Remove the unused Matrix class.

RELNOTES: None.
PiperOrigin-RevId: 190196203

1 files changed, 0 insertions, 105 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/graph/Matrix.java b/src/main/java/com/google/devtools/build/lib/graph/Matrix.java
deleted file mode 100644
index c302458f84..0000000000
--- a/src/main/java/com/google/devtools/build/lib/graph/Matrix.java
+++ /dev/null
@@ -1,105 +0,0 @@
-// Copyright 2014 The Bazel Authors. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//    http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package com.google.devtools.build.lib.graph;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-/**
- * <p>A simple and inefficient directed graph with the adjacency
- * relation represented as a 2-D bit-matrix. </p>
- *
- * <p> Used as an adjunct to Digraph for performing certain algorithms
- * which are more naturally implemented on this representation,
- * e.g. transitive closure and reduction. </p>
- *
- * <p> Not many operations are supported. </p>
- */
-final class Matrix<T> {
-
-  /**
-   * Constructs a square bit-matrix, initially empty, with the ith row/column
-   * corresponding to the ith element of 'labels', in iteration order.
-   *
-   * Does not retain a references to 'labels'.
-   */
-  public Matrix(Set<T> labels) {
-    this.N = labels.size();
-    this.values = new ArrayList<T>(N);
-    this.indices = new HashMap<>();
-    this.m = new boolean[N][N];
-
-    for (T label: labels) {
-      int idx = values.size();
-      values.add(label);
-      indices.put(label, idx);
-    }
-  }
-
-  /**
-   * Constructs a matrix from the set of logical values specified.  There is
-   * one row/column for each node in the graph, and the entry matrix[i,j] is
-   * set iff there is an edge in 'graph' from the node labelled values[i] to
-   * the node labelled values[j].
-   */
-  public Matrix(Digraph<T> graph) {
-    this(graph.getLabels());
-
-    for (Node<T> nfrom: graph.getNodes()) {
-      Integer ifrom = indices.get(nfrom.getLabel());
-      for (Node<T> nto: nfrom.getSuccessors()) {
-        Integer ito = indices.get(nto.getLabel());
-        m[ifrom][ito] = true;
-      }
-    }
-  }
-
-  /**
-   * The size of one side of the matrix.
-   */
-  private final int N;
-
-  /**
-   * The logical values associated with each row/column.
-   */
-  private final List<T> values;
-
-  /**
-   * The mapping from logical values to row/column index.
-   */
-  private final Map<T, Integer>  indices;
-
-  /**
-   * The bit-matrix itself.
-   * m[from][to] indicates an edge from-->to.
-   */
-  private final boolean[][] m;
-
-  @Override
-  public String toString() {
-    StringBuilder sb = new StringBuilder();
-    for (int ii = 0; ii < N; ++ii) {
-      for (int jj = 0; jj < N; ++jj) {
-        sb.append(m[ii][jj] ? '1' : '0');
-      }
-      sb.append(' ').append(values.get(ii)).append('\n');
-    }
-    return sb.toString();
-  }
-
-}