MultiInputStreamTest.java revision 1d580d0f6ee4f21eb309ba7b509d2c6d671c4044 
1/*
2 * Copyright (C) 2007 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.io;
18
19import com.google.common.collect.Lists;
20
21import java.io.ByteArrayInputStream;
22import java.io.FilterInputStream;
23import java.io.IOException;
24import java.io.InputStream;
25import java.util.Collections;
26import java.util.List;
27
28/**
29 * Test class for {@link MultiInputStream}.
30 *
31 * @author Chris Nokleberg
32 */
33public class MultiInputStreamTest extends IoTestCase {
34
35  public void testJoin() throws Exception {
36    joinHelper(0);
37    joinHelper(1);
38    joinHelper(0, 0, 0);
39    joinHelper(10, 20);
40    joinHelper(10, 0, 20);
41    joinHelper(0, 10, 20);
42    joinHelper(10, 20, 0);
43    joinHelper(10, 20, 1);
44    joinHelper(1, 1, 1, 1, 1, 1, 1, 1);
45    joinHelper(1, 0, 1, 0, 1, 0, 1, 0);
46  }
47
48  public void testOnlyOneOpen() throws Exception {
49    final InputSupplier<InputStream> supplier = newByteSupplier(0, 50);
50    final int[] counter = new int[1];
51    InputSupplier<InputStream> checker = new InputSupplier<InputStream>() {
52      @Override
53      public InputStream getInput() throws IOException {
54        if (counter[0]++ != 0) {
55          throw new IllegalStateException("More than one supplier open");
56        }
57        return new FilterInputStream(supplier.getInput()) {
58          @Override public void close() throws IOException {
59            super.close();
60            counter[0]--;
61          }
62        };
63      }
64    };
65    @SuppressWarnings("unchecked")
66    byte[] result = ByteStreams.toByteArray(
67        ByteStreams.join(checker, checker, checker));
68    assertEquals(150, result.length);
69  }
70
71  private void joinHelper(Integer... spans) throws Exception {
72    List<InputSupplier<InputStream>> suppliers = Lists.newArrayList();
73    int start = 0;
74    for (Integer span : spans) {
75      suppliers.add(newByteSupplier(start, span));
76      start += span;
77    }
78    InputSupplier<InputStream> joined = ByteStreams.join(suppliers);
79    assertTrue(ByteStreams.equal(newByteSupplier(0, start), joined));
80  }
81
82  public void testReadSingleByte() throws Exception {
83    InputSupplier<InputStream> supplier = newByteSupplier(0, 10);
84    @SuppressWarnings("unchecked")
85    InputSupplier<InputStream> joined = ByteStreams.join(supplier, supplier);
86    assertEquals(20, ByteStreams.length(joined));
87    InputStream in = joined.getInput();
88    assertFalse(in.markSupported());
89    assertEquals(10, in.available());
90    int total = 0;
91    while (in.read() != -1) {
92      total++;
93    }
94    assertEquals(0, in.available());
95    assertEquals(20, total);
96  }
97
98  public void testSkip() throws Exception {
99    MultiInputStream multi = new MultiInputStream(
100        Collections.singleton(new InputSupplier<InputStream>() {
101          @Override
102          public InputStream getInput() {
103            return new ByteArrayInputStream(newPreFilledByteArray(0, 50)) {
104              @Override public long skip(long n) {
105                return 0;
106              }
107            };
108          }
109        }).iterator());
110    multi.skip(-1);
111    multi.skip(-1);
112    multi.skip(0);
113    ByteStreams.skipFully(multi, 20);
114    assertEquals(20, multi.read());
115  }
116
117  private static InputSupplier<InputStream> newByteSupplier(final int start, final int size) {
118    return new InputSupplier<InputStream>() {
119      @Override
120      public InputStream getInput() {
121        return new ByteArrayInputStream(newPreFilledByteArray(start, size));
122      }
123    };
124  }
125}
126