4c553c5a5b
This is a major change of how the filters are interpreted. If everything works how it should, it should not affect you unless you are hacking the filters themselves. Anyway, this change should make a huge improvement in the filter performance as previous benchmarks showed that our major problem lies in the recursion itself. There are also some changes in nest and protocols, related mostly to spreading const declarations throughout the whole BIRD and also to refactored dynamic attribute definitions. The need of these came up during the whole work and it is too difficult to split out these not-so-related changes.
177 lines
3.6 KiB
C
177 lines
3.6 KiB
C
/*
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* Filters: utility functions
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*
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* Copyright 1998 Pavel Machek <pavel@ucw.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*/
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#include "lib/alloca.h"
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#include "nest/bird.h"
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#include "conf/conf.h"
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#include "filter/filter.h"
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/**
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* find_tree
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* @t: tree to search in
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* @val: value to find
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*
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* Search for given value in the tree. I relies on fact that sorted tree is populated
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* by &f_val structures (that can be compared by val_compare()). In each node of tree,
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* either single value (then t->from==t->to) or range is present.
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*
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* Both set matching and |switch() { }| construction is implemented using this function,
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* thus both are as fast as they can be.
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*/
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const struct f_tree *
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find_tree(const struct f_tree *t, const struct f_val *val)
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{
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if (!t)
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return NULL;
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if ((val_compare(&(t->from), val) != 1) &&
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(val_compare(&(t->to), val) != -1))
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return t;
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if (val_compare(&(t->from), val) == -1)
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return find_tree(t->right, val);
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else
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return find_tree(t->left, val);
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}
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static struct f_tree *
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build_tree_rec(struct f_tree **buf, int l, int h)
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{
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struct f_tree *n;
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int pos;
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if (l >= h)
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return NULL;
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pos = (l+h)/2;
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n = buf[pos];
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n->left = build_tree_rec(buf, l, pos);
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n->right = build_tree_rec(buf, pos+1, h);
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return n;
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}
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static int
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tree_compare(const void *p1, const void *p2)
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{
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return val_compare(&((* (struct f_tree **) p1)->from), &((* (struct f_tree **) p2)->from));
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}
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/**
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* build_tree
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* @from: degenerated tree (linked by @tree->left) to be transformed into form suitable for find_tree()
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*
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* Transforms degenerated tree into balanced tree.
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*/
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struct f_tree *
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build_tree(struct f_tree *from)
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{
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struct f_tree *tmp, *root;
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struct f_tree **buf;
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int len, i;
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if (from == NULL)
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return NULL;
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len = 0;
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for (tmp = from; tmp != NULL; tmp = tmp->left)
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len++;
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if (len <= 1024)
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buf = alloca(len * sizeof(struct f_tree *));
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else
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buf = xmalloc(len * sizeof(struct f_tree *));
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/* Convert a degenerated tree into an sorted array */
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i = 0;
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for (tmp = from; tmp != NULL; tmp = tmp->left)
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buf[i++] = tmp;
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qsort(buf, len, sizeof(struct f_tree *), tree_compare);
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root = build_tree_rec(buf, 0, len);
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if (len > 1024)
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xfree(buf);
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return root;
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}
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struct f_tree *
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f_new_tree(void)
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{
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struct f_tree * ret;
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ret = cfg_alloc(sizeof(struct f_tree));
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ret->left = ret->right = NULL;
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ret->from.type = ret->to.type = T_VOID;
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ret->from.val.i = ret->to.val.i = 0;
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ret->data = NULL;
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return ret;
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}
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/**
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* same_tree
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* @t1: first tree to be compared
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* @t2: second one
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*
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* Compares two trees and returns 1 if they are same
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*/
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int
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same_tree(const struct f_tree *t1, const struct f_tree *t2)
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{
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if ((!!t1) != (!!t2))
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return 0;
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if (!t1)
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return 1;
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if (val_compare(&(t1->from), &(t2->from)))
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return 0;
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if (val_compare(&(t1->to), &(t2->to)))
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return 0;
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if (!same_tree(t1->left, t2->left))
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return 0;
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if (!same_tree(t1->right, t2->right))
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return 0;
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if (!f_same(t1->data, t2->data))
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return 0;
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return 1;
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}
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static void
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tree_node_format(const struct f_tree *t, buffer *buf)
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{
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if (t == NULL)
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return;
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tree_node_format(t->left, buf);
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val_format(&(t->from), buf);
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if (val_compare(&(t->from), &(t->to)) != 0)
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{
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buffer_puts(buf, "..");
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val_format(&(t->to), buf);
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}
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buffer_puts(buf, ", ");
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tree_node_format(t->right, buf);
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}
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void
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tree_format(const struct f_tree *t, buffer *buf)
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{
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buffer_puts(buf, "[");
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tree_node_format(t, buf);
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if (buf->pos == buf->end)
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return;
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/* Undo last separator */
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if (buf->pos[-1] != '[')
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buf->pos -= 2;
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buffer_puts(buf, "]");
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}
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