1 Commits (9b68875d68b409eb2efdb68a4b623aaacc10a5b6)

Author	SHA1	Message	Date
rjl493456442	bc1ec69008	trie/pathdb: state iterator (snapshot integration pt 4) (#30654) ... In this pull request, the state iterator is implemented. It's mostly a copy-paste from the original state snapshot package, but still has some important changes to highlight here: (a) The iterator for the disk layer consists of a diff iterator and a disk iterator. Originally, the disk layer in the state snapshot was a wrapper around the disk, and its corresponding iterator was also a wrapper around the disk iterator. However, due to structural differences, the disk layer iterator is divided into two parts: - The disk iterator, which traverses the content stored on disk. - The diff iterator, which traverses the aggregated state buffer. Checkout `BinaryIterator` and `FastIterator` for more details. (b) The staleness management is improved in the diffAccountIterator and diffStorageIterator Originally, in the `diffAccountIterator`, the layer’s staleness had to be checked within the Next function to ensure the iterator remained usable. Additionally, a read lock on the associated diff layer was required to first retrieve the account blob. This read lock protection is essential to prevent concurrent map read/write. Afterward, a staleness check was performed to ensure the retrieved data was not outdated. The entire logic can be simplified as follows: a loadAccount callback is provided to retrieve account data. If the corresponding state is immutable (e.g., diff layers in the path database), the staleness check can be skipped, and a single account data retrieval is sufficient. However, if the corresponding state is mutable (e.g., the disk layer in the path database), the callback can operate as follows: ```go func(hash common.Hash) ([]byte, error) { dl.lock.RLock() defer dl.lock.RUnlock() if dl.stale { return nil, errSnapshotStale } return dl.buffer.states.mustAccount(hash) } ``` The callback solution can eliminate the complexity for managing concurrency with the read lock for atomic operation.	2 months ago