1 files changed, 170 insertions, 0 deletions
diff --git a/src/com/google/common/io/protocol/ProtoBufType.java b/src/com/google/common/io/protocol/ProtoBufType.java
new file mode 100644
index 0000000..4b6408e
--- /dev/null
+++ b/src/com/google/common/io/protocol/ProtoBufType.java
@@ -0,0 +1,170 @@
+// 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;
+  }
+}