Core: Add REST spec and request for committing changes against multiple tables

core/src/main/java/org/apache/iceberg/rest/RESTSerializers.java

@@ -42,6 +42,8 @@
 import org.apache.iceberg.catalog.TableIdentifier;
 import org.apache.iceberg.catalog.TableIdentifierParser;
 import org.apache.iceberg.rest.auth.OAuth2Util;
+import org.apache.iceberg.rest.requests.CommitTransactionRequest;
+import org.apache.iceberg.rest.requests.CommitTransactionRequestParser;
 import org.apache.iceberg.rest.requests.ImmutableReportMetricsRequest;
 import org.apache.iceberg.rest.requests.ReportMetricsRequest;
 import org.apache.iceberg.rest.requests.ReportMetricsRequestParser;
@@ -83,7 +85,10 @@ public static void registerAll(ObjectMapper mapper) {
         .addDeserializer(ReportMetricsRequest.class, new ReportMetricsRequestDeserializer<>())
         .addSerializer(ImmutableReportMetricsRequest.class, new ReportMetricsRequestSerializer<>())
         .addDeserializer(
-            ImmutableReportMetricsRequest.class, new ReportMetricsRequestDeserializer<>());
+            ImmutableReportMetricsRequest.class, new ReportMetricsRequestDeserializer<>())
+        .addSerializer(CommitTransactionRequest.class, new CommitTransactionRequestSerializer())
+        .addDeserializer(
+            CommitTransactionRequest.class, new CommitTransactionRequestDeserializer());
     mapper.registerModule(module);
   }
 
@@ -280,4 +285,24 @@ public T deserialize(JsonParser p, DeserializationContext context) throws IOExce
       return (T) ReportMetricsRequestParser.fromJson(jsonNode);
     }
   }
+
+  public static class CommitTransactionRequestSerializer
+      extends JsonSerializer<CommitTransactionRequest> {
+    @Override
+    public void serialize(
+        CommitTransactionRequest request, JsonGenerator gen, SerializerProvider serializers)
+        throws IOException {
+      CommitTransactionRequestParser.toJson(request, gen);
+    }
+  }
+
+  public static class CommitTransactionRequestDeserializer
+      extends JsonDeserializer<CommitTransactionRequest> {
+    @Override
+    public CommitTransactionRequest deserialize(JsonParser p, DeserializationContext context)
+        throws IOException {
+      JsonNode jsonNode = p.getCodec().readTree(p);
+      return CommitTransactionRequestParser.fromJson(jsonNode);
+    }
+  }
 }

core/src/main/java/org/apache/iceberg/rest/ResourcePaths.java

@@ -85,4 +85,8 @@ public String metrics(TableIdentifier identifier) {
         RESTUtil.encodeString(identifier.name()),
         "metrics");
   }
+
+  public String commitTransaction() {
+    return SLASH.join("v1", prefix, "transactions", "commit");
+  }
 }

core/src/main/java/org/apache/iceberg/rest/requests/CommitTransactionRequest.java

@@ -0,0 +1,47 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.iceberg.rest.requests;
+
+import java.util.List;
+import org.apache.iceberg.relocated.com.google.common.base.Preconditions;
+import org.apache.iceberg.relocated.com.google.common.collect.ImmutableList;
+import org.apache.iceberg.rest.RESTRequest;
+
+public class CommitTransactionRequest implements RESTRequest {
+  private final List<UpdateTableRequest> tableChanges;
+
+  public CommitTransactionRequest(List<UpdateTableRequest> tableChanges) {
+    this.tableChanges = tableChanges;
+    validate();
+  }
+
+  public List<UpdateTableRequest> tableChanges() {
+    return ImmutableList.copyOf(tableChanges);
+  }
+
+  @Override
+  public void validate() {
+    Preconditions.checkArgument(null != tableChanges, "Invalid table changes: null");
+    Preconditions.checkArgument(!tableChanges.isEmpty(), "Invalid table changes: empty");
+    for (UpdateTableRequest tableChange : tableChanges) {
+      Preconditions.checkArgument(
+          null != tableChange.identifier(), "Invalid table changes: table identifier required");
+    }
+  }
+}

core/src/main/java/org/apache/iceberg/rest/requests/CommitTransactionRequestParser.java

@@ -0,0 +1,126 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.iceberg.rest.requests;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonNode;
+import java.io.IOException;
+import java.util.List;
+import org.apache.iceberg.MetadataUpdate;
+import org.apache.iceberg.MetadataUpdateParser;
+import org.apache.iceberg.catalog.TableIdentifier;
+import org.apache.iceberg.catalog.TableIdentifierParser;
+import org.apache.iceberg.relocated.com.google.common.base.Preconditions;
+import org.apache.iceberg.relocated.com.google.common.collect.Lists;
+import org.apache.iceberg.util.JsonUtil;
+
+public class CommitTransactionRequestParser {
+  private static final String TABLE_CHANGES = "table-changes";
+  private static final String IDENTIFIER = "identifier";
+  private static final String REQUIREMENTS = "requirements";
+  private static final String UPDATES = "updates";
+
+  private CommitTransactionRequestParser() {}
+
+  public static String toJson(CommitTransactionRequest request) {
+    return toJson(request, false);
+  }
+
+  public static String toJson(CommitTransactionRequest request, boolean pretty) {
+    return JsonUtil.generate(gen -> toJson(request, gen), pretty);
+  }
+
+  public static void toJson(CommitTransactionRequest request, JsonGenerator gen)
+      throws IOException {
+    Preconditions.checkArgument(null != request, "Invalid commit tx request: null");
+
+    gen.writeStartObject();
+    gen.writeFieldName(TABLE_CHANGES);
+    gen.writeStartArray();
+
+    for (UpdateTableRequest tableChange : request.tableChanges()) {
+      gen.writeStartObject();
+
+      gen.writeFieldName(IDENTIFIER);
+      TableIdentifierParser.toJson(tableChange.identifier(), gen);
+
+      gen.writeArrayFieldStart(REQUIREMENTS);
+      for (UpdateTableRequest.UpdateRequirement updateRequirement : tableChange.requirements()) {
+        UpdateRequirementParser.toJson(updateRequirement, gen);
+      }
+      gen.writeEndArray();
+
+      gen.writeArrayFieldStart(UPDATES);
+      for (MetadataUpdate metadataUpdate : tableChange.updates()) {
+        MetadataUpdateParser.toJson(metadataUpdate, gen);
+      }
+      gen.writeEndArray();
+
+      gen.writeEndObject();
+    }
+
+    gen.writeEndArray();
+    gen.writeEndObject();
+  }
+
+  public static CommitTransactionRequest fromJson(String json) {
+    return JsonUtil.parse(json, CommitTransactionRequestParser::fromJson);
+  }
+
+  public static CommitTransactionRequest fromJson(JsonNode json) {
+    Preconditions.checkArgument(null != json, "Cannot parse commit tx request from null object");
+
+    List<UpdateTableRequest> tableChanges = Lists.newArrayList();
+    JsonNode changes = JsonUtil.get(TABLE_CHANGES, json);
+
+    Preconditions.checkArgument(
+        changes.isArray(), "Cannot parse commit tx request from non-array: %s", changes);
+
+    for (JsonNode node : changes) {
+      TableIdentifier identifier = null;
+      List<UpdateTableRequest.UpdateRequirement> requirements = Lists.newArrayList();
+      List<MetadataUpdate> updates = Lists.newArrayList();
+
+      if (node.hasNonNull(IDENTIFIER)) {
+        identifier = TableIdentifierParser.fromJson(JsonUtil.get(IDENTIFIER, node));
+      }
+
+      if (node.hasNonNull(REQUIREMENTS)) {
+        JsonNode requirementsNode = JsonUtil.get(REQUIREMENTS, node);
+        Preconditions.checkArgument(
+            requirementsNode.isArray(),
+            "Cannot parse requirements from non-array: %s",
+            requirementsNode);
+        requirementsNode.forEach(req -> requirements.add(UpdateRequirementParser.fromJson(req)));
+      }
+
+      if (node.hasNonNull(UPDATES)) {
+        JsonNode updatesNode = JsonUtil.get(UPDATES, node);
+        Preconditions.checkArgument(
+            updatesNode.isArray(), "Cannot parse metadata updates from non-array: %s", updatesNode);
+
+        updatesNode.forEach(update -> updates.add(MetadataUpdateParser.fromJson(update)));
+      }
+
+      tableChanges.add(new UpdateTableRequest(identifier, requirements, updates));
+    }
+
+    return new CommitTransactionRequest(tableChanges);
+  }
+}

core/src/main/java/org/apache/iceberg/rest/requests/UpdateTableRequest.java

@@ -23,6 +23,7 @@
 import org.apache.iceberg.MetadataUpdate;
 import org.apache.iceberg.SnapshotRef;
 import org.apache.iceberg.TableMetadata;
+import org.apache.iceberg.catalog.TableIdentifier;
 import org.apache.iceberg.exceptions.CommitFailedException;
 import org.apache.iceberg.relocated.com.google.common.base.MoreObjects;
 import org.apache.iceberg.relocated.com.google.common.base.Preconditions;
@@ -33,6 +34,7 @@
 
 public class UpdateTableRequest implements RESTRequest {
 
+  private TableIdentifier identifier;
   private List<UpdateRequirement> requirements;
   private List<MetadataUpdate> updates;
 
@@ -45,6 +47,14 @@ public UpdateTableRequest(List<UpdateRequirement> requirements, List<MetadataUpd
     this.updates = updates;
   }
 
+  UpdateTableRequest(
+      TableIdentifier identifier,
+      List<UpdateRequirement> requirements,
+      List<MetadataUpdate> updates) {
+    this(requirements, updates);
+    this.identifier = identifier;
+  }
+
   @Override
   public void validate() {}
 
@@ -56,6 +66,10 @@ public List<MetadataUpdate> updates() {
     return updates != null ? updates : ImmutableList.of();
   }
 
+  public TableIdentifier identifier() {
+    return identifier;
+  }
+
   @Override
   public String toString() {
     return MoreObjects.toStringHelper(this)