Soroban Base64 URL Encoding

:warning: Code in this repo is demo material only. It has not been audited. Do not use to hold, protect, or secure anything.

This repo contains Soroban contracts that demonstrate how to encode base64 url encode.

The contract in this repo accepts a fixed size bytes, presumed to be some 32-byte hash, and encodes it to a 43-byte base64 url encoded string.

Costs

Encoding a 32-byte hash into base64 url form uses the following resources.

When using a statically allocated buffer of exact size:

• WASM Size = 1,066 bytes
• CPU Instructions = 1,048,023

This size and instruction cost is rather minimal, especially when compared to the same contract that doesn't do the base64 encode:

• WASM Size = 601 bytes
• CPU Instructions = 852,844

Meaning the base64 encode is only 465 bytes and 195,179 cpu instructions.

Example

❯ soroban contract invoke --network local --source me --id CAOBK5RB74ZCYKJBUSWCKKXBYSXCL3ZEJBAZZ3NAS2SL45MI5BGG2JNH -- encode --hash 7b2274797065223a22776562617574686e2e676574222c2263687384a7831326
"eyJ0eXBlIjoid2ViYXV0aG4uZ2V0IiwiY2hzhKeDEyY"