// Copyright 2007 Google Inc.
// All Rights Reserved.
package com.google.common.io.protocol;
import java.util.*;
/**
* This class can be used to create a memory model of a .proto file. Currently,
* it is assumed that tags ids are not large. This could be improved by storing
* a start offset, relaxing the assumption to a dense number space.
*/
public class ProtoBufType {
// Note: Values 0..15 are reserved for wire types!
public static final int TYPE_UNDEFINED = 16;
public static final int TYPE_DOUBLE = 17;
public static final int TYPE_FLOAT = 18;
public static final int TYPE_INT64 = 19;
public static final int TYPE_UINT64 = 20;
public static final int TYPE_INT32 = 21;
public static final int TYPE_FIXED64 = 22;
public static final int TYPE_FIXED32 = 23;
public static final int TYPE_BOOL = 24;
public static final int TYPE_DATA = 25;
public static final int TYPE_GROUP = 26;
public static final int TYPE_MESSAGE = 27;
public static final int TYPE_TEXT = 28;
public static final int TYPE_UINT32 = 29;
public static final int TYPE_ENUM = 30;
public static final int TYPE_SFIXED32 = 31;
public static final int TYPE_SFIXED64 = 32;
// new protobuf 2 types
public static final int TYPE_SINT32 = 33;
public static final int TYPE_SINT64 = 34;
public static final int TYPE_BYTES = 35;
public static final int TYPE_STRING = 36;
public static final int MASK_TYPE = 0x0ff;
public static final int MASK_MODIFIER = 0x0ff00;
public static final int REQUIRED = 0x100;
public static final int OPTIONAL = 0x200;
public static final int REPEATED = 0x400;
private final StringBuffer types = new StringBuffer();
private final Vector data = new Vector();
private final String typeName;
/**
* Empty constructor.
*/
public ProtoBufType() {
typeName = null;
}
/**
* Constructor including a type name for debugging purposes.
*/
public ProtoBufType(String typeName) {
this.typeName = typeName;
}
/**
* Adds a tag description. The data parameter contains the group definition
* for group elements and the default value for regular elements.
*
* @param optionsAndType any legal combination (bitwise or) of REQUIRED
* or OPTIONAL and REPEATED and one of the TYPE_
* constants
* @param tag the tag id
* @param data the type for group elements (or the default value for
* regular elements in future versions)
* @return this is returned to permit cascading
*/
public ProtoBufType addElement(int optionsAndType, int tag, Object data) {
while (types.length() <= tag) {
types.append((char) TYPE_UNDEFINED);
this.data.addElement(null);
}
types.setCharAt(tag, (char) optionsAndType);
this.data.setElementAt(data, tag);
return this;
}
/**
* Returns the type for the given tag id (without modifiers such as OPTIONAL,
* REPEATED). For undefined tags, TYPE_UNDEFINED is returned.
*/
public int getType(int tag) {
return (tag < 0 || tag >= types.length())
? TYPE_UNDEFINED
: (types.charAt(tag) & MASK_TYPE);
}
/**
* Returns a bit combination of the modifiers for the given tag id
* (OPTIONAL, REPEATED, REQUIRED). For undefined tags, OPTIONAL|REPEATED
* is returned.
*/
public int getModifiers(int tag) {
return (tag < 0 || tag >= types.length())
? (OPTIONAL | REPEATED)
: (types.charAt(tag) & MASK_MODIFIER);
}
/**
* Returns the data associated to a given tag (either the default value for
* regular elements or a ProtoBufType for groups and messages). For undefined
* tags, null is returned.
*/
public Object getData(int tag) {
return (tag < 0 || tag >= data.size()) ? null : data.elementAt(tag);
}
/**
* Returns the type name set in the constructor for debugging purposes.
*/
public String toString() {
return typeName;
}
/**
* {@inheritDoc}
* <p>Two ProtoBufTypes are equals if the fields types are the same.
*/
public boolean equals(Object object) {
if (null == object) {
// trivial check
return false;
} else if (this == object) {
// trivial check
return true;
} else if (this.getClass() != object.getClass()) {
// different class
return false;
}
ProtoBufType other = (ProtoBufType) object;
return stringEquals(types, other.types);
}
/**
* {@inheritDoc}
*/
public int hashCode() {
if (types != null) {
return types.hashCode();
} else {
return super.hashCode();
}
}
public static boolean stringEquals(CharSequence a, CharSequence b) {
if (a == b) return true;
int length;
if (a != null && b != null && (length = a.length()) == b.length()) {
if (a instanceof String && b instanceof String) {
return a.equals(b);
} else {
for (int i = 0; i < length; i++) {
if (a.charAt(i) != b.charAt(i)) return false;
}
return true;
}
}
return false;
}
}
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