// Copyright 2018 Google Inc. // // 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 // // http://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. // /////////////////////////////////////////////////////////////////////////////// #ifndef TINK_UTIL_ISTREAM_INPUT_STREAM_H_ #define TINK_UTIL_ISTREAM_INPUT_STREAM_H_ #include #include #include #include "tink/input_stream.h" #include "tink/util/status.h" #include "tink/util/statusor.h" namespace crypto { namespace tink { namespace util { // An InputStream that reads from a std::istream. class IstreamInputStream : public crypto::tink::InputStream { public: // Constructs an InputStream that will read from the 'input' istream, // using a buffer of the specified size, if any (if no legal 'buffer_size' // is given, a reasonable default will be used). explicit IstreamInputStream(std::unique_ptr input, int buffer_size = -1); ~IstreamInputStream() override; crypto::tink::util::StatusOr Next(const void** data) override; void BackUp(int count) override; int64_t Position() const override; private: util::Status status_; std::unique_ptr input_; std::unique_ptr buffer_; const int buffer_size_; int64_t position_; // current position in the istream (from the beginning) // Counters that describe the state of the data in buffer_. int count_in_buffer_; // # of bytes available in buffer_ int count_backedup_; // # of bytes available in buffer_ that were backed up int buffer_offset_; // offset at which the returned bytes start in buffer_ }; } // namespace util } // namespace tink } // namespace crypto #endif // TINK_UTIL_ISTREAM_INPUT_STREAM_H_