Add SorobanDataBuilder to prepare sorobanData easily.

src/main/java/org/stellar/sdk/SorobanDataBuilder.java

@@ -0,0 +1,166 @@
+package org.stellar.sdk;
+
+import java.io.IOException;
+import java.util.Collection;
+import javax.annotation.Nullable;
+import lombok.Builder;
+import lombok.NonNull;
+import lombok.Value;
+import org.stellar.sdk.xdr.ExtensionPoint;
+import org.stellar.sdk.xdr.Int64;
+import org.stellar.sdk.xdr.LedgerFootprint;
+import org.stellar.sdk.xdr.LedgerKey;
+import org.stellar.sdk.xdr.SorobanResources;
+import org.stellar.sdk.xdr.SorobanTransactionData;
+import org.stellar.sdk.xdr.Uint32;
+import org.stellar.sdk.xdr.XdrUnsignedInteger;
+
+/**
+ * Supports building {@link SorobanTransactionData} structures with various items set to specific
+ * values.
+ *
+ * <p>This is recommended for when you are building {@link BumpFootprintExpirationOperation} and
+ * {@link RestoreFootprintOperation} operations to avoid (re)building the entire data structure from
+ * scratch.
+ */
+public class SorobanDataBuilder {
+  private final SorobanTransactionData data;
+
+  /** Creates a new builder with an empty {@link SorobanTransactionData}. */
+  public SorobanDataBuilder() {
+    data =
+        new SorobanTransactionData.Builder()
+            .resources(
+                new SorobanResources.Builder()
+                    .footprint(
+                        new LedgerFootprint.Builder()
+                            .readOnly(new LedgerKey[] {})
+                            .readWrite(new LedgerKey[] {})
+                            .build())
+                    .instructions(new Uint32(new XdrUnsignedInteger(0)))
+                    .readBytes(new Uint32(new XdrUnsignedInteger(0)))
+                    .writeBytes(new Uint32(new XdrUnsignedInteger(0)))
+                    .extendedMetaDataSizeBytes(new Uint32(new XdrUnsignedInteger(0)))
+                    .build())
+            .refundableFee(new Int64(0L))
+            .ext(new ExtensionPoint.Builder().discriminant(0).build())
+            .build();
+  }
+
+  /**
+   * Creates a new builder from a base64 representation of {@link SorobanTransactionData}.
+   *
+   * @param sorobanData base64 representation of {@link SorobanTransactionData}
+   */
+  public SorobanDataBuilder(String sorobanData) {
+    try {
+      data = SorobanTransactionData.fromXdrBase64(sorobanData);
+    } catch (IOException e) {
+      throw new IllegalArgumentException("Invalid SorobanData: " + sorobanData, e);
+    }
+  }
+
+  /**
+   * Creates a new builder from a {@link SorobanTransactionData}.
+   *
+   * @param sorobanData {@link SorobanTransactionData}.
+   */
+  public SorobanDataBuilder(SorobanTransactionData sorobanData) {
+    try {
+      data = SorobanTransactionData.fromXdrByteArray(sorobanData.toXdrByteArray());
+    } catch (IOException e) {
+      throw new IllegalArgumentException("Invalid SorobanData: " + sorobanData, e);
+    }
+  }
+
+  /**
+   * Sets the "refundable" fee portion of the Soroban data.
+   *
+   * @param fee the refundable fee to set (int64)
+   * @return this builder instance
+   */
+  public SorobanDataBuilder setRefundableFee(long fee) {
+    data.setRefundableFee(new Int64(fee));
+    return this;
+  }
+
+  /**
+   * Sets up the resource metrics.
+   *
+   * <p>You should almost NEVER need this, as its often generated/provided to you by transaction
+   * simulation/preflight from a Soroban RPC server.
+   *
+   * @param resources the resource metrics to set
+   * @return this builder instance
+   */
+  public SorobanDataBuilder setResources(Resources resources) {
+    data.getResources()
+        .setInstructions(new Uint32(new XdrUnsignedInteger(resources.getCpuInstructions())));
+    data.getResources().setReadBytes(new Uint32(new XdrUnsignedInteger(resources.getReadBytes())));
+    data.getResources()
+        .setWriteBytes(new Uint32(new XdrUnsignedInteger(resources.getWriteBytes())));
+    data.getResources()
+        .setExtendedMetaDataSizeBytes(
+            new Uint32(new XdrUnsignedInteger(resources.getMetadataBytes())));
+    return this;
+  }
+
+  /**
+   * Sets the read-only portion of the storage access footprint to be a certain set of ledger keys.
+   *
+   * <p>Passing {@code null} will leave that portion of the footprint untouched. If you want to
+   * clear a portion of the footprint, pass an empty collection.
+   *
+   * @param readOnly the set of ledger keys to set in the read-only portion of the transaction's
+   *     sorobanData
+   * @return this builder instance
+   */
+  public SorobanDataBuilder setReadOnly(@Nullable Collection<LedgerKey> readOnly) {
+    if (readOnly != null) {
+      data.getResources().getFootprint().setReadOnly(readOnly.toArray(new LedgerKey[0]));
+    }
+    return this;
+  }
+
+  /**
+   * Sets the read-write portion of the storage access footprint to be a certain set of ledger keys.
+   *
+   * <p>Passing {@code null} will leave that portion of the footprint untouched. If you want to
+   * clear a portion of the footprint, pass an empty collection.
+   *
+   * @param readWrite the set of ledger keys to set in the read-write portion of the transaction's
+   *     sorobanData
+   * @return this builder instance
+   */
+  public SorobanDataBuilder setReadWrite(@Nullable Collection<LedgerKey> readWrite) {
+    if (readWrite != null) {
+      data.getResources().getFootprint().setReadWrite(readWrite.toArray(new LedgerKey[0]));
+    }
+    return this;
+  }
+
+  /**
+   * @return the copy of the final {@link SorobanTransactionData}.
+   */
+  public SorobanTransactionData build() {
+    try {
+      return SorobanTransactionData.fromXdrByteArray(data.toXdrByteArray());
+    } catch (IOException e) {
+      throw new IllegalArgumentException("Copy SorobanData failed, please report this bug.", e);
+    }
+  }
+
+  /** Represents the resource metrics of the Soroban data. */
+  @Builder(toBuilder = true)
+  @Value
+  public static class Resources {
+    // number of CPU instructions (uint32)
+    @NonNull Long cpuInstructions;
+    // number of bytes being read (uint32)
+    @NonNull Long readBytes;
+    // number of bytes being written (uint32)
+    @NonNull Long writeBytes;
+    // number of extended metadata bytes (uint32)
+    @NonNull Long metadataBytes;
+  }
+}

src/main/java/org/stellar/sdk/Transaction.java

@@ -58,7 +58,7 @@ public class Transaction extends AbstractTransaction {
     this.mPreconditions = preconditions;
     this.mFee = fee;
     this.mMemo = memo != null ? memo : Memo.none();
-    this.mSorobanData = sorobanData;
+    this.mSorobanData = sorobanData != null ? new SorobanDataBuilder(sorobanData).build() : null;
   }
 
   // setEnvelopeType is only used in tests which is why this method is package protected

src/main/java/org/stellar/sdk/TransactionBuilder.java

@@ -5,7 +5,6 @@
 import static org.stellar.sdk.TransactionPreconditions.TIMEOUT_INFINITE;
 
 import com.google.common.base.Function;
-import java.io.IOException;
 import java.math.BigInteger;
 import java.util.Collection;
 import java.util.List;
@@ -264,29 +263,36 @@ public static org.stellar.sdk.xdr.TimeBounds buildTimeBounds(long minTime, long
   }
 
   /**
-   * Sets Soroban data to the transaction. TODO: After adding SorobanServer, add more descriptions.
+   * Sets the transaction's internal Soroban transaction data (resources, footprint, etc.).
+   *
+   * <p>For non-contract(non-Soroban) transactions, this setting has no effect. In the case of
+   * Soroban transactions, this is either an instance of {@link SorobanTransactionData} or a
+   * base64-encoded string of said structure. This is usually obtained from the simulation response
+   * based on a transaction with a Soroban operation (e.g. {@link InvokeHostFunctionOperation},
+   * providing necessary resource and storage footprint estimations for contract invocation.
    *
    * @param sorobanData Soroban data to set
    * @return Builder object so you can chain methods.
    */
   public TransactionBuilder setSorobanData(SorobanTransactionData sorobanData) {
-    this.mSorobanData = sorobanData;
+    this.mSorobanData = new SorobanDataBuilder(sorobanData).build();
     return this;
   }
 
   /**
-   * Sets Soroban data to the transaction. TODO: After adding SorobanServer, add more descriptions.
+   * Sets the transaction's internal Soroban transaction data (resources, footprint, etc.).
+   *
+   * <p>For non-contract(non-Soroban) transactions, this setting has no effect. In the case of
+   * Soroban transactions, this is either an instance of {@link SorobanTransactionData} or a
+   * base64-encoded string of said structure. This is usually obtained from the simulation response
+   * based on a transaction with a Soroban operation (e.g. {@link InvokeHostFunctionOperation},
+   * providing necessary resource and storage footprint estimations for contract invocation.
    *
    * @param sorobanData Soroban data to set
    * @return Builder object so you can chain methods.
    */
   public TransactionBuilder setSorobanData(String sorobanData) {
-    SorobanTransactionData data;
-    try {
-      data = SorobanTransactionData.fromXdrBase64(sorobanData);
-    } catch (IOException e) {
-      throw new IllegalArgumentException("Invalid Soroban data: " + sorobanData, e);
-    }
-    return setSorobanData(data);
+    this.mSorobanData = new SorobanDataBuilder(sorobanData).build();
+    return this;
   }
 }

src/test/java/org/stellar/sdk/SorobanDataBuilderTest.java

@@ -0,0 +1,145 @@
+package org.stellar.sdk;
+
+import static com.google.common.collect.ImmutableList.of;
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotSame;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import org.junit.Test;
+import org.stellar.sdk.xdr.ExtensionPoint;
+import org.stellar.sdk.xdr.Int64;
+import org.stellar.sdk.xdr.LedgerEntryType;
+import org.stellar.sdk.xdr.LedgerFootprint;
+import org.stellar.sdk.xdr.LedgerKey;
+import org.stellar.sdk.xdr.SorobanResources;
+import org.stellar.sdk.xdr.SorobanTransactionData;
+import org.stellar.sdk.xdr.Uint32;
+import org.stellar.sdk.xdr.XdrUnsignedInteger;
+
+public class SorobanDataBuilderTest {
+  LedgerKey readOnly =
+      new LedgerKey.Builder()
+          .discriminant(LedgerEntryType.ACCOUNT)
+          .account(
+              new LedgerKey.LedgerKeyAccount.Builder()
+                  .accountID(
+                      KeyPair.fromAccountId(
+                              "GB7TAYRUZGE6TVT7NHP5SMIZRNQA6PLM423EYISAOAP3MKYIQMVYP2JO")
+                          .getXdrAccountId())
+                  .build())
+          .build();
+  LedgerKey readWrite =
+      new LedgerKey.Builder()
+          .discriminant(LedgerEntryType.ACCOUNT)
+          .account(
+              new LedgerKey.LedgerKeyAccount.Builder()
+                  .accountID(
+                      KeyPair.fromAccountId(
+                              "GAHJJJKMOKYE4RVPZEWZTKH5FVI4PA3VL7GK2LFNUBSGBV6OJP7TQSLX")
+                          .getXdrAccountId())
+                  .build())
+          .build();
+
+  SorobanTransactionData emptySorobanData =
+      new SorobanTransactionData.Builder()
+          .resources(
+              new SorobanResources.Builder()
+                  .footprint(
+                      new LedgerFootprint.Builder()
+                          .readOnly(new LedgerKey[] {})
+                          .readWrite(new LedgerKey[] {})
+                          .build())
+                  .instructions(new Uint32(new XdrUnsignedInteger(0)))
+                  .readBytes(new Uint32(new XdrUnsignedInteger(0)))
+                  .writeBytes(new Uint32(new XdrUnsignedInteger(0)))
+                  .extendedMetaDataSizeBytes(new Uint32(new XdrUnsignedInteger(0)))
+                  .build())
+          .refundableFee(new Int64(0L))
+          .ext(new ExtensionPoint.Builder().discriminant(0).build())
+          .build();
+
+  SorobanTransactionData presetSorobanData =
+      new SorobanTransactionData.Builder()
+          .resources(
+              new SorobanResources.Builder()
+                  .footprint(
+                      new LedgerFootprint.Builder()
+                          .readOnly(new LedgerKey[] {readOnly})
+                          .readWrite(new LedgerKey[] {readWrite})
+                          .build())
+                  .instructions(new Uint32(new XdrUnsignedInteger(1)))
+                  .readBytes(new Uint32(new XdrUnsignedInteger(2)))
+                  .writeBytes(new Uint32(new XdrUnsignedInteger(3)))
+                  .extendedMetaDataSizeBytes(new Uint32(new XdrUnsignedInteger(4)))
+                  .build())
+          .refundableFee(new Int64(5L))
+          .ext(new ExtensionPoint.Builder().discriminant(0).build())
+          .build();
+
+  @Test
+  public void testConstructorFromEmpty() {
+    SorobanTransactionData actualData = new SorobanDataBuilder().build();
+    assertEquals(emptySorobanData, actualData);
+  }
+
+  @Test
+  public void testConstructorFromBase64() throws IOException {
+    String base64 = presetSorobanData.toXdrBase64();
+    SorobanTransactionData actualData = new SorobanDataBuilder(base64).build();
+    assertEquals(presetSorobanData, actualData);
+  }
+
+  @Test
+  public void testConstructorFromSorobanTransactionData() {
+    SorobanTransactionData actualData = new SorobanDataBuilder(presetSorobanData).build();
+    assertEquals(presetSorobanData, actualData);
+  }
+
+  @Test
+  public void testSetProperties() {
+    SorobanTransactionData actualData =
+        new SorobanDataBuilder()
+            .setReadOnly(of(readOnly))
+            .setReadWrite(of(readWrite))
+            .setRefundableFee(5)
+            .setResources(
+                new SorobanDataBuilder.Resources.ResourcesBuilder()
+                    .cpuInstructions(1L)
+                    .readBytes(2L)
+                    .writeBytes(3L)
+                    .metadataBytes(4L)
+                    .build())
+            .build();
+    assertEquals(presetSorobanData, actualData);
+  }
+
+  @Test
+  public void testLeavesUntouchedFootprintsUntouched() {
+    SorobanTransactionData data0 =
+        new SorobanDataBuilder(presetSorobanData).setReadOnly(null).build();
+    assertArrayEquals(
+        new LedgerKey[] {readOnly}, data0.getResources().getFootprint().getReadOnly());
+
+    SorobanTransactionData data1 =
+        new SorobanDataBuilder(presetSorobanData).setReadOnly(new ArrayList<>()).build();
+    assertArrayEquals(new LedgerKey[] {}, data1.getResources().getFootprint().getReadOnly());
+
+    SorobanTransactionData data3 =
+        new SorobanDataBuilder(presetSorobanData).setReadWrite(null).build();
+    assertArrayEquals(
+        new LedgerKey[] {readWrite}, data3.getResources().getFootprint().getReadWrite());
+
+    SorobanTransactionData data4 =
+        new SorobanDataBuilder(presetSorobanData).setReadWrite(new ArrayList<>()).build();
+    assertArrayEquals(new LedgerKey[] {}, data4.getResources().getFootprint().getReadWrite());
+  }
+
+  @Test
+  public void testBuildCopy() {
+    SorobanTransactionData actualData = new SorobanDataBuilder(presetSorobanData).build();
+    assertEquals(presetSorobanData, actualData);
+    assertNotSame(presetSorobanData, actualData);
+  }
+}