Struct MessageView

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pub struct MessageView<'a> { /* private fields */ }

Expand description

A zero-copy view over an encoded ProtoCache message.

Implementations§

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impl<'a> MessageView<'a>

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pub fn new(words: &'a [u32]) -> Option<Self>

Parses a message header from words.

The view may borrow a larger enclosing slice; call Self::detect when the exact encoded extent is needed.

Examples found in repository ?

examples/basic.rs (line 9)

3fn main() {
4    let mut buffer = Buffer::new();
5    let name = serialize_str("Ada", &mut buffer).expect("name is encodable");
6    let mut fields = [serialize_scalar(42_i32), name];
7    serialize_message(&mut fields, &mut buffer).expect("message is encodable");
8
9    let view = MessageView::new(buffer.view()).expect("valid ProtoCache message");
10    let id = view.scalar::<i32>(0).expect("id field");
11    let name = view
12        .string(1)
13        .and_then(|value| value.as_str())
14        .expect("UTF-8 name field");
15
16    println!("id={id}, name={name}");
17}

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pub fn from_words(words: &'a [u32]) -> Option<Self>

Alias for Self::new used by generated bindings.

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pub fn raw_words(self) -> &'a [u32]

Returns the minimum message header/body slice retained by this view.

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pub fn detect_len(words: &'a [u32]) -> Option<usize>

Detects the complete encoded message length, including referenced data.

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pub fn detect(words: &'a [u32]) -> Option<&'a [u32]>

Returns the exact encoded slice occupied by a valid message.

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pub fn has_field(self, id: usize) -> bool

Returns whether the message contains the field with zero-based id.

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pub fn field(self, id: usize) -> Option<FieldView<'a>>

Returns a raw field view for zero-based id.

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pub fn expect_field(self, id: usize) -> FieldView<'a>

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pub fn scalar<T: Scalar>(self, id: usize) -> Option<T>

Examples found in repository ?

examples/basic.rs (line 10)

3fn main() {
4    let mut buffer = Buffer::new();
5    let name = serialize_str("Ada", &mut buffer).expect("name is encodable");
6    let mut fields = [serialize_scalar(42_i32), name];
7    serialize_message(&mut fields, &mut buffer).expect("message is encodable");
8
9    let view = MessageView::new(buffer.view()).expect("valid ProtoCache message");
10    let id = view.scalar::<i32>(0).expect("id field");
11    let name = view
12        .string(1)
13        .and_then(|value| value.as_str())
14        .expect("UTF-8 name field");
15
16    println!("id={id}, name={name}");
17}

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pub fn string(self, id: usize) -> Option<StringView<'a>>

Examples found in repository ?

examples/basic.rs (line 12)

3fn main() {
4    let mut buffer = Buffer::new();
5    let name = serialize_str("Ada", &mut buffer).expect("name is encodable");
6    let mut fields = [serialize_scalar(42_i32), name];
7    serialize_message(&mut fields, &mut buffer).expect("message is encodable");
8
9    let view = MessageView::new(buffer.view()).expect("valid ProtoCache message");
10    let id = view.scalar::<i32>(0).expect("id field");
11    let name = view
12        .string(1)
13        .and_then(|value| value.as_str())
14        .expect("UTF-8 name field");
15
16    println!("id={id}, name={name}");
17}