/**
* Creates a new directory with the given name and location
*
* @param name The fully qualified name of the new directory.
* @return MICROBIT_OK on success, MICROBIT_INVALID_PARAMETER if the path is invalid, or MICROBT_NO_RESOURCES if the FileSystem is full.
*/
int MicroBitFileSystem::createDirectory(char const *name)
{
DirectoryEntry* directory; // Directory holding this file.
DirectoryEntry* dirent; // Entry in the direcoty of this file.
// Protect against accidental re-initialisation
if ((status & MBFS_STATUS_INITIALISED) == 0)
return MICROBIT_NOT_SUPPORTED;
// Reject invalid filenames.
if (!isValidFilename(name))
return MICROBIT_INVALID_PARAMETER;
// Determine the directory for this file.
directory = getDirectoryOf(name);
if (directory == NULL)
return MICROBIT_INVALID_PARAMETER;
// Find the DirectoryEntry associated with the given name (if it exists).
// We don't permit files or directories with the same name.
dirent = getDirectoryEntry(name, directory);
if (dirent)
return MICROBIT_INVALID_PARAMETER;
dirent = createFile(name, directory, true);
if (dirent == NULL)
return MICROBIT_NO_RESOURCES;
return MICROBIT_OK;
}
std::string prefixSanityFix(std::string prefix) {
prefix.erase(std::remove_if(prefix.begin(), prefix.end(), ::isspace), prefix.end());
prefix.erase(std::remove(prefix.begin(), prefix.end(), '/'), prefix.end());
prefix.erase(std::remove(prefix.begin(), prefix.end(), '\\'), prefix.end());
prefix.erase(std::remove(prefix.begin(), prefix.end(), '.'), prefix.end());
prefix.erase(std::remove(prefix.begin(), prefix.end(), ':'), prefix.end());
if (!isValidFilename(prefix)) {
return
{
};
}
return prefix;
}
/**
* Open a new file, and obtain a new file handle (int) to
* read/write/seek the file. The flags are:
* - MB_READ : read from the file.
* - MB_WRITE : write to the file.
* - MB_CREAT : create a new file, if it doesn't already exist.
*
* If a file is opened that doesn't exist, and MB_CREAT isn't passed,
* an error is returned, otherwise the file is created.
*
* @param filename name of the file to open, must contain only printable characters.
* @param flags One or more of MB_READ, MB_WRITE or MB_CREAT.
* @return return the file handle,MICROBIT_NOT_SUPPORTED if the file system has
* not been initialised MICROBIT_INVALID_PARAMETER if the filename is
* too large, MICROBIT_NO_RESOURCES if the file system is full.
*
* @code
* MicroBitFileSystem f();
* int fd = f.open("test.txt", MB_WRITE|MB_CREAT);
* if(fd<0)
* print("file open error");
* @endcode
*/
int MicroBitFileSystem::open(char const * filename, uint32_t flags)
{
FileDescriptor *file; // File Descriptor of this file.
DirectoryEntry* directory; // Directory holding this file.
DirectoryEntry* dirent; // Entry in the direcoty of this file.
int id; // FileDescriptor id to be return to the caller.
// Protect against accidental re-initialisation
if ((status & MBFS_STATUS_INITIALISED) == 0)
return MICROBIT_NOT_SUPPORTED;
// Reject invalid filenames.
if(!isValidFilename(filename))
return MICROBIT_INVALID_PARAMETER;
// Determine the directory for this file.
directory = getDirectoryOf(filename);
if (directory == NULL)
return MICROBIT_INVALID_PARAMETER;
// Find the DirectoryEntry assoviate with the given file (if it exists).
dirent = getDirectoryEntry(filename, directory);
// Only permit files to be opened once...
// also, detemrine a valid ID for this open file as we go.
file = openFiles;
id = 0;
while (file && dirent)
{
if (file->dirent == dirent)
return MICROBIT_NOT_SUPPORTED;
if (file->id == id)
{
id++;
file = openFiles;
continue;
}
file = file->next;
}
if (dirent == NULL)
{
// If the file doesn't exist, and we haven't been asked to create it, then there's nothing we can do.
if (!(flags & MB_CREAT))
return MICROBIT_INVALID_PARAMETER;
dirent = createFile(filename, directory, false);
if (dirent == NULL)
return MICROBIT_NO_RESOURCES;
}
// Try to add a new FileDescriptor into this directory.
file = new FileDescriptor;
if (file == NULL)
return MICROBIT_NO_RESOURCES;
// Populate the FileDescriptor
file->flags = (flags & ~(MB_CREAT));
file->id = id;
file->length = dirent->flags == MBFS_DIRECTORY_ENTRY_NEW ? 0 : dirent->length;
file->seek = (flags & MB_APPEND) ? file->length : 0;
file->dirent = dirent;
file->directory = directory;
file->cacheLength = 0;
// Add the file descriptor to the chain of open files.
file->next = openFiles;
openFiles = file;
// Return the FileDescriptor id to the user
return file->id;
}