374 lines
11 KiB
Nim
374 lines
11 KiB
Nim
# nimbus-eth1
|
|
# Copyright (c) 2023-2024 Status Research & Development GmbH
|
|
# Licensed under either of
|
|
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
|
|
# http://www.apache.org/licenses/LICENSE-2.0)
|
|
# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
|
|
# http://opensource.org/licenses/MIT)
|
|
# at your option. This file may not be copied, modified, or distributed
|
|
# except according to those terms.
|
|
|
|
## Aristo DB -- Transaction interface
|
|
## ==================================
|
|
##
|
|
{.push raises: [].}
|
|
|
|
import
|
|
std/tables,
|
|
results,
|
|
"."/[aristo_desc, aristo_filter, aristo_get, aristo_layers, aristo_hashify]
|
|
|
|
func isTop*(tx: AristoTxRef): bool
|
|
func level*(db: AristoDbRef): int
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Private helpers
|
|
# ------------------------------------------------------------------------------
|
|
|
|
func getDbDescFromTopTx(tx: AristoTxRef): Result[AristoDbRef,AristoError] =
|
|
if not tx.isTop():
|
|
return err(TxNotTopTx)
|
|
let db = tx.db
|
|
if tx.level != db.stack.len:
|
|
return err(TxStackGarbled)
|
|
ok db
|
|
|
|
proc getTxUid(db: AristoDbRef): uint =
|
|
if db.txUidGen == high(uint):
|
|
db.txUidGen = 0
|
|
db.txUidGen.inc
|
|
db.txUidGen
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public functions, getters
|
|
# ------------------------------------------------------------------------------
|
|
|
|
func txTop*(db: AristoDbRef): Result[AristoTxRef,AristoError] =
|
|
## Getter, returns top level transaction if there is any.
|
|
if db.txRef.isNil:
|
|
err(TxNoPendingTx)
|
|
else:
|
|
ok(db.txRef)
|
|
|
|
func isTop*(tx: AristoTxRef): bool =
|
|
## Getter, returns `true` if the argument `tx` referes to the current top
|
|
## level transaction.
|
|
tx.db.txRef == tx and tx.db.top.txUid == tx.txUid
|
|
|
|
func level*(tx: AristoTxRef): int =
|
|
## Getter, positive nesting level of transaction argument `tx`
|
|
tx.level
|
|
|
|
func level*(db: AristoDbRef): int =
|
|
## Getter, non-negative nesting level (i.e. number of pending transactions)
|
|
if not db.txRef.isNil:
|
|
result = db.txRef.level
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public functions
|
|
# ------------------------------------------------------------------------------
|
|
|
|
func to*(tx: AristoTxRef; T: type[AristoDbRef]): T =
|
|
## Getter, retrieves the parent database descriptor from argument `tx`
|
|
tx.db
|
|
|
|
proc forkTx*(
|
|
tx: AristoTxRef; # Transaction descriptor
|
|
dontHashify = false; # Process/fix MPT hashes
|
|
): Result[AristoDbRef,AristoError] =
|
|
## Clone a transaction into a new DB descriptor accessing the same backend
|
|
## database (if any) as the argument `db`. The new descriptor is linked to
|
|
## the transaction parent and is fully functional as a forked instance (see
|
|
## comments on `aristo_desc.reCentre()` for details.)
|
|
##
|
|
## Input situation:
|
|
## ::
|
|
## tx -> db0 with tx is top transaction, tx.level > 0
|
|
##
|
|
## Output situation:
|
|
## ::
|
|
## tx -> db0 \
|
|
## > share the same backend
|
|
## tx1 -> db1 /
|
|
##
|
|
## where `tx.level > 0`, `db1.level == 1` and `db1` is returned. The
|
|
## transaction `tx1` can be retrieved via `db1.txTop()`.
|
|
##
|
|
## The new DB descriptor will contain a copy of the argument transaction
|
|
## `tx` as top layer of level 1 (i.e. this is he only transaction.) Rolling
|
|
## back will end up at the backend layer (incl. backend filter.)
|
|
##
|
|
## If the arguent flag `dontHashify` is passed `true`, the clone descriptor
|
|
## will *NOT* be hashified right after construction.
|
|
##
|
|
## Use `aristo_desc.forget()` to clean up this descriptor.
|
|
##
|
|
let db = tx.db
|
|
|
|
# Verify `tx` argument
|
|
if db.txRef == tx:
|
|
if db.top.txUid != tx.txUid:
|
|
return err(TxArgStaleTx)
|
|
elif db.stack.len <= tx.level:
|
|
return err(TxArgStaleTx)
|
|
elif db.stack[tx.level].txUid != tx.txUid:
|
|
return err(TxArgStaleTx)
|
|
|
|
# Provide new empty stack layer
|
|
let stackLayer = block:
|
|
let rc = db.getIdgBE()
|
|
if rc.isOk:
|
|
LayerRef(
|
|
delta: LayerDeltaRef(),
|
|
final: LayerFinalRef(vGen: rc.value))
|
|
elif rc.error == GetIdgNotFound:
|
|
LayerRef.init()
|
|
else:
|
|
return err(rc.error)
|
|
|
|
# Set up clone associated to `db`
|
|
let txClone = ? db.fork(rawToplayer = true)
|
|
txClone.top = db.layersCc tx.level # Provide tx level 1 stack
|
|
txClone.stack = @[stackLayer] # Zero level stack
|
|
txClone.roFilter = db.roFilter # No need to copy (done when updated)
|
|
txClone.backend = db.backend
|
|
txClone.top.txUid = 1
|
|
txClone.txUidGen = 1
|
|
|
|
# Install transaction similar to `tx` on clone
|
|
txClone.txRef = AristoTxRef(
|
|
db: txClone,
|
|
txUid: 1,
|
|
level: 1)
|
|
|
|
if not dontHashify:
|
|
discard txClone.hashify().valueOr:
|
|
discard txClone.forget()
|
|
return err(error[1])
|
|
|
|
ok(txClone)
|
|
|
|
|
|
proc forkTop*(
|
|
db: AristoDbRef;
|
|
dontHashify = false; # Process/fix MPT hashes
|
|
): Result[AristoDbRef,AristoError] =
|
|
## Variant of `forkTx()` for the top transaction if there is any. Otherwise
|
|
## the top layer is cloned, only.
|
|
##
|
|
## Use `aristo_desc.forget()` to clean up this descriptor.
|
|
##
|
|
if db.txRef.isNil:
|
|
let dbClone = ? db.fork(rawToplayer = true)
|
|
|
|
dbClone.top = db.layersCc # Is a deep copy
|
|
dbClone.roFilter = db.roFilter # No need to copy contents when updated
|
|
dbClone.backend = db.backend
|
|
|
|
if not dontHashify:
|
|
discard dbClone.hashify().valueOr:
|
|
discard dbClone.forget()
|
|
return err(error[1])
|
|
return ok(dbClone)
|
|
|
|
db.txRef.forkTx dontHashify
|
|
|
|
|
|
proc exec*(
|
|
tx: AristoTxRef;
|
|
action: AristoDbAction;
|
|
dontHashify = false; # Process/fix MPT hashes
|
|
): Result[void,AristoError] =
|
|
## Execute function argument `action()` on a temporary `tx.forkTx()`
|
|
## transaction clone database. After return, the temporary database gets
|
|
## destroyed.
|
|
##
|
|
## If the arguent flag `dontHashify` is passed `true`, the clone database
|
|
## will *NOT* be hashified right after construction.
|
|
##
|
|
let db = ? tx.forkTx dontHashify
|
|
db.action()
|
|
? db.forget()
|
|
ok()
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public functions: Transaction frame
|
|
# ------------------------------------------------------------------------------
|
|
|
|
proc txBegin*(db: AristoDbRef): Result[AristoTxRef,AristoError] =
|
|
## Starts a new transaction.
|
|
##
|
|
## Example:
|
|
## ::
|
|
## proc doSomething(db: AristoDbRef) =
|
|
## let tx = db.begin
|
|
## defer: tx.rollback()
|
|
## ... continue using db ...
|
|
## tx.commit()
|
|
##
|
|
if db.level != db.stack.len:
|
|
return err(TxStackGarbled)
|
|
|
|
db.stack.add db.top
|
|
db.top = LayerRef(
|
|
delta: LayerDeltaRef(),
|
|
final: db.top.final.dup,
|
|
txUid: db.getTxUid)
|
|
|
|
db.txRef = AristoTxRef(
|
|
db: db,
|
|
txUid: db.top.txUid,
|
|
parent: db.txRef,
|
|
level: db.stack.len)
|
|
|
|
ok db.txRef
|
|
|
|
|
|
proc rollback*(
|
|
tx: AristoTxRef; # Top transaction on database
|
|
): Result[void,AristoError] =
|
|
## Given a *top level* handle, this function discards all database operations
|
|
## performed for this transactio. The previous transaction is returned if
|
|
## there was any.
|
|
##
|
|
let db = ? tx.getDbDescFromTopTx()
|
|
|
|
# Roll back to previous layer.
|
|
db.top = db.stack[^1]
|
|
db.stack.setLen(db.stack.len-1)
|
|
|
|
db.txRef = db.txRef.parent
|
|
ok()
|
|
|
|
|
|
proc commit*(
|
|
tx: AristoTxRef; # Top transaction on database
|
|
): Result[void,AristoError] =
|
|
## Given a *top level* handle, this function accepts all database operations
|
|
## performed through this handle and merges it to the previous layer. The
|
|
## previous transaction is returned if there was any.
|
|
##
|
|
let db = ? tx.getDbDescFromTopTx()
|
|
discard db.hashify().valueOr:
|
|
return err(error[1])
|
|
|
|
# Pop layer from stack and merge database top layer onto it
|
|
let merged = block:
|
|
if db.top.delta.sTab.len == 0 and
|
|
db.top.delta.kMap.len == 0 and
|
|
db.top.delta.pAmk.len == 0:
|
|
# Avoid `layersMergeOnto()`
|
|
db.top.delta = db.stack[^1].delta
|
|
db.stack.setLen(db.stack.len-1)
|
|
db.top
|
|
else:
|
|
let layer = db.stack[^1]
|
|
db.stack.setLen(db.stack.len-1)
|
|
db.top.layersMergeOnto(layer[], db.stack)
|
|
layer
|
|
|
|
# Install `merged` stack top layer and update stack
|
|
db.top = merged
|
|
db.txRef = tx.parent
|
|
if 0 < db.stack.len:
|
|
db.txRef.txUid = db.getTxUid
|
|
db.top.txUid = db.txRef.txUid
|
|
|
|
ok()
|
|
|
|
|
|
proc collapse*(
|
|
tx: AristoTxRef; # Top transaction on database
|
|
commit: bool; # Commit if `true`, otherwise roll back
|
|
): Result[void,AristoError] =
|
|
## Iterated application of `commit()` or `rollback()` performing the
|
|
## something similar to
|
|
## ::
|
|
## while true:
|
|
## discard tx.commit() # ditto for rollback()
|
|
## if db.topTx.isErr: break
|
|
## tx = db.topTx.value
|
|
##
|
|
let db = ? tx.getDbDescFromTopTx()
|
|
|
|
if commit:
|
|
# For commit, hashify the current layer if requested and install it
|
|
discard db.hashify().valueOr:
|
|
return err(error[1])
|
|
|
|
db.top.txUid = 0
|
|
db.stack.setLen(0)
|
|
db.txRef = AristoTxRef(nil)
|
|
ok()
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public functions: save database
|
|
# ------------------------------------------------------------------------------
|
|
|
|
proc stow*(
|
|
db: AristoDbRef; # Database
|
|
persistent = false; # Stage only unless `true`
|
|
chunkedMpt = false; # Partial data (e.g. from `snap`)
|
|
): Result[void,AristoError] =
|
|
## If there is no backend while the `persistent` argument is set `true`,
|
|
## the function returns immediately with an error. The same happens if there
|
|
## is a pending transaction.
|
|
##
|
|
## The function then merges the data from the top layer cache into the
|
|
## backend stage area. After that, the top layer cache is cleared.
|
|
##
|
|
## Staging the top layer cache might fail withh a partial MPT when it is
|
|
## set up from partial MPT chunks as it happens with `snap` sync processing.
|
|
## In this case, the `chunkedMpt` argument must be set `true` (see alse
|
|
## `fwdFilter`.)
|
|
##
|
|
## If the argument `persistent` is set `true`, all the staged data are merged
|
|
## into the physical backend database and the staged data area is cleared.
|
|
##
|
|
if not db.txRef.isNil:
|
|
return err(TxPendingTx)
|
|
if 0 < db.stack.len:
|
|
return err(TxStackGarbled)
|
|
if persistent and not db.canResolveBackendFilter():
|
|
return err(TxBackendNotWritable)
|
|
|
|
discard db.hashify().valueOr:
|
|
return err(error[1])
|
|
|
|
let fwd = db.fwdFilter(db.top, chunkedMpt).valueOr:
|
|
return err(error[1])
|
|
|
|
if fwd.isValid:
|
|
# Merge `top` layer into `roFilter`
|
|
db.merge(fwd).isOkOr:
|
|
return err(error[1])
|
|
db.top = LayerRef(
|
|
delta: LayerDeltaRef(),
|
|
final: LayerFinalRef())
|
|
if db.roFilter.isValid:
|
|
db.top.final.vGen = db.roFilter.vGen
|
|
else:
|
|
let rc = db.getIdgUBE()
|
|
if rc.isOk:
|
|
db.top.final.vGen = rc.value
|
|
else:
|
|
# It is OK if there was no `Idg`. Otherwise something serious happened
|
|
# and there is no way to recover easily.
|
|
doAssert rc.error == GetIdgNotFound
|
|
|
|
if persistent:
|
|
? db.resolveBackendFilter()
|
|
db.roFilter = FilterRef(nil)
|
|
|
|
# Delete/clear top
|
|
db.top = LayerRef(
|
|
delta: LayerDeltaRef(),
|
|
final: LayerFinalRef(vGen: db.vGen),
|
|
txUid: db.top.txUid)
|
|
|
|
ok()
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# End
|
|
# ------------------------------------------------------------------------------
|