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Diffstat (limited to 'java/src/main/java/com/google/protobuf/FieldSet.java')
| -rw-r--r-- | java/src/main/java/com/google/protobuf/FieldSet.java | 712 |
1 files changed, 712 insertions, 0 deletions
diff --git a/java/src/main/java/com/google/protobuf/FieldSet.java b/java/src/main/java/com/google/protobuf/FieldSet.java new file mode 100644 index 0000000..93e55f2 --- /dev/null +++ b/java/src/main/java/com/google/protobuf/FieldSet.java @@ -0,0 +1,712 @@ +// Protocol Buffers - Google's data interchange format +// Copyright 2008 Google Inc. All rights reserved. +// http://code.google.com/p/protobuf/ +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +package com.google.protobuf; + +import java.util.ArrayList; +import java.util.Collections; +import java.util.Iterator; +import java.util.TreeMap; +import java.util.List; +import java.util.Map; +import java.io.IOException; + +/** + * A class which represents an arbitrary set of fields of some message type. + * This is used to implement {@link DynamicMessage}, and also to represent + * extensions in {@link GeneratedMessage}. This class is package-private, + * since outside users should probably be using {@link DynamicMessage}. + * + * @author kenton@google.com Kenton Varda + */ +final class FieldSet<FieldDescriptorType extends + FieldSet.FieldDescriptorLite<FieldDescriptorType>> { + /** + * Interface for a FieldDescriptor or lite extension descriptor. This + * prevents FieldSet from depending on {@link Descriptors.FieldDescriptor}. + */ + public interface FieldDescriptorLite<T extends FieldDescriptorLite<T>> + extends Comparable<T> { + int getNumber(); + WireFormat.FieldType getLiteType(); + WireFormat.JavaType getLiteJavaType(); + boolean isRepeated(); + boolean isPacked(); + Internal.EnumLiteMap<?> getEnumType(); + + // If getLiteJavaType() == MESSAGE, this merges a message object of the + // type into a builder of the type. Returns {@code to}. + MessageLite.Builder internalMergeFrom( + MessageLite.Builder to, MessageLite from); + } + + private Map<FieldDescriptorType, Object> fields; + + /** Construct a new FieldSet. */ + private FieldSet() { + // Use a TreeMap because fields need to be in canonical order when + // serializing. + // TODO(kenton): Maybe use some sort of sparse array instead? It would + // even make sense to store the first 16 or so tags in a flat array + // to make DynamicMessage faster. + fields = new TreeMap<FieldDescriptorType, Object>(); + } + + /** + * Construct an empty FieldSet. This is only used to initialize + * DEFAULT_INSTANCE. + */ + private FieldSet(final boolean dummy) { + this.fields = Collections.emptyMap(); + } + + /** Construct a new FieldSet. */ + public static <T extends FieldSet.FieldDescriptorLite<T>> + FieldSet<T> newFieldSet() { + return new FieldSet<T>(); + } + + /** Get an immutable empty FieldSet. */ + @SuppressWarnings("unchecked") + public static <T extends FieldSet.FieldDescriptorLite<T>> + FieldSet<T> emptySet() { + return DEFAULT_INSTANCE; + } + @SuppressWarnings("unchecked") + private static final FieldSet DEFAULT_INSTANCE = new FieldSet(true); + + /** Make this FieldSet immutable from this point forward. */ + @SuppressWarnings("unchecked") + public void makeImmutable() { + for (final Map.Entry<FieldDescriptorType, Object> entry: + fields.entrySet()) { + if (entry.getKey().isRepeated()) { + final List value = (List)entry.getValue(); + fields.put(entry.getKey(), Collections.unmodifiableList(value)); + } + } + fields = Collections.unmodifiableMap(fields); + } + + // ================================================================= + + /** See {@link Message.Builder#clear()}. */ + public void clear() { + fields.clear(); + } + + /** + * Get a simple map containing all the fields. + */ + public Map<FieldDescriptorType, Object> getAllFields() { + return Collections.unmodifiableMap(fields); + } + + /** + * Get an iterator to the field map. This iterator should not be leaked + * out of the protobuf library as it is not protected from mutation. + */ + public Iterator<Map.Entry<FieldDescriptorType, Object>> iterator() { + return fields.entrySet().iterator(); + } + + /** + * Useful for implementing + * {@link Message#hasField(Descriptors.FieldDescriptor)}. + */ + public boolean hasField(final FieldDescriptorType descriptor) { + if (descriptor.isRepeated()) { + throw new IllegalArgumentException( + "hasField() can only be called on non-repeated fields."); + } + + return fields.get(descriptor) != null; + } + + /** + * Useful for implementing + * {@link Message#getField(Descriptors.FieldDescriptor)}. This method + * returns {@code null} if the field is not set; in this case it is up + * to the caller to fetch the field's default value. + */ + public Object getField(final FieldDescriptorType descriptor) { + return fields.get(descriptor); + } + + /** + * Useful for implementing + * {@link Message.Builder#setField(Descriptors.FieldDescriptor,Object)}. + */ + @SuppressWarnings("unchecked") + public void setField(final FieldDescriptorType descriptor, + Object value) { + if (descriptor.isRepeated()) { + if (!(value instanceof List)) { + throw new IllegalArgumentException( + "Wrong object type used with protocol message reflection."); + } + + // Wrap the contents in a new list so that the caller cannot change + // the list's contents after setting it. + final List newList = new ArrayList(); + newList.addAll((List)value); + for (final Object element : newList) { + verifyType(descriptor.getLiteType(), element); + } + value = newList; + } else { + verifyType(descriptor.getLiteType(), value); + } + + fields.put(descriptor, value); + } + + /** + * Useful for implementing + * {@link Message.Builder#clearField(Descriptors.FieldDescriptor)}. + */ + public void clearField(final FieldDescriptorType descriptor) { + fields.remove(descriptor); + } + + /** + * Useful for implementing + * {@link Message#getRepeatedFieldCount(Descriptors.FieldDescriptor)}. + */ + public int getRepeatedFieldCount(final FieldDescriptorType descriptor) { + if (!descriptor.isRepeated()) { + throw new IllegalArgumentException( + "getRepeatedField() can only be called on repeated fields."); + } + + final Object value = fields.get(descriptor); + if (value == null) { + return 0; + } else { + return ((List) value).size(); + } + } + + /** + * Useful for implementing + * {@link Message#getRepeatedField(Descriptors.FieldDescriptor,int)}. + */ + public Object getRepeatedField(final FieldDescriptorType descriptor, + final int index) { + if (!descriptor.isRepeated()) { + throw new IllegalArgumentException( + "getRepeatedField() can only be called on repeated fields."); + } + + final Object value = fields.get(descriptor); + + if (value == null) { + throw new IndexOutOfBoundsException(); + } else { + return ((List) value).get(index); + } + } + + /** + * Useful for implementing + * {@link Message.Builder#setRepeatedField(Descriptors.FieldDescriptor,int,Object)}. + */ + @SuppressWarnings("unchecked") + public void setRepeatedField(final FieldDescriptorType descriptor, + final int index, + final Object value) { + if (!descriptor.isRepeated()) { + throw new IllegalArgumentException( + "getRepeatedField() can only be called on repeated fields."); + } + + final Object list = fields.get(descriptor); + if (list == null) { + throw new IndexOutOfBoundsException(); + } + + verifyType(descriptor.getLiteType(), value); + ((List) list).set(index, value); + } + + /** + * Useful for implementing + * {@link Message.Builder#addRepeatedField(Descriptors.FieldDescriptor,Object)}. + */ + @SuppressWarnings("unchecked") + public void addRepeatedField(final FieldDescriptorType descriptor, + final Object value) { + if (!descriptor.isRepeated()) { + throw new IllegalArgumentException( + "addRepeatedField() can only be called on repeated fields."); + } + + verifyType(descriptor.getLiteType(), value); + + final Object existingValue = fields.get(descriptor); + List list; + if (existingValue == null) { + list = new ArrayList(); + fields.put(descriptor, list); + } else { + list = (List) existingValue; + } + + list.add(value); + } + + /** + * Verifies that the given object is of the correct type to be a valid + * value for the given field. (For repeated fields, this checks if the + * object is the right type to be one element of the field.) + * + * @throws IllegalArgumentException The value is not of the right type. + */ + private static void verifyType(final WireFormat.FieldType type, + final Object value) { + if (value == null) { + throw new NullPointerException(); + } + + boolean isValid = false; + switch (type.getJavaType()) { + case INT: isValid = value instanceof Integer ; break; + case LONG: isValid = value instanceof Long ; break; + case FLOAT: isValid = value instanceof Float ; break; + case DOUBLE: isValid = value instanceof Double ; break; + case BOOLEAN: isValid = value instanceof Boolean ; break; + case STRING: isValid = value instanceof String ; break; + case BYTE_STRING: isValid = value instanceof ByteString; break; + case ENUM: + // TODO(kenton): Caller must do type checking here, I guess. + isValid = value instanceof Internal.EnumLite; + break; + case MESSAGE: + // TODO(kenton): Caller must do type checking here, I guess. + isValid = value instanceof MessageLite; + break; + } + + if (!isValid) { + // TODO(kenton): When chaining calls to setField(), it can be hard to + // tell from the stack trace which exact call failed, since the whole + // chain is considered one line of code. It would be nice to print + // more information here, e.g. naming the field. We used to do that. + // But we can't now that FieldSet doesn't use descriptors. Maybe this + // isn't a big deal, though, since it would only really apply when using + // reflection and generally people don't chain reflection setters. + throw new IllegalArgumentException( + "Wrong object type used with protocol message reflection."); + } + } + + // ================================================================= + // Parsing and serialization + + /** + * See {@link Message#isInitialized()}. Note: Since {@code FieldSet} + * itself does not have any way of knowing about required fields that + * aren't actually present in the set, it is up to the caller to check + * that all required fields are present. + */ + @SuppressWarnings("unchecked") + public boolean isInitialized() { + for (final Map.Entry<FieldDescriptorType, Object> entry: + fields.entrySet()) { + final FieldDescriptorType descriptor = entry.getKey(); + if (descriptor.getLiteJavaType() == WireFormat.JavaType.MESSAGE) { + if (descriptor.isRepeated()) { + for (final MessageLite element: + (List<MessageLite>) entry.getValue()) { + if (!element.isInitialized()) { + return false; + } + } + } else { + if (!((MessageLite) entry.getValue()).isInitialized()) { + return false; + } + } + } + } + + return true; + } + + /** + * Given a field type, return the wire type. + * + * @returns One of the {@code WIRETYPE_} constants defined in + * {@link WireFormat}. + */ + static int getWireFormatForFieldType(final WireFormat.FieldType type, + boolean isPacked) { + if (isPacked) { + return WireFormat.WIRETYPE_LENGTH_DELIMITED; + } else { + return type.getWireType(); + } + } + + /** + * Like {@link #mergeFrom(Message)}, but merges from another {@link FieldSet}. + */ + @SuppressWarnings("unchecked") + public void mergeFrom(final FieldSet<FieldDescriptorType> other) { + for (final Map.Entry<FieldDescriptorType, Object> entry: + other.fields.entrySet()) { + final FieldDescriptorType descriptor = entry.getKey(); + final Object otherValue = entry.getValue(); + + if (descriptor.isRepeated()) { + Object value = fields.get(descriptor); + if (value == null) { + // Our list is empty, but we still need to make a defensive copy of + // the other list since we don't know if the other FieldSet is still + // mutable. + fields.put(descriptor, new ArrayList((List) otherValue)); + } else { + // Concatenate the lists. + ((List) value).addAll((List) otherValue); + } + } else if (descriptor.getLiteJavaType() == WireFormat.JavaType.MESSAGE) { + Object value = fields.get(descriptor); + if (value == null) { + fields.put(descriptor, otherValue); + } else { + // Merge the messages. + fields.put(descriptor, + descriptor.internalMergeFrom( + ((MessageLite) value).toBuilder(), (MessageLite) otherValue) + .build()); + } + + } else { + fields.put(descriptor, otherValue); + } + } + } + + // TODO(kenton): Move static parsing and serialization methods into some + // other class. Probably WireFormat. + + /** + * Read a field of any primitive type from a CodedInputStream. Enums, + * groups, and embedded messages are not handled by this method. + * + * @param input The stream from which to read. + * @param type Declared type of the field. + * @return An object representing the field's value, of the exact + * type which would be returned by + * {@link Message#getField(Descriptors.FieldDescriptor)} for + * this field. + */ + public static Object readPrimitiveField( + CodedInputStream input, + final WireFormat.FieldType type) throws IOException { + switch (type) { + case DOUBLE : return input.readDouble (); + case FLOAT : return input.readFloat (); + case INT64 : return input.readInt64 (); + case UINT64 : return input.readUInt64 (); + case INT32 : return input.readInt32 (); + case FIXED64 : return input.readFixed64 (); + case FIXED32 : return input.readFixed32 (); + case BOOL : return input.readBool (); + case STRING : return input.readString (); + case BYTES : return input.readBytes (); + case UINT32 : return input.readUInt32 (); + case SFIXED32: return input.readSFixed32(); + case SFIXED64: return input.readSFixed64(); + case SINT32 : return input.readSInt32 (); + case SINT64 : return input.readSInt64 (); + + case GROUP: + throw new IllegalArgumentException( + "readPrimitiveField() cannot handle nested groups."); + case MESSAGE: + throw new IllegalArgumentException( + "readPrimitiveField() cannot handle embedded messages."); + case ENUM: + // We don't handle enums because we don't know what to do if the + // value is not recognized. + throw new IllegalArgumentException( + "readPrimitiveField() cannot handle enums."); + } + + throw new RuntimeException( + "There is no way to get here, but the compiler thinks otherwise."); + } + + /** See {@link Message#writeTo(CodedOutputStream)}. */ + public void writeTo(final CodedOutputStream output) + throws IOException { + for (final Map.Entry<FieldDescriptorType, Object> entry: + fields.entrySet()) { + writeField(entry.getKey(), entry.getValue(), output); + } + } + + /** + * Like {@link #writeTo} but uses MessageSet wire format. + */ + public void writeMessageSetTo(final CodedOutputStream output) + throws IOException { + for (final Map.Entry<FieldDescriptorType, Object> entry: + fields.entrySet()) { + final FieldDescriptorType descriptor = entry.getKey(); + if (descriptor.getLiteJavaType() == WireFormat.JavaType.MESSAGE && + !descriptor.isRepeated() && !descriptor.isPacked()) { + output.writeMessageSetExtension(entry.getKey().getNumber(), + (MessageLite) entry.getValue()); + } else { + writeField(descriptor, entry.getValue(), output); + } + } + } + + /** + * Write a single tag-value pair to the stream. + * + * @param output The output stream. + * @param type The field's type. + * @param number The field's number. + * @param value Object representing the field's value. Must be of the exact + * type which would be returned by + * {@link Message#getField(Descriptors.FieldDescriptor)} for + * this field. + */ + private static void writeElement(final CodedOutputStream output, + final WireFormat.FieldType type, + final int number, + final Object value) throws IOException { + // Special case for groups, which need a start and end tag; other fields + // can just use writeTag() and writeFieldNoTag(). + if (type == WireFormat.FieldType.GROUP) { + output.writeGroup(number, (MessageLite) value); + } else { + output.writeTag(number, getWireFormatForFieldType(type, false)); + writeElementNoTag(output, type, value); + } + } + + /** + * Write a field of arbitrary type, without its tag, to the stream. + * + * @param output The output stream. + * @param type The field's type. + * @param value Object representing the field's value. Must be of the exact + * type which would be returned by + * {@link Message#getField(Descriptors.FieldDescriptor)} for + * this field. + */ + private static void writeElementNoTag( + final CodedOutputStream output, + final WireFormat.FieldType type, + final Object value) throws IOException { + switch (type) { + case DOUBLE : output.writeDoubleNoTag ((Double ) value); break; + case FLOAT : output.writeFloatNoTag ((Float ) value); break; + case INT64 : output.writeInt64NoTag ((Long ) value); break; + case UINT64 : output.writeUInt64NoTag ((Long ) value); break; + case INT32 : output.writeInt32NoTag ((Integer ) value); break; + case FIXED64 : output.writeFixed64NoTag ((Long ) value); break; + case FIXED32 : output.writeFixed32NoTag ((Integer ) value); break; + case BOOL : output.writeBoolNoTag ((Boolean ) value); break; + case STRING : output.writeStringNoTag ((String ) value); break; + case GROUP : output.writeGroupNoTag ((MessageLite) value); break; + case MESSAGE : output.writeMessageNoTag ((MessageLite) value); break; + case BYTES : output.writeBytesNoTag ((ByteString ) value); break; + case UINT32 : output.writeUInt32NoTag ((Integer ) value); break; + case SFIXED32: output.writeSFixed32NoTag((Integer ) value); break; + case SFIXED64: output.writeSFixed64NoTag((Long ) value); break; + case SINT32 : output.writeSInt32NoTag ((Integer ) value); break; + case SINT64 : output.writeSInt64NoTag ((Long ) value); break; + + case ENUM: + output.writeEnumNoTag(((Internal.EnumLite) value).getNumber()); + break; + } + } + + /** Write a single field. */ + public static void writeField(final FieldDescriptorLite<?> descriptor, + final Object value, + final CodedOutputStream output) + throws IOException { + WireFormat.FieldType type = descriptor.getLiteType(); + int number = descriptor.getNumber(); + if (descriptor.isRepeated()) { + final List valueList = (List)value; + if (descriptor.isPacked()) { + output.writeTag(number, WireFormat.WIRETYPE_LENGTH_DELIMITED); + // Compute the total data size so the length can be written. + int dataSize = 0; + for (final Object element : valueList) { + dataSize += computeElementSizeNoTag(type, element); + } + output.writeRawVarint32(dataSize); + // Write the data itself, without any tags. + for (final Object element : valueList) { + writeElementNoTag(output, type, element); + } + } else { + for (final Object element : valueList) { + writeElement(output, type, number, element); + } + } + } else { + writeElement(output, type, number, value); + } + } + + /** + * See {@link Message#getSerializedSize()}. It's up to the caller to cache + * the resulting size if desired. + */ + public int getSerializedSize() { + int size = 0; + for (final Map.Entry<FieldDescriptorType, Object> entry: + fields.entrySet()) { + size += computeFieldSize(entry.getKey(), entry.getValue()); + } + return size; + } + + /** + * Like {@link #getSerializedSize} but uses MessageSet wire format. + */ + public int getMessageSetSerializedSize() { + int size = 0; + for (final Map.Entry<FieldDescriptorType, Object> entry: + fields.entrySet()) { + final FieldDescriptorType descriptor = entry.getKey(); + if (descriptor.getLiteJavaType() == WireFormat.JavaType.MESSAGE && + !descriptor.isRepeated() && !descriptor.isPacked()) { + size += CodedOutputStream.computeMessageSetExtensionSize( + entry.getKey().getNumber(), (MessageLite) entry.getValue()); + } else { + size += computeFieldSize(descriptor, entry.getValue()); + } + } + return size; + } + + /** + * Compute the number of bytes that would be needed to encode a + * single tag/value pair of arbitrary type. + * + * @param type The field's type. + * @param number The field's number. + * @param value Object representing the field's value. Must be of the exact + * type which would be returned by + * {@link Message#getField(Descriptors.FieldDescriptor)} for + * this field. + */ + private static int computeElementSize( + final WireFormat.FieldType type, + final int number, final Object value) { + int tagSize = CodedOutputStream.computeTagSize(number); + if (type == WireFormat.FieldType.GROUP) { + tagSize *= 2; + } + return tagSize + computeElementSizeNoTag(type, value); + } + + /** + * Compute the number of bytes that would be needed to encode a + * particular value of arbitrary type, excluding tag. + * + * @param type The field's type. + * @param value Object representing the field's value. Must be of the exact + * type which would be returned by + * {@link Message#getField(Descriptors.FieldDescriptor)} for + * this field. + */ + private static int computeElementSizeNoTag( + final WireFormat.FieldType type, final Object value) { + switch (type) { + // Note: Minor violation of 80-char limit rule here because this would + // actually be harder to read if we wrapped the lines. + case DOUBLE : return CodedOutputStream.computeDoubleSizeNoTag ((Double )value); + case FLOAT : return CodedOutputStream.computeFloatSizeNoTag ((Float )value); + case INT64 : return CodedOutputStream.computeInt64SizeNoTag ((Long )value); + case UINT64 : return CodedOutputStream.computeUInt64SizeNoTag ((Long )value); + case INT32 : return CodedOutputStream.computeInt32SizeNoTag ((Integer )value); + case FIXED64 : return CodedOutputStream.computeFixed64SizeNoTag ((Long )value); + case FIXED32 : return CodedOutputStream.computeFixed32SizeNoTag ((Integer )value); + case BOOL : return CodedOutputStream.computeBoolSizeNoTag ((Boolean )value); + case STRING : return CodedOutputStream.computeStringSizeNoTag ((String )value); + case GROUP : return CodedOutputStream.computeGroupSizeNoTag ((MessageLite)value); + case MESSAGE : return CodedOutputStream.computeMessageSizeNoTag ((MessageLite)value); + case BYTES : return CodedOutputStream.computeBytesSizeNoTag ((ByteString )value); + case UINT32 : return CodedOutputStream.computeUInt32SizeNoTag ((Integer )value); + case SFIXED32: return CodedOutputStream.computeSFixed32SizeNoTag((Integer )value); + case SFIXED64: return CodedOutputStream.computeSFixed64SizeNoTag((Long )value); + case SINT32 : return CodedOutputStream.computeSInt32SizeNoTag ((Integer )value); + case SINT64 : return CodedOutputStream.computeSInt64SizeNoTag ((Long )value); + + case ENUM: + return CodedOutputStream.computeEnumSizeNoTag( + ((Internal.EnumLite) value).getNumber()); + } + + throw new RuntimeException( + "There is no way to get here, but the compiler thinks otherwise."); + } + + /** + * Compute the number of bytes needed to encode a particular field. + */ + public static int computeFieldSize(final FieldDescriptorLite<?> descriptor, + final Object value) { + WireFormat.FieldType type = descriptor.getLiteType(); + int number = descriptor.getNumber(); + if (descriptor.isRepeated()) { + if (descriptor.isPacked()) { + int dataSize = 0; + for (final Object element : (List)value) { + dataSize += computeElementSizeNoTag(type, element); + } + return dataSize + + CodedOutputStream.computeTagSize(number) + + CodedOutputStream.computeRawVarint32Size(dataSize); + } else { + int size = 0; + for (final Object element : (List)value) { + size += computeElementSize(type, number, element); + } + return size; + } + } else { + return computeElementSize(type, number, value); + } + } +} |