dual state & read only EVM
This commit implements a dual state approach. The dual state approach
separates public and private state by making the core vm environment
context aware.
Although not currently implemented it will need to prohibit value
transfers and it must initialise all transactions from accounts on the
public state. This means that sending transactions increments the
account nonce on the public state and contract addresses are derived
from the public state when initialised by a transaction. For obvious
reasons, contract created by private contracts are still derived from
public state.
This is required in order to have consensus over the public state at all
times as non-private participants would still process the transaction on
the public state even though private payload can not be decrypted. This
means that participants of a private group must do the same in order to
have public consensus. However the creation of the contract and
interaction still occurs on the private state.
It implements support for the following calling model:
S: sender, (X): private, X: public, ->: direction, [ ]: read only mode
1. S -> A -> B
2. S -> (A) -> (B)
3. S -> (A) -> [ B -> C ]
It does not support
1. (S) -> A
2. (S) -> (A)
3. S -> (A) -> B
Implemented "read only" mode for the EVM. Read only mode is checked
during any opcode that could potentially modify the state. If such an
opcode is encountered during "read only", it throws an exception.
The EVM is flagged "read only" when a private contract calls in to
public state.
- Replace "crypto/rand" to "math/rand" for files content generation
- Remove swarm/network_test.go.Shuffle and swarm/btm/btm_test.go.Shuffle - because go1.9 support dropped (see https://github.com/ethereum/go-ethereum/pull/17807 and comments to swarm/network_test.go.Shuffle)
On file access LDBStore's tryAccessIdx() function created a faulty
GC Index Data entry, because not indexing the ikey correctly.
That caused the chunk addresses/hashes to start with '00' and the last
two digits were dropped. => Incorrect chunk address.
Besides the fix, the commit also contains a schema change which will
run the CleanGCIndex() function to clean the GC index from erroneous
entries.
Note: CleanGCIndex() rebuilds the index from scratch which can take
a really-really long time with a huge DB (possibly an hour).
Access count was not incremented when chunk was retrieved
from cache. So the garbage collector might have deleted the most
frequently accessed chunk from disk.
Co-authored-by: Ferenc Szabo <ferenc.szabo@ethereum.org>
SatpalSandhu61
Jitendra Bhurat
Michael Gu
Trung Nguyen
namtruong
fixanoid
Samer Falah
amalraj.manigmail.com
vsmk98
Péter Szilágyi
Alexey Sharov
Ferenc Szabo
mr_franklin
gary rong
lash
Andrew Chiw