refactor into TriggerRunner

alembic/env.py

@@ -17,8 +17,8 @@ if config.config_file_name is not None:
 # DEXORDER SETUP
 from sys import path
 path.append('src')
-import dexorder.db.model
+import dexorder.database.model
-target_metadata = dexorder.db.model.Base.metadata
+target_metadata = dexorder.database.model.Base.metadata
 config.set_main_option('sqlalchemy.url', dexorder.config.db_url)
 
 # other values from the config, defined by the needs of env.py,

alembic/script.py.mako

@@ -9,7 +9,7 @@ from typing import Sequence, Union
 
 from alembic import op
 import sqlalchemy as sa
-import dexorder.db
+import dexorder.database
 ${imports if imports else ""}
 
 # revision identifiers, used by Alembic.

src/dexorder/__init__.py

@@ -17,5 +17,5 @@ from .util import async_yield
 from .base.fixed import Fixed2, FixedDecimals, Dec18
 from .configuration import config
 from .base.account import Account # must come before context
-from .base.context import ctx
 from .base.token import Token, tokens
+from .database import db

src/dexorder/base/blockstate.py

@@ -1,14 +1,14 @@
+import logging
 from collections import defaultdict
 from contextvars import ContextVar
-from logging import Logger
 from typing import Union, TypeVar, Generic, Any
 
 from sortedcontainers import SortedList
 
 from dexorder import NARG
-from dexorder.db.model.block import Block
+from dexorder.database.model.block import Block
 
-log = Logger('dexorder.blockstate')
+log = logging.getLogger(__name__)
 
 
 class BlockState:

src/dexorder/base/event_manager.py

@@ -1,3 +1,6 @@
+from typing import Union
+
+from defaultlist import defaultlist
 from eth_utils import keccak
 
 from dexorder.base.blockstate import BlockDict
@@ -7,18 +10,17 @@ class EventManager:
     def __init__(self):
         self.all_topics = set()
         self.triggers:dict[str,BlockDict] = {}
+        self.rings = defaultlist(list)
 
-    def add_handler(self, topic: str, callback):
+    def add_handler(self, topic: Union[bytes,str], callback):
-        if not topic.startswith('0x'):
+        if type(topic) is str:
-            topic = '0x'+keccak(text=topic).hex().lower()
+            topic = bytes.fromhex(topic[2:]) if topic.startswith('0x') else keccak(text=topic)
         triggers = self.triggers.get(topic)
         if triggers is None:
             triggers = self.triggers[topic] = BlockDict(topic)
         triggers.add(callback)
         self.all_topics.add(topic)
 
-    def handle_logs(self, logs):
+    def publish_topic(self, topic, data):
-        for log in logs:
+        for callback, _ in self.triggers.get(topic, {}).items():
-            for callback, _ in self.triggers.get(log.topics[0].hex(), []).items():
+            callback(data)
-                callback(log)
-

src/dexorder/base/token.py

@@ -4,11 +4,11 @@ from decimal import Decimal
 from sqlalchemy.orm import Mapped
 from web3 import Web3
 
-from dexorder import config, ctx, Blockchain, NARG, FixedDecimals, ADDRESS_0
+from dexorder import config, Blockchain, NARG, FixedDecimals, ADDRESS_0
 from dexorder.blockchain import ByBlockchainDict
 from dexorder.base.chain import Polygon, ArbitrumOne, Ethereum
 from dexorder.contract import ContractProxy, abis
-import dexorder.db.column as col
+import dexorder.database.column as col
 
 
 class Token (ContractProxy, FixedDecimals):

src/dexorder/bin/executable.py

@@ -41,6 +41,7 @@ def execute(main:Coroutine, shutdown=None, parse_args=True):
     loop.run_until_complete(task)
     x = task.exception()
     if x is not None:
+        if x.__class__ not in ignorable_exceptions:
             print_exception(x)
         for t in asyncio.all_tasks():
             t.cancel()

src/dexorder/bin/main.py

@@ -1,122 +1,17 @@
 import logging
 from asyncio import CancelledError
 
-from hexbytes import HexBytes
-from web3 import AsyncWeb3, WebsocketProviderV2, AsyncHTTPProvider
-from web3.types import FilterParams
-
-from dexorder import config, Blockchain
-from dexorder.base.blockstate import BlockState, BlockDict
-from dexorder.base.event_manager import EventManager
 from dexorder.bin.executable import execute
-from dexorder.configuration import resolve_rpc_url
+from dexorder.trigger_runner import TriggerRunner
-from dexorder.db.model import Block
 
 log = logging.getLogger('dexorder')
 
 ROOT_AGE = 10 # todo set per chain
 
 
-wallets = BlockDict('wallets')
-
-def handle_transfer(event):
-    to_address = event.topics[2].hex()
-    wallets.add(to_address)
-
-def setup_triggers(event_manager: EventManager):
-    event_manager.add_handler('Transfer(address,address,uint256)', handle_transfer)
-
-
-async def main():
-    """
-     1. load root stateBlockchain
-        a. if no root, init from head
-        b. if root is old, batch forward by height
-     2. discover new heads
-        2b. find in-memory ancestor else use root
-     3. context = ancestor->head diff
-     4. query global log filter
-     5. process new vaults
-     6. process new orders and cancels
-        a. new pools
-     7. process Swap events and generate pool prices
-     8. process price horizons
-     9. process token movement
-    10. process swap triggers (zero constraint tranches)
-    11. process price tranche triggers
-    12. process horizon tranche triggers
-    13. filter by time tranche triggers
-    14. bundle execution requests and send tx. tx has require(block<deadline)
-    15. on tx confirmation, the block height of all executed trigger requests is set to the tx block
-    """
-
-    # db.connect()
-    # blockchain.connect()
-    ws_provider = WebsocketProviderV2(resolve_rpc_url(config.ws_url))
-    w3ws = AsyncWeb3.persistent_websocket(ws_provider)
-    http_provider = AsyncHTTPProvider(resolve_rpc_url(config.rpc_url))
-    w3 = AsyncWeb3(http_provider)
-    # w3.middleware_onion.remove('attrdict')
-
-    try:
-        chain_id = await w3ws.eth.chain_id
-        Blockchain.set_cur(Blockchain.for_id(chain_id))
-
-        event_manager = EventManager()
-
-        # todo load root
-        state = None
-        async with w3ws as w3ws:
-            await w3ws.eth.subscribe('newHeads')
-            while True:
-                async for head in w3ws.listen_to_websocket():
-                    log.debug('head', head)
-                    block_data = await w3.eth.get_block(head.hash.hex(), True)
-                    block = Block(chain=chain_id,height=block_data.number,hash=block_data.hash,parent=block_data.parentHash,data=block_data)
-                    block.set_latest(block)
-                    block.set_cur(block)
-                    if state is None:
-                        state = BlockState(block,{})
-                        BlockState.set_cur(state)
-                        setup_triggers(event_manager)
-                        log.info('Created new empty root state')
-                    else:
-                        ancestor = BlockState.cur().add_block(block)
-                        if ancestor is None:
-                            log.debug(f'discarded late-arriving head {block}')
-                        elif type(ancestor) is int:
-                            # todo backfill batches
-                            log.error(f'backfill unimplemented for range {ancestor} to {block}')
-                        else:
-                            logs_filter = FilterParams(topics=list(event_manager.all_topics), blockhash=HexBytes(block.hash).hex())
-                            log.debug(f'get logs {logs_filter}')
-                            logs = await w3.eth.get_logs(logs_filter)
-                            if logs:
-                                log.debug('handle logs')
-                                event_manager.handle_logs(logs)
-                        # check for root promotion
-                        if block.height - state.root_block.height > ROOT_AGE:
-                            b = block
-                            try:
-                                for _ in range(1,ROOT_AGE):
-                                    # we walk backwards ROOT_AGE and promote what's there
-                                    b = state.by_hash[b.parent]
-                            except KeyError:
-                                pass
-                            else:
-                                log.debug(f'promoting root {b}')
-                                state.promote_root(b)
-                log.debug('wallets: '+' '.join(k for k,_ in wallets.items()))
-    except CancelledError:
-        pass
-    finally:
-        if ws_provider.is_connected():
-            await ws_provider.disconnect()
-
-
 if __name__ == '__main__':
     logging.basicConfig(level=logging.INFO)
     log = logging.getLogger('dexorder')
     log.setLevel(logging.DEBUG)
-    execute(main())
+    execute(TriggerRunner().run())
     log.info('exiting')

src/dexorder/blockchain/by_blockchain.py

@@ -1,6 +1,6 @@
 from typing import Generic, TypeVar, Any, Iterator
 
-from dexorder import ctx, NARG
+from dexorder import NARG
 
 _T = TypeVar('_T')
 

src/dexorder/blockchain/connection.py

@@ -1,9 +1,24 @@
-from web3 import HTTPProvider, Web3
+from contextvars import ContextVar
-from web3.middleware import geth_poa_middleware, simple_cache_middleware
+
+from hexbytes import HexBytes
+from web3 import WebsocketProviderV2, AsyncWeb3, AsyncHTTPProvider
 
-from dexorder import ctx
 from dexorder.blockchain.util import get_contract_data
 from ..configuration import resolve_rpc_url
+from ..configuration.resolve import resolve_ws_url
+
+
+_w3 = ContextVar('w3')
+
+class W3:
+    @staticmethod
+    def cur() -> AsyncWeb3:
+        return _w3.get()
+
+    @staticmethod
+    def set_cur(value:AsyncWeb3):
+        _w3.set(value)
+
 
 
 def connect(rpc_url=None):
@@ -13,11 +28,28 @@ def connect(rpc_url=None):
     use create_w3() and set w3.eth.default_account separately
     """
     w3 = create_w3(rpc_url)
-    ctx.w3 = w3
+    W3.set_cur(w3)
     return w3
 
 
 def create_w3(rpc_url=None):
+    # todo create a proxy w3 that rotates among rpc urls
+    # self.w3s = tuple(create_w3(url) for url in rpc_url_or_tag)
+    # chain_id = self.w3s[0].eth.chain_id
+    # assert all(w3.eth.chain_id == chain_id for w3 in self.w3s) # all rpc urls must be the same blockchain
+    # self.w3iter = itertools.cycle(self.w3s)
+
+    url = resolve_rpc_url(rpc_url)
+    w3 = AsyncWeb3(AsyncHTTPProvider(url))
+    # w3.middleware_onion.inject(geth_poa_middleware, layer=0) # todo is this line needed?
+    # w3.middleware_onion.add(simple_cache_middleware)
+    w3.middleware_onion.remove('attrdict')
+    w3.middleware_onion.add(clean_input_async, 'clean_input')
+    w3.eth.Contract = _make_contract(w3.eth)
+    return w3
+
+
+def create_w3_ws(ws_url=None):
     """
     this constructs a Web3 object but does NOT attach it to the context.  consider using connect(...) instead
     this does *not* attach any signer to the w3.  make sure to inject the proper middleware with Account.attach(w3)
@@ -27,15 +59,44 @@ def create_w3(rpc_url=None):
     # chain_id = self.w3s[0].eth.chain_id
     # assert all(w3.eth.chain_id == chain_id for w3 in self.w3s) # all rpc urls must be the same blockchain
     # self.w3iter = itertools.cycle(self.w3s)
-
+    ws_provider = WebsocketProviderV2(resolve_ws_url(ws_url))
-    url = resolve_rpc_url(rpc_url)
+    w3 = AsyncWeb3.persistent_websocket(ws_provider)
-    w3 = Web3(HTTPProvider(url))
+    w3.middleware_onion.remove('attrdict')
-    w3.middleware_onion.inject(geth_poa_middleware, layer=0)
+    # w3.middleware_onion.add(clean_input, 'clean_input')
-    w3.middleware_onion.add(simple_cache_middleware)
     w3.eth.Contract = _make_contract(w3.eth)
     return w3
 
 
+def _clean(obj):
+    if type(obj) is HexBytes:
+        return bytes(obj)
+    elif type(obj) is list:
+        return [_clean(v) for v in obj]
+    elif type(obj) is dict:
+        return {k:_clean(v) for k,v in obj.items()}
+    return obj
+
+def _make_clean_input_middleware(make_request,_w3):
+    def _clean_input(method, params):
+        # do pre-processing here
+        # perform the RPC request, getting the response
+        response = make_request(method, params)
+        # do post-processing here
+        response = _clean(response)
+        # finally return the response
+        return response
+    return _clean_input
+
+
+async def clean_input_async(make_request, w3):
+    # do one-time setup operations here
+    return _make_clean_input_middleware(make_request, w3)
+
+def clean_input(make_request, w3):
+    # do one-time setup operations here
+    return _make_clean_input_middleware(make_request, w3)
+
+
 def _make_contract(w3_eth):
     def f(address, abi_or_name): # if abi, then it must already be in native object format, not a string
         if type(abi_or_name) is str:

src/dexorder/configuration/resolve.py

@@ -11,3 +11,15 @@ def resolve_rpc_url(rpc_url=None):
     except KeyError:
         pass
     return rpc_url
+
+
+def resolve_ws_url(ws_url=None):
+    if ws_url is None:
+        ws_url = config.ws_url
+    if ws_url == 'test':
+        return 'ws://localhost:8545'
+    try:
+        return config.rpc_urls[ws_url]  # look up aliases
+    except KeyError:
+        pass
+    return ws_url

src/dexorder/database/__init__.py

@@ -0,0 +1,67 @@
+from contextvars import ContextVar
+
+import sqlalchemy
+from sqlalchemy import Engine
+from sqlalchemy.orm import Session, SessionTransaction
+
+from .migrate import migrate_database
+from .. import config
+
+
+_engine = ContextVar[Engine]('engine', default=None)
+_session = ContextVar[Session]('session', default=None)
+
+
+class Db:
+    def transaction(self) -> SessionTransaction:
+        """
+        this type of block should be at the top-level of any group of db operations.  it will automatically commit
+        and close the session at the end of the scope
+
+        ```
+        with db.transaction():
+            do_database_stuff()
+        ```
+
+        if you want to do manual commits, use:
+        ```
+        with db.session:
+            do_database_stuff()
+        ```
+        """
+        return self.session.begin()
+
+    @property
+    def session(self) -> Session:
+        s = _session.get()
+        if s is None:
+            engine = _engine.get()
+            if engine is None:
+                raise RuntimeError('Cannot create session: no database engine set. Use dexorder.db.connect() first')
+            s = Session(engine, expire_on_commit=False)
+            # noinspection PyTypeChecker
+            _session.set(s)
+        return s
+
+    # noinspection PyShadowingNames
+    @staticmethod
+    def connect(url=None, migrate=True, reconnect=False, dump_sql=None):
+        if _engine.get() is not None and not reconnect:
+            return
+        if url is None:
+            url = config.db_url
+        if dump_sql is None:
+            dump_sql = config.dump_sql
+        engine = sqlalchemy.create_engine(url, echo=dump_sql)
+        if migrate:
+            migrate_database()
+        with engine.connect() as connection:
+            connection.execute(sqlalchemy.text("SET TIME ZONE 'UTC'"))
+            result = connection.execute(sqlalchemy.text("select version_num from alembic_version"))
+        for row in result:
+            print(f'database revision {row[0]}')
+            _engine.set(engine)
+            return db
+        raise Exception('database version not found')
+
+db = Db()

src/dexorder/database/column.py

@@ -1,4 +1,6 @@
+from hexbytes import HexBytes
 from sqlalchemy import SMALLINT, INTEGER, BIGINT
+from sqlalchemy.dialects.postgresql import BYTEA
 from sqlalchemy.orm import mapped_column
 from typing_extensions import Annotated
 
@@ -75,6 +77,8 @@ Int256 = Annotated[int, mapped_column(t.IntBits(256, True))]
 
 Address = Annotated[str, mapped_column(t.Address())]
 
+Bytes = Annotated[bytes, mapped_column(BYTEA)]
+
 BlockCol = Annotated[int, mapped_column(BIGINT)]
 
 Blockchain = Annotated[NativeBlockchain, mapped_column(t.Blockchain)]

src/dexorder/database/model/base.py

@@ -1,7 +1,5 @@
 from sqlalchemy.orm import DeclarativeBase, declared_attr
 
-from dexorder import ctx
-
 
 # add Base as the -last- class inherited on classes which should get tables
 class Base(DeclarativeBase):
@@ -9,8 +7,3 @@ class Base(DeclarativeBase):
     @declared_attr.directive
     def __tablename__(cls) -> str:
         return cls.__name__.lower()
-
-    @classmethod
-    def get(cls, **kwargs):
-        return ctx.session.get(cls, kwargs)
-

src/dexorder/database/model/block.py

@@ -3,7 +3,7 @@ from contextvars import ContextVar
 from sqlalchemy.dialects.postgresql import JSONB
 from sqlalchemy.orm import Mapped, mapped_column
 
-from dexorder.db.model import Base
+from dexorder.database.model import Base
 
 
 class Block(Base):
@@ -11,10 +11,10 @@ class Block(Base):
     height: Mapped[int] = mapped_column(primary_key=True)  # timescaledb index
     hash: Mapped[bytes] = mapped_column(primary_key=True)
     parent: Mapped[bytes]
-    data: Mapped[dict] = mapped_column(JSONB)
+    data: Mapped[dict] = mapped_column('data',JSONB)
 
     def __str__(self):
-        return f'{self.height}_{self.hash.hex()}'
+        return f'{self.height}_{self.hash}'
 
     @staticmethod
     def cur() -> 'Block':

src/dexorder/database/model/vault_tokens.py

@@ -0,0 +1,12 @@
+import logging
+
+from sqlalchemy.orm import Mapped, mapped_column
+
+from dexorder.database.column import Address
+from dexorder.database.model import Base
+
+log = logging.getLogger(__name__)
+
+class VaultToken (Base):
+    vault:Mapped[Address] = mapped_column(primary_key=True)
+    token:Mapped[Address] = mapped_column(primary_key=True)

src/dexorder/db/__init__.py

@@ -1,25 +0,0 @@
-import sqlalchemy
-
-from .migrate import migrate_database
-from .. import config, ctx
-
-
-# noinspection PyShadowingNames
-def connect(url=None, migrate=True, reconnect=False, dump_sql=None):
-    if ctx.engine is not None and not reconnect:
-        return
-    if url is None:
-        url = config.db_url
-    if dump_sql is None:
-        dump_sql = config.dump_sql
-    engine = sqlalchemy.create_engine(url, echo=dump_sql)
-    if migrate:
-        migrate_database()
-    with engine.connect() as connection:
-        connection.execute(sqlalchemy.text("SET TIME ZONE 'UTC'"))
-        result = connection.execute(sqlalchemy.text("select version_num from alembic_version"))
-    for row in result:
-        print(f'database revision {row[0]}')
-        ctx.engine = engine
-        return
-    raise Exception('database version not found')

src/dexorder/trigger_runner.py

@@ -0,0 +1,166 @@
+import asyncio
+import logging
+from typing import Callable, Union
+
+from web3 import AsyncWeb3
+from web3.contract.contract import ContractEvents
+from web3.exceptions import LogTopicError
+
+from dexorder import Blockchain, db, blockchain
+from dexorder.base.blockstate import BlockState, BlockDict
+from dexorder.blockchain.connection import create_w3_ws, W3
+from dexorder.blockchain.util import get_contract_data
+from dexorder.database.model import Block
+from dexorder.database.model.vault_tokens import VaultToken
+from dexorder.util import hexstr, topic
+
+log = logging.getLogger(__name__)
+
+
+vault_addresses = BlockDict('v')
+underfunded_vaults = BlockDict('ufv')
+active_orders = BlockDict('a')
+pool_prices = BlockDict('p')
+wallets = BlockDict('wallets') # todo remove debug
+
+
+class TriggerRunner:
+
+    def __init__(self):
+        self.root_age = 10 # todo set per chain
+        self.events:list[tuple[Callable[[dict],None],ContractEvents,dict]] = []
+
+    async def run(self):
+        """
+         1. load root stateBlockchain
+            a. if no root, init from head
+            b. if root is old, batch forward by height
+         2. discover new heads
+            2b. find in-memory ancestor else use root
+         3. context = ancestor->head diff
+         4. query global log filter
+         5. process new vaults
+         6. process new orders and cancels
+            a. new pools
+         7. process Swap events and generate pool prices
+         8. process price horizons
+         9. process token movement
+        10. process swap triggers (zero constraint tranches)
+        11. process price tranche triggers
+        12. process horizon tranche triggers
+        13. filter by time tranche triggers
+        14. bundle execution requests and send tx. tx has require(block<deadline)
+        15. on tx confirmation, the block height of all executed trigger requests is set to the tx block
+        """
+
+        db.connect()
+        w3 = blockchain.connect()
+        w3ws = create_w3_ws()
+
+        chain_id = await w3ws.eth.chain_id
+        Blockchain.set_cur(Blockchain.for_id(chain_id))
+
+        # todo load root
+        state = None
+        async with w3ws as w3ws:
+            await w3ws.eth.subscribe('newHeads')
+            while True:
+                async for head in w3ws.listen_to_websocket():
+                    session = None
+                    try:
+                        log.debug('head', head)
+                        # block_data = await w3.eth.get_block(head['hash'], True)
+                        block_data = (await w3.provider.make_request('eth_getBlockByHash',[hexstr(head['hash']),False]))['result']
+                        block = Block(chain=chain_id, height=int(block_data['number'],0),
+                                      hash=bytes.fromhex(block_data['hash'][2:]), parent=bytes.fromhex(block_data['parentHash'][2:]), data=block_data)
+                        block.set_latest(block)
+                        block.set_cur(block)
+                        if state is None:
+                            state = BlockState(block, {})
+                            BlockState.set_cur(state)
+                            self.setup_triggers(w3)
+                            log.info('Created new empty root state')
+                        else:
+                            ancestor = BlockState.cur().add_block(block)
+                            if ancestor is None:
+                                log.debug(f'discarded late-arriving head {block}')
+                            elif type(ancestor) is int:
+                                # todo backfill batches
+                                log.error(f'backfill unimplemented for range {ancestor} to {block}')
+                            else:
+                                futures = []
+                                for callback, event, log_filter in self.events:
+                                    log_filter['blockhash'] = w3.to_hex(block.hash)
+                                    futures.append(w3.eth.get_logs(log_filter))
+                                results = await asyncio.gather(*futures)
+                                if session is None:
+                                    session = db.session
+                                    session.begin()
+                                session.add(block)
+                                for result, (callback,event,filter_args) in zip(results,self.events):
+                                    for log_event in result:
+                                        callback(log_event)
+                            # check for root promotion
+                            if block.height - state.root_block.height > self.root_age:
+                                b = block
+                                try:
+                                    for _ in range(1, self.root_age):
+                                        # we walk backwards self.root_age and promote what's there
+                                        b = state.by_hash[b.parent]
+                                except KeyError:
+                                    pass
+                                else:
+                                    log.debug(f'promoting root {b}')
+                                    state.promote_root(b)
+                    except:
+                        if session is not None:
+                            session.rollback()
+                        raise
+                    else:
+                        if session is not None:
+                            session.commit()
+
+
+    def handle_transfer(self, event):
+        w3 = W3.cur()
+        try:
+            transfer = w3.eth.contract(abi=get_contract_data('ERC20')['abi']).events.Transfer().process_log(event)
+        except LogTopicError:
+            return
+        to_address = transfer['args']['to']
+        print('transfer', to_address)
+        if to_address in vault_addresses:
+            # todo publish event to vault watchers
+            db.session.add(VaultToken(vault=to_address, token=event.address))
+        if to_address in underfunded_vaults:
+            # todo flag underfunded vault (check token type?)
+            pass
+        BlockDict('wallets').add(to_address)
+
+
+    def handle_swap(self, event):
+        w3 = W3.cur()
+        try:
+            swap = w3.eth.contract(abi=get_contract_data('IUniswapV3PoolEvents')['abi']).events.Swap().process_log(event)
+        except LogTopicError:
+            return
+        try:
+            sqrt_price = swap['args']['sqrtPriceX96']
+        except KeyError:
+            return
+        addr = event['address']
+        price = sqrt_price * sqrt_price / 2**(96*2)
+        print(f'pool {addr} {price}')
+        # pool_prices[addr] =
+
+    def add_event_trigger(self, callback:Callable[[dict],None], event: ContractEvents, log_filter: Union[dict,str]=None):
+        if log_filter is None:
+            log_filter = {'topics':[topic(event.abi)]}
+        self.events.append((callback, event, log_filter))
+
+    def setup_triggers(self, w3: AsyncWeb3):
+        transfer = w3.eth.contract(abi=get_contract_data('ERC20')['abi']).events.Transfer()
+        self.add_event_trigger(self.handle_transfer, transfer)
+
+        swap = w3.eth.contract(abi=get_contract_data('IUniswapV3PoolEvents')['abi']).events.Swap()
+        self.add_event_trigger(self.handle_swap, swap)

src/dexorder/util/__init__.py

@@ -1,5 +1,8 @@
 import re
 
+from eth_utils import keccak
+from hexbytes import HexBytes
+
 from .async_yield import async_yield
 from .tick_math import nearest_available_ticks, round_tick, spans_tick, spans_range
 
@@ -12,3 +15,20 @@ def align_decimal(value, left_columns) -> str:
     pad = max(left_columns - len(re.sub(r'[^0-9]*$','',s.split('.')[0])), 0)
     return ' ' * pad + s
 
+def hexstr(value):
+    """ returns an 0x-prefixed hex string """
+    if type(value) is HexBytes:
+        return value.hex()
+    elif type(value) is bytes:
+        return '0x'+bytes.hex()
+    elif type(value) is str:
+        return value if value.startswith('0x') else '0x' + value
+    else:
+        raise ValueError
+
+
+def topic(event_abi):
+    event_name = f'{event_abi["name"]}(' + ','.join(i['type'] for i in event_abi['inputs']) + ')'
+    result = '0x' + keccak(text=event_name).hex()
+    print(event_name, result)
+    return result

test/test_blockstate.py

@@ -1,5 +1,5 @@
 from dexorder.base.blockstate import BlockState, BlockDict
-from dexorder.db.model.block import Block
+from dexorder.database.model.block import Block
 
 block_10 = Block(chain=1, height=10, hash=bytes.fromhex('10'), parent=bytes.fromhex('09'), data=None)
 block_11a = Block(chain=1, height=11, hash=bytes.fromhex('1a'), parent=block_10.hash, data=None)