plutonomicon/shrinker

Shrink Plutus scripts

P L U T O N O M I C O N

Introduction

The Plutonomicon is a developer-driven guide to the Plutus smart contract language in practice.

Since this ecosystem is moving at a breakneck speed, we ask that ANY information posted that is not confirmed to work on chain be labelled as 🔧 work in progress.

Available resources

We currently provide the following resources, broadly organized by topic.

Fundamentals and explanations

• The Fundamentals of Plutus, which gives a brief introduction to the Plutus language.
• Plutus from a Transaction Perspective, which gives another perspective to the environment Plutus runs in.
• Plutus Numeric Hierarchy, which gives an overview of the Plutus numerical type class stack, as well as the extensions to it provided by plutus-numeric.
• User guide to plutus-numeric, which gives a more 'example-driven' explanation for how to do certain common tasks using plutus-numeric.
• How Stake Validators Actually Work, which gives an explanation of 'Stake Validators'.

Design patterns

• Forward Minting Policy. Also described in another writeup. Some caution is required, as you may not wish to directly reference a script to obtain a hash used to identify the two scripts, as this method details.
• Come and Go Proof Tokens
• State Thread Token Pattern
• DistributedMap, describing an on-chain implementation of key-value mappings. This is naive, and mostly designed for conceptual illustration.
• Consistency of a Distributed Map, which explains some ways of operating on a distributed map.
• Stick Breaking Set, describing an on-chain method of proving presence or absence in a set.
• On-Chain Association List With Constant Time Insert-Removal, describing a pattern that can be used to replicate account-style maps without breaking transaction size limits. This is the optimized version of the naive version of that data structure.
• Transaction Tokens provide an method of deferring validation to minting policies for the purpose of validating entire transactions rather than the unlocking of individual UTxOs.
  • The Transaction Token Pattern document introduces the pattern.
  • The Transaction Token Protocol Architecture document introduces a conceptual and practical framework leveraging the pattern for specifying and implementing protocols.
  • The Protocol Category Sketch document sketches a formalism to establish a formalism that places protocols described according the the Architecture into the language of symmetric monoidal categories, and works through some examples of how wiring diagrams and aid specification and implementation.

Testing and optimization

• Staying In Bounds, which describes the testing interface for Plutus on-chain size provided by plutus-size-check.

Script Optimization Techniques:

• Reducing Plutus Script Sizes
• Optimizations to reduce CPU and Mem consumption
• Shrinker (shrinker is currently unmaintained)

Plutus Vulnerabilities:

• Common Plutus Vulnerabilities

Discussion

To discuss the projects and the content under the Plutonomicon umbrella, join our Discord: https://discord.gg/722KnTC8jF

Running the website

If you'd like to run a live version of the website locally:

nix run

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Footnotes

1. Try Obsidian or VSCode with vscode-memo for editing. ↩

shrinker's Issues

GHC 9.2 support

Why plutus-pab and playground deps?

I wonder why do we need plutus-pab and playground dependencies in the compiled code optimization library.
Can you please remove them if they are not used.

Got compilation error

I've tried to use shrinker but got this on compilation:

Configuring library for shrinker-0.1..
Preprocessing library for shrinker-0.1..
Building library for shrinker-0.1..
[1 of 9] Compiling Shrink.Types     ( src/Shrink/Types.hs, dist/build/Shrink/Types.o, dist/build/Shrink/Types.dyn_o )
[2 of 9] Compiling Shrink.ScopeM    ( src/Shrink/ScopeM.hs, dist/build/Shrink/ScopeM.o, dist/build/Shrink/ScopeM.dyn_o )
[3 of 9] Compiling Shrink.Tactics.Util ( src/Shrink/Tactics/Util.hs, dist/build/Shrink/Tactics/Util.o, dist/build/Shrink/Tactics/Util.dyn_o )
[4 of 9] Compiling Shrink.Tactics.Safe ( src/Shrink/Tactics/Safe.hs, dist/build/Shrink/Tactics/Safe.o, dist/build/Shrink/Tactics/Safe.dyn_o )
[5 of 9] Compiling Shrink.Tactics.Tactics ( src/Shrink/Tactics/Tactics.hs, dist/build/Shrink/Tactics/Tactics.o, dist/build/Shrink/Tactics/Tactics.dyn_o )
[6 of 9] Compiling Shrink.Names     ( src/Shrink/Names.hs, dist/build/Shrink/Names.o, dist/build/Shrink/Names.dyn_o )
[7 of 9] Compiling Shrink           ( src/Shrink.hs, dist/build/Shrink.o, dist/build/Shrink.dyn_o )
[8 of 9] Compiling Shrink.PlutusTX  ( src/Shrink/PlutusTX.hs, dist/build/Shrink/PlutusTX.o, dist/build/Shrink/PlutusTX.dyn_o )

src/Shrink/PlutusTX.hs:26:9: error:
    • The constructor ‘SerializedCode’ should have 3 arguments, but has been given 2
    • In the pattern: SerializedCode _ maybePirByteString
      In a case alternative:
          SerializedCode _ maybePirByteString
            -> SerializedCode scriptBc maybePirByteString
      In the expression:
        case comped of
          SerializedCode _ maybePirByteString
            -> SerializedCode scriptBc maybePirByteString
          DeserializedCode _ maybePir -> DeserializedCode prog maybePir
   |
26 |         SerializedCode _ maybePirByteString -> SerializedCode scriptBc maybePirByteString
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
cabal: Failed to build shrinker-0.1 (which is required by
test:gero-onchain-test from gero-gov-0.1.0.0, test:gero-gov-test from
gero-gov-0.1.0.0 and others). See the build log above for details.

Maybe it's caused by plutus version mismatch.
we use on our project plutus: c8c5183f7facd967d48fe07b3b14465b8dd48fe7 (2021-12-27)

Shrinker hangs

Without shrinker it takes about 9 sec to run test suite on the gero-gov project.
When I've added shrinker I had to stop it on 7th minute. 100% cpu with memory slowly rising.

If you have access to gero-gov, you can try it out in this branch:
ak/try-shrinker

Overview of optimisations?

I've asked this before, but do you have an up-to-date overview of the current optimisations?

Incomplete substitutions

When I feed shrinkScript this UPLC: "(program 1.0.0 ((\i0 -> force i1 (\i0 -> \i0 -> \i0 -> i2)) ((\i0 -> \i0 -> \i0 -> (\i0 -> \i0 -> i2 i4 6 "Hello") (\i0 -> \i0 -> \i0 -> delay (\i0 -> i1 i4 i3 i2)) (\i0 -> i1)) (delay (\i0 -> \i0 -> i2)) (delay (\i0 -> \i0 -> i1)) (\i0 -> i1))))"`

I get "(program 1.0.0 (force ((\\i0 -> delay (\\i0 -> i1 (delay (\\i0 -> \\i0 -> i1)) 6 i2)) \"Hello\") (\\i0 -> \\i0 -> \\i0 -> i2)))"

but there's obvious opportunity to reduce it further: (\\i0 -> delay (\\i0 -> i1 (delay (\\i0 -> \\i0 -> i1)) 6 i2)) \"Hello\") ==> (delay (\\i0 -> i1 (delay (\\i0 -> \\i0 -> i1)) 6 \"Hello\")))