Struct holochain_core_types::chain_header::ChainHeader

pub struct ChainHeader { /* fields omitted */ }

ChainHeader of a source chain "Item" The address of the ChainHeader is used as the Item's key in the source chain hash table ChainHeaders are linked to next header in chain and next header of same type in chain

Implementations

impl ChainHeader

pub fn new(
    entry_type: &EntryType,
    entry_address: &Address,
    provenances: &[Provenance],
    link: &Option<Address>,
    link_same_type: &Option<Address>,
    link_update_delete: &Option<Address>,
    timestamp: &Iso8601
) -> Self

build a new ChainHeader from a chain, entry type and entry. a ChainHeader is immutable, but the chain is mutable if chain.push() is used. this means that a header becomes invalid and useless as soon as the chain is mutated the only valid usage of a header is to immediately push it onto a chain in a Pair. normally (outside unit tests) the generation of valid headers is internal to the chain::SourceChain trait and should not need to be handled manually

@see chain::entry::Entry

pub fn entry_type(&self) -> &EntryType

entry_type getter

pub fn timestamp(&self) -> &Iso8601

timestamp getter

pub fn link(&self) -> Option<Address>

link getter

pub fn entry_address(&self) -> &Address

entry_address getter

pub fn link_same_type(&self) -> Option<Address>

link_same_type getter

pub fn link_update_delete(&self) -> Option<Address>

link_update_delete getter

pub fn provenances(&self) -> &Vec<Provenance>

entry_signature getter

Trait Implementations

impl AddressableContent for ChainHeader

fn content(&self) -> Content

the Content that would be stored in a ContentAddressableStorage the default implementation covers anything that implements From for JsonString

fn try_from_content(content: &Content) -> JsonResult<Self>

restore/deserialize the original struct/type from serialized Content the default implementation covers anything that implements From for Foo

fn address(&self) -> HashString

the Address the Content would be available at once stored in a ContentAddressableStorage default implementation is provided as hashing Content with sha256 the default implementation should cover most use-cases it is critical that there are no hash collisions across all stored AddressableContent it is recommended to implement an "address space" prefix for address algorithms that don't offer strong cryptographic guarantees like sha et. al.

impl Clone for ChainHeader

fn clone(&self) -> ChainHeader

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ChainHeader

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ChainHeader

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
    __D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl Eq for ChainHeader

impl<'a> From<&'a ChainHeader> for JsonString

fn from(v: &ChainHeader) -> JsonString

Performs the conversion.

impl From<ChainHeader> for JsonString

fn from(v: ChainHeader) -> JsonString

Performs the conversion.

impl Hash for ChainHeader

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, 

Feeds a slice of this type into the given Hasher.

impl PartialEq<ChainHeader> for ChainHeader

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl Serialize for ChainHeader

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error> where
    __S: Serializer, 

Serialize this value into the given Serde serializer.

impl StructuralEq for ChainHeader

impl StructuralPartialEq for ChainHeader

impl<'a> TryFrom<&'a JsonString> for ChainHeader

type Error = JsonError

The type returned in the event of a conversion error.

fn try_from(json_string: &JsonString) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<JsonString> for ChainHeader

type Error = JsonError

The type returned in the event of a conversion error.

fn try_from(json_string: JsonString) -> Result<Self, Self::Error>

Performs the conversion.