Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 The Android Open Source Project |
| 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 | |
| 17 | package com.android.internal.util; |
| 18 | |
| 19 | import android.os.FileUtils; |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 20 | import android.util.Slog; |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 21 | |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 22 | import java.io.BufferedInputStream; |
| 23 | import java.io.BufferedOutputStream; |
| 24 | import java.io.File; |
| 25 | import java.io.FileInputStream; |
| 26 | import java.io.FileOutputStream; |
| 27 | import java.io.IOException; |
| 28 | import java.io.InputStream; |
| 29 | import java.io.OutputStream; |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 30 | import java.util.zip.ZipEntry; |
| 31 | import java.util.zip.ZipOutputStream; |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 32 | |
| 33 | import libcore.io.IoUtils; |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 34 | import libcore.io.Streams; |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 35 | |
| 36 | /** |
| 37 | * Utility that rotates files over time, similar to {@code logrotate}. There is |
| 38 | * a single "active" file, which is periodically rotated into historical files, |
| 39 | * and eventually deleted entirely. Files are stored under a specific directory |
| 40 | * with a well-known prefix. |
| 41 | * <p> |
| 42 | * Instead of manipulating files directly, users implement interfaces that |
| 43 | * perform operations on {@link InputStream} and {@link OutputStream}. This |
| 44 | * enables atomic rewriting of file contents in |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 45 | * {@link #rewriteActive(Rewriter, long)}. |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 46 | * <p> |
| 47 | * Users must periodically call {@link #maybeRotate(long)} to perform actual |
| 48 | * rotation. Not inherently thread safe. |
| 49 | */ |
| 50 | public class FileRotator { |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 51 | private static final String TAG = "FileRotator"; |
Jeff Sharkey | e7bb71d | 2012-02-28 15:13:08 -0800 | [diff] [blame] | 52 | private static final boolean LOGD = false; |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 53 | |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 54 | private final File mBasePath; |
| 55 | private final String mPrefix; |
| 56 | private final long mRotateAgeMillis; |
| 57 | private final long mDeleteAgeMillis; |
| 58 | |
| 59 | private static final String SUFFIX_BACKUP = ".backup"; |
| 60 | private static final String SUFFIX_NO_BACKUP = ".no_backup"; |
| 61 | |
| 62 | // TODO: provide method to append to active file |
| 63 | |
| 64 | /** |
| 65 | * External class that reads data from a given {@link InputStream}. May be |
| 66 | * called multiple times when reading rotated data. |
| 67 | */ |
| 68 | public interface Reader { |
| 69 | public void read(InputStream in) throws IOException; |
| 70 | } |
| 71 | |
| 72 | /** |
| 73 | * External class that writes data to a given {@link OutputStream}. |
| 74 | */ |
| 75 | public interface Writer { |
| 76 | public void write(OutputStream out) throws IOException; |
| 77 | } |
| 78 | |
| 79 | /** |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 80 | * External class that reads existing data from given {@link InputStream}, |
| 81 | * then writes any modified data to {@link OutputStream}. |
| 82 | */ |
| 83 | public interface Rewriter extends Reader, Writer { |
| 84 | public void reset(); |
| 85 | public boolean shouldWrite(); |
| 86 | } |
| 87 | |
| 88 | /** |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 89 | * Create a file rotator. |
| 90 | * |
| 91 | * @param basePath Directory under which all files will be placed. |
| 92 | * @param prefix Filename prefix used to identify this rotator. |
| 93 | * @param rotateAgeMillis Age in milliseconds beyond which an active file |
| 94 | * may be rotated into a historical file. |
| 95 | * @param deleteAgeMillis Age in milliseconds beyond which a rotated file |
| 96 | * may be deleted. |
| 97 | */ |
| 98 | public FileRotator(File basePath, String prefix, long rotateAgeMillis, long deleteAgeMillis) { |
| 99 | mBasePath = Preconditions.checkNotNull(basePath); |
| 100 | mPrefix = Preconditions.checkNotNull(prefix); |
| 101 | mRotateAgeMillis = rotateAgeMillis; |
| 102 | mDeleteAgeMillis = deleteAgeMillis; |
| 103 | |
| 104 | // ensure that base path exists |
| 105 | mBasePath.mkdirs(); |
| 106 | |
| 107 | // recover any backup files |
| 108 | for (String name : mBasePath.list()) { |
| 109 | if (!name.startsWith(mPrefix)) continue; |
| 110 | |
| 111 | if (name.endsWith(SUFFIX_BACKUP)) { |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 112 | if (LOGD) Slog.d(TAG, "recovering " + name); |
| 113 | |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 114 | final File backupFile = new File(mBasePath, name); |
| 115 | final File file = new File( |
| 116 | mBasePath, name.substring(0, name.length() - SUFFIX_BACKUP.length())); |
| 117 | |
| 118 | // write failed with backup; recover last file |
| 119 | backupFile.renameTo(file); |
| 120 | |
| 121 | } else if (name.endsWith(SUFFIX_NO_BACKUP)) { |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 122 | if (LOGD) Slog.d(TAG, "recovering " + name); |
| 123 | |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 124 | final File noBackupFile = new File(mBasePath, name); |
| 125 | final File file = new File( |
| 126 | mBasePath, name.substring(0, name.length() - SUFFIX_NO_BACKUP.length())); |
| 127 | |
| 128 | // write failed without backup; delete both |
| 129 | noBackupFile.delete(); |
| 130 | file.delete(); |
| 131 | } |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | /** |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 136 | * Delete all files managed by this rotator. |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 137 | */ |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 138 | public void deleteAll() { |
| 139 | final FileInfo info = new FileInfo(mPrefix); |
| 140 | for (String name : mBasePath.list()) { |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 141 | if (info.parse(name)) { |
| 142 | // delete each file that matches parser |
| 143 | new File(mBasePath, name).delete(); |
| 144 | } |
| 145 | } |
| 146 | } |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 147 | |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 148 | /** |
| 149 | * Dump all files managed by this rotator for debugging purposes. |
| 150 | */ |
| 151 | public void dumpAll(OutputStream os) throws IOException { |
| 152 | final ZipOutputStream zos = new ZipOutputStream(os); |
| 153 | try { |
| 154 | final FileInfo info = new FileInfo(mPrefix); |
| 155 | for (String name : mBasePath.list()) { |
| 156 | if (info.parse(name)) { |
| 157 | final ZipEntry entry = new ZipEntry(name); |
| 158 | zos.putNextEntry(entry); |
| 159 | |
| 160 | final File file = new File(mBasePath, name); |
| 161 | final FileInputStream is = new FileInputStream(file); |
| 162 | try { |
| 163 | Streams.copy(is, zos); |
| 164 | } finally { |
| 165 | IoUtils.closeQuietly(is); |
| 166 | } |
| 167 | |
| 168 | zos.closeEntry(); |
| 169 | } |
| 170 | } |
| 171 | } finally { |
| 172 | IoUtils.closeQuietly(zos); |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 173 | } |
| 174 | } |
| 175 | |
| 176 | /** |
| 177 | * Process currently active file, first reading any existing data, then |
| 178 | * writing modified data. Maintains a backup during write, which is restored |
| 179 | * if the write fails. |
| 180 | */ |
| 181 | public void rewriteActive(Rewriter rewriter, long currentTimeMillis) |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 182 | throws IOException { |
| 183 | final String activeName = getActiveName(currentTimeMillis); |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 184 | rewriteSingle(rewriter, activeName); |
| 185 | } |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 186 | |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 187 | @Deprecated |
| 188 | public void combineActive(final Reader reader, final Writer writer, long currentTimeMillis) |
| 189 | throws IOException { |
| 190 | rewriteActive(new Rewriter() { |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 191 | @Override |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 192 | public void reset() { |
| 193 | // ignored |
| 194 | } |
| 195 | |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 196 | @Override |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 197 | public void read(InputStream in) throws IOException { |
| 198 | reader.read(in); |
| 199 | } |
| 200 | |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 201 | @Override |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 202 | public boolean shouldWrite() { |
| 203 | return true; |
| 204 | } |
| 205 | |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 206 | @Override |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 207 | public void write(OutputStream out) throws IOException { |
| 208 | writer.write(out); |
| 209 | } |
| 210 | }, currentTimeMillis); |
| 211 | } |
| 212 | |
| 213 | /** |
| 214 | * Process all files managed by this rotator, usually to rewrite historical |
| 215 | * data. Each file is processed atomically. |
| 216 | */ |
| 217 | public void rewriteAll(Rewriter rewriter) throws IOException { |
| 218 | final FileInfo info = new FileInfo(mPrefix); |
| 219 | for (String name : mBasePath.list()) { |
| 220 | if (!info.parse(name)) continue; |
| 221 | |
| 222 | // process each file that matches parser |
| 223 | rewriteSingle(rewriter, name); |
| 224 | } |
| 225 | } |
| 226 | |
| 227 | /** |
| 228 | * Process a single file atomically, first reading any existing data, then |
| 229 | * writing modified data. Maintains a backup during write, which is restored |
| 230 | * if the write fails. |
| 231 | */ |
| 232 | private void rewriteSingle(Rewriter rewriter, String name) throws IOException { |
| 233 | if (LOGD) Slog.d(TAG, "rewriting " + name); |
| 234 | |
| 235 | final File file = new File(mBasePath, name); |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 236 | final File backupFile; |
| 237 | |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 238 | rewriter.reset(); |
| 239 | |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 240 | if (file.exists()) { |
| 241 | // read existing data |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 242 | readFile(file, rewriter); |
| 243 | |
| 244 | // skip when rewriter has nothing to write |
| 245 | if (!rewriter.shouldWrite()) return; |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 246 | |
| 247 | // backup existing data during write |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 248 | backupFile = new File(mBasePath, name + SUFFIX_BACKUP); |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 249 | file.renameTo(backupFile); |
| 250 | |
| 251 | try { |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 252 | writeFile(file, rewriter); |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 253 | |
| 254 | // write success, delete backup |
| 255 | backupFile.delete(); |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 256 | } catch (Throwable t) { |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 257 | // write failed, delete file and restore backup |
| 258 | file.delete(); |
| 259 | backupFile.renameTo(file); |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 260 | throw rethrowAsIoException(t); |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 261 | } |
| 262 | |
| 263 | } else { |
| 264 | // create empty backup during write |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 265 | backupFile = new File(mBasePath, name + SUFFIX_NO_BACKUP); |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 266 | backupFile.createNewFile(); |
| 267 | |
| 268 | try { |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 269 | writeFile(file, rewriter); |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 270 | |
| 271 | // write success, delete empty backup |
| 272 | backupFile.delete(); |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 273 | } catch (Throwable t) { |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 274 | // write failed, delete file and empty backup |
| 275 | file.delete(); |
| 276 | backupFile.delete(); |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 277 | throw rethrowAsIoException(t); |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 278 | } |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | /** |
| 283 | * Read any rotated data that overlap the requested time range. |
| 284 | */ |
| 285 | public void readMatching(Reader reader, long matchStartMillis, long matchEndMillis) |
| 286 | throws IOException { |
| 287 | final FileInfo info = new FileInfo(mPrefix); |
| 288 | for (String name : mBasePath.list()) { |
| 289 | if (!info.parse(name)) continue; |
| 290 | |
| 291 | // read file when it overlaps |
| 292 | if (info.startMillis <= matchEndMillis && matchStartMillis <= info.endMillis) { |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 293 | if (LOGD) Slog.d(TAG, "reading matching " + name); |
| 294 | |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 295 | final File file = new File(mBasePath, name); |
| 296 | readFile(file, reader); |
| 297 | } |
| 298 | } |
| 299 | } |
| 300 | |
| 301 | /** |
| 302 | * Return the currently active file, which may not exist yet. |
| 303 | */ |
| 304 | private String getActiveName(long currentTimeMillis) { |
| 305 | String oldestActiveName = null; |
| 306 | long oldestActiveStart = Long.MAX_VALUE; |
| 307 | |
| 308 | final FileInfo info = new FileInfo(mPrefix); |
| 309 | for (String name : mBasePath.list()) { |
| 310 | if (!info.parse(name)) continue; |
| 311 | |
| 312 | // pick the oldest active file which covers current time |
| 313 | if (info.isActive() && info.startMillis < currentTimeMillis |
| 314 | && info.startMillis < oldestActiveStart) { |
| 315 | oldestActiveName = name; |
| 316 | oldestActiveStart = info.startMillis; |
| 317 | } |
| 318 | } |
| 319 | |
| 320 | if (oldestActiveName != null) { |
| 321 | return oldestActiveName; |
| 322 | } else { |
| 323 | // no active file found above; create one starting now |
| 324 | info.startMillis = currentTimeMillis; |
| 325 | info.endMillis = Long.MAX_VALUE; |
| 326 | return info.build(); |
| 327 | } |
| 328 | } |
| 329 | |
| 330 | /** |
| 331 | * Examine all files managed by this rotator, renaming or deleting if their |
| 332 | * age matches the configured thresholds. |
| 333 | */ |
| 334 | public void maybeRotate(long currentTimeMillis) { |
| 335 | final long rotateBefore = currentTimeMillis - mRotateAgeMillis; |
| 336 | final long deleteBefore = currentTimeMillis - mDeleteAgeMillis; |
| 337 | |
| 338 | final FileInfo info = new FileInfo(mPrefix); |
Mikael Gullstrand | bbf1861 | 2013-12-13 10:44:50 +0100 | [diff] [blame] | 339 | String[] baseFiles = mBasePath.list(); |
| 340 | if (baseFiles == null) { |
| 341 | return; |
| 342 | } |
| 343 | |
| 344 | for (String name : baseFiles) { |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 345 | if (!info.parse(name)) continue; |
| 346 | |
| 347 | if (info.isActive()) { |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 348 | if (info.startMillis <= rotateBefore) { |
| 349 | // found active file; rotate if old enough |
| 350 | if (LOGD) Slog.d(TAG, "rotating " + name); |
| 351 | |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 352 | info.endMillis = currentTimeMillis; |
| 353 | |
| 354 | final File file = new File(mBasePath, name); |
| 355 | final File destFile = new File(mBasePath, info.build()); |
| 356 | file.renameTo(destFile); |
| 357 | } |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 358 | } else if (info.endMillis <= deleteBefore) { |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 359 | // found rotated file; delete if old enough |
Jeff Sharkey | 63abc37 | 2012-01-11 18:38:16 -0800 | [diff] [blame] | 360 | if (LOGD) Slog.d(TAG, "deleting " + name); |
| 361 | |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 362 | final File file = new File(mBasePath, name); |
| 363 | file.delete(); |
| 364 | } |
| 365 | } |
| 366 | } |
| 367 | |
| 368 | private static void readFile(File file, Reader reader) throws IOException { |
| 369 | final FileInputStream fis = new FileInputStream(file); |
| 370 | final BufferedInputStream bis = new BufferedInputStream(fis); |
| 371 | try { |
| 372 | reader.read(bis); |
| 373 | } finally { |
| 374 | IoUtils.closeQuietly(bis); |
| 375 | } |
| 376 | } |
| 377 | |
| 378 | private static void writeFile(File file, Writer writer) throws IOException { |
| 379 | final FileOutputStream fos = new FileOutputStream(file); |
| 380 | final BufferedOutputStream bos = new BufferedOutputStream(fos); |
| 381 | try { |
| 382 | writer.write(bos); |
| 383 | bos.flush(); |
| 384 | } finally { |
| 385 | FileUtils.sync(fos); |
| 386 | IoUtils.closeQuietly(bos); |
| 387 | } |
| 388 | } |
| 389 | |
Jeff Sharkey | 6de357e | 2012-05-09 13:33:52 -0700 | [diff] [blame] | 390 | private static IOException rethrowAsIoException(Throwable t) throws IOException { |
| 391 | if (t instanceof IOException) { |
| 392 | throw (IOException) t; |
| 393 | } else { |
| 394 | throw new IOException(t.getMessage(), t); |
| 395 | } |
| 396 | } |
| 397 | |
Jeff Sharkey | a27a3e8 | 2012-01-08 16:41:36 -0800 | [diff] [blame] | 398 | /** |
| 399 | * Details for a rotated file, either parsed from an existing filename, or |
| 400 | * ready to be built into a new filename. |
| 401 | */ |
| 402 | private static class FileInfo { |
| 403 | public final String prefix; |
| 404 | |
| 405 | public long startMillis; |
| 406 | public long endMillis; |
| 407 | |
| 408 | public FileInfo(String prefix) { |
| 409 | this.prefix = Preconditions.checkNotNull(prefix); |
| 410 | } |
| 411 | |
| 412 | /** |
| 413 | * Attempt parsing the given filename. |
| 414 | * |
| 415 | * @return Whether parsing was successful. |
| 416 | */ |
| 417 | public boolean parse(String name) { |
| 418 | startMillis = endMillis = -1; |
| 419 | |
| 420 | final int dotIndex = name.lastIndexOf('.'); |
| 421 | final int dashIndex = name.lastIndexOf('-'); |
| 422 | |
| 423 | // skip when missing time section |
| 424 | if (dotIndex == -1 || dashIndex == -1) return false; |
| 425 | |
| 426 | // skip when prefix doesn't match |
| 427 | if (!prefix.equals(name.substring(0, dotIndex))) return false; |
| 428 | |
| 429 | try { |
| 430 | startMillis = Long.parseLong(name.substring(dotIndex + 1, dashIndex)); |
| 431 | |
| 432 | if (name.length() - dashIndex == 1) { |
| 433 | endMillis = Long.MAX_VALUE; |
| 434 | } else { |
| 435 | endMillis = Long.parseLong(name.substring(dashIndex + 1)); |
| 436 | } |
| 437 | |
| 438 | return true; |
| 439 | } catch (NumberFormatException e) { |
| 440 | return false; |
| 441 | } |
| 442 | } |
| 443 | |
| 444 | /** |
| 445 | * Build current state into filename. |
| 446 | */ |
| 447 | public String build() { |
| 448 | final StringBuilder name = new StringBuilder(); |
| 449 | name.append(prefix).append('.').append(startMillis).append('-'); |
| 450 | if (endMillis != Long.MAX_VALUE) { |
| 451 | name.append(endMillis); |
| 452 | } |
| 453 | return name.toString(); |
| 454 | } |
| 455 | |
| 456 | /** |
| 457 | * Test if current file is active (no end timestamp). |
| 458 | */ |
| 459 | public boolean isActive() { |
| 460 | return endMillis == Long.MAX_VALUE; |
| 461 | } |
| 462 | } |
| 463 | } |