Struct KeywordState 

pub struct KeywordState {
    pub live_indices: Vec<u64>,
    pub index_to_doc: HashMap<u64, [u8; 16]>,
    pub total_writes: u64,
    pub epoch: Epoch,
}

Everything the client knows about one keyword.

Serialised as part of ClientStateTable and encrypted with K_state.

Fields

live_indices: Vec<u64>

Indices of live (non-deleted) entries for this keyword in the EDB. Each index i maps to EDB tag: PRF(K_tag, keyword || i || epoch) This is the authoritative source for O(1) search token generation.

index_to_doc: HashMap<u64, [u8; 16]>

Maps EDB index → document UUID. Used during delete to find which indices to evict from live_indices.

total_writes: u64

Monotonically increasing total write counter (never decremented). Provides unique, fresh indices for every add even after deletes.

epoch: Epoch

Current epoch. Incremented on every delete for this keyword. Old tags (from prior epochs) become permanently unreachable — this is the mechanism behind Backward Security Type-II.

Implementations

impl KeywordState

pub fn new() -> Self

Create fresh state for a keyword that has never been written.

pub fn next_index(&mut self) -> u64

Allocate the next fresh index for an add operation. Returns the index; callers must push it into live_indices themselves.

pub fn record_add(&mut self, index: u64, doc_id: Uuid)

Register a newly written index → doc mapping.

pub fn evict_doc(&mut self, doc_id: Uuid) -> bool

Remove all indices that map to doc_id. Returns true if at least one index was removed (doc was indexed here).

Trait Implementations

impl Clone for KeywordState

fn clone(&self) -> KeywordState

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for KeywordState

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

Formats the value using the given formatter.

impl Default for KeywordState

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for KeywordState

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Drop for KeywordState

fn drop(&mut self)

Executes the destructor for this type.

impl Serialize for KeywordState

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Zeroize for KeywordState

fn zeroize(&mut self)

Zero out this object from memory using Rust intrinsics which ensure the zeroization operation is not “optimized away” by the compiler.