1 /*
2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <zlib.h>
23 
24 #include "got_error.h"
25 
26 #include "delta.h"
27 #include "path.h"
28 
29 #ifndef nitems
30 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
31 #endif
32 
33 struct delta_test {
34 	const char *base;
35 	const char *delta;
36 	size_t delta_len;
37 	const char *expected;
38 } delta_tests[] = {
39 	/* base len 0, target len 4, append 4 'x' */
40 	{ "", "\x00\x04\x04xxxx", 7, "xxxx" },
41 	/* copy 4 bytes at offset 0 from base, append 4 'x' */
42 	{ "aabbccdd", "\x08\x08\x90\x04\x04xxxx", 9, "aabbxxxx" },
43 	/* copy 4 bytes at offset 4 from base, append 4 'x' */
44 	{ "aabbccdd", "\x08\x08\x91\x04\x04\x04xxxx", 10, "ccddxxxx" },
45 };
46 
47 static const struct got_error *
48 compress_to_file(FILE **outfile, const char *input, size_t inlen)
49 {
50 	const struct got_error *err = NULL;
51 	z_stream z;
52 	char buf[2048];
53 	char *inbuf;
54 	int ret;
55 	size_t n;
56 
57 	memset(&z, 0, sizeof(z));
58 	z.zalloc = Z_NULL;
59 	z.zfree = Z_NULL;
60 
61 	if (deflateInit(&z, 8) != Z_OK)
62 		return got_error(GOT_ERR_IO);
63 
64 	*outfile = got_opentemp();
65 	if (*outfile == NULL)
66 		return got_error_from_errno();
67 
68 	z.next_in = (Bytef *)input;
69 	z.avail_in = inlen;
70 	z.next_out = buf;
71 	z.avail_out = sizeof(buf);
72 	/* Our output buffer is large enough so one round should be enough. */
73 	ret = deflate(&z, Z_FINISH);
74 	if (ret != Z_STREAM_END || z.avail_out == 0) {
75 		err = got_error(GOT_ERR_COMPRESSION);
76 		goto done;
77 	}
78 
79 	deflateEnd(&z);
80 
81 	n = fwrite(buf, 1, z.avail_out, *outfile);
82 	if (n != z.avail_out)
83 		err = got_ferror(*outfile, GOT_ERR_IO);
84 done:
85 	if (err) {
86 		fclose(*outfile);
87 		*outfile = NULL;
88 	} else
89 		rewind(*outfile);
90 	return err;
91 }
92 
93 static int
94 delta_combine()
95 {
96 	const struct got_error *err = NULL;
97 	int i;
98 	FILE *result_file;
99 
100 	result_file = got_opentemp();
101 	if (result_file == NULL)
102 		return 1;
103 
104 	for (i = 0; i < nitems(delta_tests); i++) {
105 		struct delta_test *dt = &delta_tests[i];
106 		FILE *base_file;
107 		char buf[1024];
108 		size_t n, len, result_len;
109 
110 		len = strlen(dt->base);
111 		err = compress_to_file(&base_file, dt->base, len);
112 		if (err)
113 			break;
114 
115 		err = got_delta_apply(base_file, dt->delta, dt->delta_len,
116 		    result_file);
117 		fclose(base_file);
118 		if (err)
119 			break;
120 		result_len = strlen(dt->expected);
121 		n = fread(buf, result_len, 1, result_file);
122 		if (n != 1 || strncmp(buf, dt->expected, result_len) != 0) {
123 			err = got_ferror(result_file, GOT_ERR_BAD_DELTA);
124 			break;
125 		}
126 		rewind(result_file);
127 	}
128 
129 	fclose(result_file);
130 	return (err == NULL);
131 }
132 
133 #define RUN_TEST(expr, name) \
134 	{ test_ok = (expr);  \
135 	printf("test %s %s\n", (name), test_ok ? "ok" : "failed"); \
136 	failure = (failure || !test_ok); }
137 
138 int
139 main(int argc, const char *argv[])
140 {
141 	int test_ok;
142 	int failure = 0;
143 
144 	if (argc != 1) {
145 		fprintf(stderr, "usage: delta_test [REPO_PATH]\n");
146 		return 1;
147 	}
148 
149 	RUN_TEST(delta_combine(), "delta_combine");
150 
151 	return failure ? 1 : 0;
152 }