Struct OpenOptions

pub struct OpenOptions { /* private fields */ }

Flags and parameters which control how a PosixMq message queue is opened or created.

Implementations

impl OpenOptions

pub fn readonly() -> Self

Open message queue for receiving only.

pub fn writeonly() -> Self

Open message queue for sending only.

pub fn readwrite() -> Self

Open message queue both for sending and receiving.

pub fn mode(&mut self, mode: u32) -> &mut Self

Set permissions to create the queue with.

Some bits might be cleared by the process’s umask when creating the queue, and unknown bits are ignored.

This field is ignored if the queue already exists or should not be created. If this method is not called, queues are created with mode 600.

pub fn max_msg_len(&mut self, max_msg_len: usize) -> &mut Self

Set the maximum size of each message.

recv() will fail if given a buffer smaller than this value.

If max_msg_len and capacity are both zero (or not set), the queue will be created with a maximum length and capacity decided by the operating system.
If this value is specified, capacity should also be, or opening the message queue might fail.

pub fn capacity(&mut self, capacity: usize) -> &mut Self

Set the maximum number of messages in the queue.

When the queue is full, further send()s will either block or fail with an error of type ErrorKind::WouldBlock.

If both capacity and max_msg_len are zero (or not set), the queue will be created with a maximum length and capacity decided by the operating system.
If this value is specified, max_msg_len should also be, or opening the message queue might fail.

pub fn create(&mut self) -> &mut Self

Create message queue if it doesn’t exist.

pub fn create_new(&mut self) -> &mut Self

Create a new queue, failing if the queue already exists.

pub fn existing(&mut self) -> &mut Self

Require the queue to already exist, failing if it doesn’t.

pub fn nonblocking(&mut self) -> &mut Self

Open the message queue in non-blocking mode.

This must be done if you want to use the message queue with mio.

pub fn open<N: AsRef<[u8]> + ?Sized>(&self, name: &N) -> Result<PosixMq, Error>

Open a queue with the specified options.

If the name doesn’t start with a ‘/’, one will be prepended.

Errors

• Queue doesn’t exist (ENOENT) => ErrorKind::NotFound
• Name is just “/” (ENOENT) or is empty => ErrorKind::NotFound
• Queue already exists (EEXISTS) => ErrorKind::AlreadyExists
• Not permitted to open in this mode (EACCESS) => ErrorKind::PermissionDenied
• More than one ‘/’ in name (EACCESS) => ErrorKind::PermissionDenied
• Invalid capacities (EINVAL) => ErrorKind::InvalidInput
• Capacities too high (EMFILE) => ErrorKind::Other
• Posix message queues are disabled (ENOSYS) => ErrorKind::Other
• Name contains ‘\0’ => ErrorKind::InvalidInput
• Name is too long (ENAMETOOLONG) => ErrorKind::Other
• Unlikely (ENFILE, EMFILE, ENOMEM, ENOSPC) => ErrorKind::Other
• Possibly other

pub fn open_c(&self, name: &CStr) -> Result<PosixMq, Error>

Open a queue with the specified options and without inspecting name or allocating.

This can on NetBSD be used to access message queues with names that doesn’t start with a ‘/’.

Errors

• Queue doesn’t exist (ENOENT) => ErrorKind::NotFound
• Name is just “/” (ENOENT) => ErrorKind::NotFound
• Queue already exists (EEXISTS) => ErrorKind::AlreadyExists
• Not permitted to open in this mode (EACCESS) => ErrorKind::PermissionDenied
• More than one ‘/’ in name (EACCESS) => ErrorKind::PermissionDenied
• Invalid capacities (EINVAL) => ErrorKind::InvalidInput
• Posix message queues are disabled (ENOSYS) => ErrorKind::Other
• Name is empty (EINVAL) => ErrorKind::InvalidInput
• Name is too long (ENAMETOOLONG) => ErrorKind::Other
• Unlikely (ENFILE, EMFILE, ENOMEM, ENOSPC) => ErrorKind::Other
• Possibly other

Trait Implementations

impl Clone for OpenOptions

fn clone(&self) -> OpenOptions

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for OpenOptions

fn fmt(&self, fmtr: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for OpenOptions

fn eq(&self, other: &OpenOptions) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for OpenOptions

impl Eq for OpenOptions

impl StructuralPartialEq for OpenOptions