Move some routines to solver_utils.h/cc

This moves a couple of routines from solver.cc into solver_utils.h/cc
so that they can also be used by the upcoming GradientProblemSolver.

Change-Id: I627b32ad3dc639422aacde78a8e391459d947e99
diff --git a/internal/ceres/CMakeLists.txt b/internal/ceres/CMakeLists.txt
index ec9dee3..9c49503 100644
--- a/internal/ceres/CMakeLists.txt
+++ b/internal/ceres/CMakeLists.txt
@@ -98,6 +98,7 @@
     scratch_evaluate_preparer.cc
     single_linkage_clustering.cc
     solver.cc
+    solver_utils.cc
     sparse_matrix.cc
     sparse_normal_cholesky_solver.cc
     split.cc
diff --git a/internal/ceres/solver.cc b/internal/ceres/solver.cc
index 2c5be80..209cfe3 100644
--- a/internal/ceres/solver.cc
+++ b/internal/ceres/solver.cc
@@ -34,16 +34,16 @@
 #include <algorithm>
 #include <sstream>   // NOLINT
 #include <vector>
+#include "ceres/gradient_checking_cost_function.h"
 #include "ceres/internal/port.h"
 #include "ceres/parameter_block_ordering.h"
 #include "ceres/preprocessor.h"
-#include "ceres/gradient_checking_cost_function.h"
 #include "ceres/problem.h"
 #include "ceres/problem_impl.h"
 #include "ceres/program.h"
+#include "ceres/solver_utils.h"
 #include "ceres/stringprintf.h"
 #include "ceres/types.h"
-#include "ceres/version.h"
 #include "ceres/wall_time.h"
 
 namespace ceres {
@@ -311,16 +311,6 @@
   internal::StringAppendF(report, "%d", ordering.back());
 }
 
-void SetSummaryFinalCost(Solver::Summary* summary) {
-  summary->final_cost = summary->initial_cost;
-  // We need the loop here, instead of just looking at the last
-  // iteration because the minimizer maybe making non-monotonic steps.
-  for (int i = 0; i < summary->iterations.size(); ++i) {
-    const IterationSummary& iteration_summary = summary->iterations[i];
-    summary->final_cost = min(iteration_summary.cost, summary->final_cost);
-  }
-}
-
 void SummarizeGivenProgram(const internal::Program& program,
                            Solver::Summary* summary) {
   summary->num_parameter_blocks     = program.NumParameterBlocks();
@@ -357,6 +347,7 @@
   summary->line_search_type                   = options.line_search_type;
   summary->linear_solver_type_given           = options.linear_solver_type;
   summary->max_lbfgs_rank                     = options.max_lbfgs_rank;
+
   summary->minimizer_type                     = options.minimizer_type;
   summary->nonlinear_conjugate_gradient_type  = options.nonlinear_conjugate_gradient_type;  //  NOLINT
   summary->num_linear_solver_threads_given    = options.num_linear_solver_threads;          //  NOLINT
@@ -380,7 +371,7 @@
   summary->num_threads_used               = pp.options.num_threads;
   summary->preconditioner_type_used       = pp.options.preconditioner_type;                 // NOLINT
 
-  SetSummaryFinalCost(summary);
+  internal::SetSummaryFinalCost(summary);
 
   if (pp.reduced_program.get() != NULL) {
     SummarizeReducedProgram(*pp.reduced_program, summary);
@@ -441,44 +432,6 @@
   }
 }
 
-string VersionString() {
-  string value = string(CERES_VERSION_STRING);
-
-#ifdef CERES_NO_LAPACK
-  value += "-no_lapack";
-#else
-  value += "-lapack";
-#endif
-
-#ifndef CERES_NO_SUITESPARSE
-  value += "-suitesparse";
-#endif
-
-#ifndef CERES_NO_CXSPARSE
-  value += "-cxsparse";
-#endif
-
-#ifdef CERES_USE_EIGEN_SPARSE
-  value += "-eigensparse";
-#endif
-
-#ifdef CERES_RESTRUCT_SCHUR_SPECIALIZATIONS
-  value += "-no_schur_specializations";
-#endif
-
-#ifdef CERES_USE_OPENMP
-  value += "-openmp";
-#else
-  value += "-no_openmp";
-#endif
-
-#ifdef CERES_NO_CUSTOM_BLAS
-  value += "-no_custom_blas";
-#endif
-
-  return value;
-}
-
 }  // namespace
 
 bool Solver::Options::IsValid(string* error) const {
@@ -640,6 +593,8 @@
 };
 
 string Solver::Summary::FullReport() const {
+  using internal::VersionString;
+
   string report = string("\nSolver Summary (v " + VersionString() + ")\n\n");
 
   StringAppendF(&report, "%45s    %21s\n", "Original", "Reduced");
@@ -840,9 +795,7 @@
 };
 
 bool Solver::Summary::IsSolutionUsable() const {
-  return (termination_type == CONVERGENCE ||
-          termination_type == NO_CONVERGENCE ||
-          termination_type == USER_SUCCESS);
+  return internal::IsSolutionUsable(*this);
 }
 
 }  // namespace ceres
diff --git a/internal/ceres/solver_utils.cc b/internal/ceres/solver_utils.cc
new file mode 100644
index 0000000..bd304e7
--- /dev/null
+++ b/internal/ceres/solver_utils.cc
@@ -0,0 +1,78 @@
+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2014 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)
+
+#include <string>
+
+#include "ceres/internal/port.h"
+#include "ceres/version.h"
+
+namespace ceres {
+namespace internal {
+
+string VersionString() {
+  string value = string(CERES_VERSION_STRING);
+
+#ifdef CERES_NO_LAPACK
+  value += "-no_lapack";
+#else
+  value += "-lapack";
+#endif
+
+#ifndef CERES_NO_SUITESPARSE
+  value += "-suitesparse";
+#endif
+
+#ifndef CERES_NO_CXSPARSE
+  value += "-cxsparse";
+#endif
+
+#ifdef CERES_USE_EIGEN_SPARSE
+  value += "-eigensparse";
+#endif
+
+#ifdef CERES_RESTRUCT_SCHUR_SPECIALIZATIONS
+  value += "-no_schur_specializations";
+#endif
+
+#ifdef CERES_USE_OPENMP
+  value += "-openmp";
+#else
+  value += "-no_openmp";
+#endif
+
+#ifdef CERES_NO_CUSTOM_BLAS
+  value += "-no_custom_blas";
+#endif
+
+  return value;
+}
+
+}  // namespace internal
+}  // namespace ceres
diff --git a/internal/ceres/solver_utils.h b/internal/ceres/solver_utils.h
new file mode 100644
index 0000000..41c8a6e
--- /dev/null
+++ b/internal/ceres/solver_utils.h
@@ -0,0 +1,58 @@
+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2014 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)
+
+#include <algorithm>
+#include <string>
+
+namespace ceres {
+namespace internal {
+
+template <typename SummaryType>
+bool IsSolutionUsable(const SummaryType& summary) {
+  return (summary.termination_type == CONVERGENCE ||
+          summary.termination_type == NO_CONVERGENCE ||
+          summary.termination_type == USER_SUCCESS);
+}
+
+template <typename SummaryType>
+void SetSummaryFinalCost(SummaryType* summary) {
+  summary->final_cost = summary->initial_cost;
+  // We need the loop here, instead of just looking at the last
+  // iteration because the minimizer maybe making non-monotonic steps.
+  for (int i = 0; i < summary->iterations.size(); ++i) {
+    const IterationSummary& iteration_summary = summary->iterations[i];
+    summary->final_cost = min(iteration_summary.cost, summary->final_cost);
+  }
+}
+
+string VersionString();
+
+}  // namespace internal
+}  // namespace ceres