1 /*
2 * Copyright (C) 2019, Google LLC.
3 * and other copyright owners as documented in the project's IP log.
4 *
5 * This program and the accompanying materials are made available
6 * under the terms of the Eclipse Distribution License v1.0 which
7 * accompanies this distribution, is reproduced below, and is
8 * available at http://www.eclipse.org/org/documents/edl-v10.php
9 *
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or
13 * without modification, are permitted provided that the following
14 * conditions are met:
15 *
16 * - Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 *
19 * - Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials provided
22 * with the distribution.
23 *
24 * - Neither the name of the Eclipse Foundation, Inc. nor the
25 * names of its contributors may be used to endorse or promote
26 * products derived from this software without specific prior
27 * written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 */
43
44 package org.eclipse.jgit.transport;
45
46 import java.text.MessageFormat;
47
48 import org.eclipse.jgit.annotations.Nullable;
49 import org.eclipse.jgit.errors.PackProtocolException;
50 import org.eclipse.jgit.internal.JGitText;
51
52 /**
53 * Represents either a filter specified in a protocol "filter" line, or a
54 * placeholder to indicate no filtering.
55 *
56 * @since 5.4
57 */
58 public final class FilterSpec {
59
60 private final long blobLimit;
61
62 private final long treeDepthLimit;
63
64 private FilterSpec(long blobLimit, long treeDepthLimit) {
65 this.blobLimit = blobLimit;
66 this.treeDepthLimit = treeDepthLimit;
67 }
68
69 /**
70 * Process the content of "filter" line from the protocol. It has a shape
71 * like:
72 *
73 * <ul>
74 * <li>"blob:none"
75 * <li>"blob:limit=N", with N >= 0
76 * <li>"tree:DEPTH", with DEPTH >= 0
77 * </ul>
78 *
79 * @param filterLine
80 * the content of the "filter" line in the protocol
81 * @return a FilterSpec representing the given filter
82 * @throws PackProtocolException
83 * invalid filter because due to unrecognized format or
84 * negative/non-numeric filter.
85 */
86 public static FilterSpec fromFilterLine(String filterLine)
87 throws PackProtocolException {
88 if (filterLine.equals("blob:none")) { //$NON-NLS-1$
89 return FilterSpec.withBlobLimit(0);
90 } else if (filterLine.startsWith("blob:limit=")) { //$NON-NLS-1$
91 long blobLimit = -1;
92 try {
93 blobLimit = Long
94 .parseLong(filterLine.substring("blob:limit=".length())); //$NON-NLS-1$
95 } catch (NumberFormatException e) {
96 // Do not change blobLimit so that we throw a
97 // PackProtocolException later.
98 }
99 if (blobLimit >= 0) {
100 return FilterSpec.withBlobLimit(blobLimit);
101 }
102 } else if (filterLine.startsWith("tree:")) { //$NON-NLS-1$
103 long treeDepthLimit = -1;
104 try {
105 treeDepthLimit = Long
106 .parseLong(filterLine.substring("tree:".length())); //$NON-NLS-1$
107 } catch (NumberFormatException e) {
108 // Do not change blobLimit so that we throw a
109 // PackProtocolException later.
110 }
111 if (treeDepthLimit >= 0) {
112 return FilterSpec.withTreeDepthLimit(treeDepthLimit);
113 }
114 }
115
116 // Did not match any known filter format.
117 throw new PackProtocolException(
118 MessageFormat.format(JGitText.get().invalidFilter, filterLine));
119 }
120
121 /**
122 * @param blobLimit
123 * the blob limit in a "blob:[limit]" or "blob:none" filter line
124 * @return a filter spec which filters blobs above a certain size
125 */
126 static FilterSpec withBlobLimit(long blobLimit) {
127 if (blobLimit < 0) {
128 throw new IllegalArgumentException(
129 "blobLimit cannot be negative: " + blobLimit); //$NON-NLS-1$
130 }
131 return new FilterSpec(blobLimit, -1);
132 }
133
134 /**
135 * @param treeDepthLimit
136 * the tree depth limit in a "tree:[depth]" filter line
137 * @return a filter spec which filters blobs and trees beyond a certain tree
138 * depth
139 */
140 static FilterSpec withTreeDepthLimit(long treeDepthLimit) {
141 if (treeDepthLimit < 0) {
142 throw new IllegalArgumentException(
143 "treeDepthLimit cannot be negative: " + treeDepthLimit); //$NON-NLS-1$
144 }
145 return new FilterSpec(-1, treeDepthLimit);
146 }
147
148 /**
149 * A placeholder that indicates no filtering.
150 */
151 public static final FilterSpecec.html#FilterSpec">FilterSpec NO_FILTER = new FilterSpec(-1, -1);
152
153 /**
154 * @return -1 if this filter does not filter blobs based on size, or a
155 * non-negative integer representing the max size of blobs to allow
156 */
157 public long getBlobLimit() {
158 return blobLimit;
159 }
160
161 /**
162 * @return -1 if this filter does not filter blobs and trees based on depth,
163 * or a non-negative integer representing the max tree depth of
164 * blobs and trees to fetch
165 */
166 public long getTreeDepthLimit() {
167 return treeDepthLimit;
168 }
169
170 /**
171 * @return true if this filter doesn't filter out anything
172 */
173 public boolean isNoOp() {
174 return blobLimit == -1 && treeDepthLimit == -1;
175 }
176
177 /**
178 * @return the filter line which describes this spec, e.g. "filter blob:limit=42"
179 */
180 @Nullable
181 public String filterLine() {
182 if (blobLimit == 0) {
183 return GitProtocolConstants.OPTION_FILTER + " blob:none"; //$NON-NLS-1$
184 }
185
186 if (blobLimit > 0) {
187 return GitProtocolConstants.OPTION_FILTER + " blob:limit=" + blobLimit; //$NON-NLS-1$
188 }
189
190 return null;
191 }
192 }