Directory.hpp

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// ======================================================================
// \title Os/Directory.hpp
// \brief Os::Directory interface definition
// ======================================================================
 
#ifndef _OS_DIRECTORY_HPP_
#define _OS_DIRECTORY_HPP_
 
#include <FpConfig.hpp>
#include <Os/Os.hpp>
#include <Fw/Types/String.hpp>
 
namespace Os {
 
struct DirectoryHandle {};
 
class DirectoryInterface {
  public:
    enum Status {
        OP_OK, 
        DOESNT_EXIST, 
        NO_PERMISSION, 
        NOT_OPENED, 
        NOT_DIR, 
        NO_MORE_FILES, 
        FILE_LIMIT, 
        BAD_DESCRIPTOR, 
        ALREADY_EXISTS, 
        NOT_SUPPORTED, 
        OTHER_ERROR, 
    };
 
    enum OpenMode {
        READ,               
        CREATE_IF_MISSING,  
        CREATE_EXCLUSIVE,   
        MAX_OPEN_MODE       
    };
 
    DirectoryInterface() = default;
 
    virtual ~DirectoryInterface() = default;
 
    DirectoryInterface(const DirectoryInterface& other) = delete;
 
    DirectoryInterface& operator=(const DirectoryInterface& other) = delete;
 
    virtual DirectoryHandle* getHandle() = 0;
 
    static DirectoryInterface* getDelegate(DirectoryHandleStorage& aligned_new_memory);
 
 
    // -----------------------------------------------------------------
    // Directory operations to be implemented by an OSAL implementation
    // -----------------------------------------------------------------
    // These functions are to be overridden in each OS implementation
    // See an example in in Os/Posix/Directory.hpp
 
    virtual Status open(const char* path, OpenMode mode) = 0;
 
    virtual Status rewind() = 0;
 
    virtual Status read(char * fileNameBuffer, FwSizeType buffSize) = 0;
 
    // virtual Status read(Fw::StringBase& filename) = 0;
 
    virtual void close() = 0;
 
 
};
 
class Directory final : public DirectoryInterface {
  public:
    Directory();
 
    ~Directory() final;
 
    DirectoryHandle* getHandle() override;
 
 
    // ------------------------------------------------------------
    // Implementation-specific Directory member functions
    // ------------------------------------------------------------
    // These functions are overridden in each OS implementation (e.g. in Os/Posix/Directory.hpp)
 
    Status open(const char* path, OpenMode mode) override;
 
    bool isOpen();
 
    Status rewind() override;
 
    Status read(char * fileNameBuffer, FwSizeType buffSize) override;
 
 
    void close() override;
 
 
    // ------------------------------------------------------------
    // Common functions built on top of OS-specific functions
    // ------------------------------------------------------------
 
    Status read(Fw::StringBase& filename);
 
    Status readDirectory(Fw::String filenameArray[], const FwSizeType arraySize, FwSizeType& filenameCount);
 
    Status getFileCount(FwSizeType& fileCount);
 
  private:
    bool m_is_open; 
 
  private:
    // This section is used to store the implementation-defined Directory handle. To Os::Directory and fprime, this type is
    // opaque and thus normal allocation cannot be done. Instead, we allow the implementor to store then handle in
    // the byte-array here and set `handle` to that address for storage.
    alignas(FW_HANDLE_ALIGNMENT) DirectoryHandleStorage m_handle_storage;  
    DirectoryInterface& m_delegate;
};
 
}
 
#endif