mirror of
https://github.com/jart/cosmopolitan.git
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2fc507c98f
* modelines: tw -> sw shiftwidth, not textwidth. * space-surround modelines * fix irregular modelines * Fix modeline in titlegen.c
124 lines
4.4 KiB
C
124 lines
4.4 KiB
C
/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
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│ vi: set noet ft=c ts=8 sw=8 fenc=utf-8 :vi │
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╚──────────────────────────────────────────────────────────────────────────────╝
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│ │
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│ Musl Libc │
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│ Copyright © 2005-2020 Rich Felker, et al. │
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│ │
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│ Permission is hereby granted, free of charge, to any person obtaining │
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│ a copy of this software and associated documentation files (the │
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│ "Software"), to deal in the Software without restriction, including │
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│ without limitation the rights to use, copy, modify, merge, publish, │
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│ distribute, sublicense, and/or sell copies of the Software, and to │
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│ permit persons to whom the Software is furnished to do so, subject to │
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│ the following conditions: │
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│ │
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│ The above copyright notice and this permission notice shall be │
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│ included in all copies or substantial portions of the Software. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
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│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF │
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│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. │
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│ IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY │
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│ CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, │
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│ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE │
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│ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
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│ │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/mem/mem.h"
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#include "libc/str/str.h"
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#include "third_party/musl/tsearch.internal.h"
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asm(".ident\t\"\\n\\n\
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Musl libc (MIT License)\\n\
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Copyright 2005-2020 Rich Felker, et. al.\"");
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asm(".include \"libc/disclaimer.inc\"");
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static inline int height(struct node *n) { return n ? n->h : 0; }
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static int rot(void **p, struct node *x, int dir /* deeper side */)
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{
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struct node *y = x->a[dir];
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struct node *z = y->a[!dir];
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int hx = x->h;
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int hz = height(z);
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if (hz > height(y->a[dir])) {
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/*
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* x
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* / \ dir z
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* A y / \
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* / \ --> x y
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* z D /| |\
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* / \ A B C D
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* B C
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*/
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x->a[dir] = z->a[!dir];
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y->a[!dir] = z->a[dir];
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z->a[!dir] = x;
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z->a[dir] = y;
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x->h = hz;
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y->h = hz;
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z->h = hz+1;
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} else {
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/*
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* x y
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* / \ / \
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* A y --> x D
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* / \ / \
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* z D A z
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*/
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x->a[dir] = z;
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y->a[!dir] = x;
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x->h = hz+1;
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y->h = hz+2;
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z = y;
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}
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*p = z;
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return z->h - hx;
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}
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/* balance *p, return 0 if height is unchanged. */
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int __tsearch_balance(void **p)
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{
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struct node *n = *p;
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int h0 = height(n->a[0]);
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int h1 = height(n->a[1]);
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if (h0 - h1 + 1u < 3u) {
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int old = n->h;
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n->h = h0<h1 ? h1+1 : h0+1;
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return n->h - old;
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}
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return rot(p, n, h0<h1);
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}
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void *tsearch(const void *key, void **rootp,
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int (*cmp)(const void *, const void *))
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{
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if (!rootp)
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return 0;
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void **a[MAXH];
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struct node *n = *rootp;
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struct node *r;
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int i=0;
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a[i++] = rootp;
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for (;;) {
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if (!n)
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break;
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int c = cmp(key, n->key);
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if (!c)
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return n;
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a[i++] = &n->a[c>0];
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n = n->a[c>0];
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}
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r = malloc(sizeof *r);
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if (!r)
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return 0;
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r->key = key;
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r->a[0] = r->a[1] = 0;
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r->h = 1;
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/* insert new node, rebalance ancestors. */
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*a[--i] = r;
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while (i && __tsearch_balance(a[--i]));
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return r;
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}
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