| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| FromFileSystem |
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| 2.3333333333333335;2.333 | ||||
| FromFileSystem$Builder |
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| 2.3333333333333335;2.333 | ||||
| FromFileSystem$Builder$Work |
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| 2.3333333333333335;2.333 |
| 1 | /** | |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one | |
| 3 | * or more contributor license agreements. See the NOTICE file | |
| 4 | * distributed with this work for additional information | |
| 5 | * regarding copyright ownership. The ASF licenses this file | |
| 6 | * to you under the Apache License, Version 2.0 (the | |
| 7 | * "License"); you may not use this file except in compliance | |
| 8 | * with the License. You may obtain a copy of the License at | |
| 9 | * | |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 | |
| 11 | * | |
| 12 | * Unless required by applicable law or agreed to in writing, | |
| 13 | * software distributed under the License is distributed on an | |
| 14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
| 15 | * KIND, either express or implied. See the License for the | |
| 16 | * specific language governing permissions and limitations | |
| 17 | * under the License. | |
| 18 | */ | |
| 19 | package org.apache.creadur.whisker.scan; | |
| 20 | ||
| 21 | import java.io.File; | |
| 22 | import java.io.IOException; | |
| 23 | import java.util.ArrayList; | |
| 24 | import java.util.Collection; | |
| 25 | import java.util.LinkedList; | |
| 26 | import java.util.Queue; | |
| 27 | import java.util.Set; | |
| 28 | import java.util.TreeSet; | |
| 29 | ||
| 30 | /** | |
| 31 | * Scans directories for resources, within a file system. | |
| 32 | */ | |
| 33 | public class FromFileSystem { | |
| 34 | ||
| 35 | /** | |
| 36 | * Base constructor. | |
| 37 | */ | |
| 38 | public FromFileSystem() { | |
| 39 | 0 | super(); |
| 40 | 0 | } |
| 41 | ||
| 42 | /** | |
| 43 | * Builds description based on given directory. | |
| 44 | * @param base names the base directory, not null | |
| 45 | * @return collected directories within the base, not null | |
| 46 | * @throws IOException when the scanning fails | |
| 47 | */ | |
| 48 | public Collection<Directory> withBase(final String base) | |
| 49 | throws IOException { | |
| 50 | 0 | return new Builder(base).build(); |
| 51 | } | |
| 52 | ||
| 53 | /** | |
| 54 | * Builds a description of a file system. | |
| 55 | */ | |
| 56 | private final static class Builder { | |
| 57 | /** Initial capacity for the backing array. */ | |
| 58 | private static final int DEFAULT_INITIAL_CAPACITY = 64; | |
| 59 | /** Directory scanning base. */ | |
| 60 | private final File base; | |
| 61 | /** Directories scanned. */ | |
| 62 | private final Set<Directory> directories; | |
| 63 | /** Queues work not yet complete. */ | |
| 64 | private final Queue<Work> workInProgress; | |
| 65 | /** Stores work done. */ | |
| 66 | private final Collection<Work> workDone; | |
| 67 | ||
| 68 | /** | |
| 69 | * Constructs a builder with given base | |
| 70 | * (and default backing array). | |
| 71 | * @param base not null | |
| 72 | */ | |
| 73 | public Builder(final String base) { | |
| 74 | 0 | this(base, DEFAULT_INITIAL_CAPACITY); |
| 75 | 0 | } |
| 76 | ||
| 77 | /** | |
| 78 | * Constructs a builder. | |
| 79 | * @param base not null | |
| 80 | * @param initialCapacity initial capacity for backing array | |
| 81 | */ | |
| 82 | public Builder(final String base, final int initialCapacity) { | |
| 83 | 0 | super(); |
| 84 | 0 | this.base = new File(base); |
| 85 | 0 | directories = new TreeSet<Directory>(); |
| 86 | 0 | workInProgress = new LinkedList<Work>(); |
| 87 | 0 | workDone = new ArrayList<Work>(initialCapacity); |
| 88 | 0 | } |
| 89 | ||
| 90 | /** | |
| 91 | * Builds directories. | |
| 92 | * @return not null | |
| 93 | * @throws IOException when scanning fails | |
| 94 | */ | |
| 95 | public Collection<Directory> build() throws IOException { | |
| 96 | 0 | put(base).andWork().untilDone(); |
| 97 | 0 | return directories; |
| 98 | } | |
| 99 | ||
| 100 | /** | |
| 101 | * Waiting until work done. | |
| 102 | */ | |
| 103 | 0 | private void untilDone() { } |
| 104 | ||
| 105 | /** | |
| 106 | * Adds file work to the queue. | |
| 107 | * @param file not null | |
| 108 | * @return this, not null | |
| 109 | */ | |
| 110 | private Builder put(final File file) { | |
| 111 | 0 | return put(new Work(file)); |
| 112 | } | |
| 113 | ||
| 114 | /** | |
| 115 | * Queues work. | |
| 116 | * @param work not null | |
| 117 | * @return this, not null | |
| 118 | */ | |
| 119 | private Builder put(final Work work) { | |
| 120 | 0 | if (work != null) { |
| 121 | 0 | if (workDone.contains(work)) { |
| 122 | 0 | alreadyDone(work); |
| 123 | } else { | |
| 124 | 0 | this.workInProgress.add(work); |
| 125 | } | |
| 126 | } | |
| 127 | 0 | return this; |
| 128 | } | |
| 129 | ||
| 130 | /** | |
| 131 | * Notes that work has already been done. | |
| 132 | * @param work not null | |
| 133 | */ | |
| 134 | private void alreadyDone(final Work work) { | |
| 135 | 0 | System.out.println("Already done " + work); |
| 136 | 0 | } |
| 137 | ||
| 138 | /** | |
| 139 | * Starts work. | |
| 140 | * @return this, not null | |
| 141 | */ | |
| 142 | private Builder andWork() { | |
| 143 | 0 | while (!workInProgress.isEmpty()) { |
| 144 | 0 | workDone.add(workOn(workInProgress.poll())); |
| 145 | } | |
| 146 | 0 | return this; |
| 147 | } | |
| 148 | ||
| 149 | /** | |
| 150 | * Performs work. | |
| 151 | * @param next not null | |
| 152 | * @return the work done, not null | |
| 153 | */ | |
| 154 | private Work workOn(final Work next) { | |
| 155 | 0 | for (final String name: next.contents()) { |
| 156 | 0 | put(next.whenDirectory(name)); |
| 157 | } | |
| 158 | 0 | directories.add(next.build()); |
| 159 | 0 | return next; |
| 160 | } | |
| 161 | ||
| 162 | /** | |
| 163 | * Computes the contents of a directory. | |
| 164 | */ | |
| 165 | private static final class Work { | |
| 166 | /** Represents base directory. */ | |
| 167 | private static final String BASE_DIRECTORY = "."; | |
| 168 | /** Names the directory. */ | |
| 169 | private final String name; | |
| 170 | /** The directory worked on. */ | |
| 171 | private final File file; | |
| 172 | ||
| 173 | /** | |
| 174 | * Constructs work. | |
| 175 | * @param file not null | |
| 176 | */ | |
| 177 | public Work(final File file) { | |
| 178 | 0 | this(BASE_DIRECTORY, file); |
| 179 | 0 | } |
| 180 | ||
| 181 | /** | |
| 182 | * Constructs work. | |
| 183 | * @param name not null | |
| 184 | * @param file not null | |
| 185 | */ | |
| 186 | 0 | public Work(final String name, final File file) { |
| 187 | 0 | if (!file.exists()) { |
| 188 | 0 | throw new IllegalArgumentException( |
| 189 | "Expected '" + file.getAbsolutePath() + "' to exist"); | |
| 190 | } | |
| 191 | 0 | if (!file.isDirectory()) { |
| 192 | 0 | throw new IllegalArgumentException( |
| 193 | "Expected '" + file.getAbsolutePath() + "' to be a directory"); | |
| 194 | } | |
| 195 | 0 | this.name = name; |
| 196 | 0 | this.file = file; |
| 197 | 0 | } |
| 198 | ||
| 199 | /** | |
| 200 | * Gets the contents of the work directory. | |
| 201 | * @return not null | |
| 202 | */ | |
| 203 | public String[] contents() { | |
| 204 | 0 | final String[] contents = file.list(); |
| 205 | 0 | if (contents == null) { |
| 206 | 0 | throw new IllegalArgumentException("Cannot list content of " + file); |
| 207 | } | |
| 208 | 0 | return contents; |
| 209 | } | |
| 210 | ||
| 211 | /** | |
| 212 | * Builds a directory. | |
| 213 | * @return not null | |
| 214 | */ | |
| 215 | public Directory build() { | |
| 216 | 0 | final Directory result = new Directory().setName(name); |
| 217 | 0 | for (final String name : contents()) { |
| 218 | 0 | if (isResource(name)) { |
| 219 | 0 | result.addResource(name); |
| 220 | } | |
| 221 | } | |
| 222 | 0 | return result; |
| 223 | } | |
| 224 | ||
| 225 | /** | |
| 226 | * Is the named file a resource? | |
| 227 | * @param name not null | |
| 228 | * @return true when the named file is a resource, | |
| 229 | * false otherwise | |
| 230 | */ | |
| 231 | private boolean isResource(final String name) { | |
| 232 | 0 | return !isDirectory(name); |
| 233 | } | |
| 234 | ||
| 235 | /** | |
| 236 | * Is the named file a directory? | |
| 237 | * @param name not null | |
| 238 | * @return true when the named file is a directory, | |
| 239 | * false otherwise | |
| 240 | */ | |
| 241 | private boolean isDirectory(final String name) { | |
| 242 | 0 | return file(name).isDirectory(); |
| 243 | } | |
| 244 | ||
| 245 | /** | |
| 246 | * Creates new work. | |
| 247 | * @param name not null | |
| 248 | * @return work for the named directory, | |
| 249 | * or null when the resource named is not a directory | |
| 250 | */ | |
| 251 | public Work whenDirectory(final String name) { | |
| 252 | 0 | final File file = file(name); |
| 253 | final Work result; | |
| 254 | 0 | if (file.isDirectory()) { |
| 255 | 0 | result = new Work(path(name), file); |
| 256 | } else { | |
| 257 | 0 | result = null; |
| 258 | } | |
| 259 | 0 | return result; |
| 260 | } | |
| 261 | ||
| 262 | /** | |
| 263 | * Converts a name to a path relative to base. | |
| 264 | * @param name not null | |
| 265 | * @return not null | |
| 266 | */ | |
| 267 | private String path(final String name) { | |
| 268 | final String result; | |
| 269 | 0 | if (isBaseDirectory()) { |
| 270 | 0 | result = name; |
| 271 | } else { | |
| 272 | 0 | result = this.name + "/" + name; |
| 273 | } | |
| 274 | 0 | return result; |
| 275 | } | |
| 276 | ||
| 277 | /** | |
| 278 | * This the work done in the base directory. | |
| 279 | * @return true when this is the base, false otherwise. | |
| 280 | */ | |
| 281 | private boolean isBaseDirectory() { | |
| 282 | 0 | return BASE_DIRECTORY.equals(this.name); |
| 283 | } | |
| 284 | ||
| 285 | /** | |
| 286 | * Creates a file. | |
| 287 | * @param name not null | |
| 288 | * @return file with given name | |
| 289 | */ | |
| 290 | private File file(String name) { | |
| 291 | 0 | return new File(this.file, name); |
| 292 | } | |
| 293 | ||
| 294 | /** | |
| 295 | * Computes some suitable hash. | |
| 296 | * @return a hash code | |
| 297 | * @see java.lang.Object#hashCode() | |
| 298 | */ | |
| 299 | @Override | |
| 300 | public int hashCode() { | |
| 301 | 0 | final int prime = 31; |
| 302 | 0 | int result = 1; |
| 303 | 0 | result = prime * result |
| 304 | + ((file == null) ? 0 : file.hashCode()); | |
| 305 | 0 | result = prime * result |
| 306 | + ((name == null) ? 0 : name.hashCode()); | |
| 307 | 0 | return result; |
| 308 | } | |
| 309 | ||
| 310 | /** | |
| 311 | * Equal when both name and file are equal. | |
| 312 | * @param obj possibly null | |
| 313 | * @return true when equal, false otherwise | |
| 314 | * @see java.lang.Object#equals(java.lang.Object) | |
| 315 | */ | |
| 316 | @Override | |
| 317 | public boolean equals(final Object obj) { | |
| 318 | 0 | if (this == obj) { |
| 319 | 0 | return true; |
| 320 | } | |
| 321 | 0 | if (obj == null) { |
| 322 | 0 | return false; |
| 323 | } | |
| 324 | 0 | if (getClass() != obj.getClass()) { |
| 325 | 0 | return false; |
| 326 | } | |
| 327 | 0 | final Work other = (Work) obj; |
| 328 | 0 | if (file == null) { |
| 329 | 0 | if (other.file != null) |
| 330 | 0 | return false; |
| 331 | 0 | } else if (!file.equals(other.file)) |
| 332 | 0 | return false; |
| 333 | 0 | if (name == null) { |
| 334 | 0 | if (other.name != null) { |
| 335 | 0 | return false; |
| 336 | } | |
| 337 | 0 | } else if (!name.equals(other.name)) { |
| 338 | 0 | return false; |
| 339 | } | |
| 340 | 0 | return true; |
| 341 | } | |
| 342 | ||
| 343 | /** | |
| 344 | * Something suitable for logging. | |
| 345 | * @return not null | |
| 346 | * @see java.lang.Object#toString() | |
| 347 | */ | |
| 348 | @Override | |
| 349 | public String toString() { | |
| 350 | 0 | return "Work [name=" + name + ", file=" + file + "]"; |
| 351 | } | |
| 352 | } | |
| 353 | } | |
| 354 | } |