276 lines
9.8 KiB
Nim
276 lines
9.8 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/options,
|
|
results,
|
|
./aristo_tx/[tx_fork, tx_frame, tx_stow],
|
|
"."/[aristo_desc, aristo_get]
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public functions, getters
|
|
# ------------------------------------------------------------------------------
|
|
|
|
func txTop*(db: AristoDbRef): Result[AristoTxRef,AristoError] =
|
|
## Getter, returns top level transaction if there is any.
|
|
db.txFrameTop()
|
|
|
|
func isTop*(tx: AristoTxRef): bool =
|
|
## Getter, returns `true` if the argument `tx` referes to the current top
|
|
## level transaction.
|
|
tx.txFrameIsTop()
|
|
|
|
func level*(tx: AristoTxRef): int =
|
|
## Getter, positive nesting level of transaction argument `tx`
|
|
tx.txFrameLevel()
|
|
|
|
func level*(db: AristoDbRef): int =
|
|
## Getter, non-negative nesting level (i.e. number of pending transactions)
|
|
db.txFrameLevel()
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public functions
|
|
# ------------------------------------------------------------------------------
|
|
|
|
func to*(tx: AristoTxRef; T: type[AristoDbRef]): T =
|
|
## Getter, retrieves the parent database descriptor from argument `tx`
|
|
tx.db
|
|
|
|
|
|
proc forkTx*(
|
|
db: AristoDbRef;
|
|
backLevel: int; # Backward location of transaction
|
|
dontHashify = false; # Process/fix MPT hashes
|
|
): Result[AristoDbRef,AristoError] =
|
|
## Fork a new descriptor obtained from parts of the argument database
|
|
## as described by arguments `db` and `backLevel`.
|
|
##
|
|
## If the argument `backLevel` is non-negative, the forked descriptor will
|
|
## provide the database view where the first `backLevel` transaction layers
|
|
## are stripped and the remaing layers are squashed into a single transaction.
|
|
##
|
|
## If `backLevel` is `-1`, a database descriptor with empty transaction
|
|
## layers will be provided where the `roFilter` between database and
|
|
## transaction layers are kept in place.
|
|
##
|
|
## If `backLevel` is `-2`, a database descriptor with empty transaction
|
|
## layers will be provided without an `roFilter`.
|
|
##
|
|
## The returned database descriptor will always have transaction level one.
|
|
## If there were no transactions that could be squashed, an empty
|
|
## transaction is added.
|
|
##
|
|
## If the arguent flag `dontHashify` is passed `true`, the forked descriptor
|
|
## will *NOT* be hashified right after construction.
|
|
##
|
|
## Use `aristo_desc.forget()` to clean up this descriptor.
|
|
##
|
|
# Fork top layer (with or without pending transaction)?
|
|
if backLevel == 0:
|
|
return db.txForkTop dontHashify
|
|
|
|
# Fork bottom layer (=> 0 < db.stack.len)
|
|
if backLevel == db.stack.len:
|
|
return db.txForkBase dontHashify
|
|
|
|
# Inspect transaction stack
|
|
if 0 < backLevel:
|
|
var tx = db.txRef
|
|
if tx.isNil or db.stack.len < backLevel:
|
|
return err(TxLevelTooDeep)
|
|
|
|
# Fetch tx of level `backLevel` (seed to skip some items)
|
|
for _ in 0 ..< backLevel:
|
|
tx = tx.parent
|
|
if tx.isNil:
|
|
return err(TxStackGarbled)
|
|
return tx.txFork dontHashify
|
|
|
|
# Plain fork, include `roFilter`
|
|
if backLevel == -1:
|
|
let xb = ? db.fork(noFilter=false)
|
|
discard xb.txFrameBegin()
|
|
return ok(xb)
|
|
|
|
# Plain fork, unfiltered backend
|
|
if backLevel == -2:
|
|
let xb = ? db.fork(noFilter=true)
|
|
discard xb.txFrameBegin()
|
|
return ok(xb)
|
|
|
|
err(TxLevelUseless)
|
|
|
|
|
|
proc findTx*(
|
|
db: AristoDbRef;
|
|
vid: VertexID; # Pivot vertex (typically `VertexID(1)`)
|
|
key: HashKey; # Hash key of pivot vertex
|
|
): Result[int,AristoError] =
|
|
## Find the transaction where the vertex with ID `vid` exists and has the
|
|
## Merkle hash key `key`. If there is no transaction available, search in
|
|
## the filter and then in the backend.
|
|
##
|
|
## If the above procedure succeeds, an integer indicating the transaction
|
|
## level integer is returned:
|
|
##
|
|
## * `0` -- top level, current layer
|
|
## * `1`, `2`, ... -- some transaction level further down the stack
|
|
## * `-1` -- the filter between transaction stack and database backend
|
|
## * `-2` -- the databse backend
|
|
##
|
|
## A successful return code might be used for the `forkTx()` call for
|
|
## creating a forked descriptor that provides the pair `(vid,key)`.
|
|
##
|
|
if not vid.isValid or
|
|
not key.isValid:
|
|
return err(TxArgsUseless)
|
|
|
|
if db.txRef.isNil:
|
|
# Try `(vid,key)` on top layer
|
|
let topKey = db.top.delta.kMap.getOrVoid vid
|
|
if topKey == key:
|
|
return ok(0)
|
|
|
|
else:
|
|
# Find `(vid,key)` on transaction layers
|
|
var n = 0
|
|
for (n,tx,layer,error) in db.txRef.txFrameWalk:
|
|
if error != AristoError(0):
|
|
return err(error)
|
|
if layer.delta.kMap.getOrVoid(vid) == key:
|
|
return ok(n)
|
|
|
|
# Try bottom layer
|
|
let botKey = db.stack[0].delta.kMap.getOrVoid vid
|
|
if botKey == key:
|
|
return ok(db.stack.len)
|
|
|
|
# Try `(vid,key)` on roFilter
|
|
if not db.roFilter.isNil:
|
|
let roKey = db.roFilter.kMap.getOrVoid vid
|
|
if roKey == key:
|
|
return ok(-1)
|
|
|
|
# Try `(vid,key)` on unfiltered backend
|
|
block:
|
|
let beKey = db.getKeyUbe(vid).valueOr: VOID_HASH_KEY
|
|
if beKey == key:
|
|
return ok(-2)
|
|
|
|
err(TxNotFound)
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# 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()
|
|
##
|
|
db.txFrameBegin()
|
|
|
|
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.
|
|
##
|
|
tx.txFrameRollback()
|
|
|
|
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.
|
|
##
|
|
tx.txFrameCommit()
|
|
|
|
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.txTop.isErr: break
|
|
## tx = db.txTop.value
|
|
##
|
|
tx.txFrameCollapse commit
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public functions: save to database
|
|
# ------------------------------------------------------------------------------
|
|
|
|
proc persist*(
|
|
db: AristoDbRef; # Database
|
|
nxtFid = none(FilterID); # Next filter ID (zero is OK)
|
|
chunkedMpt = false; # Partial data (e.g. from `snap`)
|
|
): Result[void,AristoError] =
|
|
## Persistently store data onto backend database. If the system is running
|
|
## without a database backend, the function returns immediately with an
|
|
## error. The same happens if there is a pending transaction.
|
|
##
|
|
## The function merges all staged data from the top layer cache onto the
|
|
## backend stage area. After that, the top layer cache is cleared.
|
|
##
|
|
## Finally, the staged data are merged into the physical backend database
|
|
## and the staged data area is cleared. Wile performing this last step,
|
|
## the recovery journal is updated (if available.)
|
|
##
|
|
## If the argument `nxtFid` is passed non-zero, it will be the ID for the
|
|
## next recovery journal record. If non-zero, this ID must be greater than
|
|
## all previous IDs (e.g. block number when stowing after block execution.)
|
|
##
|
|
## Staging the top layer cache might fail with 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()`.)
|
|
##
|
|
db.txStow(nxtFid, persistent=true, chunkedMpt=chunkedMpt)
|
|
|
|
proc stow*(
|
|
db: AristoDbRef; # Database
|
|
chunkedMpt = false; # Partial data (e.g. from `snap`)
|
|
): Result[void,AristoError] =
|
|
## This function is similar to `persist()` stopping short of performing the
|
|
## final step storing on the persistent database. It fails if there is a
|
|
## pending transaction.
|
|
##
|
|
## The function merges all staged data from the top layer cache onto the
|
|
## backend stage area and leaves it there. This function can be seen as
|
|
## a sort of a bottom level transaction `commit()`.
|
|
##
|
|
## Staging the top layer cache might fail with 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()`.)
|
|
##
|
|
db.txStow(nxtFid=none(FilterID), persistent=false, chunkedMpt=chunkedMpt)
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# End
|
|
# ------------------------------------------------------------------------------
|