1 /* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
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 "tensorflow/core/kernels/string_util.h"
16
17 #include "tensorflow/core/lib/core/errors.h"
18
19 namespace tensorflow {
20
21 // Sets unit value based on str.
ParseUnicodeEncoding(const string & str,UnicodeEncoding * encoding)22 Status ParseUnicodeEncoding(const string& str, UnicodeEncoding* encoding) {
23 if (str == "UTF-8") {
24 *encoding = UnicodeEncoding::UTF8;
25 } else if (str == "UTF-16-BE") {
26 *encoding = UnicodeEncoding::UTF16BE;
27 } else if (str == "UTF-32-BE") {
28 *encoding = UnicodeEncoding::UTF32BE;
29 } else {
30 return errors::InvalidArgument(
31 strings::StrCat("Invalid encoding \"", str,
32 "\": Should be one of: UTF-8, UTF-16-BE, UTF-32-BE"));
33 }
34 return OkStatus();
35 }
36
37 // Sets unit value based on str.
ParseCharUnit(const string & str,CharUnit * unit)38 Status ParseCharUnit(const string& str, CharUnit* unit) {
39 if (str == "BYTE") {
40 *unit = CharUnit::BYTE;
41 } else if (str == "UTF8_CHAR") {
42 *unit = CharUnit::UTF8_CHAR;
43 } else {
44 return errors::InvalidArgument(strings::StrCat(
45 "Invalid unit \"", str, "\": Should be one of: BYTE, UTF8_CHAR"));
46 }
47 return OkStatus();
48 }
49
50 // Return the number of Unicode characters in a UTF-8 string.
51 // Result may be incorrect if the input string is not valid UTF-8.
UTF8StrLen(const string & str)52 int32 UTF8StrLen(const string& str) {
53 const int32_t byte_size = str.size();
54 const char* const end = str.data() + byte_size;
55 const char* ptr = str.data();
56 int32_t skipped_count = 0;
57 while (ptr < end) {
58 skipped_count += IsTrailByte(*ptr++) ? 1 : 0;
59 }
60 const int32_t result = byte_size - skipped_count;
61 return result;
62 }
63
64 } // namespace tensorflow
65