eth_abi_lite

eth_abi_lite is a lite fork of eth_abi, aiming to support EVM abi encode/decode functionality without external dependencies on eth_utils, eth_typing, toolz, or cytoolz.

eth_abi_lite can be used as a drop-in replacement for eth_abi==3.0.0.

Install with pip install eth_abi_lite

Motivation

1. Many packages in the ethereum ecosystem have conflicting version requirements for dependencies such as eth_utils, eth_typing, toolz, or cytoolz. Removing these dependencies allows a package to be used in more environments.
2. These dependencies are rather heavy if all you want is basic abi encoding/decoding functionality.

Does eth_abi_lite work the same as eth_abi?

eth_abi_lite can be used as a drop-in replacement for eth_abi==3.0.0. The one functional difference is that eth_abi's low level pad functions are no longer curry-able. In most cases this difference will not be noticed.

eth_abi_lite passes eth_abi's standard test suite when running tox:

...
======================== 751 passed, 3 skipped in 18.45s ========================
____________________________________ summary ____________________________________
  py37-core: commands succeeded                                                  
  py38-core: commands succeeded                                                  
  py39-core: commands succeeded                                                  
  py310-core: commands succeeded                                                 
  congratulations :)                                                             

(tests for linting and docs removed)

Is eth_abi_lite faster?

According to testing with tuna on a good laptop:

• eth_abi_lite takes about 18 ms to import
• eth_abi takes about 180 ms to import

eth_abi_lite is faster to import because it loads fewer dependencies. This is useful in the context of cli tools where startup times matter.

Survey of imported items

eth_abi_lite imports the following items from its dependencies:

Items Imported From eth_utils

• big_endian_to_int
• compose_if_tuple
• int_to_big_endian
• is_address
• is_boolean
• is_bytes
• is_integer
• is_list_like
• is_number
• is_text
• to_canonical_address
• to_checksum_address
• to_normalized_address
• to_tuple

Items Imported From eth_typing

• TypeStr
• Decodable

Items Imported From eth_utils.toolz

• toolz.functoolz.curry

The Changes

The changes from eth_abi to eth_abi_lite consist mostly of copying portions of eth_utils and eth_typing.

The basic idea is that every time something is imported from eth_utils or eth_typing, that thing is instead imported from a lite version of that package.

Step 1. Create eth_utils_lite

Copy these items from eth_utils to eth_utils_lite

• eth_utils/abi.py
• eth_utils/address.py
• eth_utils/conversions.py
• eth_utils/crypto.py
• eth_utils/decorators.py
• eth_utils/encoding.py
• eth_utils/functional.py
• eth_utils/hexadecimal.py
• eth_utils/types.py

The only non-mutual dependency in these modules is eth_hash.keccak() in eth_utils/crypto.py. Replace this function with pycryptodome's keccak implementation directly.

Also in eth_utils/functional.py, remove the functions that are decorated by toolz.compose.

It is possible to prune these files more aggressively, but leaving the files unchanged minimizes the chances of introducing bugs.

Step 2. Create eth_typing_lite

Copy these items from eth_typing to eth_typing_lite:

• Address
• AnyAddress
• ChecksumAddress
• Decodable
• HexAddress
• HexStr
• Primitives
• TypeStr

These are all of the eth_typing types used by eth_abi_lite and eth_utils_lite.

Step 3. Create eth_abi_lite

1. Copy all files from eth_abi into eth_abi_lite
2. Replace all instances of
   • eth_utils with eth_utils
   • eth_typing with eth_typing_lite
   • eth_abi with eth_abi_lite
3. Replace the toolz.curry decoration on eth_abi.zpad and eth_abi.fpad with functools.partial decoration.