1 /* 2 * Copyright (C) 2024 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef MEDIAPROVIDER_PDF_JNI_PDFCLIENT_UTILS_BYTE_VALUE_H_ 18 #define MEDIAPROVIDER_PDF_JNI_PDFCLIENT_UTILS_BYTE_VALUE_H_ 19 20 #include <functional> 21 #include <vector> 22 23 namespace pdfClient_utils { 24 // Wrapper around a Pdfium function to make it easier to get a bytestring. 25 // Many Pdfium functions have the following form: 26 // size_t FPDF_GetFooString(other_args ..., void* buffer, size_t buffer_len); 27 // These functions return the number of bytes in the result, regardless of the 28 // value of buffer_len. If buffer_len >= the number of bytes in the result, 29 // buffer is also filled in with the result value. 30 // 31 // GetBytes accepts a |result| vector, where the result will be stored, and a 32 // std::function that accepts a void* buffer and size_t buffer_len (with any 33 // other arguments being pre-bound using, e.g., BindFront, a lambda, or a 34 // wrapper). 35 // |result| will be filled in with the bytes returned, and be resized to match 36 // the size of the returned bytestring. 37 // Any data already in |result| will be overridden or deleted. 38 template <class T> 39 void GetBytes(std::vector<char>* result, const std::function<size_t(T*, size_t)>& f); 40 } // namespace pdfClient_utils 41 #endif // MEDIAPROVIDER_PDF_JNI_PDFCLIENT_UTILS_BYTE_VALUE_H_