This PR significantly changes the APIs for instantiating Ethereum nodes in
a Go program. The new APIs are not backwards-compatible, but we feel that
this is made up for by the much simpler way of registering services on
node.Node. You can find more information and rationale in the design
document: https://gist.github.com/renaynay/5bec2de19fde66f4d04c535fd24f0775.
There is also a new feature in Node's Go API: it is now possible to
register arbitrary handlers on the user-facing HTTP server. In geth, this
facility is used to enable GraphQL.
There is a single minor change relevant for geth users in this PR: The
GraphQL API is no longer available separately from the JSON-RPC HTTP
server. If you want GraphQL, you need to enable it using the
./geth --http --graphql flag combination.
The --graphql.port and --graphql.addr flags are no longer available.
# Conflicts:
# cmd/faucet/faucet.go
# cmd/geth/chaincmd.go
# cmd/geth/config.go
# cmd/geth/consolecmd.go
# cmd/geth/main.go
# cmd/utils/flags.go
# cmd/wnode/main.go
# core/rawdb/freezer.go
# eth/api_backend.go
# eth/backend.go
# ethclient/ethclient_test.go
# ethstats/ethstats.go
# graphql/service.go
# internal/ethapi/backend.go
# les/api_backend.go
# les/api_test.go
# les/checkpointoracle/oracle.go
# les/client.go
# les/commons.go
# les/server.go
# miner/stresstest/stress_clique.go
# miner/stresstest/stress_ethash.go
# mobile/geth.go
# node/api.go
# node/node.go
# node/node_example_test.go
# node/node_test.go
# node/rpcstack.go
# node/rpcstack_test.go
# node/service.go
# node/service_test.go
# node/utils_test.go
# p2p/simulations/examples/ping-pong.go
# p2p/testing/peerpool.go
# p2p/testing/protocolsession.go
# p2p/testing/protocoltester.go
# whisper/mailserver/server_test.go
# whisper/whisperv6/api_test.go
# whisper/whisperv6/filter_test.go
# whisper/whisperv6/whisper.go
# whisper/whisperv6/whisper_test.go
* Not hash, keep the files
* Calculate savings
* Fix
* Fix
* Fix
* Fix
* RestAPI to support local boltdb
* Not error on read-only db
* Changes so far
* Continue
* More
* Roll back a bit
* Restore newline
* something compiles
* Fix restapi
* Fix block number
* Fix reads
* Use plain writer
* Maps for storage reads and writes
* Clean up coersions
* Fix accounts/abi/bind
* Fix tests
* More fixes
* more fixes
* More fixes
* Fixes
* Fixed core/state
* Fixed eth tests
* Move code, fix linter
* Fix test
* Fix linter
* Fix linter
* Fix linter, badger_db to support AbstractKV
* Increase IdealBatchSize for badger
* Fix linter
* Fix linter
* core: initial version of state snapshots
* core/state: lazy sorting, snapshot invalidation
* core/state/snapshot: extract and split cap method, cover corners
* snapshot: iteration and buffering optimizations
* core/state/snapshot: unlink snapshots from blocks, quad->linear cleanup
* 123
* core/rawdb, core/state/snapshot: runtime snapshot generation
* core/state/snapshot: fix difflayer origin-initalization after flatten
* add "to merge"
* core/state/snapshot: implement snapshot layer iteration
* core/state/snapshot: node behavioural difference on bloom content
* core: journal the snapshot inside leveldb, not a flat file
* core/state/snapshot: bloom, metrics and prefetcher fixes
* core/state/snapshot: move iterator out into its own files
* core/state/snapshot: implement iterator priority for fast direct data lookup
* core/state/snapshot: full featured account iteration
* core/state/snapshot: faster account iteration, CLI integration
* core: fix broken tests due to API changes + linter
* core/state: fix an account resurrection issue
* core/tests: test for destroy+recreate contract with storage
* squashme
* core/state/snapshot, tests: sync snap gen + snaps in consensus tests
* core/state: extend snapshotter to handle account resurrections
* core/state: fix account root hash update point
* core/state: fix resurrection state clearing and access
* core/state/snapshot: handle deleted accounts in fast iterator
* core: more blockchain tests
* core/state/snapshot: fix various iteration issues due to destruct set
* core: fix two snapshot iterator flaws, decollide snap storage prefix
* core/state/snapshot/iterator: fix two disk iterator flaws
* core/rawdb: change SnapshotStoragePrefix to avoid prefix collision with preimagePrefix
* params: begin v1.9.13 release cycle
* cmd/checkpoint-admin: add some documentation (#20697)
* go.mod: update duktape to fix sprintf warnings (#20777)
This revision of go-duktype fixes the following warning
```
duk_logging.c: In function ‘duk__logger_prototype_log_shared’:
duk_logging.c:184:64: warning: ‘Z’ directive writing 1 byte into a region of size between 0 and 9 [-Wformat-overflow=]
184 | sprintf((char *) date_buf, "%04d-%02d-%02dT%02d:%02d:%02d.%03dZ",
| ^
In file included from /usr/include/stdio.h:867,
from duk_logging.c:5:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:36:10: note: ‘__builtin___sprintf_chk’ output between 25 and 85 bytes into a destination of size 32
36 | return __builtin___sprintf_chk (__s, __USE_FORTIFY_LEVEL - 1,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
37 | __bos (__s), __fmt, __va_arg_pack ());
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
* core/rawdb: fix freezer table test error check
Fixes: Condition is always 'false' because 'err' is always 'nil'
* core/rawdb: improve table database (#20703)
This PR fixes issues in TableDatabase.
TableDatabase is a wrapper of underlying ethdb.Database with an additional prefix.
The prefix is applied to all entries it maintains. However when we try to retrieve entries
from it we don't handle the key properly. In theory the prefix should be truncated and
only user key is returned. But we don't do it in some cases, e.g. the iterator and batch
replayer created from it. So this PR is the fix to these issues.
* eth: when triggering a sync, check the head header TD, not block
* internal/web3ext: fix clique console apis to work on missing arguments
* rpc: dont log an error if user configures --rpcapi=rpc... (#20776)
This just prevents a false negative ERROR warning when, for some unknown
reason, a user attempts to turn on the module rpc even though it's already going
to be on.
* node, cmd/clef: report actual port used for http rpc (#20789)
* internal/ethapi: don't set sender-balance to maxuint, fixes#16999 (#20783)
Prior to this change, eth_call changed the balance of the sender account in the
EVM environment to 2^256 wei to cover the gas cost of the call execution.
We've had this behavior for a long time even though it's super confusing.
This commit sets the default call gasprice to zero instead of updating the balance,
which is better because it makes eth_call semantics less surprising. Removing
the built-in balance assignment also makes balance overrides work as expected.
* metrics: disable CPU stats (gosigar) on iOS
* cmd/devp2p: tweak DNS TTLs (#20801)
* cmd/devp2p: tweak DNS TTLs
* cmd/devp2p: bump treeNodeTTL to four weeks
* cmd/devp2p: lower route53 change limit again (#20819)
* cmd/devp2p: be very correct about route53 change splitting (#20820)
Turns out the way RDATA limits work is documented after all,
I just didn't search right. The trick to make it work is to
count UPSERTs twice.
This also adds an additional check to ensure TTL changes are
applied on existing records.
* graphql, node, rpc: fix typos in comments (#20824)
* eth: improve shutdown synchronization (#20695)
* eth: improve shutdown synchronization
Most goroutines started by eth.Ethereum didn't have any shutdown sync at
all, which lead to weird error messages when quitting the client.
This change improves the clean shutdown path by stopping all internal
components in dependency order and waiting for them to actually be
stopped before shutdown is considered done. In particular, we now stop
everything related to peers before stopping 'resident' parts such as
core.BlockChain.
* eth: rewrite sync controller
* eth: remove sync start debug message
* eth: notify chainSyncer about new peers after handshake
* eth: move downloader.Cancel call into chainSyncer
* eth: make post-sync block broadcast synchronous
* eth: add comments
* core: change blockchain stop message
* eth: change closeBloomHandler channel type
* eth/filters: fix typo on unindexedLogs function's comment (#20827)
* core: bump txpool tx max size to 128KB
* snapshotter/tests: verify snapdb post-state against trie (#20812)
* core/state/snapshot: basic trie-to-hash implementation
* tests: validate snapshot after test
* core/state/snapshot: fix review concerns
* cmd, consensus: add option to disable mmap for DAG caches/datasets (#20484)
* cmd, consensus: add option to disable mmap for DAG caches/datasets
* consensus: add benchmarks for mmap with/with lock
* cmd/clef: add newaccount command (#20782)
* cmd/clef: add newaccount command
* cmd/clef: document clef_New, update API versioning
* Update cmd/clef/intapi_changelog.md
Co-Authored-By: ligi <ligi@ligi.de>
* Update signer/core/uiapi.go
Co-Authored-By: ligi <ligi@ligi.de>
Co-authored-by: ligi <ligi@ligi.de>
* eth: add debug_accountRange API (#19645)
This new API allows reading accounts and their content by address range.
Co-authored-by: Martin Holst Swende <martin@swende.se>
Co-authored-by: Felix Lange <fjl@twurst.com>
* travis: allow cocoapods deploy to fail (#20833)
* metrics: improve TestTimerFunc (#20818)
The test failed due to what appears to be fluctuations in time.Sleep, which is
not the actual method under test. This change modifies it so we compare the
metered Max to the actual time instead of the desired time.
* README: update private network genesis spec with istanbul (#20841)
* add istanbul and muirGlacier to genesis states in README
* remove muirGlacier, relocate istanbul
* cmd/evm: Rework execution stats (#20792)
- Dump stats also for --bench flag.
- From memory stats only show number and size of allocations. This is what `test -bench` shows. I doubt others like number of GC runs are any useful, but can be added if requested.
- Now the mem stats are for single execution in case of --bench.
* cmd/devp2p, cmd/wnode, whisper: add missing calls to Timer.Stop (#20843)
* p2p/server: add UDP port mapping goroutine to wait group (#20846)
* accounts/abi faster unpacking of int256 (#20850)
* p2p/discv5: add missing Timer.Stop calls (#20853)
* miner/worker: add missing timer.Stop call (#20857)
* cmd/geth: fix bad genesis test (#20860)
* eth/filters: add missing Ticker.Stop call (#20862)
* eth/fetcher: add missing timer.Stop calls (#20861)
* event: add missing timer.Stop call in TestFeed (#20868)
* metrics: add missing calls to Ticker.Stop in tests (#20866)
* ethstats: add missing Ticker.Stop call (#20867)
* p2p/discv5, p2p/testing: add missing Timer.Stop calls in tests (#20869)
* core: add missing Timer.Stop call in TestLogReorgs (#20870)
* rpc: add missing timer.Stop calls in websocket tests (#20863)
* crypto/ecies: improve concatKDF (#20836)
This removes a bunch of weird code around the counter overflow check in
concatKDF and makes it actually work for different hash output sizes.
The overflow check worked as follows: concatKDF applies the hash function N
times, where N is roundup(kdLen, hashsize) / hashsize. N should not
overflow 32 bits because that would lead to a repetition in the KDF output.
A couple issues with the overflow check:
- It used the hash.BlockSize, which is wrong because the
block size is about the input of the hash function. Luckily, all standard
hash functions have a block size that's greater than the output size, so
concatKDF didn't crash, it just generated too much key material.
- The check used big.Int to compare against 2^32-1.
- The calculation could still overflow before reaching the check.
The new code in concatKDF doesn't check for overflow. Instead, there is a
new check on ECIESParams which ensures that params.KeyLen is < 512. This
removes any possibility of overflow.
There are a couple of miscellaneous improvements bundled in with this
change:
- The key buffer is pre-allocated instead of appending the hash output
to an initially empty slice.
- The code that uses concatKDF to derive keys is now shared between Encrypt
and Decrypt.
- There was a redundant invocation of IsOnCurve in Decrypt. This is now removed
because elliptic.Unmarshal already checks whether the input is a valid curve
point since Go 1.5.
Co-authored-by: Felix Lange <fjl@twurst.com>
* rpc: metrics for JSON-RPC method calls (#20847)
This adds a couple of metrics for tracking the timing
and frequency of method calls:
- rpc/requests gauge counts all requests
- rpc/success gauge counts requests which return err == nil
- rpc/failure gauge counts requests which return err != nil
- rpc/duration/all timer tracks timing of all requests
- rpc/duration/<method>/<success/failure> tracks per-method timing
* mobile: use bind.NewKeyedTransactor instead of duplicating (#20888)
It's better to reuse the existing code to create a keyed transactor
than to rewrite the logic again.
* internal/ethapi: add CallArgs.ToMessage method (#20854)
ToMessage is used to convert between ethapi.CallArgs and types.Message.
It reduces the length of the DoCall method by about half by abstracting out
the conversion between the CallArgs and the Message. This should improve the
code's maintainability and reusability.
* eth, les: fix flaky tests (#20897)
* les: fix flaky test
* eth: fix flaky test
* cmd/geth: enable metrics for geth import command (#20738)
* cmd/geth: enable metrics for geth import command
* cmd/geth: enable metrics-flags for import command
* core/vm: use a callcontext struct (#20761)
* core/vm: use a callcontext struct
* core/vm: fix tests
* core/vm/runtime: benchmark
* core/vm: make intpool push inlineable, unexpose callcontext
* docs/audits: add discv5 protocol audits from LA and C53 (#20898)
* .github: change gitter reference to discord link in issue template (#20896)
* couple of fixes to docs in clef (#20900)
* p2p/discover: add initial discovery v5 implementation (#20750)This adds an implementation of the current discovery v5 spec.There is full integration with cmd/devp2p and enode.Iterator in thisversion. In theory we could enable the new protocol as a replacement ofdiscovery v4 at any time. In practice, there will likely be a few morechanges to the spec and implementation before this can happen.
* build: upgrade to golangci-lint 1.24.0 (#20901)
* accounts/scwallet: remove unnecessary uses of fmt.Sprintf
* cmd/puppeth: remove unnecessary uses of fmt.Sprintf
* p2p/discv5: remove unnecessary use of fmt.Sprintf
* whisper/mailserver: remove unnecessary uses of fmt.Sprintf
* core: goimports -w tx_pool_test.go
* eth/downloader: goimports -w downloader_test.go
* build: upgrade to golangci-lint 1.24.0
* accounts/abi/bind: Refactored topics (#20851)
* accounts/abi/bind: refactored topics
* accounts/abi/bind: use store function to remove code duplication
* accounts/abi/bind: removed unused type defs
* accounts/abi/bind: error on tuples in topics
* Cosmetic changes to restart travis build
Co-authored-by: Guillaume Ballet <gballet@gmail.com>
* node: allow websocket and HTTP on the same port (#20810)
This change makes it possible to run geth with JSON-RPC over HTTP and
WebSocket on the same TCP port. The default port for WebSocket
is still 8546.
geth --rpc --rpcport 8545 --ws --wsport 8545
This also removes a lot of deprecated API surface from package rpc.
The rpc package is now purely about serving JSON-RPC and no longer
provides a way to start an HTTP server.
* crypto: improve error messages in LoadECDSA (#20718)
This improves error messages when the file is too short or too long.
Also rewrite the test for SaveECDSA because LoadECDSA has its own
test now.
Co-authored-by: Felix Lange <fjl@twurst.com>
* changed date of rpcstack.go since new file (#20904)
* accounts/abi/bind: fixed erroneous filtering of negative ints (#20865)
* accounts/abi/bind: fixed erroneous packing of negative ints
* accounts/abi/bind: added test cases for negative ints in topics
* accounts/abi/bind: fixed genIntType for go 1.12
* accounts/abi: minor nitpick
* cmd: deprecate --testnet, use named networks instead (#20852)
* cmd/utils: make goerli the default testnet
* cmd/geth: explicitly rename testnet to ropsten
* core: explicitly rename testnet to ropsten
* params: explicitly rename testnet to ropsten
* cmd: explicitly rename testnet to ropsten
* miner: explicitly rename testnet to ropsten
* mobile: allow for returning the goerli spec
* tests: explicitly rename testnet to ropsten
* docs: update readme to reflect changes to the default testnet
* mobile: allow for configuring goerli and rinkeby nodes
* cmd/geth: revert --testnet back to ropsten and mark as legacy
* cmd/util: mark --testnet flag as deprecated
* docs: update readme to properly reflect the 3 testnets
* cmd/utils: add an explicit deprecation warning on startup
* cmd/utils: swap goerli and ropsten in usage
* cmd/geth: swap goerli and ropsten in usage
* cmd/geth: if running a known preset, log it for convenience
* docs: improve readme on usage of ropsten's testnet datadir
* cmd/utils: check if legacy `testnet` datadir exists for ropsten
* cmd/geth: check for legacy testnet path in console command
* cmd/geth: use switch statement for complex conditions in main
* cmd/geth: move known preset log statement to the very top
* cmd/utils: create new ropsten configurations in the ropsten datadir
* cmd/utils: makedatadir should check for existing testnet dir
* cmd/geth: add legacy testnet flag to the copy db command
* cmd/geth: add legacy testnet flag to the inspect command
* les, les/lespay/client: add service value statistics and API (#20837)
This PR adds service value measurement statistics to the light client. It
also adds a private API that makes these statistics accessible. A follow-up
PR will add the new server pool which uses these statistics to select
servers with good performance.
This document describes the function of the new components:
https://gist.github.com/zsfelfoldi/3c7ace895234b7b345ab4f71dab102d4
Co-authored-by: rjl493456442 <garyrong0905@gmail.com>
Co-authored-by: rjl493456442 <garyrong0905@gmail.com>
* README: update min go version to 1.13 (#20911)
* travis, appveyor, build, Dockerfile: bump Go to 1.14.2 (#20913)
* travis, appveyor, build, Dockerfile: bump Go to 1.14.2
* travis, appveyor: force GO111MODULE=on for every build
* core/rawdb: fix data race between Retrieve and Close (#20919)
* core/rawdb: fixed data race between retrieve and close
closes https://github.com/ethereum/go-ethereum/issues/20420
* core/rawdb: use non-atomic load while holding mutex
* all: simplify and fix database iteration with prefix/start (#20808)
* core/state/snapshot: start fixing disk iterator seek
* ethdb, rawdb, leveldb, memorydb: implement iterators with prefix and start
* les, core/state/snapshot: iterator fixes
* all: remove two iterator methods
* all: rename Iteratee.NewIteratorWith -> NewIterator
* ethdb: fix review concerns
* params: update CHTs for the 1.9.13 release
* params: release Geth v1.9.13
* added some missing files
* post-rebase fixups
Co-authored-by: Péter Szilágyi <peterke@gmail.com>
Co-authored-by: Martin Holst Swende <martin@swende.se>
Co-authored-by: gary rong <garyrong0905@gmail.com>
Co-authored-by: Alex Willmer <alex@moreati.org.uk>
Co-authored-by: meowsbits <45600330+meowsbits@users.noreply.github.com>
Co-authored-by: Felix Lange <fjl@twurst.com>
Co-authored-by: rene <41963722+renaynay@users.noreply.github.com>
Co-authored-by: Ha ĐANG <dvietha@gmail.com>
Co-authored-by: Hanjiang Yu <42531996+de1acr0ix@users.noreply.github.com>
Co-authored-by: ligi <ligi@ligi.de>
Co-authored-by: Wenbiao Zheng <delweng@gmail.com>
Co-authored-by: Adam Schmideg <adamschmideg@users.noreply.github.com>
Co-authored-by: Jeff Wentworth <jeff@curvegrid.com>
Co-authored-by: Paweł Bylica <chfast@gmail.com>
Co-authored-by: ucwong <ucwong@126.com>
Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: Luke Champine <luke.champine@gmail.com>
Co-authored-by: Boqin Qin <Bobbqqin@gmail.com>
Co-authored-by: William Morriss <wjmelements@gmail.com>
Co-authored-by: Guillaume Ballet <gballet@gmail.com>
Co-authored-by: Raw Pong Ghmoa <58883403+q9f@users.noreply.github.com>
Co-authored-by: Felföldi Zsolt <zsfelfoldi@gmail.com>
* root was unused in BlockChain.StateAt
* TestDoubleAccountRemoval
* Preserve the original when a contract is self-destructed and then its address is touched in the same block (e.g. #
156634)
This change makes getBalance, getCode, getStorageAt, getProof,
call, getTransactionCount return an error if the block number in
the request doesn't exist. getHeaderByNumber still returns null
for missing headers.
Until this commit, when sending an RPC request that called `NewEVM`, a blank `vm.Config`
would be taken so as to set some options, based on the default configuration. If some extra
configuration switches were passed to the blockchain, those would be ignored.
This PR adds a function to get the config from the blockchain, and this is what is now used
for RPC calls.
Some subsequent changes need to be made, see https://github.com/ethereum/go-ethereum/pull/17955#pullrequestreview-182237244
for the details of the discussion.
With this commit, core/state's access to the underlying key/value database is
mediated through an interface. Database errors are tracked in StateDB and
returned by CommitTo or the new Error method.
Motivation for this change: We can remove the light client's duplicated copy of
core/state. The light client now supports node iteration, so tracing and storage
enumeration can work with the light client (not implemented in this commit).
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: 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
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 significantly reduces the dependency closure of ethclient, which no
longer depends on core/vm as of this change.
All uses of vm.Logs are replaced by []*types.Log. NewLog is gone too,
the constructor simply returned a literal.
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.
