SorobanDataBuilder

Builder for constructing SorobanTransactionDataXdr structures.

SorobanTransactionData contains the resource footprint and fee information required for Soroban smart contract transactions. This builder provides a fluent API for constructing and modifying these structures.

Use Cases

This builder is particularly useful for:

• Building com.soneso.stellar.sdk.operations.ExtendFootprintTTLOperation transactions

• Building com.soneso.stellar.sdk.operations.RestoreFootprintOperation transactions

• Manually constructing transaction footprints for testing

• Modifying simulation results before transaction submission

For most Soroban transactions, you should use SorobanServer.prepareTransaction which automatically populates the SorobanTransactionData from simulation results.

Structure

SorobanTransactionData consists of:

• Resource Fee: Additional fee for resource consumption (beyond base transaction fee)

• Resources: CPU, memory, and storage metrics

• CPU Instructions: Number of WASM instructions to execute

• Disk Read Bytes: Bytes read from ledger storage

• Write Bytes: Bytes written to ledger storage and memory

• Footprint: Ledger keys accessed by the transaction

• Read-Only: Keys read but not modified

• Read-Write: Keys both read and modified

Basic Usage

// Start with empty data
val builder = SorobanDataBuilder()
    .setResourceFee(50000)
    .setResources(SorobanDataBuilder.Resources(
        cpuInstructions = 1000000,
        diskReadBytes = 5000,
        writeBytes = 2000
    ))
    .setReadOnly(listOf(ledgerKey1))
    .setReadWrite(listOf(ledgerKey2))

val sorobanData = builder.build()

From Simulation Results

// Start with simulation results
val simulation = server.simulateTransaction(tx)
val builder = SorobanDataBuilder(simulation.transactionData!!)
    .setResourceFee(simulation.minResourceFee!! + 10000) // Add buffer

val sorobanData = builder.build()

Modifying Existing Data

// Modify existing soroban data
val updated = SorobanDataBuilder(transaction.sorobanData!!)
    .setReadWrite(listOf(additionalKey)) // Replace read-write keys
    .build()

Immutability

The builder uses defensive copying to ensure immutability:

• Each setter returns a new builder instance

• The build method returns a deep copy of the data

• Original data structures are never mutated

See also