Preconditioner refactoring.

1. Added a Preconditioner interface.
2. SCHUR_JACOBI is now its own class and is independent of
SuiteSparse.

Change-Id: Id912ab19cf3736e61d1b90ddaf5bfba33e877ec4

internal/ceres/preconditioner.cc

@@ -0,0 +1,63 @@
+// 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)
+
+#include "ceres/preconditioner.h"
+#include "glog/logging.h"
+
+namespace ceres {
+namespace internal {
+
+Preconditioner::~Preconditioner() {
+}
+
+SparseMatrixPreconditionerWrapper::SparseMatrixPreconditionerWrapper(
+    const SparseMatrix* matrix)
+    : matrix_(CHECK_NOTNULL(matrix)) {
+}
+
+SparseMatrixPreconditionerWrapper::~SparseMatrixPreconditionerWrapper() {
+}
+
+bool SparseMatrixPreconditionerWrapper::Update(const BlockSparseMatrixBase& A,
+                                               const double* D) {
+  return true;
+}
+
+void SparseMatrixPreconditionerWrapper::RightMultiply(const double* x,
+                                                      double* y) const {
+  matrix_->RightMultiply(x, y);
+}
+
+int  SparseMatrixPreconditionerWrapper::num_rows() const {
+  return matrix_->num_rows();
+}
+
+}  // namespace internal
+}  // namespace ceres