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pub use self::WireType::*;
pub const TAG_TYPE_BITS: u32 = 3;
pub const TAG_TYPE_MASK: u32 = (1u32 << TAG_TYPE_BITS) - 1;
pub const FIELD_NUMBER_MAX: u32 = 0x1fffffff;
#[derive(PartialEq, Eq, Clone, Debug)]
pub enum WireType {
WireTypeVarint = 0,
WireTypeFixed64 = 1,
WireTypeLengthDelimited = 2,
WireTypeStartGroup = 3,
WireTypeEndGroup = 4,
WireTypeFixed32 = 5,
}
impl Copy for WireType {}
impl WireType {
pub fn new(n: u32) -> Option<WireType> {
match n {
0 => Some(WireTypeVarint),
1 => Some(WireTypeFixed64),
2 => Some(WireTypeLengthDelimited),
3 => Some(WireTypeStartGroup),
4 => Some(WireTypeEndGroup),
5 => Some(WireTypeFixed32),
_ => None,
}
}
}
#[derive(Clone)]
pub struct Tag {
field_number: u32,
wire_type: WireType,
}
impl Copy for Tag {}
impl Tag {
pub fn value(self) -> u32 {
(self.field_number << TAG_TYPE_BITS) | (self.wire_type as u32)
}
pub fn new(value: u32) -> Option<Tag> {
let wire_type = WireType::new(value & TAG_TYPE_MASK);
if wire_type.is_none() {
return None;
}
let field_number = value >> TAG_TYPE_BITS;
if field_number == 0 {
return None;
}
Some(Tag {
field_number: field_number,
wire_type: wire_type.unwrap(),
})
}
pub fn make(field_number: u32, wire_type: WireType) -> Tag {
assert!(field_number > 0 && field_number <= FIELD_NUMBER_MAX);
Tag {
field_number: field_number,
wire_type: wire_type,
}
}
pub fn unpack(self) -> (u32, WireType) {
(self.field_number(), self.wire_type())
}
fn wire_type(self) -> WireType {
self.wire_type
}
pub fn field_number(self) -> u32 {
self.field_number
}
}