file_io.h

// Copyright 2021-2025 The Aerospace Corporation.
// This file is a part of SatCat5, licensed under CERN-OHL-W v2 or later.
// File I/O wrappers
 
#pragma once
 
#include <cstdio>
#include <string>
#include <satcat5/io_core.h>
 
namespace satcat5 {
    namespace io {
        class FileWriter : public satcat5::io::Writeable {
        public:
            explicit FileWriter(
                const char* filename = 0,
                bool close_on_finalize = false);
            virtual ~FileWriter();
 
            void open(const char* filename);
            void close();
 
            void seek(unsigned offset);
 
            // Required and optional function overrides.
            unsigned get_write_space() const override;
            void write_bytes(unsigned nbytes, const void* src);
            bool write_finalize() override;
            void write_abort() override;
        protected:
            void write_next(u8 data) override;
            const bool m_close_on_finalize;
            FILE* m_file;           // Current file object
            unsigned m_last_commit; // Position of last commit
        };
 
        class FileReader : public satcat5::io::Readable {
        public:
            explicit FileReader(
                const char* filename = 0,
                bool close_on_finalize = false);
            virtual ~FileReader();
 
            void open(const char* filename, unsigned len = 0);
            void close();
 
            // Required and optional function overrides.
            unsigned get_read_ready() const override;
            bool read_bytes(unsigned nbytes, void* dst);
            bool read_consume(unsigned nbytes);
            void read_finalize() override;
        protected:
            u8 read_next() override;
            const bool m_close_on_finalize;
            FILE* m_file;       // Current file object
            unsigned m_rem;     // Remaining readable bytes
        };
    }
}