Refactor EppMetrics into the EppMetric value type

This change refactors EppMetrics from the mutable self-exporting thing that it
was into a real value type EppMetric, and delegates exporting functionality to the
BigQueryMetricsEnqueuer.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132387660

java/google/registry/monitoring/whitebox/EppMetric.java

@@ -0,0 +1,228 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed 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 google.registry.monitoring.whitebox;
+
+import static com.google.apphosting.api.ApiProxy.getCurrentEnvironment;
+import static google.registry.bigquery.BigqueryUtils.toBigqueryTimestamp;
+import static org.joda.time.DateTimeZone.UTC;
+
+import com.google.api.services.bigquery.model.TableFieldSchema;
+import com.google.auto.value.AutoValue;
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Optional;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import google.registry.bigquery.BigqueryUtils.FieldType;
+import google.registry.model.eppoutput.Result.Code;
+import google.registry.request.RequestScope;
+import java.util.concurrent.TimeUnit;
+import javax.inject.Inject;
+import org.joda.time.DateTime;
+
+/**
+ * A value class for recording attributes of an EPP metric.
+ *
+ * @see BigQueryMetricsEnqueuer
+ */
+@AutoValue
+@RequestScope
+public abstract class EppMetric implements BigQueryMetric {
+
+  static final String TABLE_ID = "eppMetrics";
+  static final ImmutableList<TableFieldSchema> SCHEMA_FIELDS =
+      ImmutableList.of(
+          new TableFieldSchema().setName("requestId").setType(FieldType.STRING.name()),
+          new TableFieldSchema().setName("startTime").setType(FieldType.TIMESTAMP.name()),
+          new TableFieldSchema().setName("endTime").setType(FieldType.TIMESTAMP.name()),
+          new TableFieldSchema().setName("commandName").setType(FieldType.STRING.name()),
+          new TableFieldSchema().setName("clientId").setType(FieldType.STRING.name()),
+          new TableFieldSchema().setName("privilegeLevel").setType(FieldType.STRING.name()),
+          new TableFieldSchema().setName("eppTarget").setType(FieldType.STRING.name()),
+          new TableFieldSchema().setName("eppStatus").setType(FieldType.INTEGER.name()),
+          new TableFieldSchema().setName("attempts").setType(FieldType.INTEGER.name()));
+
+  private static final String REQUEST_LOG_ID = "com.google.appengine.runtime.request_log_id";
+
+  private static EppMetric create(
+      String requestId,
+      DateTime startTimestamp,
+      DateTime endTimestamp,
+      String commandName,
+      String clientId,
+      String privilegeLevel,
+      String eppTarget,
+      Code status,
+      int attempts) {
+    return new AutoValue_EppMetric(
+        requestId,
+        startTimestamp,
+        endTimestamp,
+        Optional.ofNullable(commandName),
+        Optional.ofNullable(clientId),
+        Optional.ofNullable(privilegeLevel),
+        Optional.ofNullable(eppTarget),
+        Optional.ofNullable(status),
+        attempts);
+  }
+
+  public abstract String getRequestId();
+
+  public abstract DateTime getStartTimestamp();
+
+  public abstract DateTime getEndTimestamp();
+
+  public abstract Optional<String> getCommandName();
+
+  public abstract Optional<String> getClientId();
+
+  public abstract Optional<String> getPrivilegeLevel();
+
+  public abstract Optional<String> getEppTarget();
+
+  public abstract Optional<Code> getStatus();
+
+  public abstract Integer getAttempts();
+
+  @Override
+  public String getTableId() {
+    return TABLE_ID;
+  }
+
+  @Override
+  public ImmutableList<TableFieldSchema> getSchemaFields() {
+    return SCHEMA_FIELDS;
+  }
+
+  @Override
+  public ImmutableMap<String, String> getBigQueryRowEncoding() {
+    // Create map builder, start with required values
+    ImmutableMap.Builder<String, String> map =
+        ImmutableMap.<String, String>builder()
+            .put("requestId", getRequestId())
+            .put(
+                "startTime",
+                toBigqueryTimestamp(getStartTimestamp().getMillis(), TimeUnit.MILLISECONDS))
+            .put(
+                "endTime",
+                toBigqueryTimestamp(getEndTimestamp().getMillis(), TimeUnit.MILLISECONDS))
+            .put("attempts", getAttempts().toString());
+    // Populate optional values, if present
+    addOptional("commandName", getCommandName(), map);
+    addOptional("clientId", getClientId(), map);
+    addOptional("privilegeLevel", getPrivilegeLevel(), map);
+    addOptional("eppTarget", getEppTarget(), map);
+    addOptional("status", getStatus(), map);
+
+    return map.build();
+  }
+
+  /**
+   * Helper method to populate an {@link com.google.common.collect.ImmutableMap.Builder} with an
+   * {@link Optional} value if the value is {@link Optional#isPresent()}.
+   */
+  private static <T> void addOptional(
+      String key, Optional<T> value, ImmutableMap.Builder<String, String> map) {
+    if (value.isPresent()) {
+      map.put(key, value.get().toString());
+    }
+  }
+
+  /** A builder to create instances of {@link EppMetric}. */
+  public static class Builder {
+
+    // Required values
+    private final String requestId;
+    private final DateTime startTimestamp;
+    private int attempts = 0;
+
+    // Optional values
+    private String commandName;
+    private String clientId;
+    private String privilegeLevel;
+    private String eppTarget;
+    private Code status;
+
+    /**
+     * Create an {@link EppMetric.Builder}.
+     *
+     * <p>The start timestamp of metrics created via this instance's {@link Builder#build()} will be
+     * the time that this builder was created.
+     */
+    @Inject
+    public Builder() {
+      this(DateTime.now(UTC));
+    }
+
+    @VisibleForTesting
+    Builder(DateTime startTimestamp) {
+      this.requestId = getCurrentEnvironment().getAttributes().get(REQUEST_LOG_ID).toString();
+      this.startTimestamp = startTimestamp;
+      this.attempts = 0;
+    }
+
+    public Builder setCommandName(String value) {
+      commandName = value;
+      return this;
+    }
+
+    public Builder setClientId(String value) {
+      clientId = value;
+      return this;
+    }
+
+    public Builder setPrivilegeLevel(String value) {
+      privilegeLevel = value;
+      return this;
+    }
+
+    public Builder setEppTarget(String value) {
+      eppTarget = value;
+      return this;
+    }
+
+    public Builder setStatus(Code value) {
+      status = value;
+      return this;
+    }
+
+    public Builder incrementAttempts() {
+      attempts++;
+      return this;
+    }
+
+    @VisibleForTesting
+    EppMetric build(DateTime endTimestamp) {
+      return EppMetric.create(
+          requestId,
+          startTimestamp,
+          endTimestamp,
+          commandName,
+          clientId,
+          privilegeLevel,
+          eppTarget,
+          status,
+          attempts);
+    }
+
+    /**
+     * Build an instance of {@link EppMetric} using this builder.
+     *
+     * <p>The end timestamp of the metric will be the current time.
+     */
+    public EppMetric build() {
+      return build(DateTime.now(UTC));
+    }
+  }
+}