* ethclient/gethclient: fix flaky test (due to map key ordering)

* accounts/keystore: fix test failing due to rand collision due to low time resolution on windows

This change introduces 2 new optional methods; `enter()` and `exit()` for js tracers, and makes `step()` optiona. The two new methods are invoked when entering and exiting a call frame (but not invoked for the outermost scope, which has it's own methods). Currently these are the data fields passed to each of them:

    enter: type (opcode), from, to, input, gas, value
    exit: output, gasUsed, error

The PR also comes with a re-write of the callTracer. As a backup we keep the previous tracing script under the name `callTracerLegacy`. Behaviour of both tracers are equivalent for the most part, although there are some small differences (improvements), where the new tracer is more correct / has more information. 

* cmd/devp2p/internal/ethtest: only use eth66 if eth66 is negotiated

* cmd/devp2p/internal/ethtest: switch on concrete type not pointer

* cmd/devp2p/internal/ethtest: switch on concrete type not pointer

* core: cmd: invert disableMemory

* core: fix missed inversion

* cmd/evm: preserve Flags but change default value

* Apply suggestions from code review

Co-authored-by: Martin Holst Swende <martin@swende.se>

Co-authored-by: Martin Holst Swende <martin@swende.se>

* cmd/evm: transaction validation tool

* cmd/evm: add hash to t9n tool

* cmd/evm: lint nits

* cmd/evm: nitpicks

Updated example genesis.json configuration section, added londonBlock within config.

les: duplicate downloader and fetcher to allow progressive refactoring

This fixes crashes in txpool tests on 32bit platforms.

This fixes crashes on 32bit builds.

This PR ensures that wiping all data associated with a node (apart from its nodekey)
will not generate already used sequence number for the ENRs, since all remote nodes
would reject them until they out-number the previously published largest one.

The big complication with this scheme is that every local update to the ENR can
potentially bump the sequence number by one. In order to ensure that local updates
do not outrun the clock, the sequence number is a millisecond-precision timestamp,
and updates are throttled to occur at most once per millisecond.

Co-authored-by: Felix Lange <fjl@twurst.com>

This change is a rewrite of the freezer code.

When writing ancient chain data to the freezer, the previous version first encoded each
individual item to a temporary buffer, then wrote the buffer. For small item sizes (for
example, in the block hash freezer table), this strategy causes a lot of system calls for
writing tiny chunks of data. It also allocated a lot of temporary []byte buffers.

In the new version, we instead encode multiple items into a re-useable batch buffer, which
is then written to the file all at once. This avoids performing a system call for every
inserted item.

To make the internal batching work, the ancient database API had to be changed. While
integrating this new API in BlockChain.InsertReceiptChain, additional optimizations were
also added there.

Co-authored-by: Felix Lange <fjl@twurst.com>

* remove rpc flags

* remove legacy rpc flags

* remove legacy rpc flags

* remove legacy rpc commands

* (hopefully) fix most of the build errors

* fix build errors

https://app.travis-ci.com/github/ethereum/go-ethereum/jobs/530318686



* cmd/utils: fix syntax error

* empty commit to unbreak travis ci

* fix syntax error

* syntax fixes

* syntax fixes

* fix

fixes "cmd/geth/usage.go:234:7: expected '(', found init (typecheck)"

* fix

* various fixes in usage.go

* various fixes in flags.go

* adds extra space

reverts the spacing to how it was before I resolved the merge conflict

* more fixes in usage.go

* fix

fix for cmd/geth/usage.go:243:17: expected operand, found ':=' (typecheck) in travis

* Update cmd/utils/flags.go

Co-authored-by: Martin Holst Swende <martin@swende.se>

* fix error

 fixes these errors:
cmd/utils/flags_legacy.go:21:2: "strings" imported but not used (typecheck)

	"strings"

	^

cmd/utils/flags_legacy.go:24:2: "github.com/ethereum/go-ethereum/node" imported but not used (typecheck)

	"github.com/ethereum/go-ethereum/node"

	^

* goimports

Co-authored-by: Martin Holst Swende <martin@swende.se>

* internal/debug: remove deprecated flags

The removed flags are removed in the main portion of geth, this removes it internally too.

* internal/debug: remove legacy --debug and legacy --backtrace flag

* Update flags.go

Co-authored-by: Martin Holst Swende <martin@swende.se>

* docs: add post-mortem

* Update docs/postmortems/2021-08-22-split-postmortem.md

Co-authored-by: Sina Mahmoodi <1591639+s1na@users.noreply.github.com>

* Update docs/postmortems/2021-08-22-split-postmortem.md

Co-authored-by: Sina Mahmoodi <1591639+s1na@users.noreply.github.com>

* Update docs/postmortems/2021-08-22-split-postmortem.md

Co-authored-by: Sina Mahmoodi <1591639+s1na@users.noreply.github.com>

* Update docs/postmortems/2021-08-22-split-postmortem.md

* Update 2021-08-22-split-postmortem.md

* Update docs/postmortems/2021-08-22-split-postmortem.md

Co-authored-by: Sina Mahmoodi <1591639+s1na@users.noreply.github.com>

Co-authored-by: Sina Mahmoodi <1591639+s1na@users.noreply.github.com>

* Add missing copyright header

* Update stacktrie_test.go

Co-authored-by: Péter Szilágyi <peterke@gmail.com>

* core: fix race conditions in txpool

* core: fixed races in the txpool

* core: rebased on master

* core: move reheap mutex

* core: renamed mutex

* core: revert Reheap changes

strorage -> storage

* core/vm: rework jumpdest analysis benchmarks

For BenchmarkJumpdestOpAnalysis use fixed code size of ~1.2MB
and classic benchmark loop.

* core/vm: clear bitvec in jumpdest analysis benchmark

Currently, setDefaults overwrites the transaction input value if only input is provided. This causes personal_sendTransaction to estimate the gas based on a transaction with empty data. eth_estimateGas never calls setDefaults so it was unaffected by this.

Revert "eth, internal/ethapi: make RPC block miner field show block sealer correctly (#23312)" (#23466)

This reverts commit 57feabea.

* accounts: new AddBackends method in manager

* node,cmd/geth: mv accman backend init to cmd/geth

* node,cmd/geth: mv scrypt config downstreawm from node

* accounts: use static buffer size for accman sub chan

minor fix

* accounts,cmd/geth: update accman backends through its event loop

* accounts,node: add comments

* accounts: un-export newBackendEvent

* accounts: use chan instead of wg in newBlockEvent

* node: rename isKeyDirEphem

* accounts,cmd: AddBackends->AddBackend

* accounts: fix potential blocking when adding backend

Support for this Ubuntu release has ended on July 22 2021 and
Launchpad no longer accepts uploads for it.

Currently rpc.BlockNumber is marshalled to JSON as a numeric value, which is
wrong because BlockNumber.UnmarshalJSON() wants it to either be hex-encoded
or string "earliest"/"latest"/"pending". As a result, the call chain

    rpc.BlockNumberOrHashWithNumber(123) -> json.Marshal() -> json.Unmarshal()

fails with error "cannot unmarshal object into Go value of type string".

WriteTo is unused, and go vet warns about it because it
doesn't match the usual signature of the io.WriterTo method.

As per benchmark results below, these changes speed up encoding/decoding of
consensus objects a bit.

    name                             old time/op    new time/op    delta
    EncodeRLP/legacy-header-8           384ns ± 1%     331ns ± 3%  -13.83%  (p=0.000 n=7+8)
    EncodeRLP/london-header-8           411ns ± 1%     359ns ± 2%  -12.53%  (p=0.000 n=8+8)
    EncodeRLP/receipt-for-storage-8     251ns ± 0%     239ns ± 0%   -4.97%  (p=0.000 n=8+8)
    EncodeRLP/receipt-full-8            319ns ± 0%     300ns ± 0%   -5.89%  (p=0.000 n=8+7)
    EncodeRLP/legacy-transaction-8      389ns ± 1%     387ns ± 1%     ~     (p=0.099 n=8+8)
    EncodeRLP/access-transaction-8      607ns ± 0%     581ns ± 0%   -4.26%  (p=0.000 n=8+8)
    EncodeRLP/1559-transaction-8        627ns ± 0%     606ns ± 1%   -3.44%  (p=0.000 n=8+8)
    DecodeRLP/legacy-header-8           831ns ± 1%     813ns ± 1%   -2.20%  (p=0.000 n=8+8)
    DecodeRLP/london-header-8           824ns ± 0%     804ns ± 1%   -2.44%  (p=0.000 n=8+7)

* rlp: pass length to byteArrayBytes

This makes it possible to inline byteArrayBytes. For arrays, the length is known
at encoder construction time, so the call to v.Len() can be avoided.

* rlp: avoid IsNil for pointer encoding

It's actually cheaper to use Elem first, because it performs less checks
on the value. If the pointer was nil, the result of Elem is 'invalid'.

* rlp: minor optimizations for slice/array encoding

For empty slices/arrays, we can avoid storing a list header entry in the
encoder buffer. Also avoid doing the tail check at encoding time because
it is already known at encoder construction time.

Generated by go1.17 fmt ./...

This PR adds functionality to the evm t8n to calculate ethash difficulty. If the caller does not provide a currentDifficulty, but instead provides the parentTimestamp (well, semi-optional, will default to 0 if not given), and parentDifficulty, we can calculate it for him.

The caller can also provide a parentUncleHash. In most, but not all cases, the parent uncle hash also affects the formula. If no such hash is provided (or, if the empty all-zero hash is provided), it's assumed that there were no uncles.

The new linter version is built with go 1.17 and thus includes the go vet
check for mismatched +build and go:build lines.

Fortunately, no new warnings are reported with this update.