indexers

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Published: Jun 7, 2017 License: ISC Imports: 16 Imported by: 0

README

indexers

Build Status ISC License GoDoc

Package indexers implements optional block chain indexes.

These indexes are typically used to enhance the amount of information available via an RPC interface.

Supported Indexers

  • Transaction-by-hash (txbyhashidx) Index
    • Creates a mapping from the hash of each transaction to the block that contains it along with its offset and length within the serialized block
  • Transaction-by-address (txbyaddridx) Index
    • Creates a mapping from every address to all transactions which either credit or debit the address
    • Requires the transaction-by-hash index
  • Address-ever-seen (existsaddridx) Index
    • Stores a key with an empty value for every address that has ever existed and was seen by the client
    • Requires the transaction-by-hash index

Installation

$ go get -u github.com/decred/dcrd/blockchain/indexers

License

Package indexers is licensed under the copyfree ISC License.

Documentation

Overview

Package indexers implements optional block chain indexes.

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func DisableLog

func DisableLog()

DisableLog disables all library log output. Logging output is disabled by default until either UseLogger or SetLogWriter are called.

func DropAddrIndex

func DropAddrIndex(db database.DB) error

DropAddrIndex drops the address index from the provided database if it exists.

func DropExistsAddrIndex

func DropExistsAddrIndex(db database.DB) error

DropExistsAddrIndex drops the exists address index from the provided database if it exists.

func DropTxIndex

func DropTxIndex(db database.DB) error

DropTxIndex drops the transaction index from the provided database if it exists. Since the address index relies on it, the address index will also be dropped when it exists.

func UseLogger

func UseLogger(logger btclog.Logger)

UseLogger uses a specified Logger to output package logging info. This should be used in preference to SetLogWriter if the caller is also using btclog.

Types

type AddrIndex

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

AddrIndex implements a transaction by address index. That is to say, it supports querying all transactions that reference a given address because they are either crediting or debiting the address. The returned transactions are ordered according to their order of appearance in the blockchain. In other words, first by block height and then by offset inside the block.

In addition, support is provided for a memory-only index of unconfirmed transactions such as those which are kept in the memory pool before inclusion in a block.

func NewAddrIndex

func NewAddrIndex(db database.DB, chainParams *chaincfg.Params) *AddrIndex

NewAddrIndex returns a new instance of an indexer that is used to create a mapping of all addresses in the blockchain to the respective transactions that involve them.

It implements the Indexer interface which plugs into the IndexManager that in turn is used by the blockchain package. This allows the index to be seamlessly maintained along with the chain.

func (*AddrIndex) AddUnconfirmedTx

func (idx *AddrIndex) AddUnconfirmedTx(tx *dcrutil.Tx, utxoView *blockchain.UtxoViewpoint)

AddUnconfirmedTx adds all addresses related to the transaction to the unconfirmed (memory-only) address index.

NOTE: This transaction MUST have already been validated by the memory pool before calling this function with it and have all of the inputs available in the provided utxo view. Failure to do so could result in some or all addresses not being indexed.

This function is safe for concurrent access.

func (*AddrIndex) ConnectBlock

func (idx *AddrIndex) ConnectBlock(dbTx database.Tx, block, parent *dcrutil.Block,
	view *blockchain.UtxoViewpoint) error

ConnectBlock is invoked by the index manager when a new block has been connected to the main chain. This indexer adds a mapping for each address the transactions in the block involve.

This is part of the Indexer interface.

func (*AddrIndex) Create

func (idx *AddrIndex) Create(dbTx database.Tx) error

Create is invoked when the indexer manager determines the index needs to be created for the first time. It creates the bucket for the address index.

This is part of the Indexer interface.

func (*AddrIndex) DisconnectBlock

func (idx *AddrIndex) DisconnectBlock(dbTx database.Tx, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error

DisconnectBlock is invoked by the index manager when a block has been disconnected from the main chain. This indexer removes the address mappings each transaction in the block involve.

This is part of the Indexer interface.

func (*AddrIndex) Init

func (idx *AddrIndex) Init() error

Init is only provided to satisfy the Indexer interface as there is nothing to initialize for this index.

This is part of the Indexer interface.

func (*AddrIndex) Key

func (idx *AddrIndex) Key() []byte

Key returns the database key to use for the index as a byte slice.

This is part of the Indexer interface.

func (*AddrIndex) Name

func (idx *AddrIndex) Name() string

Name returns the human-readable name of the index.

This is part of the Indexer interface.

func (*AddrIndex) NeedsInputs

func (idx *AddrIndex) NeedsInputs() bool

NeedsInputs signals that the index requires the referenced inputs in order to properly create the index.

This implements the NeedsInputser interface.

func (*AddrIndex) RemoveUnconfirmedTx

func (idx *AddrIndex) RemoveUnconfirmedTx(hash *chainhash.Hash)

RemoveUnconfirmedTx removes the passed transaction from the unconfirmed (memory-only) address index.

This function is safe for concurrent access.

func (*AddrIndex) TxRegionsForAddress

func (idx *AddrIndex) TxRegionsForAddress(dbTx database.Tx, addr dcrutil.Address, numToSkip, numRequested uint32, reverse bool) ([]database.BlockRegion, uint32, error)

TxRegionsForAddress returns a slice of block regions which identify each transaction that involves the passed address according to the specified number to skip, number requested, and whether or not the results should be reversed. It also returns the number actually skipped since it could be less in the case where there are not enough entries.

NOTE: These results only include transactions confirmed in blocks. See the UnconfirmedTxnsForAddress method for obtaining unconfirmed transactions that involve a given address.

This function is safe for concurrent access.

func (*AddrIndex) UnconfirmedTxnsForAddress

func (idx *AddrIndex) UnconfirmedTxnsForAddress(addr dcrutil.Address) []*dcrutil.Tx

UnconfirmedTxnsForAddress returns all transactions currently in the unconfirmed (memory-only) address index that involve the passed address. Unsupported address types are ignored and will result in no results.

This function is safe for concurrent access.

type AssertError

type AssertError string

AssertError identifies an error that indicates an internal code consistency issue and should be treated as a critical and unrecoverable error.

func (AssertError) Error

func (e AssertError) Error() string

Error returns the assertion error as a huma-readable string and satisfies the error interface.

type ExistsAddrIndex

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

ExistsAddrIndex implements an "ever seen" address index. Any address that is ever seen in a block or in the mempool is stored here as a key. Values are empty. Once an address is seen, it is never removed from this store. This results in a local version of this database that is consistent only for this peer, but at minimum contains all the addresses seen on the blockchain itself.

In addition, support is provided for a memory-only index of unconfirmed transactions such as those which are kept in the memory pool before inclusion in a block.

func NewExistsAddrIndex

func NewExistsAddrIndex(db database.DB, chainParams *chaincfg.Params) *ExistsAddrIndex

NewExistsAddrIndex returns a new instance of an indexer that is used to create a mapping of all addresses ever seen.

It implements the Indexer interface which plugs into the IndexManager that in turn is used by the blockchain package. This allows the index to be seamlessly maintained along with the chain.

func (*ExistsAddrIndex) AddUnconfirmedTx

func (idx *ExistsAddrIndex) AddUnconfirmedTx(tx *wire.MsgTx)

AddUnconfirmedTx is the exported form of addUnconfirmedTx.

This function is safe for concurrent access.

func (*ExistsAddrIndex) ConnectBlock

func (idx *ExistsAddrIndex) ConnectBlock(dbTx database.Tx, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error

ConnectBlock is invoked by the index manager when a new block has been connected to the main chain. This indexer adds a key for each address the transactions in the block involve.

This is part of the Indexer interface.

func (*ExistsAddrIndex) Create

func (idx *ExistsAddrIndex) Create(dbTx database.Tx) error

Create is invoked when the indexer manager determines the index needs to be created for the first time. It creates the bucket for the address index.

This is part of the Indexer interface.

func (*ExistsAddrIndex) DisconnectBlock

func (idx *ExistsAddrIndex) DisconnectBlock(dbTx database.Tx, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error

DisconnectBlock is invoked by the index manager when a block has been disconnected from the main chain. Note that the exists address manager never removes addresses.

This is part of the Indexer interface.

func (*ExistsAddrIndex) ExistsAddress

func (idx *ExistsAddrIndex) ExistsAddress(addr dcrutil.Address) (bool, error)

ExistsAddress is the concurrency safe, exported function that returns whether or not an address has been seen before.

func (*ExistsAddrIndex) ExistsAddresses

func (idx *ExistsAddrIndex) ExistsAddresses(addrs []dcrutil.Address) ([]bool, error)

ExistsAddresses is the concurrency safe, exported function that returns whether or not each address in a slice of addresses has been seen before.

func (*ExistsAddrIndex) Init

func (idx *ExistsAddrIndex) Init() error

Init is only provided to satisfy the Indexer interface as there is nothing to initialize for this index.

This is part of the Indexer interface.

func (*ExistsAddrIndex) Key

func (idx *ExistsAddrIndex) Key() []byte

Key returns the database key to use for the index as a byte slice.

This is part of the Indexer interface.

func (*ExistsAddrIndex) Name

func (idx *ExistsAddrIndex) Name() string

Name returns the human-readable name of the index.

This is part of the Indexer interface.

func (*ExistsAddrIndex) NeedsInputs

func (idx *ExistsAddrIndex) NeedsInputs() bool

NeedsInputs signals that the index requires the referenced inputs in order to properly create the index.

This implements the NeedsInputser interface.

type Indexer

type Indexer interface {
	// Key returns the key of the index as a byte slice.
	Key() []byte

	// Name returns the human-readable name of the index.
	Name() string

	// Create is invoked when the indexer manager determines the index needs
	// to be created for the first time.
	Create(dbTx database.Tx) error

	// Init is invoked when the index manager is first initializing the
	// index.  This differs from the Create method in that it is called on
	// every load, including the case the index was just created.
	Init() error

	// ConnectBlock is invoked when the index manager is notified that a new
	// block has been connected to the main chain.
	ConnectBlock(dbTx database.Tx, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error

	// DisconnectBlock is invoked when the index manager is notified that a
	// block has been disconnected from the main chain.
	DisconnectBlock(dbTx database.Tx, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error
}

Indexer provides a generic interface for an indexer that is managed by an index manager such as the Manager type provided by this package.

type Manager

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

Manager defines an index manager that manages multiple optional indexes and implements the blockchain.IndexManager interface so it can be seamlessly plugged into normal chain processing.

func NewManager

func NewManager(db database.DB, enabledIndexes []Indexer, params *chaincfg.Params) *Manager

NewManager returns a new index manager with the provided indexes enabled.

The manager returned satisfies the blockchain.IndexManager interface and thus cleanly plugs into the normal blockchain processing path.

func (*Manager) ConnectBlock

func (m *Manager) ConnectBlock(dbTx database.Tx, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error

ConnectBlock must be invoked when a block is extending the main chain. It keeps track of the state of each index it is managing, performs some sanity checks, and invokes each indexer.

This is part of the blockchain.IndexManager interface.

func (*Manager) DisconnectBlock

func (m *Manager) DisconnectBlock(dbTx database.Tx, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error

DisconnectBlock must be invoked when a block is being disconnected from the end of the main chain. It keeps track of the state of each index it is managing, performs some sanity checks, and invokes each indexer to remove the index entries associated with the block.

This is part of the blockchain.IndexManager interface.

func (*Manager) Init

func (m *Manager) Init(chain *blockchain.BlockChain) error

Init initializes the enabled indexes. This is called during chain initialization and primarily consists of catching up all indexes to the current best chain tip. This is necessary since each index can be disabled and re-enabled at any time and attempting to catch-up indexes at the same time new blocks are being downloaded would lead to an overall longer time to catch up due to the I/O contention.

This is part of the blockchain.IndexManager interface.

type NeedsInputser

type NeedsInputser interface {
	NeedsInputs() bool
}

NeedsInputser provides a generic interface for an indexer to specify the it requires the ability to look up inputs for a transaction.

type TxIndex

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

TxIndex implements a transaction by hash index. That is to say, it supports querying all transactions by their hash.

func NewTxIndex

func NewTxIndex(db database.DB) *TxIndex

NewTxIndex returns a new instance of an indexer that is used to create a mapping of the hashes of all transactions in the blockchain to the respective block, location within the block, and size of the transaction.

It implements the Indexer interface which plugs into the IndexManager that in turn is used by the blockchain package. This allows the index to be seamlessly maintained along with the chain.

func (*TxIndex) ConnectBlock

func (idx *TxIndex) ConnectBlock(dbTx database.Tx, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error

ConnectBlock is invoked by the index manager when a new block has been connected to the main chain. This indexer adds a hash-to-transaction mapping for every transaction in the passed block.

This is part of the Indexer interface.

func (*TxIndex) Create

func (idx *TxIndex) Create(dbTx database.Tx) error

Create is invoked when the indexer manager determines the index needs to be created for the first time. It creates the buckets for the hash-based transaction index and the internal block ID indexes.

This is part of the Indexer interface.

func (*TxIndex) DisconnectBlock

func (idx *TxIndex) DisconnectBlock(dbTx database.Tx, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error

DisconnectBlock is invoked by the index manager when a block has been disconnected from the main chain. This indexer removes the hash-to-transaction mapping for every transaction in the block.

This is part of the Indexer interface.

func (*TxIndex) Init

func (idx *TxIndex) Init() error

Init initializes the hash-based transaction index. In particular, it finds the highest used block ID and stores it for later use when connecting or disconnecting blocks.

This is part of the Indexer interface.

func (*TxIndex) Key

func (idx *TxIndex) Key() []byte

Key returns the database key to use for the index as a byte slice.

This is part of the Indexer interface.

func (*TxIndex) Name

func (idx *TxIndex) Name() string

Name returns the human-readable name of the index.

This is part of the Indexer interface.

func (*TxIndex) TxBlockRegion

func (idx *TxIndex) TxBlockRegion(hash chainhash.Hash) (*database.BlockRegion, error)

TxBlockRegion returns the block region for the provided transaction hash from the transaction index. The block region can in turn be used to load the raw transaction bytes. When there is no entry for the provided hash, nil will be returned for the both the entry and the error.

This function is safe for concurrent access.

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