mirror of
https://github.com/topjohnwu/ndk-busybox.git
synced 2024-12-03 17:31:50 +00:00
tsort: new applet
function old new delta tsort_main - 578 +578 .rodata 104884 104906 +22 applet_names 2759 2765 +6 applet_main 1596 1600 +4 packed_usage 34290 34288 -2 ------------------------------------------------------------------------------ (add/remove: 2/0 grow/shrink: 3/1 up/down: 610/-2) Total: 608 bytes Signed-off-by: David Leonard <d+busybox@adaptive-enterprises.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
David Leonard
Denys Vlasenko
parent
52a7bf6fa6
commit
4642cf5b38
188
coreutils/tsort.c
Normal file
188
coreutils/tsort.c
Normal file
@ -0,0 +1,188 @@
|
||||
/* vi: set sw=4 ts=4: */
|
||||
/*
|
||||
* tsort implementation for busybox
|
||||
*
|
||||
* public domain -- David Leonard, 2022
|
||||
*/
|
||||
//config:config TSORT
|
||||
//config: bool "tsort (0.7 kb)"
|
||||
//config: default y
|
||||
//config: help
|
||||
//config: tsort performs a topological sort.
|
||||
|
||||
//applet:IF_TSORT(APPLET(tsort, BB_DIR_USR_BIN, BB_SUID_DROP))
|
||||
|
||||
//kbuild:lib-$(CONFIG_TSORT) += tsort.o
|
||||
|
||||
/* BB_AUDIT SUSv3 compliant */
|
||||
/* http://www.opengroup.org/onlinepubs/007904975/utilities/tsort.html */
|
||||
|
||||
//usage:#define tsort_trivial_usage
|
||||
//usage: "[FILE]"
|
||||
//usage:#define tsort_full_usage "\n\n"
|
||||
//usage: "Topological sort"
|
||||
//usage:#define tsort_example_usage
|
||||
//usage: "$ echo -e \"a b\\nb c\" | tsort\n"
|
||||
//usage: "a\n"
|
||||
//usage: "b\n"
|
||||
//usage: "c\n"
|
||||
|
||||
#include "libbb.h"
|
||||
#include "common_bufsiz.h"
|
||||
|
||||
struct node {
|
||||
unsigned in_count;
|
||||
unsigned out_count;
|
||||
struct node **out;
|
||||
char name[1];
|
||||
};
|
||||
|
||||
struct globals {
|
||||
struct node **nodes;
|
||||
unsigned nodes_len;
|
||||
};
|
||||
#define G (*(struct globals*)bb_common_bufsiz1)
|
||||
#define INIT_G() do { \
|
||||
setup_common_bufsiz(); \
|
||||
BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
|
||||
G.nodes = NULL; \
|
||||
G.nodes_len = 0; \
|
||||
} while (0)
|
||||
|
||||
static struct node *
|
||||
get_node(const char *name)
|
||||
{
|
||||
struct node *n;
|
||||
unsigned a = 0;
|
||||
unsigned b = G.nodes_len;
|
||||
|
||||
/* Binary search for name */
|
||||
while (a != b) {
|
||||
unsigned m = (a + b) / 2;
|
||||
int cmp = strcmp(name, G.nodes[m]->name);
|
||||
if (cmp == 0)
|
||||
return G.nodes[m]; /* found */
|
||||
if (cmp < 0) {
|
||||
b = m;
|
||||
} else {
|
||||
a = m + 1;
|
||||
}
|
||||
}
|
||||
|
||||
/* Allocate new node */
|
||||
n = xzalloc(sizeof(*n) + strlen(name));
|
||||
//n->in_count = 0;
|
||||
//n->out_count = 0;
|
||||
//n->out = NULL;
|
||||
strcpy(n->name, name);
|
||||
|
||||
/* Insert to maintain sort */
|
||||
G.nodes = xrealloc(G.nodes, (G.nodes_len + 1) * sizeof(*G.nodes));
|
||||
memmove(&G.nodes[a + 1], &G.nodes[a],
|
||||
(G.nodes_len - a) * sizeof(*G.nodes));
|
||||
G.nodes[a] = n;
|
||||
G.nodes_len++;
|
||||
return n;
|
||||
}
|
||||
|
||||
static void
|
||||
add_edge(struct node *a, struct node *b)
|
||||
{
|
||||
a->out = xrealloc_vector(a->out, 6, a->out_count);
|
||||
a->out[a->out_count++] = b;
|
||||
b->in_count++;
|
||||
}
|
||||
|
||||
int tsort_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
||||
int tsort_main(int argc UNUSED_PARAM, char **argv)
|
||||
{
|
||||
char *line;
|
||||
size_t linesz;
|
||||
ssize_t len;
|
||||
struct node *a;
|
||||
int cycles;
|
||||
|
||||
INIT_G();
|
||||
|
||||
if (argv[1]) {
|
||||
if (argv[2])
|
||||
bb_show_usage();
|
||||
if (NOT_LONE_DASH(argv[1])) {
|
||||
close(STDIN_FILENO); /* == 0 */
|
||||
xopen(argv[1], O_RDONLY); /* fd will be 0 */
|
||||
}
|
||||
}
|
||||
|
||||
/* Read in words separated by <blank>s */
|
||||
a = NULL;
|
||||
line = NULL;
|
||||
linesz = 0;
|
||||
while ((len = getline(&line, &linesz, stdin)) != -1) {
|
||||
char *s = line;
|
||||
while (*(s = skip_whitespace(s)) != '\0') {
|
||||
struct node *b;
|
||||
char *word;
|
||||
|
||||
word = s;
|
||||
s = skip_non_whitespace(s);
|
||||
if (*s)
|
||||
*s++ = '\0';
|
||||
|
||||
/* Create nodes and edges for each word pair */
|
||||
b = get_node(word);
|
||||
if (!a) {
|
||||
a = b;
|
||||
} else {
|
||||
if (a != b)
|
||||
add_edge(a, b);
|
||||
a = NULL;
|
||||
}
|
||||
}
|
||||
}
|
||||
// Most other tools do not check for input read error (treat them as EOF)
|
||||
// die_if_ferror(in, input_filename);
|
||||
if (a)
|
||||
bb_simple_error_msg_and_die("odd input");
|
||||
free(line);
|
||||
|
||||
/*
|
||||
* Kahn's algorithm:
|
||||
* - find a node that has no incoming edges, print and remove it
|
||||
* - repeat until the graph is empty
|
||||
* - if any nodes are left, they form cycles.
|
||||
*/
|
||||
cycles = 0;
|
||||
while (G.nodes_len) {
|
||||
struct node *n;
|
||||
unsigned i;
|
||||
|
||||
/* Search for first node with no incoming edges */
|
||||
for (i = 0; i < G.nodes_len; i++) {
|
||||
if (!G.nodes[i]->in_count)
|
||||
break;
|
||||
}
|
||||
if (i == G.nodes_len) {
|
||||
/* Must be a cycle; arbitraily break it at node 0 */
|
||||
cycles++;
|
||||
i = 0;
|
||||
#ifndef TINY
|
||||
bb_error_msg("cycle at %s", G.nodes[i]->name);
|
||||
#endif
|
||||
}
|
||||
|
||||
/* Remove the node (need no longer maintain sort) */
|
||||
n = G.nodes[i];
|
||||
G.nodes[i] = G.nodes[--G.nodes_len];
|
||||
|
||||
/* And remove its outgoing edges */
|
||||
for (i = 0; i < n->out_count; i++)
|
||||
n->out[i]->in_count--;
|
||||
free(n->out);
|
||||
|
||||
puts(n->name);
|
||||
free(n);
|
||||
}
|
||||
free(G.nodes);
|
||||
|
||||
fflush_stdout_and_exit(cycles ? 1 : 0);
|
||||
}
|
||||
@ -24,7 +24,7 @@ POSIX Tools not supported:
|
||||
gencat, getconf, iconv, join, link, locale, localedef, lp, m4,
|
||||
mailx, newgrp, nl, pathchk, pax, pr, qalter, qdel, qhold, qmove,
|
||||
qmsg, qrerun, qrls, qselect, qsig, qstat, qsub, tabs, talk, tput,
|
||||
tsort, unlink, uucp, uustat, uux
|
||||
unlink, uucp, uustat, uux
|
||||
|
||||
POSIX Tools not supported (DEVELOPMENT):
|
||||
admin, cflow, ctags, cxref, delta, fort77, get, lex, make, nm, prs, rmdel,
|
||||
|
||||
110
testsuite/tsort.tests
Executable file
110
testsuite/tsort.tests
Executable file
@ -0,0 +1,110 @@
|
||||
#!/bin/sh
|
||||
|
||||
# SUSv3 compliant sort tests.
|
||||
# Public Domain, David Leonard 2022
|
||||
|
||||
. ./testing.sh
|
||||
|
||||
# name cmd expected ./input stdin
|
||||
testing "" "tsort" "a\n" "" "a a\n"
|
||||
testing "" "tsort -" "a\n" "" "a a\n"
|
||||
testing "" "tsort input" "a\n" "a a\n" ""
|
||||
testing "tsort input (w/o eol)" "tsort input" "a\n" "a a" ""
|
||||
testing "" "tsort /dev/null" "" "" ""
|
||||
|
||||
testing "tsort empty" tsort "" "" ""
|
||||
testing "tsort blank" tsort "" "" "\n"
|
||||
testing "tsort blanks" tsort "" "" "\n\n \t\n "
|
||||
|
||||
# simple inputs having exactly one solution
|
||||
testing "tsort 1-edge" tsort "a\nb\n" "" "a b\n"
|
||||
testing "tsort 2-edge" tsort "a\nb\nc\n" "" "a b b c\n"
|
||||
|
||||
|
||||
# The following test helper accommodates future variable output because, as
|
||||
# tsort is allowed to emit any total ordering that satisfies its input,
|
||||
# should the implementation changes, these tests will remain valid.
|
||||
#
|
||||
# The idea is to verify that:
|
||||
# - each input word is present EXACTLY ONCE in tsort's output
|
||||
# - for each input pair 'a b', the occurrence of 'a' APPEARS BEFORE 'b'
|
||||
# - the exit code is 0
|
||||
|
||||
tsort_test () {
|
||||
fail=
|
||||
name="$1"; shift
|
||||
args="$*"
|
||||
if [ $VERBOSE ]; then
|
||||
echo "============"
|
||||
echo "echo \"$args\" | tsort >actual"
|
||||
fi
|
||||
echo "$args" | tsort >actual
|
||||
ec=$?
|
||||
if [ $ec -ne 0 ]; then
|
||||
fail "tsort exit $ec, expected 0"
|
||||
fi
|
||||
while [ $# -ne 0 ]; do
|
||||
a=$1; shift
|
||||
b=$1; shift
|
||||
aline=$(grep -nxF "$a" <actual | cut -d: -f1)
|
||||
bline=$(grep -nxF "$b" <actual | cut -d: -f1)
|
||||
case $aline in
|
||||
"") fail "word $a missing from output ($args)";;
|
||||
*" "*) fail "word $a duplicated ($args)";;
|
||||
esac
|
||||
case $bline in
|
||||
"") fail "word $b missing from output ($args)";;
|
||||
*" "*) fail "word $b duplicated ($args)";;
|
||||
esac
|
||||
if [ $aline -gt $bline ]; then
|
||||
fail "$a appears after $b ($args)"
|
||||
fi
|
||||
done
|
||||
if [ $fail ] && [ $VERBOSE ]; then
|
||||
echo "exit $ec, actual:"
|
||||
cat actual
|
||||
fi
|
||||
rm actual
|
||||
report "$name"
|
||||
}
|
||||
|
||||
# Test that erroneous input causes an unsuccessful exit code
|
||||
# we don't test the output error message
|
||||
tsort_test_err () {
|
||||
fail=
|
||||
name="$1"; shift
|
||||
echo "$*" | tsort >/dev/null 2>/dev/null
|
||||
ec=$?
|
||||
if [ $ec -eq 0 ]; then
|
||||
fail "$name: unexpected exit 0 ($*)"
|
||||
fi
|
||||
report "$name"
|
||||
}
|
||||
|
||||
fail () {
|
||||
[ $VERBOSE ] && echo "ERROR: $*"
|
||||
fail=1
|
||||
}
|
||||
|
||||
report () {
|
||||
if [ $fail ]; then
|
||||
FAILCOUNT=$(($FAILCOUNT + 1))
|
||||
echo "FAIL: $*"
|
||||
else
|
||||
echo "PASS: $*"
|
||||
fi
|
||||
}
|
||||
|
||||
tsort_test "tsort empty2"
|
||||
tsort_test "tsort singleton" a a
|
||||
tsort_test "tsort simple" a b b c
|
||||
tsort_test "tsort 2singleton" a a b b
|
||||
tsort_test "tsort medium" a b a b b c
|
||||
tsort_test "tsort std.example" a b c c d e g g f g e f h h
|
||||
tsort_test "tsort prefixes" a aa aa aaa aaaa aaaaa a aaaaa
|
||||
|
||||
tsort_test_err "tsort odd" a
|
||||
tsort_test_err "tsort odd2" a b c
|
||||
tsort_test_err "tsort cycle" a b b a
|
||||
|
||||
exit $FAILCOUNT
|
||||
Loading…
Reference in New Issue
Block a user