vendor in leveldb

boa/util/leveldb.py

@@ -0,0 +1,32 @@
+# copy py-evm LevelDB implementation, removed in
+# https://github.com/ethereum/py-evm/commit/c2ca44a1212a287
+import plyvel
+from eth.db.backends.base import BaseDB
+
+
+class LevelDB(BaseDB):
+    # Creates db as a class variable to avoid level db lock error
+    def __init__(self, db_path, max_open_files: int = None) -> None:
+        self.db = plyvel.DB(
+            db_path,
+            create_if_missing=True,
+            error_if_exists=False,
+            max_open_files=max_open_files,
+        )
+
+    def __getitem__(self, key: bytes) -> bytes:
+        v = self.db.get(key)
+        if v is None:
+            raise KeyError(key)
+        return v
+
+    def __setitem__(self, key: bytes, value: bytes) -> None:
+        self.db.put(key, value)
+
+    def _exists(self, key: bytes) -> bool:
+        return self.db.get(key) is not None
+
+    def __delitem__(self, key: bytes) -> None:
+        if self.db.get(key) is None:
+            raise KeyError(key)
+        self.db.delete(key)

boa/vm/fork.py

@@ -9,6 +9,7 @@
 import rlp
 from eth.db.account import AccountDB, keccak
 from eth.db.backends.memory import MemoryDB
+from eth.db.cache import CacheDB
 from eth.rlp.accounts import Account
 from eth.vm.interrupt import MissingBytecode
 from eth_utils import int_to_big_endian, to_checksum_address
@@ -33,9 +34,7 @@ def __init__(self, url: str, cache_file: str = DEFAULT_CACHE_DIR):
         self._init_mem_db()
         if cache_file is not None:
             try:
-                # LevelDB has been removed from py-evm 0.8.1 onwards
-                from eth.db.backends.level import LevelDB
-                from eth.db.cache import CacheDB
+                from boa.util.leveldb import LevelDB
 
                 cache_file = os.path.expanduser(cache_file)
                 # use CacheDB as an additional layer over disk