Struct FieldSnapshot 

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

The metadata fields of one dictionary and their values.

Implementations

impl<'a> FieldSnapshot<'a>

pub fn new( dictionary: Option<&'a AppDataDictionary>, catalogue: &[ApplicationComponentDefinition], ) -> Result<Self, FieldError>

List the fields of dictionary’s registry, labelling each application field with the first catalogue definition of its ID when that definition is valid, as registration does. None is a group without a dictionary. ComponentRegistry::iter already skips an entry missing any of its three member policies, so every listed field has all three.

pub fn fields(&self) -> &[MetadataFieldDescriptor]

The group’s fields in component ID order.

pub fn field(&self, name: &str) -> Option<&MetadataFieldDescriptor>

The listed field named name. Well-known IDs sort before application IDs, so a well-known field wins a name clash.

pub fn registry(&self) -> &ComponentRegistry

The registry the fields come from.

pub fn resolve( &self, field: &MetadataFieldRef, ) -> Result<&MetadataFieldDescriptor, FieldError>

The listed field with field’s ID; its name is ignored.

pub fn value( &self, field: &MetadataFieldRef, ) -> Result<Option<MetadataValue>, FieldError>

The value of field, None when absent.

pub fn values( &self, fields: &[MetadataFieldRef], ) -> Result<Vec<MetadataFieldValue>, FieldError>

The values of fields, in request order. Each record carries the listed ref, whatever name the request used.

pub fn map_value( &self, field: &MetadataFieldRef, key: &FieldKey, ) -> Result<Option<FieldValue>, FieldError>

The value under key of the map field.

pub fn user_data( &self, fields: Option<&[MetadataFieldRef]>, inbox_ids: Option<&[InboxId]>, ) -> Result<BTreeMap<InboxId, Vec<UserFieldValue>>, FieldError>

Per-inbox values of user fields. fields = None selects every user field in ID order; inbox_ids = None selects the DM_MEMBERS pair when present (only a DM holds it) and the GROUP_MEMBERSHIP inboxes otherwise. Every selected inbox has an entry, empty when it holds no selected value. A field whose value does not decode under its committed type contributes no values; a field named twice is refused.

pub fn field_write( &self, field: &MetadataFieldRef, mutation: &ComponentMutation, ) -> Result<FieldWrite, FieldError>

Encode mutation of field under the field’s committed type.

pub fn user_data_writes( &self, values: &[UserFieldUpdate], ) -> Result<Vec<FieldWrite>, FieldError>

Encode the writer’s own-key sets and clears of user fields.

pub fn resolve_writes( &self, values: Option<&AppDataDictionary>, own: InboxId, writes: &[FieldWrite], ) -> Result<Vec<(ComponentId, AppDataUpdateOperation)>, FieldError>

The AppDataUpdate operations that carry out writes for the inbox own, given the current component values in values: this snapshot’s dictionary with any pending updates applied.

Types and the field list come from this snapshot, which must be the committed one. Each write is refused if its field is gone or changed type. Every payload is applied to its current value, so bounds, UTF-8, and key presence fail here rather than in the commit. A write that changes nothing is dropped: a clear of an absent key, a removal of an absent component, or an update whose result equals the current bytes.

pub fn write_operations( &self, values: Option<&AppDataDictionary>, own: InboxId, writes: &[FieldWrite], ) -> Result<Vec<(ComponentId, AppDataUpdateOperation)>, FieldError>

The operations of writes as Self::resolve_writes gives them, keeping an update whose result equals the current bytes: the operations a receiver would check if they were published.