv_hooks_add_list
 *
 * Adds a sorted list into another sorted list.
 *
 * Note : h->len is modified, but only incremented. This assures
 * its coherence through the function.
 *
 * j is an index to the element following the last one added in the
 * destination array.
 */
void lttv_hooks_add_list(LttvHooks *h, const LttvHooks *list) 
{
	guint i,j,k;
	LttvHookClosure *c;
	const LttvHookClosure *new_c;

	if(unlikely(list == NULL)) return;

	for(i = 0, j = 0 ; i < list->len; i++) {
		new_c = &g_array_index(list, LttvHookClosure, i);
		gboolean found=FALSE;

		/* Preliminary check for duplication */
		/* only hook and hook data is checked, not priority */
		for(k = 0; k < h->len; k++) {
			c = &g_array_index(h, LttvHookClosure, k);
			if(new_c->hook == c->hook && new_c->hook_data == c->hook_data) {
				/* Found another identical entry : increment its ref_count and
				 * jump over the source index */
				g_assert(new_c->prio == c->prio);
				found=TRUE;
				c->ref_count++;
				break;
			}
		}

		if(!found) {
			/* If not found, add it to the destination array */
			while(j < h->len) {
				c = &g_array_index(h, LttvHookClosure, j);
				if(new_c->prio < c->prio) {
					g_array_insert_val(h,j,*new_c);
					j++;
					break;
				}
				else j++;
			}
			if(j == h->len) {
				g_array_append_val(h,*new_c);
				j++;
			}
		}
	}
}


void *lttv_hooks_remove(LttvHooks *h, LttvHook f)
{
	unsigned i;

	void *hook_data;

	LttvHookClosure *c;

	for(i = 0 ; i < h->len ; i++) {
		c = &g_array_index(h, LttvHookClosure, i);
		if(c->hook == f) {
			if(c->ref_count == 1) {
				hook_data = c->hook_data;
				lttv_hooks_remove_by_position(h, i);
				return hook_data;
			} else {
				g_assert(c->ref_count != 0);
				c->ref_count--;
				return NULL;  /* We do not want anyone to free a hook_data
								 still referenced */
			}
		}
	}
	return NULL;
}


void lttv_hooks_remove_data(LttvHooks *h, LttvHook f, void *hook_data)
{
	unsigned i;

	LttvHookClosure *c;

	for(i = 0 ; i < h->len ; i++) {
		c = &g_array_index(h, LttvHookClosure, i);
		if(c->hook == f && c->hook_data == hook_data) {
			if(c->ref_count == 1) {
				lttv_hooks_remove_by_position(h, i);
				return;
			} else {
				g_assert(c->ref_count != 0);
				c->ref_count--;
				return;
			}
		}
	}
}


void lttv_hooks_remove_list(LttvHooks *h, const LttvHooks *list)
{
	guint i, j;

	LttvHookClosure *c, *c_list;

	if(list == NULL) return;
	g_assert(h != list);
	/* This iteration assume that both list are in the same order */
	for(i = 0, j = 0 ; i < h->len && j < list->len ;) {
		c = &g_array_index(h, LttvHookClosure, i);
		c_list = &g_array_index(list, LttvHookClosure, j);
		if(c->hook == c_list->hook && c->hook_data == c_list->hook_data) {
			if(c->ref_count == 1) {
				int count = h->len;
				lttv_hooks_remove_by_position(h, i);
				g_assert((count-1) == h->len);
			} else {
				g_assert(c->ref_count != 0);
				c->ref_count--;
			}
			j++;
		}
		else i++;
	}

	/* Normally the hooks in h are ordered as in list. If this is not the case,
	   try harder here. */

	if(unlikely(j < list->len)) {
		for(; j < list->len ; j++) {
			c_list = &g_array_index(list, LttvHookClosure, j);
			lttv_hooks_remove_data(h, c_list->hook, c_list->hook_data);
		}
	}
}


unsigned lttv_hooks_number(LttvHooks *h)
{
	return h->len;
}


void lttv_hooks_get(LttvHooks *h, unsigned i, LttvHook *f, void **hook_data,
		LttvHookPrio *p)
{
	LttvHookClosure *c;

	if(unlikely(i >= h->len))
	{
		*f = NULL;
		*hook_data = NULL;
		*p = 0;
		return;
	}

	c = &g_array_index(h, LttvHookClosure, i);
	*f = c->hook;
	*hook_data = c->hook_data;
	*p = c->prio;
}


void lttv_hooks_remove_by_position(LttvHooks *h, unsigned i)
{
	g_array_remove_index(h, i);
}

gboolean lttv_hooks_call(LttvHooks *h, void *call_data)
{
	gboolean ret, sum_ret = FALSE;

	LttvHookClosure *c;

	guint i;

	if(likely(h != NULL)) {
		for(i = 0 ; i < h->len ; i++) {
			c = &g_array_index(h, LttvHookClosure, i);
			ret = c->hook(c->hook_data,call_data);
			sum_ret = sum_ret || ret;
		}
	}
	return sum_ret;
}


gboolean lttv_hooks_call_check(LttvHooks *h, void *call_data)
{
	LttvHookClosure *c;

	guint i;

	for(i = 0 ; i < h->len ; i++) {
		c = &g_array_index(h, LttvHookClosure, i);
		if(unlikely(c->hook(c->hook_data,call_data))) return TRUE;
	}
	return FALSE;
}

/* Optimised for h1 == NULL, h2 != NULL. This is the case
 * for optimised computation (with specific by id hooks, but
 * no main hooks).
 *
 * The second case that should occur the most often is
 * h1 != NULL , h2 == NULL.
 */
gint lttv_hooks_call_merge(LttvHooks *h1, void *call_data1,
		LttvHooks *h2, void *call_data2)
{
	gint ret, sum_ret = 0;

	LttvHookClosure *c1, *c2;

	guint i, j;

	if(unlikely(h1 != NULL)) {
		if(unlikely(h2 != NULL)) {
			for(i = 0, j = 0 ; i < h1->len && j < h2->len ;) {
				c1 = &g_array_index(h1, LttvHookClosure, i);
				c2 = &g_array_index(h2, LttvHookClosure, j);
				if(c1->prio <= c2->prio) {
					ret = c1->hook(c1->hook_data,call_data1);
					sum_ret = sum_ret | ret;
					i++;
				} else {
					ret = c2->hook(c2->hook_data,call_data2);
					sum_ret = sum_ret | ret;
					j++;
				}
			}
			/* Finish the last list with hooks left */
			for(;i < h1->len; i++) {
				c1 = &g_array_index(h1, LttvHookClosure, i);
				ret = c1->hook(c1->hook_data,call_data1);
				sum_ret = sum_ret | ret;
			}
			for(;j < h2->len; j++) {
				c2 = &g_array_index(h2, LttvHookClosure, j);
				ret = c2->hook(c2->hook_data,call_data2);
				sum_ret = sum_ret | ret;
			}
		} else {  /* h1 != NULL && h2 == NULL */
			for(i = 0 ; i < h1->len ; i++) {
				c1 = &g_array_index(h1, LttvHookClosure, i);
				ret = c1->hook(c1->hook_data,call_data1);
				sum_ret = sum_ret | ret;
			}
		}
	} else if(likely(h2 != NULL)) { /* h1 == NULL && h2 != NULL */
		 for(j = 0 ; j < h2->len ; j++) {
			c2 = &g_array_index(h2, LttvHookClosure, j);
			ret = c2->hook(c2->hook_data,call_data2);
			sum_ret = sum_ret | ret;
		}
	}

	return sum_ret;
}

gboolean lttv_hooks_call_check_merge(LttvHooks *h1, void *call_data1,
		LttvHooks *h2, void *call_data2)
{
	LttvHookClosure *c1, *c2;

	guint i, j;

	if(unlikely(h1 != NULL)) {
		if(unlikely(h2 != NULL)) {
			for(i = 0, j = 0 ; i < h1->len && j < h2->len ;) {
				c1 = &g_array_index(h1, LttvHookClosure, i);
				c2 = &g_array_index(h2, LttvHookClosure, j);
				if(c1->prio <= c2->prio) {
					if(c1->hook(c1->hook_data,call_data1)) return TRUE;
					i++;
				} else {
					if(c2->hook(c2->hook_data,call_data2)) return TRUE;
					j++;
				}
			}
			/* Finish the last list with hooks left */
			for(;i < h1->len; i++) {
				c1 = &g_array_index(h1, LttvHookClosure, i);
				if(c1->hook(c1->hook_data,call_data1)) return TRUE;
			}
			for(;j < h2->len; j++) {
				c2 = &g_array_index(h2, LttvHookClosure, j);
				if(c2->hook(c2->hook_data,call_data2)) return TRUE;
			}
		} else { /* h2 == NULL && h1 != NULL */
			for(i = 0 ; i < h1->len ; i++) {
				c1 = &g_array_index(h1, LttvHookClosure, i);
				if(c1->hook(c1->hook_data,call_data1)) return TRUE;
			}
		}
	} else if(likely(h2 != NULL)) { /* h1 == NULL && h2 != NULL */
		for(j = 0 ; j < h2->len ; j++) {
			c2 = &g_array_index(h2, LttvHookClosure, j);
			if(c2->hook(c2->hook_data,call_data2)) return TRUE;
		}
	}

	return FALSE;
}


void lttv_hooks_print(const LttvHooks *h)
{
	LttvHookClosure *c;

	guint i;

	if(likely(h != NULL)) {
		for(i = 0 ; i < h->len ; i++) {
			c = &g_array_index(h, LttvHookClosure, i);
			printf("%p:%i:%i,", c->hook, c->ref_count, c->prio);
		}
		printf("\n");
	}

}