Struct dharmadb::persistence::Persistence

pub struct Persistence<K: ResourceKey> { /* fields omitted */ }

Encapsulates all functionality that involves reading and writing to File System.

Implementations

impl<K> Persistence<K> where
    K: ResourceKey, 

pub fn create<V: ResourceValue>(
    options: DharmaOpts
) -> Result<Persistence<K>, Errors>

Create the persistence layer that will be used to orchestrate read / writes with the File System.

Arguments

• option - The Dharma options configuration.

Returns

A result that resolves:

• Ok - The created persistence instance.
• Err - Error encountered while creating persistence layer.

pub fn get<V: ResourceValue>(&mut self, key: &K) -> Result<Option<V>, Errors>

Get the value associated with the specified key.

Arguments

• key - The key whose value to query.

returns

Result that resolves:

• Ok - Optional that may contain the result value.
• Err - Error that occurred while reading the value.

pub fn insert<V: ResourceValue>(
    &mut self,
    key: K,
    value: V
) -> Result<(), Errors>

Associate the supplied value with the key. This operation writes the record to the Write Ahead Log so that it can be recovered in case of failure.

Arguments

• key - The key.
• value - The value to save associated with the key.

Returns

A result that resolves:

• Ok - If value was successfully saved.
• Err - Error that occurred while saving value.

pub fn flush<V: ResourceValue>(
    &mut self,
    values: &Vec<(K, V)>
) -> Result<(), Errors>

Flush the list of key value pairs to disk. This method assumes that list is already sorted by key and writes the list to disk as an SSTable.

Arguments

• values - List of Key-Value pairs that need to be written to disk.

Returns

Result that signifies:

• Ok - If values were flushed to disk successfully.
• Err - Error that occurred while saving value.

pub fn recover<T: ResourceKey, U: ResourceValue>(
    options: DharmaOpts
) -> Result<Vec<(T, U)>, Errors>

Attempt to recover data from existing WAL. This operation does not ensure database recovery and could lead to data loss. WAL is deleted after this operation.

pub fn delete(&mut self, key: &K) -> Result<(), Errors>

Trait Implementations

impl<K> Drop for Persistence<K> where
    K: ResourceKey, 

fn drop(&mut self)

Executes the destructor for this type.