refactor: Merge BsonBinaryData into Blob

This PR stacks on PR #2378 and implements the refactoring to merge BsonBinaryData into Blob, as requested by the user.

Author: wu-hui

java-firestore/google-cloud-firestore/src/main/java/com/google/cloud/firestore/Blob.java

@@ -27,31 +27,91 @@ public final class Blob implements Serializable {
   private static final long serialVersionUID = 1441087101882481208L;
 
   private final ByteString byteString;
+  private final int subtype;
+  private final boolean isBson;
 
-  private Blob(ByteString byteString) {
+  private Blob(ByteString byteString, int subtype, boolean isBson) {
+    if (subtype < 0 || subtype > 255) {
+      throw new IllegalArgumentException(
+          "The subtype for Blob must be a value in the inclusive [0, 255] range.");
+    }
     this.byteString = byteString;
+    this.subtype = subtype;
+    this.isBson = isBson;
   }
 
   /**
-   * Creates a new Blob instance from the provided ByteString.
+   * Creates a new Blob instance from the provided ByteString. Defaults to subtype 0 and native
+   * representation.
    *
    * @param byteString The byteString to use for this Blob instance.
    * @return The new Blob instance
    */
   @Nonnull
   public static Blob fromByteString(@Nonnull ByteString byteString) {
-    return new Blob(byteString);
+    return new Blob(byteString, 0, false);
   }
 
   /**
    * Creates a new Blob instance from the provided bytes. Makes a copy of the bytes passed in.
+   * Defaults to subtype 0 and native representation.
    *
    * @param bytes The bytes to use for this Blob instance.
    * @return The new Blob instance
    */
   @Nonnull
   public static Blob fromBytes(@Nonnull byte[] bytes) {
-    return new Blob(ByteString.copyFrom(bytes));
+    return new Blob(ByteString.copyFrom(bytes), 0, false);
+  }
+
+  /**
+   * Creates a new Blob instance representing a BSON binary data type. Sets subtype to 0 and
+   * representation to BSON.
+   *
+   * @param bytes The bytes to use for this Blob instance.
+   * @return The new Blob instance
+   */
+  @Nonnull
+  public static Blob createBsonBinary(@Nonnull byte[] bytes) {
+    return new Blob(ByteString.copyFrom(bytes), 0, true);
+  }
+
+  /**
+   * Creates a new Blob instance representing a BSON binary data type. Sets subtype to 0 and
+   * representation to BSON.
+   *
+   * @param data The ByteString to use for this Blob instance.
+   * @return The new Blob instance
+   */
+  @Nonnull
+  public static Blob createBsonBinary(@Nonnull ByteString data) {
+    return new Blob(data, 0, true);
+  }
+
+  /**
+   * Creates a new Blob instance representing a BSON binary data type with a specific subtype. Sets
+   * representation to BSON.
+   *
+   * @param subtype The subtype to use for this instance.
+   * @param bytes The bytes to use for this Blob instance.
+   * @return The new Blob instance
+   */
+  @Nonnull
+  public static Blob createBsonBinary(int subtype, @Nonnull byte[] bytes) {
+    return new Blob(ByteString.copyFrom(bytes), subtype, true);
+  }
+
+  /**
+   * Creates a new Blob instance representing a BSON binary data type with a specific subtype. Sets
+   * representation to BSON.
+   *
+   * @param subtype The subtype to use for this instance.
+   * @param data The ByteString to use for this Blob instance.
+   * @return The new Blob instance
+   */
+  @Nonnull
+  public static Blob createBsonBinary(int subtype, @Nonnull ByteString data) {
+    return new Blob(data, subtype, true);
   }
 
   /**
@@ -74,6 +134,25 @@ public byte[] toBytes() {
     return byteString.toByteArray();
   }
 
+  /**
+   * Returns the subtype of this binary data. Defaults to 0 for both native binary and BSON binary
+   * if not specified.
+   *
+   * @return The subtype of the binary data.
+   */
+  public int subtype() {
+    return this.subtype;
+  }
+
+  /**
+   * Returns whether this Blob represents a BSON binary data type.
+   *
+   * @return True if BSON representation, false if native representation.
+   */
+  public boolean isBson() {
+    return this.isBson;
+  }
+
   /**
    * Returns true if this Blob is equal to the provided object.
    *
@@ -89,11 +168,32 @@ public boolean equals(Object obj) {
       return false;
     }
     Blob blob = (Blob) obj;
-    return Objects.equals(byteString, blob.byteString);
+    return this.subtype == blob.subtype && Objects.equals(byteString, blob.byteString);
   }
 
   @Override
   public int hashCode() {
-    return Objects.hash(byteString);
+    return Objects.hash(byteString, subtype);
+  }
+
+  @Nonnull
+  @Override
+  public String toString() {
+    String dataStr;
+    if (this.byteString.size() <= 100) {
+      dataStr =
+          com.google.common.io.BaseEncoding.base16()
+              .lowerCase()
+              .encode(this.byteString.toByteArray());
+    } else {
+      dataStr =
+          com.google.common.io.BaseEncoding.base16()
+                  .lowerCase()
+                  .encode(this.byteString.substring(0, 20).toByteArray())
+              + "... (size="
+              + this.byteString.size()
+              + ")";
+    }
+    return "Blob{subtype=" + this.subtype + ", isBson=" + this.isBson + ", data=" + dataStr + "}";
   }
 }

java-firestore/google-cloud-firestore/src/main/java/com/google/cloud/firestore/BsonBinaryData.java

@@ -482,18 +482,6 @@ public BsonTimestamp getBsonTimestamp(@Nonnull String field) {
     return (BsonTimestamp) get(field);
   }
 
-  /**
-   * Returns the value of the field as a BsonBinaryData.
-   *
-   * @param field The path to the field.
-   * @throws RuntimeException if the value is not a BsonBinaryData.
-   * @return The value of the field.
-   */
-  @Nullable
-  public BsonBinaryData getBsonBinaryData(@Nonnull String field) {
-    return (BsonBinaryData) get(field);
-  }
-
   /**
    * Gets the reference to the document.
    *

java-firestore/google-cloud-firestore/src/main/java/com/google/cloud/firestore/DocumentSnapshot.java

@@ -43,7 +43,6 @@ enum TypeOrder implements Comparable<TypeOrder> {
     BSON_TIMESTAMP,
     STRING,
     BLOB,
-    BSON_BINARY,
     REF,
     BSON_OBJECT_ID,
     GEO_POINT,
@@ -100,7 +99,7 @@ static TypeOrder fromMapValue(MapValue mapValue) {
       case BSON_TIMESTAMP:
         return TypeOrder.BSON_TIMESTAMP;
       case BSON_BINARY_DATA:
-        return TypeOrder.BSON_BINARY;
+        return TypeOrder.BLOB;
       case UNKNOWN:
       case NONE:
       default:
@@ -160,8 +159,7 @@ public int compare(@Nonnull Value left, @Nonnull Value right) {
         return compareBsonObjectId(left, right);
       case BSON_TIMESTAMP:
         return compareBsonTimestamp(left, right);
-      case BSON_BINARY:
-        return compareBsonBinary(left, right);
+
       default:
         throw new IllegalArgumentException("Cannot compare " + leftType);
     }
@@ -226,9 +224,43 @@ public static int compareUtf8Strings(String left, String right) {
   }
 
   private int compareBlobs(Value left, Value right) {
-    ByteString leftBytes = left.getBytesValue();
-    ByteString rightBytes = right.getBytesValue();
-    return compareByteStrings(leftBytes, rightBytes);
+    int leftSubtype = getSubtype(left);
+    int rightSubtype = getSubtype(right);
+    if (leftSubtype != rightSubtype) {
+      return Integer.compare(leftSubtype, rightSubtype);
+    }
+    return compareByteStrings(getData(left), getData(right));
+  }
+
+  private static int getSubtype(Value value) {
+    if (value.hasBytesValue()) {
+      return 0;
+    }
+    if (value.hasMapValue() && UserDataConverter.isBsonBinaryData(value.getMapValue())) {
+      return value
+              .getMapValue()
+              .getFieldsMap()
+              .get(MapType.RESERVED_BSON_BINARY_KEY)
+              .getBytesValue()
+              .byteAt(0)
+          & 0xFF;
+    }
+    throw new IllegalArgumentException("Cannot get subtype for non-blob value: " + value);
+  }
+
+  private static ByteString getData(Value value) {
+    if (value.hasBytesValue()) {
+      return value.getBytesValue();
+    }
+    if (value.hasMapValue() && UserDataConverter.isBsonBinaryData(value.getMapValue())) {
+      return value
+          .getMapValue()
+          .getFieldsMap()
+          .get(MapType.RESERVED_BSON_BINARY_KEY)
+          .getBytesValue()
+          .substring(1);
+    }
+    throw new IllegalArgumentException("Cannot get data for non-blob value: " + value);
   }
 
   static int compareByteStrings(ByteString leftBytes, ByteString rightBytes) {
@@ -412,14 +444,6 @@ private int compareBsonTimestamp(Value left, Value right) {
     return secondsDiff != 0 ? secondsDiff : Long.compare(lhs.increment, rhs.increment);
   }
 
-  private int compareBsonBinary(Value left, Value right) {
-    ByteString lhs =
-        left.getMapValue().getFieldsMap().get(MapType.RESERVED_BSON_BINARY_KEY).getBytesValue();
-    ByteString rhs =
-        right.getMapValue().getFieldsMap().get(MapType.RESERVED_BSON_BINARY_KEY).getBytesValue();
-    return compareByteStrings(lhs, rhs);
-  }
-
   private boolean isNaN(Value value) {
     if (value.hasDoubleValue() && Double.isNaN(value.getDoubleValue())) {
       return true;