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>
rebased https://github.com/ethereum/go-ethereum/pull/29766 . The
downstream branch appears to have been deleted and I don't have perms to
push to that fork.
`TerminalTotalDifficultyPassed` is removed. `TerminalTotalDifficulty`
must now be non-nil, and it is expected that networks are already
merged: we can only import PoW/Clique chains, not produce blocks on
them.
---------
Co-authored-by: stevemilk <wangpeculiar@gmail.com>
This PR changes how sidechains are handled.
Before the merge, it was possible to import a chain with lower td and not set it as canonical. After the merge, we expect every chain that we get via InsertChain to be canonical. Non-canonical blocks can still be inserted
with InsertBlockWIthoutSetHead.
If during the InsertChain, the existing chain is not canonical anymore, we mark it as a sidechain and send the SideChainEvents normally.
This change improves GenerateChain to support internal chain history access (ChainReader)
for the consensus engine and EVM.
GenerateChain takes a `parent` block and the number of blocks to create. With my changes,
the consensus engine and EVM can now access blocks from `parent` up to the block currently
being generated. This is required to make the BLOCKHASH instruction work, and also needed
to create real clique chains. Clique uses chain history to figure out if the current signer is in-turn,
for example.
I've also added some more accessors to BlockGen. These are helpful when creating transactions:
- g.Signer returns a signer instance for the current block
- g.Difficulty returns the current block difficulty
- g.Gas returns the remaining gas amount
Another fix in this commit concerns the receipts returned by GenerateChain. The receipts now
have properly derived fields (BlockHash, etc.) and should generally match what would be
returned by the RPC API.
This fixes an issue where the withdrawal index was not calculated correctly
for multiple withdrawals in a single block.
Co-authored-by: Gary Rong <garyrong0905@gmail.com>
Co-authored-by: Felix Lange <fjl@twurst.com>
* cmd, core, eth: init tx lookup in background
* core/rawdb: tiny log fixes to make it clearer what's happening
* core, eth: fix rebase errors
* core/rawdb: make reindexing less generic, but more optimal
* rlp: implement rlp list iterator
* core/rawdb: new implementation of tx indexing/unindex using generic tx iterator and hashing rlp-data
* core/rawdb, cmd/utils: fix review concerns
* cmd/utils: fix merge issue
* core/rawdb: add some log formatting polishes
Co-authored-by: rjl493456442 <garyrong0905@gmail.com>
Co-authored-by: Péter Szilágyi <peterke@gmail.com>
This commit adds pluggable consensus engines to go-ethereum. In short, it
introduces a generic consensus interface, and refactors the entire codebase to
use this interface.
This commit solves several issues concerning the genesis block:
* Genesis/ChainConfig loading was handled by cmd/geth code. This left
library users in the cold. They could specify a JSON-encoded
string and overwrite the config, but didn't get any of the additional
checks performed by geth.
* Decoding and writing of genesis JSON was conflated in
WriteGenesisBlock. This made it a lot harder to embed the genesis
block into the forthcoming config file loader. This commit changes
things so there is a single Genesis type that represents genesis
blocks. All uses of Write*Genesis* are changed to use the new type
instead.
* If the chain config supplied by the user was incompatible with the
current chain (i.e. the chain had already advanced beyond a scheduled
fork), it got overwritten. This is not an issue in practice because
previous forks have always had the highest total difficulty. It might
matter in the future though. The new code reverts the local chain to
the point of the fork when upgrading configuration.
The change to genesis block data removes compression library
dependencies from package core.
Reworked the EVM gas instructions to use 64bit integers rather than
arbitrary size big ints. All gas operations, be it additions,
multiplications or divisions, are checked and guarded against 64 bit
integer overflows.
In additon, most of the protocol paramaters in the params package have
been converted to uint64 and are now constants rather than variables.
* common/math: added overflow check ops
* core: vmenv, env renamed to evm
* eth, internal/ethapi, les: unmetered eth_call and cancel methods
* core/vm: implemented big.Int pool for evm instructions
* core/vm: unexported intPool methods & verification methods
* core/vm: added memoryGasCost overflow check and test
Reworked the EVM gas instructions to use 64bit integers rather than
arbitrary size big ints. All gas operations, be it additions,
multiplications or divisions, are checked and guarded against 64 bit
integer overflows.
In additon, most of the protocol paramaters in the params package have
been converted to uint64 and are now constants rather than variables.
* common/math: added overflow check ops
* core: vmenv, env renamed to evm
* eth, internal/ethapi, les: unmetered eth_call and cancel methods
* core/vm: implemented big.Int pool for evm instructions
* core/vm: unexported intPool methods & verification methods
* core/vm: added memoryGasCost overflow check and test
This commit implements EIP158 part 1, 2, 3 & 4
1. If an account is empty it's no longer written to the trie. An empty
account is defined as (balance=0, nonce=0, storage=0, code=0).
2. Delete an empty account if it's touched
3. An empty account is redefined as either non-existent or empty.
4. Zero value calls and zero value suicides no longer consume the 25k
reation costs.
params: moved core/config to params
Signed-off-by: Jeffrey Wilcke <jeffrey@ethereum.org>
The chain maker and the simulated backend now run with a homestead phase
beginning at block 0 (i.e. there's no frontier).
This commit also fixes up #2388
Added chain configuration options and write out during genesis database
insertion. If no "config" was found, nothing is written to the database.
Configurations are written on a per genesis base. This means
that any chain (which is identified by it's genesis hash) can have their
own chain settings.
This removes the burden on a single object to take care of all
validation and state processing. Now instead the validation is done by
the `core.BlockValidator` (`types.Validator`) that takes care of both
header and uncle validation through the `ValidateBlock` method and state
validation through the `ValidateState` method. The state processing is
done by a new object `core.StateProcessor` (`types.Processor`) and
accepts a new state as input and uses that to process the given block's
transactions (and uncles for rewords) to calculate the state root for
the next block (P_n + 1).
Added a `Difference` method to `types.Transactions` which sets the
receiver to the difference of a to b (NOTE: not a **and** b).
Transaction pool subscribes to RemovedTransactionEvent adding back to
those potential missing from the chain.
When a chain re-org occurs remove any transactions that were removed
from the canonical chain during the re-org as well as the receipts that
were generated in the process.
Closes#1746
* Miners do now verify their own header, not their state.
* Changed old putTx and putReceipts to be exported
* Moved writing of transactions and receipts out of the block processer
in to the chain manager. Closes#1386
* Miner post ChainHeadEvent & ChainEvent. Closes#1388