1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.compress.archivers.sevenz;
18
19 import java.io.IOException;
20 import java.util.Collections;
21 import java.util.LinkedList;
22
23 /**
24 * The unit of solid compression.
25 */
26 final class Folder {
27
28 static final Folder[] EMPTY_FOLDER_ARRAY = {};
29
30 /** List of coders used in this folder, e.g. one for compression, one for encryption. */
31 Coder[] coders;
32
33 /**
34 * Total number of input streams across all coders. This field is currently unused but technically part of the 7z API.
35 */
36 long totalInputStreams;
37
38 /** Total number of output streams across all coders. */
39 long totalOutputStreams;
40
41 /** Mapping between input and output streams. */
42 BindPair[] bindPairs;
43
44 /** Indices of input streams, one per input stream not listed in bindPairs. */
45 long[] packedStreams;
46
47 /** Unpack sizes, per each output stream. */
48 long[] unpackSizes;
49
50 /** Whether the folder has a CRC. */
51 boolean hasCrc;
52
53 /** The CRC, if present. */
54 long crc;
55
56 /**
57 * The number of unpack substreams, product of the number of output streams and the number of non-empty files in this folder.
58 */
59 int numUnpackSubStreams;
60
61 int findBindPairForInStream(final int index) {
62 if (bindPairs != null) {
63 for (int i = 0; i < bindPairs.length; i++) {
64 if (bindPairs[i].inIndex == index) {
65 return i;
66 }
67 }
68 }
69 return -1;
70 }
71
72 int findBindPairForOutStream(final int index) {
73 if (bindPairs != null) {
74 for (int i = 0; i < bindPairs.length; i++) {
75 if (bindPairs[i].outIndex == index) {
76 return i;
77 }
78 }
79 }
80 return -1;
81 }
82
83 /**
84 * Sorts Coders using bind pairs.
85 * <p>
86 * The first coder reads from the packed stream (we currently only support single input stream decoders), the second reads from the output of the first and
87 * so on.
88 * </p>
89 */
90 Iterable<Coder> getOrderedCoders() throws IOException {
91 if (packedStreams == null || coders == null || packedStreams.length == 0 || coders.length == 0) {
92 return Collections.emptyList();
93 }
94 final LinkedList<Coder> list = new LinkedList<>();
95 int current = (int) packedStreams[0]; // more that 2^31 coders?
96 while (current >= 0 && current < coders.length) {
97 if (list.contains(coders[current])) {
98 throw new IOException("folder uses the same coder more than once in coder chain");
99 }
100 list.addLast(coders[current]);
101 final int pair = findBindPairForOutStream(current);
102 current = pair != -1 ? (int) bindPairs[pair].inIndex : -1;
103 }
104 return list;
105 }
106
107 long getUnpackSize() {
108 if (totalOutputStreams == 0) {
109 return 0;
110 }
111 for (int i = (int) totalOutputStreams - 1; i >= 0; i--) {
112 if (findBindPairForOutStream(i) < 0) {
113 return unpackSizes[i];
114 }
115 }
116 return 0;
117 }
118
119 long getUnpackSizeForCoder(final Coder coder) {
120 if (coders != null) {
121 for (int i = 0; i < coders.length; i++) {
122 if (coders[i] == coder) {
123 return unpackSizes[i];
124 }
125 }
126 }
127 return 0;
128 }
129
130 @Override
131 public String toString() {
132 return "Folder with " + coders.length + " coders, " + totalInputStreams + " input streams, " + totalOutputStreams + " output streams, "
133 + bindPairs.length + " bind pairs, " + packedStreams.length + " packed streams, " + unpackSizes.length + " unpack sizes, "
134 + (hasCrc ? "with CRC " + crc : "without CRC") + " and " + numUnpackSubStreams + " unpack streams";
135 }
136 }