When we flush a batch of trie nodes into database during the state
sync, we should guarantee that all children should be flushed before
parent.
Actually the trie nodes commit order is strict by: children -> parent.
But when we flush all ready nodes into db, we don't need the order
anymore since
(1) they are all ready nodes (no more dependency)
(2) underlying database provides write atomicity
* all: freezer style syncing
core, eth, les, light: clean up freezer relative APIs
core, eth, les, trie, ethdb, light: clean a bit
core, eth, les, light: add unit tests
core, light: rewrite setHead function
core, eth: fix downloader unit tests
core: add receipt chain insertion test
core: use constant instead of hardcoding table name
core: fix rollback
core: fix setHead
core/rawdb: remove canonical block first and then iterate side chain
core/rawdb, ethdb: add hasAncient interface
eth/downloader: calculate ancient limit via cht first
core, eth, ethdb: lots of fixes
* eth/downloader: print ancient disable log only for fast sync
* core, eth, trie: bloom filter for trie node dedup during fast sync
* eth/downloader, trie: address review comments
* core, ethdb, trie: restart fast-sync bloom construction now and again
* eth/downloader: initialize fast sync bloom on startup
* eth: reenable eth/62 until we properly remove it
This PR is a more advanced form of the dirty-to-clean cacher (#18995),
where we reuse previous database write batches as datasets to uncache,
saving a dirty-trie-iteration and a dirty-trie-rlp-reencoding per block.
The current trie memory database/cache that we do pruning on stores
trie nodes as binary rlp encoded blobs, and also stores the node
relationships/references for GC purposes. However, most of the trie
nodes (everything apart from a value node) is in essence just a
collection of references.
This PR switches out the RLP encoded trie blobs with the
collapsed-but-not-serialized trie nodes. This permits most of the
references to be recovered from within the node data structure,
avoiding the need to track them a second time (expensive memory wise).
This removes a golint warning: type name will be used as trie.TrieSync by
other packages, and that stutters; consider calling this Sync.
In hexToKeybytes len(hex) is even and (even+1)/2 == even/2, remove the +1.
