hashdb

Documentation

Index

• Variables
• type ChildResolver
• type Config
• type Database
  • func New(diskdb ethdb.Database, config *Config, resolver ChildResolver) *Database
  • func (db *Database) Cap(limit common.StorageSize) error
  • func (db *Database) Close() error
  • func (db *Database) Commit(node common.Hash, report bool) error
  • func (db *Database) Dereference(root common.Hash)
  • func (db *Database) Initialized(genesisRoot common.Hash) bool
  • func (db *Database) Node(hash common.Hash) ([]byte, error)
  • func (db *Database) Nodes() []common.Hash
  • func (db *Database) Reader(root common.Hash) (*reader, error)
  • func (db *Database) Reference(child common.Hash, parent common.Hash)
  • func (db *Database) Scheme() string
  • func (db *Database) Size() (common.StorageSize, common.StorageSize)
  • func (db *Database) Update(root common.Hash, parent common.Hash, block uint64, ...) error

Variables

var Defaults = &Config{

	CleanCacheSize: 0,
}

Defaults is the default setting for database if it's not specified. Notably, clean cache is disabled explicitly,

Types

type ChildResolver

type ChildResolver interface {
	ForEach(node []byte, onChild func(common.Hash))
}

ChildResolver defines the required method to decode the provided trie node and iterate the children on top.

type Config

type Config struct {
	CleanCacheSize int // Maximum memory allowance (in bytes) for caching clean nodes
}

Config contains the settings for database.

type Database

type Database struct {
	// contains filtered or unexported fields
}

Database is an intermediate write layer between the trie data structures and the disk database. The aim is to accumulate trie writes in-memory and only periodically flush a couple tries to disk, garbage collecting the remainder.

Note, the trie Database is **not** thread safe in its mutations, but it **is** thread safe in providing individual, independent node access. The rationale behind this split design is to provide read access to RPC handlers and sync servers even while the trie is executing expensive garbage collection.

func New

func New(diskdb ethdb.Database, config *Config, resolver ChildResolver) *Database

New initializes the hash-based node database.

func (*Database) Cap

func (db *Database) Cap(limit common.StorageSize) error

Cap iteratively flushes old but still referenced trie nodes until the total memory usage goes below the given threshold.

Note, this method is a non-synchronized mutator. It is unsafe to call this concurrently with other mutators.

func (*Database) Close

func (db *Database) Close() error

Close closes the trie database and releases all held resources.

func (*Database) Commit

func (db *Database) Commit(node common.Hash, report bool) error

Commit iterates over all the children of a particular node, writes them out to disk, forcefully tearing down all references in both directions. As a side effect, all pre-images accumulated up to this point are also written.

Note, this method is a non-synchronized mutator. It is unsafe to call this concurrently with other mutators.

func (*Database) Dereference

func (db *Database) Dereference(root common.Hash)

Dereference removes an existing reference from a root node.

func (*Database) Initialized

func (db *Database) Initialized(genesisRoot common.Hash) bool

Initialized returns an indicator if state data is already initialized in hash-based scheme by checking the presence of genesis state.

func (*Database) Node

func (db *Database) Node(hash common.Hash) ([]byte, error)

Node retrieves an encoded cached trie node from memory. If it cannot be found cached, the method queries the persistent database for the content.

func (*Database) Nodes

func (db *Database) Nodes() []common.Hash

Nodes retrieves the hashes of all the nodes cached within the memory database. This method is extremely expensive and should only be used to validate internal states in test code.

func (*Database) Reader

func (db *Database) Reader(root common.Hash) (*reader, error)

Reader retrieves a node reader belonging to the given state root. An error will be returned if the requested state is not available.

func (*Database) Reference

func (db *Database) Reference(child common.Hash, parent common.Hash)

Reference adds a new reference from a parent node to a child node. This function is used to add reference between internal trie node and external node(e.g. storage trie root), all internal trie nodes are referenced together by database itself.

func (*Database) Scheme

func (db *Database) Scheme() string

Scheme returns the node scheme used in the database.

func (*Database) Size

func (db *Database) Size() (common.StorageSize, common.StorageSize)

Size returns the current storage size of the memory cache in front of the persistent database layer.

The first return will always be 0, representing the memory stored in unbounded diff layers above the dirty cache. This is only available in pathdb.

func (*Database) Update

func (db *Database) Update(root common.Hash, parent common.Hash, block uint64, nodes *trienode.MergedNodeSet, states *triestate.Set) error

Update inserts the dirty nodes in provided nodeset into database and link the account trie with multiple storage tries if necessary.