Package: sl-optimizer
Storage Layout Optimizer[!IMPORTANT]Currently, in developmentAboutsl_optimizeris a Python library designed to optimize the storage layout forSoliditysmart contracts.
Efficient storage layout can reduce the number of storage slots needed, leading to lower gas costs for both storage
and computational operations. It's important to align variables to these slots
efficiently to avoid wasted space and save some money.Problem StatementIn Solidity smart contract development, the efficient allocation of storage is a critical concern for optimizing gas costs
and overall performance. The current challenge lies in the need to carefully manage the storage layout to reduce the number
of required storage slots. The inefficient allocation of variables to these slots can result in increased gas costs for both
storage and computational operations.Wasted space due to suboptimal storage layout not only incurs unnecessary expenses but also diminishes the overall efficiency
of smart contracts. To address this issue, developers must align variables to storage slots in an optimized manner.
However, manually achieving this level of efficiency can be time-consuming and error-prone.To streamline this process and enhance the cost-effectiveness of Solidity smart contracts, thesl_optimizerPython library has been designed.
This library aims to automate and optimize the storage layout.Mathematical ComplexityThe mathematical complexity of storage layout optimization involves determining the most efficient way to pack variables
into storage slots(akaBin packing problem). This problem can be
approached with various algorithms and optimization techniques.First Fit Decreasing MethodThe First Fit Decreasing (FFD)method is a heuristic algorithm commonly used in bin packing problems, and it was
adapted for storage layout optimization in Solidity. The goal is to efficiently pack variables into 32-byte storage slots,
minimizing wasted space and optimizing gas costs.graph TD
  A[Sort variables in decreasing order of size] -->|Sorted List| B(Empty set of storage slots)
  B -->|Available Storage Slots| C{For each variable in the Sorted List}
  C -->|Iterate through slots| D(Try to find a suitable slot)
  D -->|Slot found| E{Assign variable to slot}
  D -->|No suitable slot| F[Create a new storage slot]
  E -->|Assign variable| C
  F -->|Assign variable| C
  C -->|All variables assigned| G{End}Challenges:Dependencies between variables might constrain the packing possibilities.Arrays and mappings can complicate storage layout due to their dynamic nature.Optimizing for storage efficiency must also consider the gas costs associated with reading and writing to storage.Functions that use a delegate call to interact with the implementation contract.AdditionalLayout(Storage Layout)- in code you can often find references to these names; they mean a data storage scheme that is presented in json format and can be obtained using this commandsolc --storage-layout -o output Contract.sol, an example of a smart contract storage json filehere.Storage- refers to thestoragefield in the storage layout json file and contains information about the layout of variables (storage).Type(s)- refers to thetypesfield in the storage layout json file and contains information about the types used in the smart contact.Gas- is the unit used to measure computational effort in the EVM.Solidity stores data in 32-byte chunks, also known as storageslots.More informationhere.Installationpipinstallsl_optimizerFrom source:makeinstallorpipinstall.UsageSeedocumentationfor more details.To-dorewrite tests (improve the use of utilities in code)add new samples (fixtures) for testsadd diagnostic or metric information related to optimizationadd CLIadd benchmarks (to cover optimize functionality, for local usage, not included to package)generate 3 fixtures (large nested structures & huge number of variables & cross nested structures)change algorithm First Fit Decreasing -> consideration in progress ...restructuring storage data for optimizationLicensesl_optimizeris released under the MIT License.
See theLICENSEfile for license information.