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.
There is no need to depend on the old context package now that the
minimum Go version is 1.7. The move to "context" eliminates our weird
vendoring setup. Some vendored code still uses golang.org/x/net/context
and it is now vendored in the normal way.
This change triggered new vet checks around context.WithTimeout which
didn't fire with golang.org/x/net/context.
* common/math: optimize PaddedBigBytes, use it more
name old time/op new time/op delta
PaddedBigBytes-8 71.1ns ± 5% 46.1ns ± 1% -35.15% (p=0.000 n=20+19)
name old alloc/op new alloc/op delta
PaddedBigBytes-8 48.0B ± 0% 32.0B ± 0% -33.33% (p=0.000 n=20+20)
* all: unify big.Int zero checks
Various checks were in use. This commit replaces them all with Int.Sign,
which is cheaper and less code.
eg templates:
func before(x *big.Int) bool { return x.BitLen() == 0 }
func after(x *big.Int) bool { return x.Sign() == 0 }
func before(x *big.Int) bool { return x.BitLen() > 0 }
func after(x *big.Int) bool { return x.Sign() != 0 }
func before(x *big.Int) int { return x.Cmp(common.Big0) }
func after(x *big.Int) int { return x.Sign() }
* common/math, crypto/secp256k1: make ReadBits public in package math
* common: remove CurrencyToString
Move denomination values to params instead.
* common: delete dead code
* common: move big integer operations to common/math
This commit consolidates all big integer operations into common/math and
adds tests and documentation.
There should be no change in semantics for BigPow, BigMin, BigMax, S256,
U256, Exp and their behaviour is now locked in by tests.
The BigD, BytesToBig and Bytes2Big functions don't provide additional
value, all uses are replaced by new(big.Int).SetBytes().
BigToBytes is now called PaddedBigBytes, its minimum output size
parameter is now specified as the number of bytes instead of bits. The
single use of this function is in the EVM's MSTORE instruction.
Big and String2Big are replaced by ParseBig, which is slightly stricter.
It previously accepted leading zeros for hexadecimal inputs but treated
decimal inputs as octal if a leading zero digit was present.
ParseUint64 is used in places where String2Big was used to decode a
uint64.
The new functions MustParseBig and MustParseUint64 are now used in many
places where parsing errors were previously ignored.
* common: delete unused big integer variables
* accounts/abi: replace uses of BytesToBig with use of encoding/binary
* common: remove BytesToBig
* common: remove Bytes2Big
* common: remove BigTrue
* cmd/utils: add BigFlag and use it for error-checked integer flags
While here, remove environment variable processing for DirectoryFlag
because we don't use it.
* core: add missing error checks in genesis block parser
* common: remove String2Big
* cmd/evm: use utils.BigFlag
* common/math: check for 256 bit overflow in ParseBig
This is supposed to prevent silent overflow/truncation of values in the
genesis block JSON. Without this check, a genesis block that set a
balance larger than 256 bits would lead to weird behaviour in the VM.
* cmd/utils: fixup import
Gas estimation currently mostly works, but can underestimate for more funky
refunds. This is because various ops (e.g. CALL) need more gas to run than they
actually consume (e.g. 2300 stipend that is refunded if not used). With more
intricate contract interplays, it becomes almost impossible to return a proper
value to the user.
This commit swaps out the simplistic gas estimation to a binary search approach,
honing in on the correct gas use. This does mean that gas estimation needs to
rerun the transaction log(max-price) times to measure whether it fails or not,
but it's a price paid by the transaction issuer, and it should be worth it to
support proper estimates.
The run loop, which previously contained custom opcode executes have been
removed and has been simplified to a few checks.
Each operation consists of 4 elements: execution function, gas cost function,
stack validation function and memory size function. The execution function
implements the operation's runtime behaviour, the gas cost function implements
the operation gas costs function and greatly depends on the memory and stack,
the stack validation function validates the stack and makes sure that enough
items can be popped off and pushed on and the memory size function calculates
the memory required for the operation and returns it.
This commit also allows the EVM to go unmetered. This is helpful for offline
operations such as contract calls.
To address increasing complexity in code that handles signatures, this PR
discards all notion of "different" signature types at the library level. Both
the crypto and accounts package is reduced to only be able to produce plain
canonical secp256k1 signatures. This makes the crpyto APIs much cleaner,
simpler and harder to abuse.
Environment is now a struct (not an interface). This
reduces a lot of tech-debt throughout the codebase where a virtual
machine environment had to be implemented in order to test or run it.
The new environment is suitable to be used en the json tests, core
consensus and light client.
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>
This commit includes several API changes:
- The behavior of eth_sign is changed. It now accepts an arbitrary
message, prepends the well-known string
\x19Ethereum Signed Message:\n<length of message>
hashes the result using keccak256 and calculates the signature of
the hash. This breaks backwards compatability!
- personal_sign(hash, address [, password]) is added. It has the same
semantics as eth_sign but also accepts a password. The private key
used to sign the hash is temporarily unlocked in the scope of the
request.
- personal_recover(message, signature) is added and returns the
address for the account that created a signature.
This commit replaces the deep-copy based state revert mechanism with a
linear complexity journal. This commit also hides several internal
StateDB methods to limit the number of ways in which calling code can
use the journal incorrectly.
As usual consultation and bug fixes to the initial implementation were
provided by @karalabe, @obscuren and @Arachnid. Thank you!
The need for these functions comes up in code that actually deploys and
uses contracts. As of this commit, they can be used with both
SimulatedBackend and ethclient.
SimulatedBackend gains some additional methods in the process and is now
safe for concurrent use.
In this commit, contract bindings and their backend start using the
Ethereum Go API interfaces offered by ethclient. This makes ethclient a
suitable replacement for the old remote backend and gets us one step
closer to the final stable Go API that is planned for go-ethereum 1.5.
The changes in detail:
* Pending state is optional for read only contract bindings.
BoundContract attempts to discover the Pending* methods via an
interface assertion. There are a couple of advantages to this:
ContractCaller is just two methods and can be implemented on top of
pretty much anything that provides Ethereum data. Since the backend
interfaces are now disjoint, ContractBackend can simply be declared as
a union of the reader and writer side.
* Caching of HasCode is removed. The caching could go wrong in case of
chain reorganisations and removing it simplifies the code a lot.
We'll figure out a performant way of providing ErrNoCode before the
1.5 release.
* BoundContract now ensures that the backend receives a non-nil context
with every call.
The remote backend is superseded by ethclient.
The nil backend's stated purpose was to enable testing of
accounts/abi/bind. None of its methods actually worked. A much simpler
way to get a crashing backend is to simply pass nil as the backend. With
a one-line change to the generator (removing two explicit interface
assertions), passing nil actually works.
Removing these backends means that less changes are required later.
The account management API was originally implemented as a thin layer
around crypto.KeyStore, on the grounds that several kinds of key stores
would be implemented later on. It turns out that this won't happen so
KeyStore is a superflous abstraction.
In this commit crypto.KeyStore and everything related to it moves to
package accounts and is unexported.
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.
