Description

FileSystem is an abstract file system API, LocalFileSystem is an implementation accessing files on the local machine. SubTreeFileSystem is an implementation that delegates to another implementation after prepending a fixed base path

Factory

LocalFileSystem$create() returns the object and takes no arguments.

SubTreeFileSystem$create() takes the following arguments:

• base_path, a string path

• base_fs, a FileSystem object

S3FileSystem$create() optionally takes arguments:

• anonymous: logical, default FALSE. If true, will not attempt to look up credentials using standard AWS configuration methods.

• access_key, secret_key: authentication credentials. If one is provided, the other must be as well. If both are provided, they will override any AWS configuration set at the environment level.

• session_token: optional string for authentication along with access_key and secret_key

• role_arn: string AWS ARN of an AccessRole. If provided instead of access_key and secret_key, temporary credentials will be fetched by assuming this role.

• session_name: optional string identifier for the assumed role session.

• external_id: optional unique string identifier that might be required when you assume a role in another account.

• load_frequency: integer, frequency (in seconds) with which temporary credentials from an assumed role session will be refreshed. Default is 900 (i.e. 15 minutes)

• region: AWS region to connect to. If omitted, the AWS library will provide a sensible default based on client configuration, falling back to "us-east-1" if no other alternatives are found.

• endpoint_override: If non-empty, override region with a connect string such as "localhost:9000". This is useful for connecting to file systems that emulate S3.

• scheme: S3 connection transport (default "https")

• background_writes: logical, whether OutputStream writes will be issued in the background, without blocking (default TRUE)

Methods

• $GetFileInfo(x): x may be a FileSelector or a character vector of paths. Returns a list of FileInfo

• $CreateDir(path, recursive = TRUE): Create a directory and subdirectories.

• $DeleteDir(path): Delete a directory and its contents, recursively.

• $DeleteDirContents(path): Delete a directory's contents, recursively. Like $DeleteDir(), but doesn't delete the directory itself. Passing an empty path ("") will wipe the entire filesystem tree.

• $DeleteFile(path) : Delete a file.

• $DeleteFiles(paths) : Delete many files. The default implementation issues individual delete operations in sequence.

• $Move(src, dest): Move / rename a file or directory. If the destination exists: if it is a non-empty directory, an error is returned otherwise, if it has the same type as the source, it is replaced otherwise, behavior is unspecified (implementation-dependent).

• $CopyFile(src, dest): Copy a file. If the destination exists and is a directory, an error is returned. Otherwise, it is replaced.

• $OpenInputStream(path): Open an input stream for sequential reading.

• $OpenInputFile(path): Open an input file for random access reading.

• $OpenOutputStream(path): Open an output stream for sequential writing.

• $OpenAppendStream(path): Open an output stream for appending.

Active bindings

• $type_name: string filesystem type name, such as "local", "s3", etc.

• $region: string AWS region, for S3FileSystem and SubTreeFileSystem containing a S3FileSystem

• $base_fs: for SubTreeFileSystem, the FileSystem it contains

• $base_path: for SubTreeFileSystem, the path in $base_fs which is considered root in this SubTreeFileSystem.