This change includes a lot of things, listed below.
### Split up interfaces, write vs read
The interfaces have been split up into one write-interface and one read-interface, with `Snapshot` being the gateway from write to read. This simplifies the semantics _a lot_.
Example of splitting up an interface into one readonly 'snapshot' part, and one updatable writeonly part:
```golang
type MeterSnapshot interface {
Count() int64
Rate1() float64
Rate5() float64
Rate15() float64
RateMean() float64
}
// Meters count events to produce exponentially-weighted moving average rates
// at one-, five-, and fifteen-minutes and a mean rate.
type Meter interface {
Mark(int64)
Snapshot() MeterSnapshot
Stop()
}
```
### A note about concurrency
This PR makes the concurrency model clearer. We have actual meters and snapshot of meters. The `meter` is the thing which can be accessed from the registry, and updates can be made to it.
- For all `meters`, (`Gauge`, `Timer` etc), it is assumed that they are accessed by different threads, making updates. Therefore, all `meters` update-methods (`Inc`, `Add`, `Update`, `Clear` etc) need to be concurrency-safe.
- All `meters` have a `Snapshot()` method. This method is _usually_ called from one thread, a backend-exporter. But it's fully possible to have several exporters simultaneously: therefore this method should also be concurrency-safe.
TLDR: `meter`s are accessible via registry, all their methods must be concurrency-safe.
For all `Snapshot`s, it is assumed that an individual exporter-thread has obtained a `meter` from the registry, and called the `Snapshot` method to obtain a readonly snapshot. This snapshot is _not_ guaranteed to be concurrency-safe. There's no need for a snapshot to be concurrency-safe, since exporters should not share snapshots.
Note, though: that by happenstance a lot of the snapshots _are_ concurrency-safe, being unmutable minimal representations of a value. Only the more complex ones are _not_ threadsafe, those that lazily calculate things like `Variance()`, `Mean()`.
Example of how a background exporter typically works, obtaining the snapshot and sequentially accessing the non-threadsafe methods in it:
```golang
ms := metric.Snapshot()
...
fields := map[string]interface{}{
"count": ms.Count(),
"max": ms.Max(),
"mean": ms.Mean(),
"min": ms.Min(),
"stddev": ms.StdDev(),
"variance": ms.Variance(),
```
TLDR: `snapshots` are not guaranteed to be concurrency-safe (but often are).
### Sample changes
I also changed the `Sample` type: previously, it iterated the samples fully every time `Mean()`,`Sum()`, `Min()` or `Max()` was invoked. Since we now have readonly base data, we can just iterate it once, in the constructor, and set all four values at once.
The same thing has been done for runtimehistogram.
### ResettingTimer API
Back when ResettingTImer was implemented, as part of https://github.com/ethereum/go-ethereum/pull/15910, Anton implemented a `Percentiles` on the new type. However, the method did not conform to the other existing types which also had a `Percentiles`.
1. The existing ones, on input, took `0.5` to mean `50%`. Anton used `50` to mean `50%`.
2. The existing ones returned `float64` outputs, thus interpolating between values. A value-set of `0, 10`, at `50%` would return `5`, whereas Anton's would return either `0` or `10`.
This PR removes the 'new' version, and uses only the 'legacy' percentiles, also for the ResettingTimer type.
The resetting timer snapshot was also defined so that it would expose the internal values. This has been removed, and getters for `Max, Min, Mean` have been added instead.
### Unexport types
A lot of types were exported, but do not need to be. This PR unexports quite a lot of them.
This changes implements faster post-selfdestruct iteration of storage slots for deletion, by using snapshot-storage+stacktrie to recover the trienodes to be deleted. This mechanism is only implemented for path-based schema.
For hash-based schema, the entire post-selfdestruct storage iteration is skipped, with this change, since hash-based does not actually perform deletion anyway.
---------
Co-authored-by: Martin Holst Swende <martin@swende.se>
Context: The UpdateContractCode method was introduced for the state storage commitment
schemes that include the whole code for their commitment computation. It must therefore be called
before the root hash is computed at the end of IntermediateRoot.
This should have no impact on the MPT since, in this context, the method is a no-op.
* all: implement path-based state scheme
* all: edits from review
* core/rawdb, trie/triedb/pathdb: review changes
* core, light, trie, eth, tests: reimplement pbss history
* core, trie/triedb/pathdb: track block number in state history
* trie/triedb/pathdb: add history documentation
* core, trie/triedb/pathdb: address comments from Peter's review
Important changes to list:
- Cache trie nodes by path in clean cache
- Remove root->id mappings when history is truncated
* trie/triedb/pathdb: fallback to disk if unexpect node in clean cache
* core/rawdb: fix tests
* trie/triedb/pathdb: rename metrics, change clean cache key
* trie/triedb: manage the clean cache inside of disk layer
* trie/triedb/pathdb: move journal function
* trie/triedb/path: fix tests
* trie/triedb/pathdb: fix journal
* trie/triedb/pathdb: fix history
* trie/triedb/pathdb: try to fix tests on windows
* core, trie: address comments
* trie/triedb/pathdb: fix test issues
---------
Co-authored-by: Felix Lange <fjl@twurst.com>
Co-authored-by: Martin Holst Swende <martin@swende.se>
EIP-6780: SELFDESTRUCT only in same transaction
> SELFDESTRUCT will recover all funds to the caller but not delete the account, except when called in the same transaction as creation
---------
Co-authored-by: Martin Holst Swende <martin@swende.se>
This change makes the StateDB track the state key value diff of a block transition.
We already tracked current account and storage values for the purpose of updating
the state snapshot. With this PR, we now also track the original (pre-transition) values
of accounts and storage slots.
Verkle trees store the code inside the trie. This PR changes the interface to pass the code, as well as the dirty flag to tell the trie package if the code is dirty and needs to be updated. This is a no-op for the MPT and the odr trie.
The state availability is checked during the creation of a state reader.
- In hash-based database, if the specified root node does not exist on disk disk, then
the state reader won't be created and an error will be returned.
- In path-based database, if the specified state layer is not available, then the
state reader won't be created and an error will be returned.
This change also contains a stricter semantics regarding the `Commit` operation: once it has been performed, the trie is no longer usable, and certain operations will return an error.
This removes the feature where top nodes of the proof can be elided.
It was intended to be used by the LES server, to save bandwidth
when the client had already fetched parts of the state and only needed
some extra nodes to complete the proof. Alas, it never got implemented
in the client.
This changes the journal logic to mark the state object dirty immediately when it
is reset.
We're mostly adding this change to appease the fuzzer. Marking it dirty immediately
makes no difference in practice because accounts will always be modified by EVM
right after creation.
This change renames StateTrie methods to remove the Try* prefix.
We added the Trie methods with prefix 'Try' a long time ago, working
around the problem that most existing methods of Trie did not return the
database error. This weird naming convention has persisted until now.
Co-authored-by: Gary Rong <garyrong0905@gmail.com>
This changes the Trie interface to add the plain account address as a
parameter to all storage-related methods.
After the introduction of the TryAccount* functions, TryGet, TryUpdate and
TryDelete are now only meant to read an account's storage. In their current
form, they assume that an account storage is stored in a separate trie, and
that the hashing of the slot is independent of its account's address.
The proposed structure for a stateless storage breaks these two
assumptions: the hashing of a slot key requires the address and all slots
and accounts are stored in a single trie.
This PR therefore adds an address parameter to the interface. It is ignored
in the MPT version, so this change has no functional impact, however it
will reduce the diff size when merging verkle trees.
The EmptyRootHash and EmptyCodeHash are defined everywhere in the codebase, this PR replaces all of them with unified one defined in core/types package, and also defines constants for TxRoot, WithdrawalsRoot and UncleRoot
This PR contains a small portion of the full pbss PR, namely
Remove the tracer from trie (and comitter), and instead using an accessList.
Related changes to the Nodeset.
---------
Co-authored-by: Gary Rong <garyrong0905@gmail.com>
This PR removes the notion of fakeStorage from the state objects, and instead, for any state modifications that are needed, it simply makes the changes.
This changes moves the tracking of "deleted in this block" out from snap-only domain, so that it happens regardless of whether the execution is snapshot-backed or trie-backed.
This changes the StorageTrie method to return an error when the trie
is not available. It used to return an 'empty trie' in this case, but that's
not possible anymore under PBSS.
