blob: 3910105fe6cf28b5e6647f98cfb5c9be4214700a (
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
|
// Copyright (C) 2023 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "icing/store/namespace-fingerprint-identifier.h"
#include <cstdint>
#include <string>
#include <string_view>
#include "icing/text_classifier/lib3/utils/base/statusor.h"
#include "icing/text_classifier/lib3/utils/hash/farmhash.h"
#include "icing/absl_ports/canonical_errors.h"
#include "icing/absl_ports/str_cat.h"
#include "icing/store/namespace-id.h"
#include "icing/util/encode-util.h"
namespace icing {
namespace lib {
/* static */ libtextclassifier3::StatusOr<NamespaceFingerprintIdentifier>
NamespaceFingerprintIdentifier::DecodeFromCString(
std::string_view encoded_cstr) {
if (encoded_cstr.size() < kMinEncodedLength) {
return absl_ports::InvalidArgumentError("Invalid length");
}
NamespaceId namespace_id = encode_util::DecodeIntFromCString(
encoded_cstr.substr(0, kEncodedNamespaceIdLength));
uint64_t fingerprint = encode_util::DecodeIntFromCString(
encoded_cstr.substr(kEncodedNamespaceIdLength));
return NamespaceFingerprintIdentifier(namespace_id, fingerprint);
}
NamespaceFingerprintIdentifier::NamespaceFingerprintIdentifier(
NamespaceId namespace_id, std::string_view target_str)
: namespace_id_(namespace_id),
fingerprint_(tc3farmhash::Fingerprint64(target_str)) {}
std::string NamespaceFingerprintIdentifier::EncodeToCString() const {
// encoded_namespace_id_str should be 1 to 3 bytes based on the value of
// namespace_id.
std::string encoded_namespace_id_str =
encode_util::EncodeIntToCString(namespace_id_);
// Make encoded_namespace_id_str to fixed kEncodedNamespaceIdLength bytes.
while (encoded_namespace_id_str.size() < kEncodedNamespaceIdLength) {
// C string cannot contain 0 bytes, so we append it using 1, just like what
// we do in encode_util::EncodeIntToCString.
//
// The reason that this works is because DecodeIntToString decodes a byte
// value of 0x01 as 0x00. When EncodeIntToCString returns an encoded
// namespace id that is less than 3 bytes, it means that the id contains
// unencoded leading 0x00. So here we're explicitly encoding those bytes as
// 0x01.
encoded_namespace_id_str.push_back(1);
}
return absl_ports::StrCat(encoded_namespace_id_str,
encode_util::EncodeIntToCString(fingerprint_));
}
} // namespace lib
} // namespace icing
|
