merkle_patricia_tree

v0.2.5

merkle_patricia_tree v0.2.5 MerklePatriciaTree.DB behaviour

Defines a general key-value storage to back and persist out Merkle Patricia Trie. This is generally LevelDB in the community, but for testing, we’ll generally use :ets.

We define a callback that can be implemented by a number of potential backends.

Link to this section Summary

Types

db()
db_name()
db_ref()
t()
value()

Functions

get(arg, key)

Retrieves a key from the database

get!(db, key)

Retrieves a key from the database, but raises if that key does not exist

put!(arg, key, value)

Stores a key in the database

Callbacks

get(db_ref, arg1)
init(db_name)
put!(db_ref, arg1, value)

Link to this section Types

Link to this type db() 
db() :: {t, db_ref}
Link to this type db_name() 
db_name() :: any
Link to this type db_ref() 
db_ref() :: any
Link to this type t() 
t() :: module
Link to this type value() 
value() :: binary

Link to this section Functions

Link to this function get(arg, key) 
get(db, MerklePatriciaTree.Trie.key) ::
  {:ok, value} |
  :not_found

Retrieves a key from the database.

Examples 

iex> db = MerklePatriciaTree.Test.random_ets_db()
iex> MerklePatriciaTree.DB.get(db, "name")
:not_found

iex> db = MerklePatriciaTree.Test.random_ets_db()
iex> MerklePatriciaTree.DB.put!(db, "name", "bob")
iex> MerklePatriciaTree.DB.get(db, "name")
{:ok, "bob"}
Link to this function get!(db, key) 
get!(db, MerklePatriciaTree.Trie.key) :: value

Retrieves a key from the database, but raises if that key does not exist.

Examples 

iex> db = MerklePatriciaTree.Test.random_ets_db()
iex> MerklePatriciaTree.DB.get!(db, "name")
** (MerklePatriciaTree.DB.KeyNotFoundError) cannot find key `name`

iex> db = MerklePatriciaTree.Test.random_ets_db()
iex> MerklePatriciaTree.DB.put!(db, "name", "bob")
iex> MerklePatriciaTree.DB.get!(db, "name")
"bob"
Link to this function put!(arg, key, value) 
put!(db, MerklePatriciaTree.Trie.key, value) :: :ok

Stores a key in the database.

Examples 

## Examples

iex> db = MerklePatriciaTree.Test.random_ets_db()
iex> MerklePatriciaTree.DB.put!(db, "name", "bob")
iex> MerklePatriciaTree.DB.get(db, "name")
{:ok, "bob"}
iex> MerklePatriciaTree.DB.put!(db, "name", "tom")
iex> MerklePatriciaTree.DB.get(db, "name")
{:ok, "tom"}

Link to this section Callbacks

Link to this callback get(db_ref, arg1) 
get(db_ref, MerklePatriciaTree.Trie.key) ::
  {:ok, value} |
  :not_found
Link to this callback init(db_name) 
init(db_name) :: db
Link to this callback put!(db_ref, arg1, value) 
put!(db_ref, MerklePatriciaTree.Trie.key, value) :: :ok