The total difficulty is the sum of all block difficulties from genesis
to a certain block. This value was used in PoW for deciding which chain
is heavier, and thus which chain to select. Since PoS has a different
fork selection algorithm, all blocks since the merge have a difficulty
of 0, and all total difficulties are the same for the past 2 years.
Whilst the TDs are mostly useless nowadays, there was never really a
reason to mess around removing them since they are so tiny. This
reasoning changes when we go down the path of pruned chain history. In
order to reconstruct any TD, we **must** retrieve all the headers from
chain head to genesis and then iterate all the difficulties to compute
the TD.
In a world where we completely prune past chain segments (bodies,
receipts, headers), it is not possible to reconstruct the TD at all. In
a world where we still keep chain headers and prune only the rest,
reconstructing it possible as long as we process (or download) the chain
forward from genesis, but trying to snap sync the head first and
backfill later hits the same issue, the TD becomes impossible to
calculate until genesis is backfilled.
All in all, the TD is a messy out-of-state, out-of-consensus computed
field that is overall useless nowadays, but code relying on it forces
the client into certain modes of operation and prevents other modes or
other optimizations. This PR completely nukes out the TD from the node.
It doesn't compute it, it doesn't operate on it, it's as if it didn't
even exist.
Caveats:
- Whenever we have APIs that return TD (devp2p handshake, tracer, etc.)
we return a TD of 0.
- For era files, we recompute the TD during export time (fairly quick)
to retain the format content.
- It is not possible to "verify" the merge point (i.e. with TD gone, TTD
is useless). Since we're not verifying PoW any more, just blindly trust
it, not verifying but blindly trusting the many year old merge point
seems just the same trust model.
- Our tests still need to be able to generate pre and post merge blocks,
so they need a new way to split the merge without TTD. The PR introduces
a settable ttdBlock field on the consensus object which is used by tests
as the block where originally the TTD happened. This is not needed for
live nodes, we never want to generate old blocks.
- One merge transition consensus test was disabled. With a
non-operational TD, testing how the client reacts to TTD is useless, it
cannot react.
Questions:
- Should we also drop total terminal difficulty from the genesis json?
It's a number we cannot react on any more, so maybe it would be cleaner
to get rid of even more concepts.
---------
Co-authored-by: Gary Rong <garyrong0905@gmail.com>
This PR introduces a `ContractCodeReader` interface with functions defined:
type ContractCodeReader interface {
Code(addr common.Address, codeHash common.Hash) ([]byte, error)
CodeSize(addr common.Address, codeHash common.Hash) (int, error)
}
This interface can be implemented in various ways. Although the codebase
currently includes only one implementation, additional implementations
could be created for different purposes and scenarios, such as a code
reader designed for the Verkle tree approach or one that reads code from
the witness.
*Notably, this interface modifies the function’s semantics. If the
contract code is not found, no error will be returned. An error should
only be returned in the event of an unexpected issue, primarily for
future implementations.*
The original state.Reader interface is extended with ContractCodeReader
methods, it gives us more flexibility to manipulate the reader with additional
logic on top, e.g. Hooks.
type Reader interface {
ContractCodeReader
StateReader
}
---------
Co-authored-by: Felix Lange <fjl@twurst.com>
This pull request introduces a state.Reader interface for state
accessing.
The interface could be implemented in various ways. It can be pure trie
only reader, or the combination of trie and state snapshot. What's more,
this interface allows us to have more flexibility in the future, e.g.
the
archive reader (for accessing archive state).
Additionally, this pull request removes the following metrics
- `chain/snapshot/account/reads`
- `chain/snapshot/storage/reads`
* all: implement era format, add history importer/export
* internal/era/e2store: refactor e2store to provide ReadAt interface
* internal/era/e2store: export HeaderSize
* internal/era: refactor era to use ReadAt interface
* internal/era: elevate anonymous func to named
* cmd/utils: don't store entire era file in-memory during import / export
* internal/era: better abstraction between era and e2store
* cmd/era: properly close era files
* cmd/era: don't let defers stack
* cmd/geth: add description for import-history
* cmd/utils: better bytes buffer
* internal/era: error if accumulator has more records than max allowed
* internal/era: better doc comment
* internal/era/e2store: rm superfluous reader, rm superfluous testcases, add fuzzer
* internal/era: avoid some repetition
* internal/era: simplify clauses
* internal/era: unexport things
* internal/era,cmd/utils,cmd/era: change to iterator interface for reading era entries
* cmd/utils: better defer handling in history test
* internal/era,cmd: add number method to era iterator to get the current block number
* internal/era/e2store: avoid double allocation during write
* internal/era,cmd/utils: fix lint issues
* internal/era: add ReaderAt func so entry value can be read lazily
Co-authored-by: lightclient <lightclient@protonmail.com>
Co-authored-by: Martin Holst Swende <martin@swende.se>
* internal/era: improve iterator interface
* internal/era: fix rlp decode of header and correctly read total difficulty
* cmd/era: fix rebase errors
* cmd/era: clearer comments
* cmd,internal: fix comment typos
---------
Co-authored-by: Martin Holst Swende <martin@swende.se>
This change simplifies the logic for indexing transactions and enhances the UX when transaction is not found by returning more information to users.
Transaction indexing is now considered as a part of the initial sync, and `eth.syncing` will thus be `true` if transaction indexing is not yet finished. API consumers can use the syncing status to determine if the node is ready to serve users.
* core/state, light, les: make signature of ContractCode hash-independent
* push current state for feedback
* les: fix unit test
* core, les, light: fix les unittests
* core/state, trie, les, light: fix state iterator
* core, les: address comments
* les: fix lint
---------
Co-authored-by: Gary Rong <garyrong0905@gmail.com>
This PR introduces a node scheme abstraction. The interface is only implemented by `hashScheme` at the moment, but will be extended by `pathScheme` very soon.
Apart from that, a few changes are also included which is worth mentioning:
- port the changes in the stacktrie, tracking the path prefix of nodes during commit
- use ethdb.Database for constructing trie.Database. This is not necessary right now, but it is required for path-based used to open reverse diff freezer
It seems there is no fully typed library implementation of an LRU cache.
So I wrote one. Method names are the same as github.com/hashicorp/golang-lru,
and the new type can be used as a drop-in replacement.
Two reasons to do this:
- It's much easier to understand what a cache is for when the types are right there.
- Performance: the new implementation is slightly faster and performs zero memory
allocations in Add when the cache is at capacity. Overall, memory usage of the cache
is much reduced because keys are values are no longer wrapped in interface.
This PR reduces the amount of work we do when answering header queries, e.g. when a peer
is syncing from us.
For some items, e.g block bodies, when we read the rlp-data from database, we plug it
directly into the response package. We didn't do that for headers, but instead read
headers-rlp, decode to types.Header, and re-encode to rlp. This PR changes that to keep it
in RLP-form as much as possible. When a node is syncing from us, it typically requests 192
contiguous headers. On master it has the following effect:
- For headers not in ancient: 2 db lookups. One for translating hash->number (even though
the request is by number), and another for reading by hash (this latter one is sometimes
cached).
- For headers in ancient: 1 file lookup/syscall for translating hash->number (even though
the request is by number), and another for reading the header itself. After this, it
also performes a hashing of the header, to ensure that the hash is what it expected. In
this PR, I instead move the logic for "give me a sequence of blocks" into the lower
layers, where the database can determine how and what to read from leveldb and/or
ancients.
There are basically four types of requests; three of them are improved this way. The
fourth, by hash going backwards, is more tricky to optimize. However, since we know that
the gap is 0, we can look up by the parentHash, and stlil shave off all the number->hash
lookups.
The gapped collection can be optimized similarly, as a follow-up, at least in three out of
four cases.
Co-authored-by: Felix Lange <fjl@twurst.com>
Péter Szilágyi
rjl493456442
wangjingcun
lightclient
Guillaume Ballet
Felix Lange
Marius van der Wijden
Martin Holst Swende