Add DiskInfo, disk configurations and test classes

gcloud-java-compute/src/main/java/com/google/gcloud/compute/DiskConfiguration.java

@@ -0,0 +1,203 @@
+/*
+ * Copyright 2016 Google Inc. 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 com.google.gcloud.compute;
+
+import com.google.api.services.compute.model.Disk;
+import com.google.common.base.MoreObjects;
+import com.google.common.base.MoreObjects.ToStringHelper;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+/**
+ * Base class for Google Compute Engine disk configurations. A disk can be used as primary storage
+ * for your virtual machine instances. Use {@link StandardDiskConfiguration} to create a standard
+ * disk given a disk type and size. Use {@link ImageDiskConfiguration} to create a disk from a
+ * Compute Engine disk image. Use {@link SnapshotDiskConfiguration} to create a disk from a Compute
+ * Engine disk snapshot.
+ *
+ * @see <a href="https://cloud.google.com/compute/docs/disks/">Block Storage</a>
+ */
+public abstract class DiskConfiguration implements Serializable {
+
+  private static final long serialVersionUID = -1783061701255428417L;
+
+  private final Type type;
+  private final Long sizeGb;
+  private final DiskTypeId diskType;
+
+  /**
+   * Type of a Google Compute Engine disk configuration.
+   */
+  public enum Type {
+    /**
+     * A Google Compute Engine standard disk configuration.
+     */
+    STANDARD,
+
+    /**
+     * A Google Compute Engine disk configuration that creates a disk from an image.
+     */
+    IMAGE,
+
+    /**
+     * A Google Compute Engine disk configuration that creates a disk from a snapshot.
+     */
+    SNAPSHOT
+  }
+
+  /**
+   * Base builder for disk configurations.
+   *
+   * @param <T> the disk configuration type
+   * @param <B> the disk configuration builder
+   */
+  public abstract static class Builder<T extends DiskConfiguration, B extends Builder<T, B>> {
+
+    private Type type;
+    private Long sizeGb;
+    private DiskTypeId diskType;
+
+    Builder(Type type) {
+      this.type = type;
+    }
+
+    Builder(Type type, DiskConfiguration diskConfiguration) {
+      this.type = type;
+      this.sizeGb = diskConfiguration.sizeGb;
+      this.diskType = diskConfiguration.diskType;
+    }
+
+    Builder(Type type, Disk diskPb) {
+      this.type = type;
+      this.sizeGb = diskPb.getSizeGb();
+      if (diskPb.getType() != null) {
+        this.diskType = DiskTypeId.fromUrl(diskPb.getType());
+      }
+    }
+
+    @SuppressWarnings("unchecked")
+    protected B self() {
+      return (B) this;
+    }
+
+    B type(Type type) {
+      this.type = type;
+      return self();
+    }
+
+    /**
+     * Sets the size of the persistent disk, in GB.
+     */
+    public B sizeGb(Long sizeGb) {
+      this.sizeGb = sizeGb;
+      return self();
+    }
+
+    /**
+     * Sets the identity of the disk type.
+     */
+    public B diskType(DiskTypeId diskType) {
+      this.diskType = diskType;
+      return self();
+    }
+
+    /**
+     * Creates an object.
+     */
+    public abstract T build();
+  }
+
+  DiskConfiguration(Builder builder) {
+    this.type = builder.type;
+    this.sizeGb = builder.sizeGb;
+    this.diskType = builder.diskType;
+  }
+
+  /**
+   * Returns the disk configuration's type. This method returns {@link Type#STANDARD} for a standard
+   * configuration that creates a disk given its type and size. This method returns
+   * {@link Type#SNAPSHOT} for a configuration that creates a disk from a Google Compute Engine
+   * snapshot. This method returns {@link Type#IMAGE} for a configuration that creates a disk
+   * from a Google Compute Engine image.
+   */
+  public Type type() {
+    return type;
+  }
+
+  /**
+   * Returns the size of the persistent disk, in GB.
+   */
+  public Long sizeGb() {
+    return sizeGb;
+  }
+
+  /**
+   * Returns the identity of the disk type.
+   */
+  public DiskTypeId diskType() {
+    return diskType;
+  }
+
+  /**
+   * Returns a builder for the object.
+   */
+  public abstract Builder toBuilder();
+
+  ToStringHelper toStringHelper() {
+    return MoreObjects.toStringHelper(this)
+        .add("type", type)
+        .add("sizeGb", sizeGb)
+        .add("diskType", diskType);
+  }
+
+  @Override
+  public String toString() {
+    return toStringHelper().toString();
+  }
+
+  final int baseHashCode() {
+    return Objects.hash(type, sizeGb, diskType);
+  }
+
+  final boolean baseEquals(DiskConfiguration diskConfiguration) {
+    return diskConfiguration != null
+        && getClass().equals(diskConfiguration.getClass())
+        && Objects.equals(toPb(), diskConfiguration.toPb());
+  }
+
+  abstract DiskConfiguration setProjectId(String projectId);
+
+  Disk toPb() {
+    Disk diskPb = new Disk();
+    diskPb.setSizeGb(sizeGb);
+    if (diskType != null) {
+      diskPb.setType(diskType.selfLink());
+    }
+    return diskPb;
+  }
+
+  @SuppressWarnings("unchecked")
+  static <T extends DiskConfiguration> T fromPb(Disk diskPb) {
+    if (diskPb.getSourceImage() != null) {
+      return (T) ImageDiskConfiguration.fromPb(diskPb);
+    } else if (diskPb.getSourceSnapshot() != null) {
+      return (T) SnapshotDiskConfiguration.fromPb(diskPb);
+    }
+    return (T) StandardDiskConfiguration.fromPb(diskPb);
+  }
+}