Struct CompactSize64

pub struct CompactSize64(/* private fields */);

An arbitrary CompactSize-encoded field. Used for flags, arbitrary counts, and sizes that span multiple blocks.

Security

Deserialized sizes must be validated before being used to allocate memory.

Most allocation sizes should use CompactSizeMessage, because it is limited to MAX_PROTOCOL_MESSAGE_LEN.

Serialization Examples

use zebra_chain::serialization::{CompactSize64, ZcashSerialize, MAX_PROTOCOL_MESSAGE_LEN};
use std::convert::TryFrom;

let size = CompactSize64::from(0x12);
let buf = size.zcash_serialize_to_vec().unwrap();
assert_eq!(buf, b"\x12");

let size = CompactSize64::from(0xfd);
let buf = size.zcash_serialize_to_vec().unwrap();
assert_eq!(buf, b"\xfd\xfd\x00");

let size = CompactSize64::from(0xaafd);
let buf = size.zcash_serialize_to_vec().unwrap();
assert_eq!(buf, b"\xfd\xfd\xaa");

let max_size = u64::try_from(MAX_PROTOCOL_MESSAGE_LEN).unwrap();
let size = CompactSize64::from(max_size);
let buf = size.zcash_serialize_to_vec().unwrap();
assert_eq!(buf, b"\xfe\x00\x00\x20\x00");

let size = CompactSize64::from(max_size + 1);
let buf = size.zcash_serialize_to_vec().unwrap();
assert_eq!(buf, b"\xfe\x01\x00\x20\x00");

let size = CompactSize64::from(0xbbaafd);
let buf = size.zcash_serialize_to_vec().unwrap();
assert_eq!(buf, b"\xfe\xfd\xaa\xbb\x00");

let size = CompactSize64::from(0x22ccbbaafd);
let buf = size.zcash_serialize_to_vec().unwrap();
assert_eq!(buf, b"\xff\xfd\xaa\xbb\xcc\x22\x00\x00\x00");

Deserialization Examples

use zebra_chain::serialization::{CompactSize64, ZcashDeserializeInto, MAX_PROTOCOL_MESSAGE_LEN};
use std::{convert::TryFrom, io::Cursor};

assert_eq!(
    CompactSize64::from(0x12),
    Cursor::new(b"\x12").zcash_deserialize_into().unwrap(),
);

assert_eq!(
    CompactSize64::from(0xfd),
    Cursor::new(b"\xfd\xfd\x00").zcash_deserialize_into().unwrap(),
);

assert_eq!(
    CompactSize64::from(0xaafd),
    Cursor::new(b"\xfd\xfd\xaa").zcash_deserialize_into().unwrap(),
);

let max_size = u64::try_from(MAX_PROTOCOL_MESSAGE_LEN).unwrap();
assert_eq!(
    CompactSize64::from(max_size),
    Cursor::new(b"\xfe\x00\x00\x20\x00").zcash_deserialize_into().unwrap(),
);

assert_eq!(
    CompactSize64::from(max_size + 1),
    Cursor::new(b"\xfe\x01\x00\x20\x00").zcash_deserialize_into().unwrap(),
);

assert_eq!(
    CompactSize64::from(0xbbaafd),
    Cursor::new(b"\xfe\xfd\xaa\xbb\x00").zcash_deserialize_into().unwrap(),
);

assert_eq!(
    CompactSize64::from(0x22ccbbaafd),
    Cursor::new(b"\xff\xfd\xaa\xbb\xcc\x22\x00\x00\x00").zcash_deserialize_into().unwrap(),
);

Trait Implementations

impl Clone for CompactSize64

fn clone(&self) -> CompactSize64

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CompactSize64

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

Formats the value using the given formatter.

impl From<CompactSize64> for u64

fn from(size: CompactSize64) -> Self

Converts to this type from the input type.

impl From<u64> for CompactSize64

fn from(size: u64) -> Self

Converts to this type from the input type.

impl Hash for CompactSize64

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for CompactSize64

fn cmp(&self, other: &CompactSize64) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for CompactSize64

fn eq(&self, other: &CompactSize64) -> 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 PartialOrd for CompactSize64

fn partial_cmp(&self, other: &CompactSize64) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl ZcashDeserialize for CompactSize64

fn zcash_deserialize<R: Read>(reader: R) -> Result<Self, SerializationError>

Try to read self from the given reader.

impl ZcashSerialize for CompactSize64

fn zcash_serialize<W: Write>(&self, writer: W) -> Result<(), Error>

Write self to the given writer using the canonical format.

fn zcash_serialize_to_vec(&self) -> Result<Vec<u8>, Error>

Helper function to construct a vec to serialize the current struct into

fn zcash_serialized_size(&self) -> usize

Get the size of self by using a fake writer.

impl Copy for CompactSize64

impl Eq for CompactSize64

impl StructuralPartialEq for CompactSize64