ethereum.muir_glacier.trie
State Trie ^^^^^^^^^^
.. contents:: Table of Contents :backlinks: none :local:
Introduction
The state trie is the structure responsible for storing
ethereum.muir_glacier.fork_types.Account
objects.
1""" 2State Trie 3^^^^^^^^^^ 4 5.. contents:: Table of Contents 6 :backlinks: none 7 :local: 8 9Introduction 10------------ 11 12The state trie is the structure responsible for storing 13`.fork_types.Account` objects. 14""" 15 16import copy 17from dataclasses import dataclass, field 18from typing import ( 19 Callable, 20 Dict, 21 Generic, 22 List, 23 Mapping, 24 MutableMapping, 25 Optional, 26 Sequence, 27 TypeVar, 28 Union, 29 cast, 30) 31 32from ethereum.crypto.hash import keccak256 33from ethereum.istanbul import trie as previous_trie 34from ethereum.utils.ensure import ensure 35from ethereum.utils.hexadecimal import hex_to_bytes 36 37from .. import rlp 38from ..base_types import U256, Bytes, Uint, slotted_freezable 39from .fork_types import ( 40 Account, 41 Address, 42 Receipt, 43 Root, 44 Transaction, 45 encode_account, 46) 47 48# note: an empty trie (regardless of whether it is secured) has root: 49# 50# keccak256(RLP(b'')) 51# == 52# 56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421 # noqa: E501,SC10 53# 54# also: 55# 56# keccak256(RLP(())) 57# == 58# 1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347 # noqa: E501,SC10 59# 60# which is the sha3Uncles hash in block header with no uncles 61EMPTY_TRIE_ROOT = Root( 62 hex_to_bytes( 63 "56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421" 64 ) 65) 66 67Node = Union[Account, Bytes, Transaction, Receipt, Uint, U256, None] 68K = TypeVar("K", bound=Bytes) 69V = TypeVar( 70 "V", 71 Optional[Account], 72 Optional[Bytes], 73 Bytes, 74 Optional[Transaction], 75 Optional[Receipt], 76 Uint, 77 U256, 78) 79 80 81@slotted_freezable 82@dataclass 83class LeafNode: 84 """Leaf node in the Merkle Trie""" 85 86 rest_of_key: Bytes 87 value: rlp.RLP 88 89 90@slotted_freezable 91@dataclass 92class ExtensionNode: 93 """Extension node in the Merkle Trie""" 94 95 key_segment: Bytes 96 subnode: rlp.RLP 97 98 99@slotted_freezable 100@dataclass 101class BranchNode: 102 """Branch node in the Merkle Trie""" 103 104 subnodes: List[rlp.RLP] 105 value: rlp.RLP 106 107 108InternalNode = Union[LeafNode, ExtensionNode, BranchNode] 109 110 111def encode_internal_node(node: Optional[InternalNode]) -> rlp.RLP: 112 """ 113 Encodes a Merkle Trie node into its RLP form. The RLP will then be 114 serialized into a `Bytes` and hashed unless it is less that 32 bytes 115 when serialized. 116 117 This function also accepts `None`, representing the absence of a node, 118 which is encoded to `b""`. 119 120 Parameters 121 ---------- 122 node : Optional[InternalNode] 123 The node to encode. 124 125 Returns 126 ------- 127 encoded : `rlp.RLP` 128 The node encoded as RLP. 129 """ 130 unencoded: rlp.RLP 131 if node is None: 132 unencoded = b"" 133 elif isinstance(node, LeafNode): 134 unencoded = ( 135 nibble_list_to_compact(node.rest_of_key, True), 136 node.value, 137 ) 138 elif isinstance(node, ExtensionNode): 139 unencoded = ( 140 nibble_list_to_compact(node.key_segment, False), 141 node.subnode, 142 ) 143 elif isinstance(node, BranchNode): 144 unencoded = node.subnodes + [node.value] 145 else: 146 raise AssertionError(f"Invalid internal node type {type(node)}!") 147 148 encoded = rlp.encode(unencoded) 149 if len(encoded) < 32: 150 return unencoded 151 else: 152 return keccak256(encoded) 153 154 155def encode_node(node: Node, storage_root: Optional[Bytes] = None) -> Bytes: 156 """ 157 Encode a Node for storage in the Merkle Trie. 158 159 Currently mostly an unimplemented stub. 160 """ 161 if isinstance(node, Account): 162 assert storage_root is not None 163 return encode_account(node, storage_root) 164 elif isinstance(node, (Transaction, Receipt, U256)): 165 return rlp.encode(cast(rlp.RLP, node)) 166 elif isinstance(node, Bytes): 167 return node 168 else: 169 return previous_trie.encode_node(node, storage_root) 170 171 172@dataclass 173class Trie(Generic[K, V]): 174 """ 175 The Merkle Trie. 176 """ 177 178 secured: bool 179 default: V 180 _data: Dict[K, V] = field(default_factory=dict) 181 182 183def copy_trie(trie: Trie[K, V]) -> Trie[K, V]: 184 """ 185 Create a copy of `trie`. Since only frozen objects may be stored in tries, 186 the contents are reused. 187 188 Parameters 189 ---------- 190 trie: `Trie` 191 Trie to copy. 192 193 Returns 194 ------- 195 new_trie : `Trie[K, V]` 196 A copy of the trie. 197 """ 198 return Trie(trie.secured, trie.default, copy.copy(trie._data)) 199 200 201def trie_set(trie: Trie[K, V], key: K, value: V) -> None: 202 """ 203 Stores an item in a Merkle Trie. 204 205 This method deletes the key if `value == trie.default`, because the Merkle 206 Trie represents the default value by omitting it from the trie. 207 208 Parameters 209 ---------- 210 trie: `Trie` 211 Trie to store in. 212 key : `Bytes` 213 Key to lookup. 214 value : `V` 215 Node to insert at `key`. 216 """ 217 if value == trie.default: 218 if key in trie._data: 219 del trie._data[key] 220 else: 221 trie._data[key] = value 222 223 224def trie_get(trie: Trie[K, V], key: K) -> V: 225 """ 226 Gets an item from the Merkle Trie. 227 228 This method returns `trie.default` if the key is missing. 229 230 Parameters 231 ---------- 232 trie: 233 Trie to lookup in. 234 key : 235 Key to lookup. 236 237 Returns 238 ------- 239 node : `V` 240 Node at `key` in the trie. 241 """ 242 return trie._data.get(key, trie.default) 243 244 245def common_prefix_length(a: Sequence, b: Sequence) -> int: 246 """ 247 Find the longest common prefix of two sequences. 248 """ 249 for i in range(len(a)): 250 if i >= len(b) or a[i] != b[i]: 251 return i 252 return len(a) 253 254 255def nibble_list_to_compact(x: Bytes, is_leaf: bool) -> Bytes: 256 """ 257 Compresses nibble-list into a standard byte array with a flag. 258 259 A nibble-list is a list of byte values no greater than `15`. The flag is 260 encoded in high nibble of the highest byte. The flag nibble can be broken 261 down into two two-bit flags. 262 263 Highest nibble:: 264 265 +---+---+----------+--------+ 266 | _ | _ | is_leaf | parity | 267 +---+---+----------+--------+ 268 3 2 1 0 269 270 271 The lowest bit of the nibble encodes the parity of the length of the 272 remaining nibbles -- `0` when even and `1` when odd. The second lowest bit 273 is used to distinguish leaf and extension nodes. The other two bits are not 274 used. 275 276 Parameters 277 ---------- 278 x : 279 Array of nibbles. 280 is_leaf : 281 True if this is part of a leaf node, or false if it is an extension 282 node. 283 284 Returns 285 ------- 286 compressed : `bytearray` 287 Compact byte array. 288 """ 289 compact = bytearray() 290 291 if len(x) % 2 == 0: # ie even length 292 compact.append(16 * (2 * is_leaf)) 293 for i in range(0, len(x), 2): 294 compact.append(16 * x[i] + x[i + 1]) 295 else: 296 compact.append(16 * ((2 * is_leaf) + 1) + x[0]) 297 for i in range(1, len(x), 2): 298 compact.append(16 * x[i] + x[i + 1]) 299 300 return Bytes(compact) 301 302 303def bytes_to_nibble_list(bytes_: Bytes) -> Bytes: 304 """ 305 Converts a `Bytes` into to a sequence of nibbles (bytes with value < 16). 306 307 Parameters 308 ---------- 309 bytes_: 310 The `Bytes` to convert. 311 312 Returns 313 ------- 314 nibble_list : `Bytes` 315 The `Bytes` in nibble-list format. 316 """ 317 nibble_list = bytearray(2 * len(bytes_)) 318 for byte_index, byte in enumerate(bytes_): 319 nibble_list[byte_index * 2] = (byte & 0xF0) >> 4 320 nibble_list[byte_index * 2 + 1] = byte & 0x0F 321 return Bytes(nibble_list) 322 323 324def _prepare_trie( 325 trie: Trie[K, V], 326 get_storage_root: Optional[Callable[[Address], Root]] = None, 327) -> Mapping[Bytes, Bytes]: 328 """ 329 Prepares the trie for root calculation. Removes values that are empty, 330 hashes the keys (if `secured == True`) and encodes all the nodes. 331 332 Parameters 333 ---------- 334 trie : 335 The `Trie` to prepare. 336 get_storage_root : 337 Function to get the storage root of an account. Needed to encode 338 `Account` objects. 339 340 Returns 341 ------- 342 out : `Mapping[ethereum.base_types.Bytes, Node]` 343 Object with keys mapped to nibble-byte form. 344 """ 345 mapped: MutableMapping[Bytes, Bytes] = {} 346 347 for preimage, value in trie._data.items(): 348 if isinstance(value, Account): 349 assert get_storage_root is not None 350 address = Address(preimage) 351 encoded_value = encode_node(value, get_storage_root(address)) 352 else: 353 encoded_value = encode_node(value) 354 # Empty values are represented by their absence 355 ensure(encoded_value != b"", AssertionError) 356 key: Bytes 357 if trie.secured: 358 # "secure" tries hash keys once before construction 359 key = keccak256(preimage) 360 else: 361 key = preimage 362 mapped[bytes_to_nibble_list(key)] = encoded_value 363 364 return mapped 365 366 367def root( 368 trie: Trie[K, V], 369 get_storage_root: Optional[Callable[[Address], Root]] = None, 370) -> Root: 371 """ 372 Computes the root of a modified merkle patricia trie (MPT). 373 374 Parameters 375 ---------- 376 trie : 377 `Trie` to get the root of. 378 get_storage_root : 379 Function to get the storage root of an account. Needed to encode 380 `Account` objects. 381 382 383 Returns 384 ------- 385 root : `.fork_types.Root` 386 MPT root of the underlying key-value pairs. 387 """ 388 obj = _prepare_trie(trie, get_storage_root) 389 390 root_node = encode_internal_node(patricialize(obj, Uint(0))) 391 if len(rlp.encode(root_node)) < 32: 392 return keccak256(rlp.encode(root_node)) 393 else: 394 assert isinstance(root_node, Bytes) 395 return Root(root_node) 396 397 398def patricialize( 399 obj: Mapping[Bytes, Bytes], level: Uint 400) -> Optional[InternalNode]: 401 """ 402 Structural composition function. 403 404 Used to recursively patricialize and merkleize a dictionary. Includes 405 memoization of the tree structure and hashes. 406 407 Parameters 408 ---------- 409 obj : 410 Underlying trie key-value pairs, with keys in nibble-list format. 411 level : 412 Current trie level. 413 414 Returns 415 ------- 416 node : `ethereum.base_types.Bytes` 417 Root node of `obj`. 418 """ 419 if len(obj) == 0: 420 return None 421 422 arbitrary_key = next(iter(obj)) 423 424 # if leaf node 425 if len(obj) == 1: 426 leaf = LeafNode(arbitrary_key[level:], obj[arbitrary_key]) 427 return leaf 428 429 # prepare for extension node check by finding max j such that all keys in 430 # obj have the same key[i:j] 431 substring = arbitrary_key[level:] 432 prefix_length = len(substring) 433 for key in obj: 434 prefix_length = min( 435 prefix_length, common_prefix_length(substring, key[level:]) 436 ) 437 438 # finished searching, found another key at the current level 439 if prefix_length == 0: 440 break 441 442 # if extension node 443 if prefix_length > 0: 444 prefix = arbitrary_key[level : level + prefix_length] 445 return ExtensionNode( 446 prefix, 447 encode_internal_node(patricialize(obj, level + prefix_length)), 448 ) 449 450 branches: List[MutableMapping[Bytes, Bytes]] = [] 451 for _ in range(16): 452 branches.append({}) 453 value = b"" 454 for key in obj: 455 if len(key) == level: 456 # shouldn't ever have an account or receipt in an internal node 457 if isinstance(obj[key], (Account, Receipt, Uint)): 458 raise AssertionError 459 value = obj[key] 460 else: 461 branches[key[level]][key] = obj[key] 462 463 return BranchNode( 464 [ 465 encode_internal_node(patricialize(branches[k], level + 1)) 466 for k in range(16) 467 ], 468 value, 469 )
82@slotted_freezable 83@dataclass 84class LeafNode: 85 """Leaf node in the Merkle Trie""" 86 87 rest_of_key: Bytes 88 value: rlp.RLP
Leaf node in the Merkle Trie
91@slotted_freezable 92@dataclass 93class ExtensionNode: 94 """Extension node in the Merkle Trie""" 95 96 key_segment: Bytes 97 subnode: rlp.RLP
Extension node in the Merkle Trie
100@slotted_freezable 101@dataclass 102class BranchNode: 103 """Branch node in the Merkle Trie""" 104 105 subnodes: List[rlp.RLP] 106 value: rlp.RLP
Branch node in the Merkle Trie
112def encode_internal_node(node: Optional[InternalNode]) -> rlp.RLP: 113 """ 114 Encodes a Merkle Trie node into its RLP form. The RLP will then be 115 serialized into a `Bytes` and hashed unless it is less that 32 bytes 116 when serialized. 117 118 This function also accepts `None`, representing the absence of a node, 119 which is encoded to `b""`. 120 121 Parameters 122 ---------- 123 node : Optional[InternalNode] 124 The node to encode. 125 126 Returns 127 ------- 128 encoded : `rlp.RLP` 129 The node encoded as RLP. 130 """ 131 unencoded: rlp.RLP 132 if node is None: 133 unencoded = b"" 134 elif isinstance(node, LeafNode): 135 unencoded = ( 136 nibble_list_to_compact(node.rest_of_key, True), 137 node.value, 138 ) 139 elif isinstance(node, ExtensionNode): 140 unencoded = ( 141 nibble_list_to_compact(node.key_segment, False), 142 node.subnode, 143 ) 144 elif isinstance(node, BranchNode): 145 unencoded = node.subnodes + [node.value] 146 else: 147 raise AssertionError(f"Invalid internal node type {type(node)}!") 148 149 encoded = rlp.encode(unencoded) 150 if len(encoded) < 32: 151 return unencoded 152 else: 153 return keccak256(encoded)
Encodes a Merkle Trie node into its RLP form. The RLP will then be
serialized into a Bytes
and hashed unless it is less that 32 bytes
when serialized.
This function also accepts None
, representing the absence of a node,
which is encoded to b""
.
Parameters
node : Optional[InternalNode] The node to encode.
Returns
encoded : rlp.RLP
The node encoded as RLP.
156def encode_node(node: Node, storage_root: Optional[Bytes] = None) -> Bytes: 157 """ 158 Encode a Node for storage in the Merkle Trie. 159 160 Currently mostly an unimplemented stub. 161 """ 162 if isinstance(node, Account): 163 assert storage_root is not None 164 return encode_account(node, storage_root) 165 elif isinstance(node, (Transaction, Receipt, U256)): 166 return rlp.encode(cast(rlp.RLP, node)) 167 elif isinstance(node, Bytes): 168 return node 169 else: 170 return previous_trie.encode_node(node, storage_root)
Encode a Node for storage in the Merkle Trie.
Currently mostly an unimplemented stub.
173@dataclass 174class Trie(Generic[K, V]): 175 """ 176 The Merkle Trie. 177 """ 178 179 secured: bool 180 default: V 181 _data: Dict[K, V] = field(default_factory=dict)
The Merkle Trie.
184def copy_trie(trie: Trie[K, V]) -> Trie[K, V]: 185 """ 186 Create a copy of `trie`. Since only frozen objects may be stored in tries, 187 the contents are reused. 188 189 Parameters 190 ---------- 191 trie: `Trie` 192 Trie to copy. 193 194 Returns 195 ------- 196 new_trie : `Trie[K, V]` 197 A copy of the trie. 198 """ 199 return Trie(trie.secured, trie.default, copy.copy(trie._data))
Create a copy of trie
. Since only frozen objects may be stored in tries,
the contents are reused.
Parameters
trie: Trie
Trie to copy.
Returns
new_trie : Trie[K, V]
A copy of the trie.
202def trie_set(trie: Trie[K, V], key: K, value: V) -> None: 203 """ 204 Stores an item in a Merkle Trie. 205 206 This method deletes the key if `value == trie.default`, because the Merkle 207 Trie represents the default value by omitting it from the trie. 208 209 Parameters 210 ---------- 211 trie: `Trie` 212 Trie to store in. 213 key : `Bytes` 214 Key to lookup. 215 value : `V` 216 Node to insert at `key`. 217 """ 218 if value == trie.default: 219 if key in trie._data: 220 del trie._data[key] 221 else: 222 trie._data[key] = value
Stores an item in a Merkle Trie.
This method deletes the key if value == trie.default
, because the Merkle
Trie represents the default value by omitting it from the trie.
Parameters
trie: Trie
Trie to store in.
key : Bytes
Key to lookup.
value : V
Node to insert at key
.
225def trie_get(trie: Trie[K, V], key: K) -> V: 226 """ 227 Gets an item from the Merkle Trie. 228 229 This method returns `trie.default` if the key is missing. 230 231 Parameters 232 ---------- 233 trie: 234 Trie to lookup in. 235 key : 236 Key to lookup. 237 238 Returns 239 ------- 240 node : `V` 241 Node at `key` in the trie. 242 """ 243 return trie._data.get(key, trie.default)
Gets an item from the Merkle Trie.
This method returns trie.default
if the key is missing.
Parameters
trie: Trie to lookup in. key : Key to lookup.
Returns
node : V
Node at key
in the trie.
246def common_prefix_length(a: Sequence, b: Sequence) -> int: 247 """ 248 Find the longest common prefix of two sequences. 249 """ 250 for i in range(len(a)): 251 if i >= len(b) or a[i] != b[i]: 252 return i 253 return len(a)
Find the longest common prefix of two sequences.
256def nibble_list_to_compact(x: Bytes, is_leaf: bool) -> Bytes: 257 """ 258 Compresses nibble-list into a standard byte array with a flag. 259 260 A nibble-list is a list of byte values no greater than `15`. The flag is 261 encoded in high nibble of the highest byte. The flag nibble can be broken 262 down into two two-bit flags. 263 264 Highest nibble:: 265 266 +---+---+----------+--------+ 267 | _ | _ | is_leaf | parity | 268 +---+---+----------+--------+ 269 3 2 1 0 270 271 272 The lowest bit of the nibble encodes the parity of the length of the 273 remaining nibbles -- `0` when even and `1` when odd. The second lowest bit 274 is used to distinguish leaf and extension nodes. The other two bits are not 275 used. 276 277 Parameters 278 ---------- 279 x : 280 Array of nibbles. 281 is_leaf : 282 True if this is part of a leaf node, or false if it is an extension 283 node. 284 285 Returns 286 ------- 287 compressed : `bytearray` 288 Compact byte array. 289 """ 290 compact = bytearray() 291 292 if len(x) % 2 == 0: # ie even length 293 compact.append(16 * (2 * is_leaf)) 294 for i in range(0, len(x), 2): 295 compact.append(16 * x[i] + x[i + 1]) 296 else: 297 compact.append(16 * ((2 * is_leaf) + 1) + x[0]) 298 for i in range(1, len(x), 2): 299 compact.append(16 * x[i] + x[i + 1]) 300 301 return Bytes(compact)
Compresses nibble-list into a standard byte array with a flag.
A nibble-list is a list of byte values no greater than 15
. The flag is
encoded in high nibble of the highest byte. The flag nibble can be broken
down into two two-bit flags.
Highest nibble::
+---+---+----------+--------+
| _ | _ | is_leaf | parity |
+---+---+----------+--------+
3 2 1 0
The lowest bit of the nibble encodes the parity of the length of the
remaining nibbles -- 0
when even and 1
when odd. The second lowest bit
is used to distinguish leaf and extension nodes. The other two bits are not
used.
Parameters
x : Array of nibbles. is_leaf : True if this is part of a leaf node, or false if it is an extension node.
Returns
compressed : bytearray
Compact byte array.
304def bytes_to_nibble_list(bytes_: Bytes) -> Bytes: 305 """ 306 Converts a `Bytes` into to a sequence of nibbles (bytes with value < 16). 307 308 Parameters 309 ---------- 310 bytes_: 311 The `Bytes` to convert. 312 313 Returns 314 ------- 315 nibble_list : `Bytes` 316 The `Bytes` in nibble-list format. 317 """ 318 nibble_list = bytearray(2 * len(bytes_)) 319 for byte_index, byte in enumerate(bytes_): 320 nibble_list[byte_index * 2] = (byte & 0xF0) >> 4 321 nibble_list[byte_index * 2 + 1] = byte & 0x0F 322 return Bytes(nibble_list)
Converts a Bytes
into to a sequence of nibbles (bytes with value < 16).
Parameters
bytes_:
The Bytes
to convert.
Returns
nibble_list : Bytes
The Bytes
in nibble-list format.
368def root( 369 trie: Trie[K, V], 370 get_storage_root: Optional[Callable[[Address], Root]] = None, 371) -> Root: 372 """ 373 Computes the root of a modified merkle patricia trie (MPT). 374 375 Parameters 376 ---------- 377 trie : 378 `Trie` to get the root of. 379 get_storage_root : 380 Function to get the storage root of an account. Needed to encode 381 `Account` objects. 382 383 384 Returns 385 ------- 386 root : `.fork_types.Root` 387 MPT root of the underlying key-value pairs. 388 """ 389 obj = _prepare_trie(trie, get_storage_root) 390 391 root_node = encode_internal_node(patricialize(obj, Uint(0))) 392 if len(rlp.encode(root_node)) < 32: 393 return keccak256(rlp.encode(root_node)) 394 else: 395 assert isinstance(root_node, Bytes) 396 return Root(root_node)
Computes the root of a modified merkle patricia trie (MPT).
Parameters
trie :
Trie
to get the root of.
get_storage_root :
Function to get the storage root of an account. Needed to encode
Account
objects.
Returns
root : .fork_types.Root
MPT root of the underlying key-value pairs.
399def patricialize( 400 obj: Mapping[Bytes, Bytes], level: Uint 401) -> Optional[InternalNode]: 402 """ 403 Structural composition function. 404 405 Used to recursively patricialize and merkleize a dictionary. Includes 406 memoization of the tree structure and hashes. 407 408 Parameters 409 ---------- 410 obj : 411 Underlying trie key-value pairs, with keys in nibble-list format. 412 level : 413 Current trie level. 414 415 Returns 416 ------- 417 node : `ethereum.base_types.Bytes` 418 Root node of `obj`. 419 """ 420 if len(obj) == 0: 421 return None 422 423 arbitrary_key = next(iter(obj)) 424 425 # if leaf node 426 if len(obj) == 1: 427 leaf = LeafNode(arbitrary_key[level:], obj[arbitrary_key]) 428 return leaf 429 430 # prepare for extension node check by finding max j such that all keys in 431 # obj have the same key[i:j] 432 substring = arbitrary_key[level:] 433 prefix_length = len(substring) 434 for key in obj: 435 prefix_length = min( 436 prefix_length, common_prefix_length(substring, key[level:]) 437 ) 438 439 # finished searching, found another key at the current level 440 if prefix_length == 0: 441 break 442 443 # if extension node 444 if prefix_length > 0: 445 prefix = arbitrary_key[level : level + prefix_length] 446 return ExtensionNode( 447 prefix, 448 encode_internal_node(patricialize(obj, level + prefix_length)), 449 ) 450 451 branches: List[MutableMapping[Bytes, Bytes]] = [] 452 for _ in range(16): 453 branches.append({}) 454 value = b"" 455 for key in obj: 456 if len(key) == level: 457 # shouldn't ever have an account or receipt in an internal node 458 if isinstance(obj[key], (Account, Receipt, Uint)): 459 raise AssertionError 460 value = obj[key] 461 else: 462 branches[key[level]][key] = obj[key] 463 464 return BranchNode( 465 [ 466 encode_internal_node(patricialize(branches[k], level + 1)) 467 for k in range(16) 468 ], 469 value, 470 )
Structural composition function.
Used to recursively patricialize and merkleize a dictionary. Includes memoization of the tree structure and hashes.
Parameters
obj : Underlying trie key-value pairs, with keys in nibble-list format. level : Current trie level.
Returns
node : ethereum.base_types.Bytes
Root node of obj
.