1 // Copyright (C) 2019 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "icing/index/term-id-codec.h"
16
17 #include <cstdint>
18 #include <limits>
19 #include <memory>
20
21 #include "icing/text_classifier/lib3/utils/base/statusor.h"
22 #include "icing/absl_ports/canonical_errors.h"
23 #include "icing/legacy/core/icing-string-util.h"
24 #include "icing/util/status-macros.h"
25
26 namespace icing {
27 namespace lib {
28
Create(uint32_t max_main_tvi,uint32_t max_lite_tvi)29 libtextclassifier3::StatusOr<std::unique_ptr<TermIdCodec>> TermIdCodec::Create(
30 uint32_t max_main_tvi, uint32_t max_lite_tvi) {
31 uint64_t sum =
32 static_cast<uint64_t>(max_main_tvi) + static_cast<uint64_t>(max_lite_tvi);
33 if (sum > std::numeric_limits<uint32_t>::max()) {
34 return absl_ports::InvalidArgumentError(IcingStringUtil::StringPrintf(
35 "Sum of max_main_tvi, %d, and max_lite_tvi, %d must be less than the "
36 "uint32_t max, %d.",
37 max_main_tvi, max_lite_tvi, std::numeric_limits<uint32_t>::max()));
38 }
39
40 // TODO(cassiewang): When we convert these values to signed ints, we should
41 // check to make sure they're >= 0.
42
43 return std::unique_ptr<TermIdCodec>(
44 new TermIdCodec(max_main_tvi, max_lite_tvi));
45 }
46
EncodeTvi(uint32_t tvi,TviType tvi_type) const47 libtextclassifier3::StatusOr<uint32_t> TermIdCodec::EncodeTvi(
48 uint32_t tvi, TviType tvi_type) const {
49 switch (tvi_type) {
50 case TviType::MAIN:
51 if (tvi >= max_main_tvi_) {
52 return absl_ports::InvalidArgumentError(IcingStringUtil::StringPrintf(
53 "Main tvi %d is greater "
54 "than or equal to the max_main_tvi %d",
55 tvi, max_main_tvi_));
56 }
57 return tvi;
58 case TviType::LITE: {
59 if (tvi >= max_lite_tvi_) {
60 return absl_ports::InvalidArgumentError(IcingStringUtil::StringPrintf(
61 "Lite tvi %d is greater "
62 "than or equal to the max_lite_tvi %d",
63 tvi, max_lite_tvi_));
64 }
65 return max_main_tvi_ + tvi;
66 }
67 }
68 }
69
DecodeTviType(uint32_t term_id) const70 libtextclassifier3::StatusOr<TviType> TermIdCodec::DecodeTviType(
71 uint32_t term_id) const {
72 if (term_id < max_main_tvi_) {
73 return TviType::MAIN;
74 } else if (term_id < max_term_id()) {
75 return TviType::LITE;
76 }
77 return absl_ports::InvalidArgumentError(IcingStringUtil::StringPrintf(
78 "Given TermId %d is greater than or equal to the max TermId %d", term_id,
79 max_term_id()));
80 }
81
82 libtextclassifier3::StatusOr<TermIdCodec::DecodedTermInfo>
DecodeTermInfo(uint32_t term_id) const83 TermIdCodec::DecodeTermInfo(uint32_t term_id) const {
84 DecodedTermInfo result;
85 ICING_ASSIGN_OR_RETURN(result.tvi_type, DecodeTviType(term_id));
86 switch (result.tvi_type) {
87 case TviType::MAIN:
88 result.tvi = term_id;
89 break;
90 case TviType::LITE:
91 result.tvi = term_id - max_main_tvi_;
92 break;
93 }
94 return result;
95 }
96
97 } // namespace lib
98 } // namespace icing
99