tests/tests/location/src/android/location/cts/asn1/base/Asn1Choice.java - platform/cts - Git at Google

 /*
  * Copyright (C) 2017 The Android Open Source Project
  *
  * 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 android.location.cts.asn1.base;

 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;

 import java.nio.ByteBuffer;

 import javax.annotation.Nullable;

 /**
  * Implements ASN.1 functionality.
  *
  */
 public abstract class Asn1Choice extends Asn1Object {
   /**
    * Dummy non-tag used as default tag for CHOICE, which reflects the BER encoding idea
    * that CHOICE is not an object in itself, it just gets coded as its value. This means
    * that it doesn't matter whether the choice object tag is designated as IMPLICIT or
    * EXPLICIT, it gets coded the same way anyway.
    */
   private static final Asn1Tag DUMMY_DEFAULT_TAG = new Asn1Tag(null, Integer.MIN_VALUE) {
     @Override
     public int getTaggedLength(int valueLength) {
       return valueLength;
     }

     @Override
     public void writeTagAndLength(ByteBuffer buf, boolean constructed, int valueLength) {
       // Do nothing.
     }

     @Override
     int getValue() {
       throw new UnsupportedOperationException("This is not a real tag.");
     }
   };

   /**
    * Returns true if the type has an extension marker.
    */
   protected abstract boolean isExtensible();

   /**
    * Returns true if the value set is an extension value.
    */
   protected abstract boolean hasExtensionValue();

   /**
    * Returns the ordinal of the chosen value (extension values re-start at 0),
    * or null if no value is set.
    */
   @Nullable protected abstract Integer getSelectionOrdinal();

   @Nullable protected abstract ChoiceComponent getSelectedComponent();

   /**
    * Returns the chosen value.
    */
   protected abstract Asn1Object getValue();

   /**
    * Returns the number of choices available for the current value of
    * {@code hasExtensionValue()}. If no value has been set, the number of
    * choices for a non-extension value is returned.
    */
   protected abstract int getOptionCount();

   /**
    * Creates a new instance of the type specified by the parameters, sets
    * the current value of this instance to it and returns the newly created
    * value.
    */
   protected abstract Asn1Object createAndSetValue(boolean isExtensionValue,
                                                   int ordinal);

   /**
    * Given an Asn1Tag, creates and sets the value of this enumeration to a newly created object.
    * Used in BER decoding.
    *
    * @param tag the tag read from the input stream (less the "constructed" bit)
    * @return the newly created enumeration component
    * @throws IllegalArgumentException if the tag is not recognized. This currently includes
    * extension values.
    */
   protected abstract ChoiceComponent createAndSetValue(Asn1Tag tag);

   @Override Asn1Tag getDefaultTag() {
     return DUMMY_DEFAULT_TAG;
   }

   @Override boolean isConstructed() {
     return true;
   }


   @Override
   public int getBerValueLength() {
     if (hasExtensionValue()) {
       throw new UnsupportedOperationException("BER for extension values is unsupported");
     }
     ChoiceComponent select = getSelectedComponent();
     if (select == null) {
       throw new NullPointerException("No component set");
     }
     if (select.getTag() != null) {
       int valueLen;
       if (select.isImplicitTagging()) {
         valueLen = getValue().getBerValueLength();
       } else {
         valueLen = getValue().getBerLength();
       }
       return select.getTag().getTaggedLength(valueLen);
     }
     return getValue().getBerLength();
   }

   @Override
   public void encodeBerValue(ByteBuffer buf) {
     if (hasExtensionValue()) {
       throw new UnsupportedOperationException("BER for extension values is unsupported");
     }
     ChoiceComponent select = getSelectedComponent();
     if (select == null) {
       throw new NullPointerException("No component set");
     }
     Asn1Object value = getValue();
     if (select.getTag() != null) {
       if (select.isImplicitTagging()) {
         select.getTag().writeTagAndLength(buf, value.isConstructed(), value.getBerValueLength());
         value.encodeBerValue(buf);
       } else {
         select.getTag().writeTagAndLength(buf, true, value.getBerLength());
         value.encodeBer(buf);
       }
     } else {
       value.encodeBer(buf);
     }
   }

   @Override
   public void decodeBerValue(ByteBuffer buf) {
     Asn1Tag tag = Asn1Tag.peekTag(buf);
     ChoiceComponent select = createAndSetValue(tag);
     if (select == null) {
       throw new IllegalArgumentException("Unknown selection tag: " + tag);
     }
     Asn1Object element = getValue();
     if (select.getTag() != null) {
       Asn1Tag.readTag(buf); // Read the tag off.
       int valueLen = Asn1Tag.readLength(buf);

       if (valueLen != buf.remaining()) {
         throw new IllegalArgumentException("Length mismatch: expected=" + buf.remaining()
             + ", actual=" + valueLen);
       }

       if (select.isImplicitTagging()) {
         element.decodeBerValue(buf);
         return;
       }
     }
     element.decodeBer(buf);
   }

   @Override
   public void decodeBer(ByteBuffer buf) {
     if (getTag() != null) {
       // This CHOICE is tagged
       Asn1Tag tag = Asn1Tag.readTag(buf);
       int len = Asn1Tag.readLength(buf);
       checkTag(tag, getTag());
     }
     decodeBerValue(buf);
   }

   private Iterable<BitStream> encodePerImpl(boolean aligned) {
     ImmutableList.Builder<BitStream> listBuilder = ImmutableList.builder();
     if (isExtensible()) {
       BitStream extensionMarker = new BitStream();
       extensionMarker.appendBit(hasExtensionValue());
       listBuilder.add(extensionMarker);
     }

     int optionCount = getOptionCount();
     Integer selectionOrdinal = getSelectionOrdinal();
     Preconditions.checkState(optionCount == 0 || selectionOrdinal != null,
                              "No value set.");
     if (hasExtensionValue()) {
       if (aligned) {
         listBuilder.addAll(
             PerAlignedUtils.encodeNormallySmallWholeNumber(selectionOrdinal));
       } else {
         listBuilder.addAll(
             PerUnalignedUtils.encodeNormallySmallWholeNumber(
               selectionOrdinal));
       }
     } else if (optionCount > 1) {
       if (aligned) {
         listBuilder.add(
             PerAlignedUtils.encodeSmallConstrainedWholeNumber(
                 selectionOrdinal, 0, optionCount - 1));
       } else {
         listBuilder.add(
             PerUnalignedUtils.encodeConstrainedWholeNumber(
                 selectionOrdinal, 0, optionCount - 1));
       }
     }

     if (optionCount > 0) {
       Asn1Object value = getValue();
       if (hasExtensionValue()) {
         if (aligned) {
           listBuilder.addAll(PerAlignedUtils.encodeOpenTypeField(value));
         } else {
           listBuilder.addAll(
               PerUnalignedUtils.encodeOpenTypeField(value));
         }
       } else {
         if (aligned) {
           listBuilder.addAll(value.encodePerAligned());
         } else {
           listBuilder.addAll(value.encodePerUnaligned());
         }
       }
     }
     return listBuilder.build();
   }

   @Override public Iterable<BitStream> encodePerUnaligned() {
     return encodePerImpl(false);
   }

   @Override public Iterable<BitStream> encodePerAligned() {
     return encodePerImpl(true);
   }

   private void decodePerImpl(BitStreamReader reader, boolean aligned) {
     boolean extensionValued = false;
     Integer selectionOrdinal = 0;
     if (isExtensible()) {
       extensionValued = reader.readBit();
     }
     if (extensionValued) {
       if (aligned) {
         selectionOrdinal = PerAlignedUtils.decodeNormallySmallWholeNumber(reader);
       } else {
         selectionOrdinal = PerUnalignedUtils.decodeNormallySmallWholeNumber(reader);
       }
     } else if (getOptionCount() > 1) {
       if (aligned) {
         selectionOrdinal = PerAlignedUtils.decodeSmallConstrainedWholeNumber(
             reader, 0, getOptionCount() - 1);
       } else {
         selectionOrdinal = PerUnalignedUtils.decodeConstrainedWholeNumber(
             reader, 0, getOptionCount() - 1);
       }
     }
     if (extensionValued) {
       Asn1Object element = createAndSetValue(extensionValued, selectionOrdinal);
       if (aligned) {
         PerAlignedUtils.decodeOpenTypeField(reader, element);
       } else {
         PerUnalignedUtils.decodeOpenTypeField(reader, element);
       }
     } else if (getOptionCount() > 0) {
       Asn1Object element = createAndSetValue(extensionValued, selectionOrdinal);
       if (aligned) {
         element.decodePerAligned(reader);
       } else {
         element.decodePerUnaligned(reader);
       }
     }
   }

   @Override public void decodePerUnaligned(BitStreamReader reader) {
     decodePerImpl(reader, false);
   }

   @Override public void decodePerAligned(BitStreamReader reader) {
     decodePerImpl(reader, true);
   }
 }
	/*
	* Copyright (C) 2017 The Android Open Source Project
	*
	* 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 android.location.cts.asn1.base;

	import com.google.common.base.Preconditions;
	import com.google.common.collect.ImmutableList;

	import java.nio.ByteBuffer;

	import javax.annotation.Nullable;

	/**
	* Implements ASN.1 functionality.
	*
	*/
	public abstract class Asn1Choice extends Asn1Object {
	/**
	* Dummy non-tag used as default tag for CHOICE, which reflects the BER encoding idea
	* that CHOICE is not an object in itself, it just gets coded as its value. This means
	* that it doesn't matter whether the choice object tag is designated as IMPLICIT or
	* EXPLICIT, it gets coded the same way anyway.
	*/
	private static final Asn1Tag DUMMY_DEFAULT_TAG = new Asn1Tag(null, Integer.MIN_VALUE) {
	@Override
	public int getTaggedLength(int valueLength) {
	return valueLength;
	}

	@Override
	public void writeTagAndLength(ByteBuffer buf, boolean constructed, int valueLength) {
	// Do nothing.
	}

	@Override
	int getValue() {
	throw new UnsupportedOperationException("This is not a real tag.");
	}
	};

	/**
	* Returns true if the type has an extension marker.
	*/
	protected abstract boolean isExtensible();

	/**
	* Returns true if the value set is an extension value.
	*/
	protected abstract boolean hasExtensionValue();

	/**
	* Returns the ordinal of the chosen value (extension values re-start at 0),
	* or null if no value is set.
	*/
	@Nullable protected abstract Integer getSelectionOrdinal();

	@Nullable protected abstract ChoiceComponent getSelectedComponent();

	/**
	* Returns the chosen value.
	*/
	protected abstract Asn1Object getValue();

	/**
	* Returns the number of choices available for the current value of
	* {@code hasExtensionValue()}. If no value has been set, the number of
	* choices for a non-extension value is returned.
	*/
	protected abstract int getOptionCount();

	/**
	* Creates a new instance of the type specified by the parameters, sets
	* the current value of this instance to it and returns the newly created
	* value.
	*/
	protected abstract Asn1Object createAndSetValue(boolean isExtensionValue,
	int ordinal);

	/**
	* Given an Asn1Tag, creates and sets the value of this enumeration to a newly created object.
	* Used in BER decoding.
	*
	* @param tag the tag read from the input stream (less the "constructed" bit)
	* @return the newly created enumeration component
	* @throws IllegalArgumentException if the tag is not recognized. This currently includes
	* extension values.
	*/
	protected abstract ChoiceComponent createAndSetValue(Asn1Tag tag);

	@Override Asn1Tag getDefaultTag() {
	return DUMMY_DEFAULT_TAG;
	}

	@Override boolean isConstructed() {
	return true;
	}


	@Override
	public int getBerValueLength() {
	if (hasExtensionValue()) {
	throw new UnsupportedOperationException("BER for extension values is unsupported");
	}
	ChoiceComponent select = getSelectedComponent();
	if (select == null) {
	throw new NullPointerException("No component set");
	}
	if (select.getTag() != null) {
	int valueLen;
	if (select.isImplicitTagging()) {
	valueLen = getValue().getBerValueLength();
	} else {
	valueLen = getValue().getBerLength();
	}
	return select.getTag().getTaggedLength(valueLen);
	}
	return getValue().getBerLength();
	}

	@Override
	public void encodeBerValue(ByteBuffer buf) {
	if (hasExtensionValue()) {
	throw new UnsupportedOperationException("BER for extension values is unsupported");
	}
	ChoiceComponent select = getSelectedComponent();
	if (select == null) {
	throw new NullPointerException("No component set");
	}
	Asn1Object value = getValue();
	if (select.getTag() != null) {
	if (select.isImplicitTagging()) {
	select.getTag().writeTagAndLength(buf, value.isConstructed(), value.getBerValueLength());
	value.encodeBerValue(buf);
	} else {
	select.getTag().writeTagAndLength(buf, true, value.getBerLength());
	value.encodeBer(buf);
	}
	} else {
	value.encodeBer(buf);
	}
	}

	@Override
	public void decodeBerValue(ByteBuffer buf) {
	Asn1Tag tag = Asn1Tag.peekTag(buf);
	ChoiceComponent select = createAndSetValue(tag);
	if (select == null) {
	throw new IllegalArgumentException("Unknown selection tag: " + tag);
	}
	Asn1Object element = getValue();
	if (select.getTag() != null) {
	Asn1Tag.readTag(buf); // Read the tag off.
	int valueLen = Asn1Tag.readLength(buf);

	if (valueLen != buf.remaining()) {
	throw new IllegalArgumentException("Length mismatch: expected=" + buf.remaining()
	+ ", actual=" + valueLen);
	}

	if (select.isImplicitTagging()) {
	element.decodeBerValue(buf);
	return;
	}
	}
	element.decodeBer(buf);
	}

	@Override
	public void decodeBer(ByteBuffer buf) {
	if (getTag() != null) {
	// This CHOICE is tagged
	Asn1Tag tag = Asn1Tag.readTag(buf);
	int len = Asn1Tag.readLength(buf);
	checkTag(tag, getTag());
	}
	decodeBerValue(buf);
	}

	private Iterable<BitStream> encodePerImpl(boolean aligned) {
	ImmutableList.Builder<BitStream> listBuilder = ImmutableList.builder();
	if (isExtensible()) {
	BitStream extensionMarker = new BitStream();
	extensionMarker.appendBit(hasExtensionValue());
	listBuilder.add(extensionMarker);
	}

	int optionCount = getOptionCount();
	Integer selectionOrdinal = getSelectionOrdinal();
	Preconditions.checkState(optionCount == 0 \|\| selectionOrdinal != null,
	"No value set.");
	if (hasExtensionValue()) {
	if (aligned) {
	listBuilder.addAll(
	PerAlignedUtils.encodeNormallySmallWholeNumber(selectionOrdinal));
	} else {
	listBuilder.addAll(
	PerUnalignedUtils.encodeNormallySmallWholeNumber(
	selectionOrdinal));
	}
	} else if (optionCount > 1) {
	if (aligned) {
	listBuilder.add(
	PerAlignedUtils.encodeSmallConstrainedWholeNumber(
	selectionOrdinal, 0, optionCount - 1));
	} else {
	listBuilder.add(
	PerUnalignedUtils.encodeConstrainedWholeNumber(
	selectionOrdinal, 0, optionCount - 1));
	}
	}

	if (optionCount > 0) {
	Asn1Object value = getValue();
	if (hasExtensionValue()) {
	if (aligned) {
	listBuilder.addAll(PerAlignedUtils.encodeOpenTypeField(value));
	} else {
	listBuilder.addAll(
	PerUnalignedUtils.encodeOpenTypeField(value));
	}
	} else {
	if (aligned) {
	listBuilder.addAll(value.encodePerAligned());
	} else {
	listBuilder.addAll(value.encodePerUnaligned());
	}
	}
	}
	return listBuilder.build();
	}

	@Override public Iterable<BitStream> encodePerUnaligned() {
	return encodePerImpl(false);
	}

	@Override public Iterable<BitStream> encodePerAligned() {
	return encodePerImpl(true);
	}

	private void decodePerImpl(BitStreamReader reader, boolean aligned) {
	boolean extensionValued = false;
	Integer selectionOrdinal = 0;
	if (isExtensible()) {
	extensionValued = reader.readBit();
	}
	if (extensionValued) {
	if (aligned) {
	selectionOrdinal = PerAlignedUtils.decodeNormallySmallWholeNumber(reader);
	} else {
	selectionOrdinal = PerUnalignedUtils.decodeNormallySmallWholeNumber(reader);
	}
	} else if (getOptionCount() > 1) {
	if (aligned) {
	selectionOrdinal = PerAlignedUtils.decodeSmallConstrainedWholeNumber(
	reader, 0, getOptionCount() - 1);
	} else {
	selectionOrdinal = PerUnalignedUtils.decodeConstrainedWholeNumber(
	reader, 0, getOptionCount() - 1);
	}
	}
	if (extensionValued) {
	Asn1Object element = createAndSetValue(extensionValued, selectionOrdinal);
	if (aligned) {
	PerAlignedUtils.decodeOpenTypeField(reader, element);
	} else {
	PerUnalignedUtils.decodeOpenTypeField(reader, element);
	}
	} else if (getOptionCount() > 0) {
	Asn1Object element = createAndSetValue(extensionValued, selectionOrdinal);
	if (aligned) {
	element.decodePerAligned(reader);
	} else {
	element.decodePerUnaligned(reader);
	}
	}
	}

	@Override public void decodePerUnaligned(BitStreamReader reader) {
	decodePerImpl(reader, false);
	}

	@Override public void decodePerAligned(BitStreamReader reader) {
	decodePerImpl(reader, true);
	}
	}