| // Copyright 2019 The Pigweed Authors |
| // |
| // 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 |
| // |
| // https://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. |
| |
| // This size report uses pw::string::Format and std::snprintf to write a single |
| // printf-style string to a buffer. The number of bytes written is returned. |
| // |
| // This compares the overhead of using pw::string::Format to directly calling |
| // std::snprintf and determining the number of bytes written. It demonstrates |
| // that the code for using pw::string::Format is much simpler. |
| |
| #include <cstddef> |
| #include <cstdio> |
| |
| #include "pw_bloat/bloat_this_binary.h" |
| #include "pw_string/format.h" |
| |
| #ifndef USE_FORMAT |
| #error "USE_FORMAT must be defined!" |
| #endif // USE_FORMAT |
| |
| namespace pw::string { |
| |
| char* volatile get_buffer; |
| volatile unsigned get_size; |
| |
| unsigned OutputStringsToBuffer() { |
| char* buffer = get_buffer; |
| unsigned buffer_size = get_size; |
| |
| #if USE_FORMAT |
| // The code for using pw::string::Format is much simpler and safer. |
| return Format(std::span(buffer, buffer_size), |
| "hello %s %d", |
| get_buffer, |
| get_size) |
| .size(); |
| #else // std::snprintf |
| if (buffer_size == 0u) { |
| return 0; |
| } |
| |
| int result = |
| std::snprintf(buffer, buffer_size, "hello %s %d", get_buffer, get_size); |
| if (result < 0) { |
| buffer[0] = '\0'; |
| return 0; |
| } |
| if (static_cast<size_t>(result) >= buffer_size) { |
| return buffer_size - 1; |
| } |
| return result; |
| #endif // USE_FORMAT |
| } |
| |
| } // namespace pw::string |
| |
| int main() { |
| pw::bloat::BloatThisBinary(); |
| return pw::string::OutputStringsToBuffer(); |
| } |