| // 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 build a string |
| // in a buffer with multiple calls. The process aborts if an error occurs and |
| // the total string size is returned. |
| // |
| // This compares the overhead of using pw::string::Format to directly calling |
| // std::snprintf and doing error handling. It demonstrates that the code for |
| // using pw::string::Format is much simpler. |
| |
| #include "pw_bloat/bloat_this_binary.h" |
| |
| #ifndef USE_FORMAT |
| #error "USE_FORMAT must be defined" |
| #endif // USE_FORMAT |
| |
| #if USE_FORMAT |
| |
| #include "pw_string/format.h" |
| |
| #define FORMAT_FUNCTION(...) \ |
| pw::string::Format(std::span(buffer, buffer_size - string_size), __VA_ARGS__) |
| #define CHECK_RESULT(result) ProcessResult(&string_size, result) |
| |
| namespace { |
| |
| bool ProcessResult(unsigned* total, pw::StatusWithSize result) { |
| *total += result.size(); |
| return result.ok(); |
| } |
| |
| } // namespace |
| |
| #else // std::snprintf |
| |
| #include <cstdio> |
| |
| #define FORMAT_FUNCTION(...) std::snprintf(buffer, buffer_size, __VA_ARGS__) |
| #define CHECK_RESULT(result) \ |
| ProcessResult(buffer, &string_size, buffer_size - string_size, result) |
| |
| namespace { |
| |
| bool ProcessResult(char* buffer, unsigned* total, unsigned size, int result) { |
| if (result < 0) { |
| // Null-terminate since snprintf doesn't report the written count. |
| buffer[size] = '\0'; |
| return false; |
| } |
| |
| if (static_cast<unsigned>(result) >= size) { |
| if (size > 0u) { |
| *total += size - 1; |
| } |
| return false; |
| } |
| |
| *total += result; |
| return true; |
| } |
| |
| } // namespace |
| |
| #endif // USE_FORMAT |
| |
| #define FORMAT_CASE(...) \ |
| if (!CHECK_RESULT(FORMAT_FUNCTION(__VA_ARGS__))) { \ |
| return string_size; \ |
| } |
| |
| namespace pw::string { |
| |
| char buffer_1[128]; |
| char buffer_2[128]; |
| |
| char* volatile get_buffer_1 = buffer_1; |
| char* volatile get_buffer_2 = buffer_2; |
| volatile unsigned get_size; |
| |
| unsigned OutputStringsToBuffer() { |
| char* buffer = get_buffer_1; |
| const char* string = get_buffer_2; |
| |
| unsigned buffer_size = get_size; |
| unsigned string_size = 0; |
| |
| FORMAT_CASE("The quick brown"); |
| FORMAT_CASE("%s", string); |
| FORMAT_CASE("jumped over the %s d%ug.", string, buffer_size); |
| FORMAT_CASE("One two %s %d %s", "three", 4, "five"); |
| FORMAT_CASE("a %c %x d %s %f g", 'b', 0xc, "e", 0.0f); |
| |
| FORMAT_CASE("The quick brown"); |
| FORMAT_CASE("%s", string); |
| FORMAT_CASE("jumped over the %s d%ug.", string, buffer_size); |
| FORMAT_CASE("One two %s %d %s", "three", 4, "five"); |
| FORMAT_CASE("a %c %x d %s %f g", 'b', 0xc, "e", 0.0f); |
| |
| return string_size; |
| } |
| |
| } // namespace pw::string |
| |
| int main() { |
| pw::bloat::BloatThisBinary(); |
| return pw::string::OutputStringsToBuffer(); |
| } |