Struct rain_task::Output

pub struct Output {
    pub spec: ObjectSpec,
    // some fields omitted
}

One instance of output DataObject.

The output can be either empty (as is initially), set to represent an existing file, set to represent an existing directory, or written to as a Write. These three are mutually exclusive, set_dir_path and set_file_path may be used only once, and not before or after get_writer.

This object is thread-safe and the internal state is guarded by a mutex. Calling get_writer locks this mutex and holds it until the returned guard is dropped. This means fast (lockless) writes to the Write but you need to make sure your other threads do not starve or deadlock.

Fields

spec: ObjectSpec

The original output description

Methods

impl Output

pub fn stage_directory<P: AsRef<Path>>(&mut self, path: P) -> TaskResult<()>

Submit the given directory as the output contents. Moves the directory to the staging area. You should make sure no files in the directory are open after this operation.

Panics if the output was submitted to and on I/O errors. Returns an error if the output is not a directory type.

pub fn stage_file<P: AsRef<Path>>(&mut self, path: P) -> TaskResult<()>

Submit the given file as the output contents. Moves the file to the staging area. You should make sure that the file is not open after this operation.

Panics if the output was submitted or written to and on I/O errors. Returns an error if the output is not a file directory type.

pub fn stage_input(&mut self, object: &DataInstance) -> TaskResult<()>

Set the output to a given input data object. No data is copied in this case and the governor is informed of the pass-through. The input must belong to the same task (this is not checked). Not allowed if the output was submitted or written to.

pub fn check_directory(&self) -> TaskResult<()>

A shorthand to check that the input is a directory.

Returns Err(TaskError) if not a directory.

pub fn check_blob(&self) -> TaskResult<()>

A shorthand to check that the input is a file or data blob.

Returns Err(TaskError) if not a blob.

pub fn get_content_type(&self) -> String

Get the content-type of the object.

Returns the type set in the executor if any, or the type in the spec. Returns "" for directories.

pub fn set_content_type(     &mut self,     ctype: impl Into<String> ) -> TaskResult<()>

Sets the content type of the object.

Returns an error for directories, incompatible content types and if it has been already set.

pub fn set_user_info(     &mut self,     key: impl Into<String>,     val: UserValue )

Sets the info.user[key] to value.

Any old value is overwriten.

pub fn make_file_backed(&mut self) -> TaskResult<()>

If the output is empty or backed by memory, it is converted to a file. Does nothing if already backed by a file. Returns an error for staged files and inputs.

Trait Implementations

impl Debug for Output

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Display for Output

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Write for Output

fn write(&mut self, buf: &[u8]) -> Result<usize>

Write a buffer into this object, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this write.

fn write_fmt(&mut self, fmt: Arguments) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

Important traits for &'a mut R

impl<'a, R> Read for &'a mut R where
    R: Read + ?Sized, impl<'a, W> Write for &'a mut W where
    W: Write + ?Sized, impl<'a, I> Iterator for &'a mut I where
    I: Iterator + ?Sized,  type Item = <I as Iterator>::Item;

fn by_ref(&mut self) -> &mut Self

Creates a "by reference" adaptor for this instance of Write.