1 // Copyright 2019 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 // https://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, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14
15 #include "pw_string/string_builder.h"
16
17 #include <cstdio>
18
19 #include "pw_string/format.h"
20 #include "pw_string/util.h"
21
22 namespace pw {
23
clear()24 void StringBuilder::clear() {
25 size_ = 0;
26 NullTerminate();
27 status_ = OkStatus();
28 last_status_ = OkStatus();
29 }
30
append(size_t count,char ch)31 StringBuilder& StringBuilder::append(size_t count, char ch) {
32 char* const append_destination = &buffer_[size_];
33 std::memset(append_destination, ch, ResizeAndTerminate(count));
34 return *this;
35 }
36
append(const char * str,size_t count)37 StringBuilder& StringBuilder::append(const char* str, size_t count) {
38 char* const append_destination = &buffer_[size_];
39 std::memcpy(append_destination, str, ResizeAndTerminate(count));
40 return *this;
41 }
42
append(const char * str)43 StringBuilder& StringBuilder::append(const char* str) {
44 // Use buffer_.size() - size() as the maximum length so that strings too long
45 // to fit in the buffer will request one character too many, which sets the
46 // status to RESOURCE_EXHAUSTED.
47 return append(str, string::Length(str, buffer_.size() - size()));
48 }
49
append(const std::string_view & str)50 StringBuilder& StringBuilder::append(const std::string_view& str) {
51 return append(str.data(), str.size());
52 }
53
append(const std::string_view & str,size_t pos,size_t count)54 StringBuilder& StringBuilder::append(const std::string_view& str,
55 size_t pos,
56 size_t count) {
57 if (pos > str.size()) {
58 SetErrorStatus(Status::OutOfRange());
59 return *this;
60 }
61
62 return append(str.data() + pos, std::min(str.size() - pos, count));
63 }
64
ResizeAndTerminate(size_t chars_to_append)65 size_t StringBuilder::ResizeAndTerminate(size_t chars_to_append) {
66 const size_t copied = std::min(chars_to_append, max_size() - size());
67 size_ += copied;
68 NullTerminate();
69
70 if (buffer_.empty() || chars_to_append != copied) {
71 SetErrorStatus(Status::ResourceExhausted());
72 } else {
73 last_status_ = OkStatus();
74 }
75 return copied;
76 }
77
resize(size_t new_size)78 void StringBuilder::resize(size_t new_size) {
79 if (new_size <= size_) {
80 size_ = new_size;
81 NullTerminate();
82 last_status_ = OkStatus();
83 } else {
84 SetErrorStatus(Status::OutOfRange());
85 }
86 }
87
Format(const char * format,...)88 StringBuilder& StringBuilder::Format(const char* format, ...) {
89 va_list args;
90 va_start(args, format);
91 FormatVaList(format, args);
92 va_end(args);
93
94 return *this;
95 }
96
FormatVaList(const char * format,va_list args)97 StringBuilder& StringBuilder::FormatVaList(const char* format, va_list args) {
98 HandleStatusWithSize(
99 string::FormatVaList(buffer_.subspan(size_), format, args));
100 return *this;
101 }
102
CopySizeAndStatus(const StringBuilder & other)103 void StringBuilder::CopySizeAndStatus(const StringBuilder& other) {
104 size_ = other.size_;
105 status_ = other.status_;
106 last_status_ = other.last_status_;
107 }
108
HandleStatusWithSize(StatusWithSize written)109 void StringBuilder::HandleStatusWithSize(StatusWithSize written) {
110 const Status status = written.status();
111 last_status_ = status;
112 if (!status.ok()) {
113 status_ = status;
114 }
115
116 size_ += written.size();
117 }
118
SetErrorStatus(Status status)119 void StringBuilder::SetErrorStatus(Status status) {
120 last_status_ = status;
121 status_ = status;
122 }
123
124 } // namespace pw
125