This pull request introduces a mechanism to compress trienode history by
storing only the node diffs between consecutive versions.
- For full nodes, only the modified children are recorded in the history;
- For short nodes, only the modified value is stored;
If the node type has changed, or if the node is newly created or
deleted, the entire node value is stored instead.
To mitigate the overhead of reassembling nodes from diffs during history
reads, checkpoints are introduced by periodically storing full node values.
The current checkpoint interval is set to every 16 mutations, though
this parameter may be made configurable in the future.
This avoids copying the input []byte while decoding trie nodes. In most
cases, particularly when the input slice is provided by the underlying
database, this optimization is safe to use.
For cases where the origin of the input slice is unclear, the copying version
is retained. The new code performs better even when the input must be
copied, because it is now only copied once in decodeNode.
* add node.go unit test file node_test.go
* add node_test.go file license and rollback trie_test.go
* fix unused variable v
* trie: fix license year
Co-authored-by: Péter Szilágyi <peterke@gmail.com>
* trie: store nodes as pointers
This avoids memory copies when unwrapping node interface values.
name old time/op new time/op delta
Get 388ns ± 8% 215ns ± 2% -44.56% (p=0.000 n=15+15)
GetDB 363ns ± 3% 202ns ± 2% -44.21% (p=0.000 n=15+15)
UpdateBE 1.57µs ± 2% 1.29µs ± 3% -17.80% (p=0.000 n=13+15)
UpdateLE 1.92µs ± 2% 1.61µs ± 2% -16.25% (p=0.000 n=14+14)
HashBE 2.16µs ± 6% 2.18µs ± 6% ~ (p=0.436 n=15+15)
HashLE 7.43µs ± 3% 7.21µs ± 3% -2.96% (p=0.000 n=15+13)
* trie: close temporary databases in GetDB benchmark
* trie: don't keep []byte from DB load around
Nodes decoded from a DB load kept hashes and values as sub-slices of
the DB value. This can be a problem because loading from leveldb often
returns []byte with a cap that's larger than necessary, increasing
memory usage.
* trie: unload old cached nodes
* trie, core/state: use cache unloading for account trie
* trie: use explicit private flags (fixes Go 1.5 reflection issue).
* trie: fixup cachegen overflow at request of nick
* core/state: rename journal size constant
