Struct Message

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pub struct Message(/* private fields */);

Expand description

Message primitive

Implementations§

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impl Message

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pub fn new() -> Option<Self>

Creates empty message

Returns None if unable to allocate memory

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pub fn with_capaicty(size: usize) -> Option<Self>

Creates message with pre-allocated buffer of provided size

Returns None if unable to allocate memory

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pub fn dup(&self) -> Option<Self>

Creates new copy of the message.

Returns None if unable to allocate memory

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pub fn reserve(&mut self, capacity: usize) -> Result<(), ErrorCode>

Reserves additional space to accommodate specified capacity

Does nothing, if message already has enough space.

Returns error only if reallocation failed

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pub fn len(&self) -> usize

Returns length of message body

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pub fn capaciy(&self) -> usize

Returns capacity of message body

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pub fn clear(&mut self)

Clears content of the message.

Note that it is primarily sets length of body to 0. Allocated capacity remains the same.

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pub fn truncate(&mut self, len: usize)

Shortens body length, keeping len starting elements

Has no effect if len is equal or greater to current body’s length

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pub fn truncate_start(&mut self, len: usize)

Shortens body length, keeping len last elements inside

Has no effect if len is equal or greater to current body’s length

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pub fn body(&self) -> &[u8]

Returns reference to the body content

Returns reference to the header content

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pub fn pop_u16(&mut self) -> Option<u16>

Extracts u16 from the end of body, encoding it into native byte order

Returns None if there is not enough space

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pub fn pop_u32(&mut self) -> Option<u32>

Extracts u32 from the end of body, encoding it into native byte order

Returns None if there is not enough space

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pub fn pop_u64(&mut self) -> Option<u64>

Extracts u64 from the end of body, encoding it into native byte order

Returns None if there is not enough space

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pub fn pop_front_u16(&mut self) -> Option<u16>

Extracts u16 from the start of body, encoding it into native byte order

Returns None if there is not enough space

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pub fn pop_front_u32(&mut self) -> Option<u32>

Extracts u32 from the start of body, encoding it into native byte order

Returns None if there is not enough space

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pub fn pop_front_u64(&mut self) -> Option<u64>

Extracts u64 from the start of body, encoding it into native byte order

Returns None if there is not enough space

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pub fn append_u16(&mut self, value: u16) -> Result<(), ErrorCode>

Appends u16 to the end of body, encoding it into network byte order

Returns Err if there is not enough space

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pub fn append_u32(&mut self, value: u32) -> Result<(), ErrorCode>

Appends u32 to the end of body, encoding it into network byte order

Returns Err if there is not enough space

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pub fn append_u64(&mut self, value: u64) -> Result<(), ErrorCode>

Appends u64 to the end of body, encoding it into network byte order

Returns Err if there is not enough space

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pub fn append(&mut self, bytes: &[u8]) -> Result<(), ErrorCode>

Appends bytes to the message body.

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pub fn insert_u16(&mut self, value: u16) -> Result<(), ErrorCode>

Inserts u16 at the start of body, encoding it into network byte order

Returns Err if there is not enough space

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pub fn insert_u32(&mut self, value: u32) -> Result<(), ErrorCode>

Inserts u32 at the start of body, encoding it into network byte order

Returns Err if there is not enough space

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pub fn insert_u64(&mut self, value: u64) -> Result<(), ErrorCode>

Inserts u64 at the start of body, encoding it into network byte order

Returns Err if there is not enough space

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pub fn insert(&mut self, bytes: &[u8]) -> Result<(), ErrorCode>

Inserts bytes at the start of the body.

Methods from Deref<Target = NonNull<nng_msg>>§

1.25.0 · Source

pub unsafe fn as_ref<'a>(&self) -> &'a T

Returns a shared reference to the value. If the value may be uninitialized, as_uninit_ref must be used instead.

For the mutable counterpart see as_mut.

§Safety

When calling this method, you have to ensure that the pointer is convertible to a reference.

§Examples

use std::ptr::NonNull;

let mut x = 0u32;
let ptr = NonNull::new(&mut x as *mut _).expect("ptr is null!");

let ref_x = unsafe { ptr.as_ref() };
println!("{ref_x}");

1.25.0 · Source

pub unsafe fn as_mut<'a>(&mut self) -> &'a mut T

Returns a unique reference to the value. If the value may be uninitialized, as_uninit_mut must be used instead.

For the shared counterpart see as_ref.

§Safety

When calling this method, you have to ensure that the pointer is convertible to a reference.

§Examples

use std::ptr::NonNull;

let mut x = 0u32;
let mut ptr = NonNull::new(&mut x).expect("null pointer");

let x_ref = unsafe { ptr.as_mut() };
assert_eq!(*x_ref, 0);
*x_ref += 2;
assert_eq!(*x_ref, 2);