Add an ExecutionSummary object that the Evaluator and LinearSolver can use to
report execution statistics of all kinds.

Currently a single map which maps arbitrary strings to doubles is supported,
which allows for precise timing information to be communicated.

Change-Id: Ibd930aca5c9e6cae89bcfeffe9b13e2887644881

internal/ceres/evaluator.h

diff --git a/internal/ceres/evaluator.h b/internal/ceres/evaluator.h
index 3bbf50a..f3be38c 100644
--- a/internal/ceres/evaluator.h
+++ b/internal/ceres/evaluator.h
@@ -34,6 +34,8 @@
 
 #include <string>
 #include <vector>
+
+#include "ceres/execution_summary.h"
 #include "ceres/internal/port.h"
 #include "ceres/types.h"
 
@@ -152,6 +154,8 @@
 
   // The number of residuals in the optimization problem.
   virtual int NumResiduals() const = 0;
+
+  virtual ExecutionSummary ExecutionSummary() const { return ExecutionSummary(); }
 };
 
 }  // namespace internal

internal/ceres/execution_summary.h

diff --git a/internal/ceres/execution_summary.h b/internal/ceres/execution_summary.h
new file mode 100644
index 0000000..02a4448
--- /dev/null
+++ b/internal/ceres/execution_summary.h
@@ -0,0 +1,52 @@
+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2013 Google Inc. All rights reserved.
+// http://code.google.com/p/ceres-solver/
+//
+// 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: sameeragarwal@google.com (Sameer Agarwal)
+
+#ifndef CERES_INTERNAL_EXECUTION_SUMMARY_H_
+#define CERES_INTERNAL_EXECUTION_SUMMARY_H_
+
+#include <map>
+#include <string>
+
+#include "ceres/internal/port.h"
+
+namespace ceres {
+namespace internal {
+
+// Struct used by various objects to report statistics and other
+// information about their execution. e.g., ExecutionSummary::times
+// can be used for reporting times associated with various activities.
+struct ExecutionSummary {
+  map<string, double> times;
+};
+
+}  // namespace internal
+}  // namespace ceres
+
+#endif  // CERES_INTERNAL_EXECUTION_SUMMARY_H_

internal/ceres/linear_solver.h

diff --git a/internal/ceres/linear_solver.h b/internal/ceres/linear_solver.h
index ee7fce2..6e03f60 100644
--- a/internal/ceres/linear_solver.h
+++ b/internal/ceres/linear_solver.h
@@ -42,6 +42,7 @@
 #include "ceres/casts.h"
 #include "ceres/compressed_row_sparse_matrix.h"
 #include "ceres/dense_sparse_matrix.h"
+#include "ceres/execution_summary.h"
 #include "ceres/triplet_sparse_matrix.h"
 #include "ceres/types.h"
 
@@ -255,6 +256,8 @@
                         const PerSolveOptions& per_solve_options,
                         double* x) = 0;
 
+  virtual const ExecutionSummary ExecutionSummary() const { return ExecutionSummary(); }
+
   // Factory
   static LinearSolver* Create(const Options& options);
 };