Pull new version of protobuf sources.

third_party/protobuf/src/google/protobuf/util/field_comparator.h

Index: third_party/protobuf/src/google/protobuf/util/field_comparator.h
diff --git a/third_party/protobuf/src/google/protobuf/util/field_comparator.h b/third_party/protobuf/src/google/protobuf/util/field_comparator.h
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+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// 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.
+
+// Author: ksroka@google.com (Krzysztof Sroka)
+
+#ifndef GOOGLE_PROTOBUF_UTIL_FIELD_COMPARATOR_H__
+#define GOOGLE_PROTOBUF_UTIL_FIELD_COMPARATOR_H__
+
+#include <map>
+#include <string>
+
+#include <google/protobuf/stubs/common.h>
+
+namespace google {
+namespace protobuf {
+
+class Message;
+class EnumValueDescriptor;
+class FieldDescriptor;
+
+namespace util {
+
+class FieldContext;
+
+// Base class specifying the interface for comparing protocol buffer fields.
+// Regular users should consider using or subclassing DefaultFieldComparator
+// rather than this interface.
+// Currently, this does not support comparing unknown fields.
+class LIBPROTOBUF_EXPORT FieldComparator {
+ public:
+  FieldComparator();
+  virtual ~FieldComparator();
+
+  enum ComparisonResult {
+    SAME,       // Compared fields are equal. In case of comparing submessages,
+                // user should not recursively compare their contents.
+    DIFFERENT,  // Compared fields are different. In case of comparing
+                // submessages, user should not recursively compare their
+                // contents.
+    RECURSE,    // Compared submessages need to be compared recursively.
+                // FieldComparator does not specify the semantics of recursive
+                // comparison. This value should not be returned for simple
+                // values.
+  };
+
+  // Compares the values of a field in two protocol buffer messages.
+  // Returns SAME or DIFFERENT for simple values, and SAME, DIFFERENT or RECURSE
+  // for submessages. Returning RECURSE for fields not being submessages is
+  // illegal.
+  // In case the given FieldDescriptor points to a repeated field, the indices
+  // need to be valid. Otherwise they should be ignored.
+  //
+  // FieldContext contains information about the specific instances of the
+  // fields being compared, versus FieldDescriptor which only contains general
+  // type information about the fields.
+  virtual ComparisonResult Compare(
+      const google::protobuf::Message& message_1,
+      const google::protobuf::Message& message_2,
+      const google::protobuf::FieldDescriptor* field,
+      int index_1, int index_2,
+      const google::protobuf::util::FieldContext* field_context) = 0;
+
+ private:
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FieldComparator);
+};
+
+// Basic implementation of FieldComparator.  Supports four modes of floating
+// point value comparison: exact, approximate using MathUtil::AlmostEqual
+// method, and arbitrarilly precise using MathUtil::WithinFracionOrMargin.
+class LIBPROTOBUF_EXPORT DefaultFieldComparator : public FieldComparator {
+ public:
+  enum FloatComparison {
+     EXACT,               // Floats and doubles are compared exactly.
+     APPROXIMATE,         // Floats and doubles are compared using the
+                          // MathUtil::AlmostEqual method or
+                          // MathUtil::WithinFractionOrMargin method.
+     // TODO(ksroka): Introduce third value to differenciate uses of AlmostEqual
+     //               and WithinFractionOrMargin.
+  };
+
+  // Creates new comparator with float comparison set to EXACT.
+  DefaultFieldComparator();
+
+  virtual ~DefaultFieldComparator();
+
+  virtual ComparisonResult Compare(
+      const google::protobuf::Message& message_1,
+      const google::protobuf::Message& message_2,
+      const google::protobuf::FieldDescriptor* field,
+      int index_1, int index_2,
+      const google::protobuf::util::FieldContext* field_context);
+
+  void set_float_comparison(FloatComparison float_comparison) {
+    float_comparison_ = float_comparison;
+  }
+
+  FloatComparison float_comparison() const {
+    return float_comparison_;
+  }
+
+  // Set whether the FieldComparator shall treat floats or doubles that are both
+  // NaN as equal (treat_nan_as_equal = true) or as different
+  // (treat_nan_as_equal = false). Default is treating NaNs always as different.
+  void set_treat_nan_as_equal(bool treat_nan_as_equal) {
+    treat_nan_as_equal_ = treat_nan_as_equal;
+  }
+
+  bool treat_nan_as_equal() const {
+    return treat_nan_as_equal_;
+  }
+
+  // Sets the fraction and margin for the float comparison of a given field.
+  // Uses MathUtil::WithinFractionOrMargin to compare the values.
+  //
+  // REQUIRES: field->cpp_type == FieldDescriptor::CPPTYPE_DOUBLE or
+  //           field->cpp_type == FieldDescriptor::CPPTYPE_FLOAT
+  // REQUIRES: float_comparison_ == APPROXIMATE
+  void SetFractionAndMargin(const FieldDescriptor* field, double fraction,
+                            double margin);
+
+  // Sets the fraction and margin for the float comparison of all float and
+  // double fields, unless a field has been given a specific setting via
+  // SetFractionAndMargin() above.
+  // Uses MathUtil::WithinFractionOrMargin to compare the values.
+  //
+  // REQUIRES: float_comparison_ == APPROXIMATE
+  void SetDefaultFractionAndMargin(double fraction, double margin);
+
+ private:
+  // Defines the tolerance for floating point comparison (fraction and margin).
+  struct Tolerance {
+    double fraction;
+    double margin;
+    Tolerance()
+        : fraction(0.0),
+          margin(0.0) {}
+    Tolerance(double f, double m)
+        : fraction(f),
+          margin(m) {}
+  };
+
+  // Defines the map to store the tolerances for floating point comparison.
+  typedef map<const FieldDescriptor*, Tolerance> ToleranceMap;
+
+  // The following methods get executed when CompareFields is called for the
+  // basic types (instead of submessages). They return true on success. One
+  // can use ResultFromBoolean() to convert that boolean to a ComparisonResult
+  // value.
+  bool CompareBool(const google::protobuf::FieldDescriptor& field,
+                   bool value_1, bool value_2) {
+    return value_1 == value_2;
+  }
+
+  // Uses CompareDoubleOrFloat, a helper function used by both CompareDouble and
+  // CompareFloat.
+  bool CompareDouble(const google::protobuf::FieldDescriptor& field,
+                     double value_1, double value_2);
+
+  bool CompareEnum(const google::protobuf::FieldDescriptor& field,
+                   const EnumValueDescriptor* value_1,
+                   const EnumValueDescriptor* value_2);
+
+  // Uses CompareDoubleOrFloat, a helper function used by both CompareDouble and
+  // CompareFloat.
+  bool CompareFloat(const google::protobuf::FieldDescriptor& field,
+                    float value_1, float value_2);
+
+  bool CompareInt32(const google::protobuf::FieldDescriptor& field,
+                    int32 value_1, int32 value_2) {
+    return value_1 == value_2;
+  }
+
+  bool CompareInt64(const google::protobuf::FieldDescriptor& field,
+                    int64 value_1, int64 value_2) {
+    return value_1 == value_2;
+  }
+
+  bool CompareString(const google::protobuf::FieldDescriptor& field,
+                     const string& value_1, const string& value_2) {
+    return value_1 == value_2;
+  }
+
+  bool CompareUInt32(const google::protobuf::FieldDescriptor& field,
+                     uint32 value_1, uint32 value_2) {
+    return value_1 == value_2;
+  }
+
+  bool CompareUInt64(const google::protobuf::FieldDescriptor& field,
+                     uint64 value_1, uint64 value_2) {
+    return value_1 == value_2;
+  }
+
+  // This function is used by CompareDouble and CompareFloat to avoid code
+  // duplication. There are no checks done against types of the values passed,
+  // but it's likely to fail if passed non-numeric arguments.
+  template<typename T>
+  bool CompareDoubleOrFloat(const google::protobuf::FieldDescriptor& field,
+                            T value_1, T value_2);
+
+  // Returns FieldComparator::SAME if boolean_result is true and
+  // FieldComparator::DIFFERENT otherwise.
+  ComparisonResult ResultFromBoolean(bool boolean_result) const;
+
+  FloatComparison float_comparison_;
+
+  // If true, floats and doubles that are both NaN are considered to be
+  // equal. Otherwise, two floats or doubles that are NaN are considered to be
+  // different.
+  bool treat_nan_as_equal_;
+
+  // True iff default_tolerance_ has been explicitly set.
+  //
+  // If false, then the default tolerance for flaots and doubles is that which
+  // is used by MathUtil::AlmostEquals().
+  bool has_default_tolerance_;
+
+  // Default float/double tolerance. Only meaningful if
+  // has_default_tolerance_ == true.
+  Tolerance default_tolerance_;
+
+  // Field-specific float/double tolerances, which override any default for
+  // those particular fields.
+  ToleranceMap map_tolerance_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(DefaultFieldComparator);
+};
+
+}  // namespace util
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_UTIL_FIELD_COMPARATOR_H__