summaryrefslogtreecommitdiffstats
path: root/reftable/iter.c
blob: aa9ac199b1e93bc87b41e0717c6795676deef4b5 (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
/*
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 "iter.h"

#include "system.h"

#include "block.h"
#include "generic.h"
#include "constants.h"
#include "reader.h"
#include "reftable-error.h"

static void filtering_ref_iterator_close(void *iter_arg)
{
	struct filtering_ref_iterator *fri = iter_arg;
	strbuf_release(&fri->oid);
	reftable_iterator_destroy(&fri->it);
}

static int filtering_ref_iterator_next(void *iter_arg,
				       struct reftable_record *rec)
{
	struct filtering_ref_iterator *fri = iter_arg;
	struct reftable_ref_record *ref = &rec->u.ref;
	int err = 0;
	while (1) {
		err = reftable_iterator_next_ref(&fri->it, ref);
		if (err != 0) {
			break;
		}

		if (fri->double_check) {
			struct reftable_iterator it = { NULL };

			err = reftable_table_seek_ref(&fri->tab, &it,
						      ref->refname);
			if (err == 0) {
				err = reftable_iterator_next_ref(&it, ref);
			}

			reftable_iterator_destroy(&it);

			if (err < 0) {
				break;
			}

			if (err > 0) {
				continue;
			}
		}

		if (ref->value_type == REFTABLE_REF_VAL2 &&
		    (!memcmp(fri->oid.buf, ref->value.val2.target_value,
			     fri->oid.len) ||
		     !memcmp(fri->oid.buf, ref->value.val2.value,
			     fri->oid.len)))
			return 0;

		if (ref->value_type == REFTABLE_REF_VAL1 &&
		    !memcmp(fri->oid.buf, ref->value.val1, fri->oid.len)) {
			return 0;
		}
	}

	reftable_ref_record_release(ref);
	return err;
}

static struct reftable_iterator_vtable filtering_ref_iterator_vtable = {
	.next = &filtering_ref_iterator_next,
	.close = &filtering_ref_iterator_close,
};

void iterator_from_filtering_ref_iterator(struct reftable_iterator *it,
					  struct filtering_ref_iterator *fri)
{
	assert(!it->ops);
	it->iter_arg = fri;
	it->ops = &filtering_ref_iterator_vtable;
}

static void indexed_table_ref_iter_close(void *p)
{
	struct indexed_table_ref_iter *it = p;
	block_iter_close(&it->cur);
	reftable_block_done(&it->block_reader.block);
	reftable_free(it->offsets);
	strbuf_release(&it->oid);
}

static int indexed_table_ref_iter_next_block(struct indexed_table_ref_iter *it)
{
	uint64_t off;
	int err = 0;
	if (it->offset_idx == it->offset_len) {
		it->is_finished = 1;
		return 1;
	}

	reftable_block_done(&it->block_reader.block);

	off = it->offsets[it->offset_idx++];
	err = reader_init_block_reader(it->r, &it->block_reader, off,
				       BLOCK_TYPE_REF);
	if (err < 0) {
		return err;
	}
	if (err > 0) {
		/* indexed block does not exist. */
		return REFTABLE_FORMAT_ERROR;
	}
	block_iter_seek_start(&it->cur, &it->block_reader);
	return 0;
}

static int indexed_table_ref_iter_next(void *p, struct reftable_record *rec)
{
	struct indexed_table_ref_iter *it = p;
	struct reftable_ref_record *ref = &rec->u.ref;

	while (1) {
		int err = block_iter_next(&it->cur, rec);
		if (err < 0) {
			return err;
		}

		if (err > 0) {
			err = indexed_table_ref_iter_next_block(it);
			if (err < 0) {
				return err;
			}

			if (it->is_finished) {
				return 1;
			}
			continue;
		}
		/* BUG */
		if (!memcmp(it->oid.buf, ref->value.val2.target_value,
			    it->oid.len) ||
		    !memcmp(it->oid.buf, ref->value.val2.value, it->oid.len)) {
			return 0;
		}
	}
}

int new_indexed_table_ref_iter(struct indexed_table_ref_iter **dest,
			       struct reftable_reader *r, uint8_t *oid,
			       int oid_len, uint64_t *offsets, int offset_len)
{
	struct indexed_table_ref_iter empty = INDEXED_TABLE_REF_ITER_INIT;
	struct indexed_table_ref_iter *itr = reftable_calloc(1, sizeof(*itr));
	int err = 0;

	*itr = empty;
	itr->r = r;
	strbuf_add(&itr->oid, oid, oid_len);

	itr->offsets = offsets;
	itr->offset_len = offset_len;

	err = indexed_table_ref_iter_next_block(itr);
	if (err < 0) {
		reftable_free(itr);
	} else {
		*dest = itr;
	}
	return err;
}

static struct reftable_iterator_vtable indexed_table_ref_iter_vtable = {
	.next = &indexed_table_ref_iter_next,
	.close = &indexed_table_ref_iter_close,
};

void iterator_from_indexed_table_ref_iter(struct reftable_iterator *it,
					  struct indexed_table_ref_iter *itr)
{
	assert(!it->ops);
	it->iter_arg = itr;
	it->ops = &indexed_table_ref_iter_vtable;
}