/* Sysprof -- Sampling, systemwide CPU profiler
 * Copyright 2004, Red Hat, Inc.
 * Copyright 2004, 2005, Soeren Sandmann
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include "stackstash.h"

struct StackStash
{
    int			ref_count;
    StackNode *		root;
    GHashTable *	nodes_by_data;
    GDestroyNotify	destroy;
};

static StackNode *
stack_node_new (void)
{
    StackNode *node = g_new (StackNode, 1);
    node->siblings = NULL;
    node->children = NULL;
    node->address = NULL;
    node->parent = NULL;
    node->size = 0;
    node->next = NULL;
    node->total = 0;
    return node;
}

/* "destroy", if non-NULL, is called once on every address */
static StackStash *
create_stack_stash (GDestroyNotify destroy)
{
    StackStash *stash = g_new (StackStash, 1);

    stash->root = NULL;
    stash->nodes_by_data = g_hash_table_new (g_direct_hash, g_direct_equal);
    stash->ref_count = 1;
    stash->destroy = destroy;

    return stash;
}

/* Stach */
StackStash *
stack_stash_new (GDestroyNotify destroy)
{
    return create_stack_stash (destroy);
}

void
decorate_node (StackStash *stash,
	       StackNode  *node)
{
    StackNode *n;
    gboolean toplevel = TRUE;

    /* FIXME: we will probably want to do this lazily,
     * and more efficiently (only walk the tree once).
     */
    for (n = node->parent; n != NULL; n = n->parent)
    {
	if (n->address == node->address)
	{
	    toplevel = FALSE;
	    break;
	}
    }

    node->toplevel = toplevel;

    node->next = g_hash_table_lookup (
	stash->nodes_by_data, node->address);
    g_hash_table_insert (
	stash->nodes_by_data, node->address, node);
}

void
stack_stash_add_trace (StackStash *stash,
		       gulong     *addrs,
		       int         n_addrs,
		       int         size)
{
    StackNode **location = &(stash->root);
    StackNode *parent = NULL;
    int i;

    if (!n_addrs)
	return;
    
    for (i = n_addrs - 1; i >= 0; --i)
    {
	StackNode *match = NULL;
	StackNode *n;

	for (n = *location; n != NULL; n = n->siblings)
	{
	    if (n->address == (gpointer)addrs[i])
	    {
		match = n;
		break;
	    }
	}

	if (!match)
	{
	    match = stack_node_new ();
	    match->address = (gpointer)addrs[i];
	    match->siblings = *location;
	    match->parent = parent;
	    *location = match;

	    decorate_node (stash, match);
	}

	match->total += size;

	location = &(match->children);
	parent = match;
    }

    parent->size += size;
}

static void
do_callback (StackNode *node,
	     GList *trace,
	     StackFunction func,
	     gpointer data)
{
    GList link;

    if (!node)
	return;

    if (trace)
	trace->prev = &link;

    link.next = trace;
    link.data = node->address;
    link.prev = NULL;

    if (node->size)
	func (&link, node->size, data);
    
    do_callback (node->children, &link, func, data);
    do_callback (node->siblings, trace, func, data);
}

void
stack_stash_foreach   (StackStash      *stash,
		       StackFunction    stack_func,
		       gpointer         data)
{
    do_callback (stash->root, NULL, stack_func, data);
}

void
stack_node_foreach_trace (StackNode     *node,
			  StackFunction  func,
			  gpointer       data)
{
    GList link;

    link.next = NULL;
    link.data = node->address;
    link.prev = NULL;

    if (node->size)
	func (&link, node->size, data);
    
    do_callback (node->children, &link, func, data);
}

static void
stack_node_free (StackNode *node)
{
    if (!node)
	return;

    stack_node_free (node->siblings);
    stack_node_free (node->children);

    g_free (node);
}

static void
free_key (gpointer key,
	  gpointer value,
	  gpointer data)
{
    GDestroyNotify destroy = data;

    destroy (key);
}

static void
stack_stash_free (StackStash *stash)
{
    stack_node_free (stash->root);

    if (stash->destroy)
    {
	g_hash_table_foreach (stash->nodes_by_data, free_key,
			      stash->destroy);
    }
    
    g_hash_table_destroy (stash->nodes_by_data);
    
    g_free (stash);
}

void
stack_stash_unref (StackStash *stash)
{
    stash->ref_count--;
    if (stash->ref_count == 0)
	stack_stash_free (stash);
}

StackStash *
stack_stash_ref (StackStash *stash)
{
    stash->ref_count++;
    return stash;
}

StackNode *
stack_stash_find_node (StackStash      *stash,
		       gpointer         data)
{
    g_return_val_if_fail (stash != NULL, NULL);
    
    return g_hash_table_lookup (stash->nodes_by_data, data);
}

typedef struct
{
    StackNodeFunc func;
    gpointer	  data;
} Info;

static void
do_foreach (gpointer key, gpointer value, gpointer data)
{
    Info *info = data;

    info->func (value, info->data);
}

void
stack_stash_foreach_by_address (StackStash *stash,
				StackNodeFunc func,
				gpointer      data)
{
    Info info;
    info.func = func;
    info.data = data;
	
    g_hash_table_foreach (stash->nodes_by_data, do_foreach, &info);
}

StackNode  *
stack_stash_get_root   (StackStash *stash)
{
    return stash->root;
}

static void
build_hash_table (StackNode *node,
		  StackStash *stash)
{
    if (!node)
	return;

    build_hash_table (node->siblings, stash);
    build_hash_table (node->children, stash);

    node->next = g_hash_table_lookup (
	stash->nodes_by_data, node->address);
    g_hash_table_insert (
	stash->nodes_by_data, node->address, node);
}

StackStash *
stack_stash_new_from_root (StackNode      *root,
			   GDestroyNotify  destroy)
{
    StackStash *stash = create_stack_stash (destroy);

    stash->root = root;
    
    build_hash_table (stash->root, stash);

    return stash;
}