summaryrefslogtreecommitdiffstats
path: root/reftable/refname.c
blob: bbfde15754a227c9bd418572b778d77827a59db4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
/*
  Copyright 2020 Google LLC

  Use of this source code is governed by a BSD-style
  license that can be found in the LICENSE file or at
  https://developers.google.com/open-source/licenses/bsd
*/

#include "system.h"
#include "reftable-error.h"
#include "basics.h"
#include "refname.h"
#include "reftable-iterator.h"

struct refname_needle_lesseq_args {
	char **haystack;
	const char *needle;
};

static int refname_needle_lesseq(size_t k, void *_args)
{
	struct refname_needle_lesseq_args *args = _args;
	return strcmp(args->needle, args->haystack[k]) <= 0;
}

static int modification_has_ref(struct modification *mod, const char *name)
{
	struct reftable_ref_record ref = { NULL };
	int err = 0;

	if (mod->add_len > 0) {
		struct refname_needle_lesseq_args args = {
			.haystack = mod->add,
			.needle = name,
		};
		size_t idx = binsearch(mod->add_len, refname_needle_lesseq, &args);
		if (idx < mod->add_len && !strcmp(mod->add[idx], name))
			return 0;
	}

	if (mod->del_len > 0) {
		struct refname_needle_lesseq_args args = {
			.haystack = mod->del,
			.needle = name,
		};
		size_t idx = binsearch(mod->del_len, refname_needle_lesseq, &args);
		if (idx < mod->del_len && !strcmp(mod->del[idx], name))
			return 1;
	}

	err = reftable_table_read_ref(&mod->tab, name, &ref);
	reftable_ref_record_release(&ref);
	return err;
}

static void modification_release(struct modification *mod)
{
	/* don't delete the strings themselves; they're owned by ref records.
	 */
	FREE_AND_NULL(mod->add);
	FREE_AND_NULL(mod->del);
	mod->add_len = 0;
	mod->del_len = 0;
}

static int modification_has_ref_with_prefix(struct modification *mod,
					    const char *prefix)
{
	struct reftable_iterator it = { NULL };
	struct reftable_ref_record ref = { NULL };
	int err = 0;

	if (mod->add_len > 0) {
		struct refname_needle_lesseq_args args = {
			.haystack = mod->add,
			.needle = prefix,
		};
		size_t idx = binsearch(mod->add_len, refname_needle_lesseq, &args);
		if (idx < mod->add_len &&
		    !strncmp(prefix, mod->add[idx], strlen(prefix)))
			goto done;
	}
	err = reftable_table_seek_ref(&mod->tab, &it, prefix);
	if (err)
		goto done;

	while (1) {
		err = reftable_iterator_next_ref(&it, &ref);
		if (err)
			goto done;

		if (mod->del_len > 0) {
			struct refname_needle_lesseq_args args = {
				.haystack = mod->del,
				.needle = ref.refname,
			};
			size_t idx = binsearch(mod->del_len, refname_needle_lesseq, &args);
			if (idx < mod->del_len &&
			    !strcmp(ref.refname, mod->del[idx]))
				continue;
		}

		if (strncmp(ref.refname, prefix, strlen(prefix))) {
			err = 1;
			goto done;
		}
		err = 0;
		goto done;
	}

done:
	reftable_ref_record_release(&ref);
	reftable_iterator_destroy(&it);
	return err;
}

static int validate_refname(const char *name)
{
	while (1) {
		char *next = strchr(name, '/');
		if (!*name) {
			return REFTABLE_REFNAME_ERROR;
		}
		if (!next) {
			return 0;
		}
		if (next - name == 0 || (next - name == 1 && *name == '.') ||
		    (next - name == 2 && name[0] == '.' && name[1] == '.'))
			return REFTABLE_REFNAME_ERROR;
		name = next + 1;
	}
	return 0;
}

int validate_ref_record_addition(struct reftable_table tab,
				 struct reftable_ref_record *recs, size_t sz)
{
	struct modification mod = {
		.tab = tab,
		.add = reftable_calloc(sz, sizeof(*mod.add)),
		.del = reftable_calloc(sz, sizeof(*mod.del)),
	};
	int i = 0;
	int err = 0;
	for (; i < sz; i++) {
		if (reftable_ref_record_is_deletion(&recs[i])) {
			mod.del[mod.del_len++] = recs[i].refname;
		} else {
			mod.add[mod.add_len++] = recs[i].refname;
		}
	}

	err = modification_validate(&mod);
	modification_release(&mod);
	return err;
}

static void strbuf_trim_component(struct strbuf *sl)
{
	while (sl->len > 0) {
		int is_slash = (sl->buf[sl->len - 1] == '/');
		strbuf_setlen(sl, sl->len - 1);
		if (is_slash)
			break;
	}
}

int modification_validate(struct modification *mod)
{
	struct strbuf slashed = STRBUF_INIT;
	int err = 0;
	int i = 0;
	for (; i < mod->add_len; i++) {
		err = validate_refname(mod->add[i]);
		if (err)
			goto done;
		strbuf_reset(&slashed);
		strbuf_addstr(&slashed, mod->add[i]);
		strbuf_addstr(&slashed, "/");

		err = modification_has_ref_with_prefix(mod, slashed.buf);
		if (err == 0) {
			err = REFTABLE_NAME_CONFLICT;
			goto done;
		}
		if (err < 0)
			goto done;

		strbuf_reset(&slashed);
		strbuf_addstr(&slashed, mod->add[i]);
		while (slashed.len) {
			strbuf_trim_component(&slashed);
			err = modification_has_ref(mod, slashed.buf);
			if (err == 0) {
				err = REFTABLE_NAME_CONFLICT;
				goto done;
			}
			if (err < 0)
				goto done;
		}
	}
	err = 0;
done:
	strbuf_release(&slashed);
	return err;
}