newmyfiles.cpp

#include "newmyfiles.h"

bool myfiles_fs::read(char * &result, int &lenght) {
    fs.open(filename, ios::in | ios::binary);
    fs.seekp(0, ios::end);
    lenght = fs.tellp();
    fs.seekp(0, ios::beg);  // back to start
    result = new char[lenght + 1];
    fs.read(result, lenght);
    result[lenght] = '\0';
    fs.close();
    return true;
}

bool myfiles_fs::write(char * result, int lenght) {
    fs.open(filename, ios::out | ios::binary);
    fs.write(result, lenght);
    fs.close();
    return true;
}

bool myfiles_v::read(char * &result, int &lenght) {
    fl = fopen(filename, "rb");
    fseek(fl, 0, SEEK_END);
    lenght = ftell(fl);
    fseek(fl, 0, SEEK_SET); // back to start
    result = new char[lenght + 1];
    fread(result, 1, lenght, fl);
    result[lenght] = '\0';
    fclose(fl);
    return true;
}

bool myfiles_v::write(char * result, int lenght) {
    fl = fopen(filename, "wb");
    fwrite(result, 1, lenght, fl);
    fclose(fl);
    return true;
}

bool myfiles_wapi::read(char * &result, int &lenght) {
    hFile = CreateFile(filename, GENERIC_READ | GENERIC_WRITE, 0, nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
    if (hFile == INVALID_HANDLE_VALUE)
        return false;

    DWORD dwFileSize = GetFileSize(hFile, nullptr);
    if (dwFileSize == INVALID_FILE_SIZE) {
        CloseHandle(hFile);
        return false;
    }

    result = new char[dwFileSize];
    lenght = dwFileSize;
    DWORD dwCount;
    ReadFile(hFile, result, dwFileSize, &dwCount, NULL);

    if (dwCount != dwFileSize)
        return false;

    return true;
}

bool myfiles_wapi::write(char * result, int lenght) {
    DWORD dwPtr = SetFilePointer(hFile, 0, NULL, FILE_BEGIN);
    if (dwPtr == INVALID_SET_FILE_POINTER)
        return false;

    DWORD lpNumberOfBytesWritten;
    WriteFile(hFile, result, lenght, &lpNumberOfBytesWritten, NULL);

    if (lpNumberOfBytesWritten != lenght)
        return false;

    if (!SetEndOfFile(hFile))
        return false;

    return true;
}

myfiles_wapi::~myfiles_wapi() {
    CloseHandle(hFile);
}

bool myfiles_mm::read(char * &result, int &lenght) {
    hFile = CreateFile(filename, GENERIC_READ | GENERIC_WRITE, 0, nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
    if (hFile == INVALID_HANDLE_VALUE)
        return false;

    dwFileSize = GetFileSize(hFile, nullptr);
    if (dwFileSize == INVALID_FILE_SIZE || dwFileSize == 0) {
        CloseHandle(hFile);
        return false;
    }

    hMapping = CreateFileMapping(hFile, nullptr, PAGE_READWRITE, 0, 0, nullptr);
    if (hMapping == nullptr) {
        CloseHandle(hFile);
        return false;
    }

    dataPtr = MapViewOfFile(hMapping, FILE_MAP_ALL_ACCESS, 0, 0, dwFileSize);
    if (dataPtr == nullptr) {
        CloseHandle(hMapping);
        CloseHandle(hFile);
        return false;
    }

    lenght = dwFileSize;
    result = new char[lenght + 1];
    result = strncpy(result, (char*)dataPtr, lenght);
    result[lenght] = '\0';

    return true;
}

bool myfiles_mm::write(char * result, int lenght) {
    if (lenght > dwFileSize) {/* remapping to increase the size */
        UnmapViewOfFile(dataPtr);
        if (hMapping && hMapping != nullptr)
            CloseHandle(hMapping);

        hMapping = CreateFileMapping(hFile, nullptr, PAGE_READWRITE | SEC_COMMIT, 0, lenght, nullptr);
        if (hMapping == nullptr) {
            CloseHandle(hFile);
            return false;
        }

        dataPtr = MapViewOfFile(hMapping, FILE_MAP_ALL_ACCESS, 0, 0, lenght);
        if (dataPtr == nullptr) {
            CloseHandle(hMapping);
            CloseHandle(hFile);
            return false;
        }
    }

    strcpy((char*)dataPtr, result);
    SetFilePointer(hFile, lenght, NULL, FILE_BEGIN);

    return 0;
}

myfiles_mm::~myfiles_mm() {
    UnmapViewOfFile(dataPtr);
    CloseHandle(hMapping);
    SetEndOfFile(hFile);
    CloseHandle(hFile);
}