| // Copyright 2019 Google LLC |
| // |
| // 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. |
| |
| #ifndef dap_io_h |
| #define dap_io_h |
| |
| #include <stddef.h> // size_t |
| #include <memory> // std::unique_ptr |
| #include <utility> // std::pair |
| |
| namespace dap { |
| |
| class Closable { |
| public: |
| virtual ~Closable() = default; |
| |
| // isOpen() returns true if the stream has not been closed. |
| virtual bool isOpen() = 0; |
| |
| // close() closes the stream. |
| virtual void close() = 0; |
| }; |
| |
| // Reader is an interface for reading from a byte stream. |
| class Reader : virtual public Closable { |
| public: |
| // read() attempts to read at most n bytes into buffer, returning the number |
| // of bytes read. |
| // read() will block until the stream is closed or at least one byte is read. |
| virtual size_t read(void* buffer, size_t n) = 0; |
| }; |
| |
| // Writer is an interface for writing to a byte stream. |
| class Writer : virtual public Closable { |
| public: |
| // write() writes n bytes from buffer into the stream. |
| // Returns true on success, or false if there was an error or the stream was |
| // closed. |
| virtual bool write(const void* buffer, size_t n) = 0; |
| }; |
| |
| // ReaderWriter is an interface that combines the Reader and Writer interfaces. |
| class ReaderWriter : public Reader, public Writer { |
| // create() returns a ReaderWriter that delegates the interface methods on to |
| // the provided Reader and Writer. |
| // isOpen() returns true if the Reader and Writer both return true for |
| // isOpen(). |
| // close() closes both the Reader and Writer. |
| static std::shared_ptr<ReaderWriter> create(const std::shared_ptr<Reader>&, |
| const std::shared_ptr<Writer>&); |
| }; |
| |
| // pipe() returns a ReaderWriter where the Writer streams to the Reader. |
| // Writes are internally buffered. |
| // Calling close() on either the Reader or Writer will close both ends of the |
| // stream. |
| std::shared_ptr<ReaderWriter> pipe(); |
| |
| // file() wraps file with a ReaderWriter. |
| // If closable is false, then a call to ReaderWriter::close() will not close the |
| // underlying file. |
| std::shared_ptr<ReaderWriter> file(FILE* file, bool closable = true); |
| |
| // file() opens (or creates) the file with the given path. |
| std::shared_ptr<ReaderWriter> file(const char* path); |
| |
| // spy() returns a Reader that copies all reads from the Reader r to the Writer |
| // s, using the given optional prefix. |
| std::shared_ptr<Reader> spy(const std::shared_ptr<Reader>& r, |
| const std::shared_ptr<Writer>& s, |
| const char* prefix = "\n->"); |
| |
| // spy() returns a Writer that copies all writes to the Writer w to the Writer |
| // s, using the given optional prefix. |
| std::shared_ptr<Writer> spy(const std::shared_ptr<Writer>& w, |
| const std::shared_ptr<Writer>& s, |
| const char* prefix = "\n<-"); |
| |
| // writef writes the printf style string to the writer w. |
| bool writef(const std::shared_ptr<Writer>& w, const char* msg, ...); |
| |
| } // namespace dap |
| |
| #endif // dap_io_h |