Struct RoDatabaseUnique

pub struct RoDatabaseUnique<KC, DC, Tag = (), C = DefaultComparator> { /* private fields */ }

Read-only wrapper for heed::Database.

The type tag can be used to distinguish between different database envs. Databases and txns opened within an Env will also be tagged, ensuring that txns created in an Env can only be used for DBs created/opened by the same Env.

Implementations

impl<KC, DC, Tag, C> RoDatabaseUnique<KC, DC, Tag, C>

pub fn contains_key<'a, 'txn>( &self, rotxn: &'txn RoTxn<'_, Tag>, key: &'a KC::EItem, ) -> Result<bool, TryGet>

where KC: BytesEncode<'a>, LazyDecode<DC>: BytesDecode<'txn>,

Check if the provided key exists in the db. The stored value is not decoded, if it exists.

pub fn first<'txn>( &self, rotxn: &'txn RoTxn<'_, Tag>, ) -> Result<Option<(KC::DItem, DC::DItem)>, First>

where KC: BytesDecode<'txn>, DC: BytesDecode<'txn>,

pub fn iter<'a, 'txn>( &'a self, rotxn: &'txn RoTxn<'a, Tag>, ) -> Result<impl FallibleIterator<Item = (KC::DItem, DC::DItem), Error = IterItem> + 'txn, IterInit>

where KC: BytesDecode<'txn>, DC: BytesDecode<'txn>,

pub fn iter_keys<'a, 'txn>( &'a self, rotxn: &'txn RoTxn<'a, Tag>, ) -> Result<impl FallibleIterator<Item = KC::DItem, Error = IterItem> + 'txn, IterInit>

where KC: BytesDecode<'txn>, LazyDecode<DC>: BytesDecode<'txn>,

pub fn last<'txn>( &self, rotxn: &'txn RoTxn<'_, Tag>, ) -> Result<Option<(KC::DItem, DC::DItem)>, Last>

where KC: BytesDecode<'txn>, DC: BytesDecode<'txn>,

pub fn lazy_decode(&self) -> RoDatabaseUnique<KC, LazyDecode<DC>, Tag, C>

pub fn len(&self, rotxn: &RoTxn<'_, Tag>) -> Result<u64, Len>

pub fn name(&self) -> &str

pub fn range<'a, 'range, 'txn, R>( &'a self, rotxn: &'txn RoTxn<'a, Tag>, range: &'range R, ) -> Result<impl FallibleIterator<Item = (KC::DItem, DC::DItem), Error = IterItem> + 'txn, RangeInit>

where KC: BytesDecode<'txn> + BytesEncode<'range>, DC: BytesDecode<'txn>, R: RangeBounds<KC::EItem>, C: Comparator,

pub fn rev_iter<'a, 'txn>( &'a self, rotxn: &'txn RoTxn<'a, Tag>, ) -> Result<impl FallibleIterator<Item = (KC::DItem, DC::DItem), Error = IterItem> + 'txn, IterInit>

where KC: BytesDecode<'txn>, DC: BytesDecode<'txn>,

pub fn try_get<'a, 'txn>( &self, rotxn: &'txn RoTxn<'_, Tag>, key: &'a KC::EItem, ) -> Result<Option<DC::DItem>, TryGet>

where KC: BytesEncode<'a>, DC: BytesDecode<'txn>,

pub fn get<'a, 'txn>( &self, rotxn: &'txn RoTxn<'_, Tag>, key: &'a KC::EItem, ) -> Result<DC::DItem, Get>

where KC: BytesEncode<'a>, DC: BytesDecode<'txn>,

pub fn watch(&self) -> &Receiver<()>

Available on crate feature observe only.

Receive notifications when the DB is updated

Trait Implementations

impl<KC, DC, Tag, C> Clone for RoDatabaseUnique<KC, DC, Tag, C>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<KC, DC, Tag, C> Database for RoDatabaseUnique<KC, DC, Tag, C>

type KC = KC

type DC = DC

fn name(&self) -> &str

impl<KC, DC, Tag, C> Debug for RoDatabaseUnique<KC, DC, Tag, C>

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

Formats the value using the given formatter.