file_win32_wrapper.h

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namespace file_win32_helpers {
    t_filesize get_size(HANDLE p_handle);
    void seek(HANDLE p_handle,t_sfilesize p_position,file::t_seek_mode p_mode);
    void fillOverlapped(OVERLAPPED & ol, HANDLE myEvent, t_filesize s);
    void writeOverlappedPass(HANDLE handle, HANDLE myEvent, t_filesize position, const void * in,DWORD inBytes, abort_callback & abort);
    void writeOverlapped(HANDLE handle, HANDLE myEvent, t_filesize & position, const void * in, size_t inBytes, abort_callback & abort);
    void writeStreamOverlapped(HANDLE handle, HANDLE myEvent, const void * in, size_t inBytes, abort_callback & abort);
    DWORD readOverlappedPass(HANDLE handle, HANDLE myEvent, t_filesize position, void * out, DWORD outBytes, abort_callback & abort);
    size_t readOverlapped(HANDLE handle, HANDLE myEvent, t_filesize & position, void * out, size_t outBytes, abort_callback & abort);
    size_t readStreamOverlapped(HANDLE handle, HANDLE myEvent, void * out, size_t outBytes, abort_callback & abort);
    HANDLE createFile(LPCTSTR lpFileName, DWORD dwDesiredAccess, DWORD dwShareMode, LPSECURITY_ATTRIBUTES lpSecurityAttributes, DWORD dwCreationDisposition, DWORD dwFlagsAndAttributes, HANDLE hTemplateFile, abort_callback & abort);
};

template<bool p_seekable,bool p_writeable>
class file_win32_wrapper_t : public file {
public:
    file_win32_wrapper_t(HANDLE p_handle) : m_handle(p_handle), m_position(0)
    {
    }

    static file::ptr g_CreateFile(const char * p_path,DWORD p_access,DWORD p_sharemode,LPSECURITY_ATTRIBUTES p_security_attributes,DWORD p_createmode,DWORD p_flags,HANDLE p_template) {
        SetLastError(NO_ERROR);
        HANDLE handle = uCreateFile(p_path,p_access,p_sharemode,p_security_attributes,p_createmode,p_flags,p_template);
        if (handle == INVALID_HANDLE_VALUE) {
            const DWORD code = GetLastError();
            if (p_access & GENERIC_WRITE) win32_file_write_failure(code, p_path);
            else exception_io_from_win32(code);
        }
        try {
            return g_create_from_handle(handle);
        } catch(...) {CloseHandle(handle); throw;}
    }

    static service_ptr_t<file> g_create_from_handle(HANDLE p_handle) {
        return new service_impl_t<file_win32_wrapper_t<p_seekable,p_writeable> >(p_handle);
    }


    void reopen(abort_callback & p_abort) {seek(0,p_abort);}

    void write(const void * p_buffer,t_size p_bytes,abort_callback & p_abort) {
        if (!p_writeable) throw exception_io_denied();

        PFC_STATIC_ASSERT(sizeof(t_size) >= sizeof(DWORD));

        t_size bytes_written_total = 0;

        if (sizeof(t_size) == sizeof(DWORD)) {
            p_abort.check_e();
            DWORD bytes_written = 0;
            SetLastError(ERROR_SUCCESS);
            if (!WriteFile(m_handle,p_buffer,(DWORD)p_bytes,&bytes_written,0)) exception_io_from_win32(GetLastError());
            if (bytes_written != p_bytes) throw exception_io("Write failure");
            bytes_written_total = bytes_written;
            m_position += bytes_written;
        } else {
            while(bytes_written_total < p_bytes) {
                p_abort.check_e();
                DWORD bytes_written = 0;
                DWORD delta = (DWORD) pfc::min_t<t_size>(p_bytes - bytes_written_total, 0x80000000);
                SetLastError(ERROR_SUCCESS);
                if (!WriteFile(m_handle,(const t_uint8*)p_buffer + bytes_written_total,delta,&bytes_written,0)) exception_io_from_win32(GetLastError());
                if (bytes_written != delta) throw exception_io("Write failure");
                bytes_written_total += bytes_written;
                m_position += bytes_written;
            }
        }
    }
    
    t_size read(void * p_buffer,t_size p_bytes,abort_callback & p_abort) {
        PFC_STATIC_ASSERT(sizeof(t_size) >= sizeof(DWORD));
        
        t_size bytes_read_total = 0;
        if (sizeof(t_size) == sizeof(DWORD)) {
            p_abort.check_e();
            DWORD bytes_read = 0;
            SetLastError(ERROR_SUCCESS);
            if (!ReadFile(m_handle,p_buffer,pfc::downcast_guarded<DWORD>(p_bytes),&bytes_read,0)) exception_io_from_win32(GetLastError());
            bytes_read_total = bytes_read;
            m_position += bytes_read;
        } else {
            while(bytes_read_total < p_bytes) {
                p_abort.check_e();
                DWORD bytes_read = 0;
                DWORD delta = (DWORD) pfc::min_t<t_size>(p_bytes - bytes_read_total, 0x80000000);
                SetLastError(ERROR_SUCCESS);
                if (!ReadFile(m_handle,(t_uint8*)p_buffer + bytes_read_total,delta,&bytes_read,0)) exception_io_from_win32(GetLastError());
                bytes_read_total += bytes_read;
                m_position += bytes_read;
                if (bytes_read != delta) break;
            }
        }
        return bytes_read_total;
    }


    t_filesize get_size(abort_callback & p_abort) {
        p_abort.check_e();
        return file_win32_helpers::get_size(m_handle);
    }

    t_filesize get_position(abort_callback & p_abort) {
        p_abort.check_e();
        return m_position;
    }
    
    void resize(t_filesize p_size,abort_callback & p_abort) {
        if (!p_writeable) throw exception_io_denied();
        p_abort.check_e();
        if (m_position != p_size) {
            file_win32_helpers::seek(m_handle,p_size,file::seek_from_beginning);
        }
        SetLastError(ERROR_SUCCESS);
        if (!SetEndOfFile(m_handle)) {
            DWORD code = GetLastError();
            if (m_position != p_size) try {file_win32_helpers::seek(m_handle,m_position,file::seek_from_beginning);} catch(...) {}
            exception_io_from_win32(code);
        }
        if (m_position > p_size) m_position = p_size;
        if (m_position != p_size) file_win32_helpers::seek(m_handle,m_position,file::seek_from_beginning);
    }


    void seek(t_filesize p_position,abort_callback & p_abort) {
        if (!p_seekable) throw exception_io_object_not_seekable();
        p_abort.check_e();
        if (p_position > file_win32_helpers::get_size(m_handle)) throw exception_io_seek_out_of_range();
        file_win32_helpers::seek(m_handle,p_position,file::seek_from_beginning);
        m_position = p_position;
    }

    bool can_seek() {return p_seekable;}
    bool get_content_type(pfc::string_base & out) {return false;}
    bool is_in_memory() {return false;}
    void on_idle(abort_callback & p_abort) {p_abort.check_e();}
    
    t_filetimestamp get_timestamp(abort_callback & p_abort) {
        p_abort.check_e();
        FlushFileBuffers(m_handle);
        SetLastError(ERROR_SUCCESS);
        t_filetimestamp temp;
        if (!GetFileTime(m_handle,0,0,(FILETIME*)&temp)) exception_io_from_win32(GetLastError());
        return temp;
    }

    bool is_remote() {return false;}
    ~file_win32_wrapper_t() {CloseHandle(m_handle);}
protected:
    HANDLE m_handle;
    t_filesize m_position;
};

template<bool p_writeable>
class file_win32_wrapper_overlapped_t : public file {
public:
    file_win32_wrapper_overlapped_t(HANDLE file) : m_handle(file), m_position() {
        WIN32_OP( (m_event = CreateEvent(NULL, TRUE, FALSE, NULL)) != NULL );
    }
    ~file_win32_wrapper_overlapped_t() {CloseHandle(m_event); CloseHandle(m_handle);}
    void write(const void * p_buffer,t_size p_bytes,abort_callback & p_abort) {
        if (!p_writeable) throw exception_io_denied();
        return file_win32_helpers::writeOverlapped(m_handle, m_event, m_position, p_buffer, p_bytes, p_abort);
    }
    t_size read(void * p_buffer,t_size p_bytes,abort_callback & p_abort) {
        return file_win32_helpers::readOverlapped(m_handle, m_event, m_position, p_buffer, p_bytes, p_abort);
    }

    void reopen(abort_callback & p_abort) {seek(0,p_abort);}


    t_filesize get_size(abort_callback & p_abort) {
        p_abort.check_e();
        return file_win32_helpers::get_size(m_handle);
    }

    t_filesize get_position(abort_callback & p_abort) {
        p_abort.check_e();
        return m_position;
    }
    
    void resize(t_filesize p_size,abort_callback & p_abort) {
        if (!p_writeable) throw exception_io_denied();
        p_abort.check_e();
        file_win32_helpers::seek(m_handle,p_size,file::seek_from_beginning);
        SetLastError(ERROR_SUCCESS);
        if (!SetEndOfFile(m_handle)) {
            DWORD code = GetLastError();
            exception_io_from_win32(code);
        }
        if (m_position > p_size) m_position = p_size;
    }


    void seek(t_filesize p_position,abort_callback & p_abort) {
        p_abort.check_e();
        if (p_position > file_win32_helpers::get_size(m_handle)) throw exception_io_seek_out_of_range();
        // file_win32_helpers::seek(m_handle,p_position,file::seek_from_beginning);
        m_position = p_position;
    }

    bool can_seek() {return true;}
    bool get_content_type(pfc::string_base & out) {return false;}
    bool is_in_memory() {return false;}
    void on_idle(abort_callback & p_abort) {p_abort.check_e();}
    
    t_filetimestamp get_timestamp(abort_callback & p_abort) {
        p_abort.check_e();
        FlushFileBuffers(m_handle);
        SetLastError(ERROR_SUCCESS);
        t_filetimestamp temp;
        if (!GetFileTime(m_handle,0,0,(FILETIME*)&temp)) exception_io_from_win32(GetLastError());
        return temp;
    }

    bool is_remote() {return false;}
    

    static file::ptr g_CreateFile(const char * p_path,DWORD p_access,DWORD p_sharemode,LPSECURITY_ATTRIBUTES p_security_attributes,DWORD p_createmode,DWORD p_flags,HANDLE p_template) {
        p_flags |= FILE_FLAG_OVERLAPPED;
        SetLastError(NO_ERROR);
        HANDLE handle = uCreateFile(p_path,p_access,p_sharemode,p_security_attributes,p_createmode,p_flags,p_template);
        if (handle == INVALID_HANDLE_VALUE) {
            const DWORD code = GetLastError();
            if (p_access & GENERIC_WRITE) win32_file_write_failure(code, p_path);
            else exception_io_from_win32(code);
        }
        try {
            return g_create_from_handle(handle);
        } catch(...) {CloseHandle(handle); throw;}
    }

    static file::ptr g_create_from_handle(HANDLE p_handle) {
        return new service_impl_t<file_win32_wrapper_overlapped_t<p_writeable> >(p_handle);
    }

protected:
    HANDLE m_event, m_handle;
    t_filesize m_position;
};