When serializing multiple accounts, cost of a buffer grow
can become significant. This commit tries to amortize it by
reusing the same buffer in a single `Persist()` call.
Fixes difference in state changes at mainnet's block 2442790 because contract
migration in b4eb2dc35226e6520ee4e09a56197dff91547b50a7f57edc82930fc18c75dffc
doesn't actually transfer the storage state, it only deletes the old one.
And add an error check just in case.
This is an append-only log which is read only during some RPCs.
It is rather slow to get it from base every time we need to append to
it. This commit stores all NEP5Transfers in batches, so that
only a last batch needs to be unmarshaled during block processing.
That's how it was intended to behave originally. One thing questionable here
is contract price (policy thing, basically) being moved to smartcontract
package, but it's probably fine for NEO 2.0 (as it won't change) and we'll
make something better for NEO 3.0.
1.5M block import time (VerifyBlocks disabled) on AMD Ryzen 5 1600/16GB/HDD,
before:
real 159m16.551s
user 69m58.279s
sys 7m34.334s
after:
real 139m41.836s
user 67m12.477s
sys 6m19.420s
12% which is even a bit more than could be expected from inputs analysis (that
has around 10% cache hits for a block-wide cache), worth doing.
This change reduces pressure on DB by doing the following things:
* not storing additional KV pair for SpentCoin
* storing Output right in the UnspentCoin, thus eliminating the need to get a
full transaction from DB
At the same time it makes UnspentCoin more fat and hot, but it should probably
worth it.
Also drop `GetUnspentCoinStateOrNew` as it shouldn't ever existed, UTXOs
can't come out of nowhere.
1.5M block import time (VerifyBlocks disabled) on AMD Ryzen 5 1600/16GB/HDD,
before:
real 302m9.895s
user 96m17.200s
sys 13m37.084s
after:
real 159m16.551s
user 69m58.279s
sys 7m34.334s
So it's almost two-fold which is a great improvement.
C# uses ToArray() or UintXXX(bytes) here which interprets hashes as they
should be interpreted (BE, although they always convert to LE when converting
to String just for the fun of it). It leads to state difference for us at
block 2025204 where even though we have the same value for the key, the key
itself differs, ours:
dd2b538e2a0c1db1ae5061c15be14f916bd1e678e512ffcda6d9499d8e7fe97ee71fd6b8004583d9afe09cc4dadbd5deb63d01e061009b7cffdaa674beae0f930ebe6085af900093e5fe56b34a5c220ccdcf6efc336fc5000000000000000000000000000000000010
theirs:
dd2b538e2a0c1db1ae5061c15be14f916bd1e67861e0013db6ded5dbdac49ce0afd9834500b8d61fe77ee97f8e9d49d9a6cdff12e5009b7cffdaa674beae0f930ebe6085af900093e5fe56b34a5c220ccdcf6efc336fc5000000000000000000000000000000000010
In this key there is a tx hash encoded
(e512ffcda6d9499d8e7fe97ee71fd6b84583d9afe09cc4dadbd5deb63d01e061 in LE used
by all the tools like neoscan).
I love Neo.
