Crate sp_trie

Utility functions to interact with Substrate’s Base-16 Modified Merkle Patricia tree (“trie”).

Modules

• cache
  Trie Cache
• nibble_ops
  Various re-exports from the trie-db crate. Utility methods to work on radix 16 nibble.
• recorder
  Trie recorder
• trie_types
  This module is for non generic definition of trie type. Only the Hasher trait is generic in this case.

Structs

• CompactProof
  Storage proof in compact form.
• HashKey
  Various re-exports from the memory-db crate. Key function that only uses the hash
• KeySpacedDB
  HashDB implementation that append a encoded prefix (unique id bytes) in addition to the prefix of every key value.
• KeySpacedDBMut
  HashDBMut implementation that append a encoded prefix (unique id bytes) in addition to the prefix of every key value.
• LayoutV0
  substrate trie layout
• LayoutV1
  substrate trie layout, with external value nodes.
• NodeCodec
  The Substrate format implementation of NodeCodec. Concrete implementation of a NodeCodecT with SCALE encoding.
• PrefixedKey
  Various re-exports from the memory-db crate. Key function that concatenates prefix and hash.
• Recorder
  Various re-exports from the trie-db crate. Records trie nodes as they pass it.
• StorageProof
  A proof that some set of key-value pairs are included in the storage trie. The proof contains the storage values so that the partial storage backend can be reconstructed by a verifier that does not already have access to the key-value pairs.
• TrieDBIterator
  Various re-exports from the trie-db crate. Iterator for going through all values in the trie in pre-order traversal order.
• TrieDBKeyIterator
  Various re-exports from the trie-db crate. Iterator for going through all of key with values in the trie in pre-order traversal order.
• TrieStream
  The Substrate format implementation of TrieStream. Codec-flavored TrieStream.

Enums

• CompactProofError
  Trie codec reexport, mainly child trie support for trie compact proof. Error for trie node decoding.
• Error
  Our NodeCodec-specific error. Error type used for trie related errors.
• NodePlan
  Various re-exports from the trie-db crate. A NodePlan is a blueprint for decoding a node from a byte slice. The NodePlan is created by parsing an encoded node and can be reused multiple times. This is useful as a Node borrows from a byte slice and this struct does not.
• ValuePlan
  Various re-exports from the trie-db crate. Plan for value representation in NodePlan.
• VerifyError
  Errors that may occur during proof verification. Most of the errors types simply indicate that the proof is invalid with respect to the statement being verified, and the exact error type can be used for debugging.

Statics

• EMPTY_PREFIX
  Various re-exports from the hash-db crate. An empty prefix constant. Can be use when the prefix is not use internally or for root nodes.

Traits

• AsHashDB
  Reexport from hash_db, with genericity set for Hasher trait.
• HashDBT
  Various re-exports from the hash-db crate. Trait modelling datastore keyed by a hash defined by the Hasher.
• KeyFunction
  Various re-exports from the memory-db crate.
• Query
  Various re-exports from the trie-db crate. Description of what kind of query will be made to the trie.
• Trie
  Various re-exports from the trie-db crate. A key-value datastore implemented as a database-backed modified Merkle tree.
• TrieCache
  Various re-exports from the trie-db crate. A cache that can be used to speed-up certain operations when accessing the trie.
• TrieConfiguration
  Various re-exports from the trie-db crate. This trait associates a trie definition with preferred methods. It also contains own default implementations and can be used to allow switching implementation.
• TrieLayout
  Various re-exports from the trie-db crate. Trait with definition of trie layout. Contains all associated trait needed for a trie definition or implementation.
• TrieMut
  Various re-exports from the trie-db crate. A key-value datastore implemented as a database-backed modified Merkle tree.
• TrieRecorder
  Various re-exports from the trie-db crate. A trie recorder that can be used to record all kind of TrieAccess’s.

Functions

• child_delta_trie_root
  Determine a child trie root given a hash DB and delta values. H is the default hasher, but a generic implementation may ignore this type parameter and use other hashers.
• child_trie_root
  Determine a child trie root given its ordered contents, closed form. H is the default hasher, but a generic implementation may ignore this type parameter and use other hashers.
• decode_compact
  Trie codec reexport, mainly child trie support for trie compact proof. Decode a compact proof.
• delta_trie_root
  Determine a trie root given a hash DB and delta values.
• empty_child_trie_root
  Determine the empty child trie root.
• empty_trie_root
  Determine the empty trie root.
• encode_compact
  Trie codec reexport, mainly child trie support for trie compact proof. Encode a compact proof.
• generate_trie_proof
  Create a proof for a subset of keys in a trie.
• prefixed_key
  Various re-exports from the memory-db crate. Derive a database key from hash value of the node (key) and the node prefix.
• read_child_trie_hash
  Read a hash from the child trie.
• read_child_trie_value
  Read a value from the child trie.
• read_child_trie_value_with
  Read a value from the child trie with given query.
• read_trie_value
  Read a value from the trie.
• read_trie_value_with
  Read a value from the trie with given Query.
• verify_trie_proof
  Verify a set of key-value pairs against a trie root and a proof.

Type Definitions

• CError
  Various re-exports from the trie-db crate. Alias accessor to NodeCodec associated Error type from a TrieLayout.
• DBValue
  Various re-exports from the trie-db crate. Database value
• GenericMemoryDB
  Reexport from hash_db, with genericity set for Hasher trait.
• HashDB
  Reexport from hash_db, with genericity set for Hasher trait.
• Lookup
  Querying interface, as in trie_db but less generic.
• MemoryDB
  Reexport from hash_db, with genericity set for Hasher trait. This uses a noops KeyFunction (key addressing must be hashed or using an encoding scheme that avoid key conflict).
• PrefixedMemoryDB
  Reexport from hash_db, with genericity set for Hasher trait. This uses a KeyFunction for prefixing keys internally (avoiding key conflict for non random keys).
• TrieDB
  Persistent trie database read-access interface for the a given hasher.
• TrieDBBuilder
  Builder for creating a TrieDB.
• TrieDBMut
  Persistent trie database write-access interface for the a given hasher.
• TrieDBMutBuilder
  Builder for creating a TrieDBMut.
• TrieError
  TrieDB error over TrieConfiguration trait.
• TrieHash
  Hash type for a trie layout.