Hadoop文件系统支持释疑之S3

 1 package org.apache.hadoop.fs.s3;  2  3 import java.io.BufferedInputStream;  4 import java.io.BufferedOutputStream;  5 import java.io.Closeable;  6 import java.io.File;  7 import java.io.FileInputStream;  8 import java.io.FileOutputStream;  9 import java.io.IOException;  10 import java.io.InputStream;  11 import java.io.OutputStream;  12 import java.net.URI;  13 import java.util.HashMap;  14 import java.util.Map;  15 import java.util.Set;  16 import java.util.TreeSet;  17  18 import org.apache.hadoop.conf.Configuration;  19 import org.apache.hadoop.fs.Path;  20 import org.apache.hadoop.fs.s3.INode.FileType;  21 import org.jets3t.service.S3Service;  22 import org.jets3t.service.S3ServiceException;  23 import org.jets3t.service.impl.rest.httpclient.RestS3Service;  24 import org.jets3t.service.model.S3Bucket;  25 import org.jets3t.service.model.S3Object;  26 import org.jets3t.service.security.AWSCredentials;  27  28 class Jets3tFileSystemStore implements FileSystemStore {  29  30 private static final String FILE_SYSTEM_NAME = "fs";  31 private static final String FILE_SYSTEM_VALUE = "Hadoop";  32  33 private static final String FILE_SYSTEM_TYPE_NAME = "fs-type";  34 private static final String FILE_SYSTEM_TYPE_VALUE = "block";  35  36 private static final String FILE_SYSTEM_VERSION_NAME = "fs-version";  37 private static final String FILE_SYSTEM_VERSION_VALUE = "1";  38  39 private static final Map<String, String> METADATA =  40 new HashMap<String, String>();  41  42 static {  43  METADATA.put(FILE_SYSTEM_NAME, FILE_SYSTEM_VALUE);  44  METADATA.put(FILE_SYSTEM_TYPE_NAME, FILE_SYSTEM_TYPE_VALUE);  45  METADATA.put(FILE_SYSTEM_VERSION_NAME, FILE_SYSTEM_VERSION_VALUE);  46  }  47  48 private static final String PATH_DELIMITER = Path.SEPARATOR;  49 private static final String BLOCK_PREFIX = "block_";  50  51 private Configuration conf;  52  53 private S3Service s3Service;  54  55 private S3Bucket bucket;  56  57 private int bufferSize;  58  59 public void initialize(URI uri, Configuration conf) throws IOException {  60  61 this.conf = conf;  62  63 S3Credentials s3Credentials = new S3Credentials();  64  s3Credentials.initialize(uri, conf);  65 try {  66 AWSCredentials awsCredentials =  67 new AWSCredentials(s3Credentials.getAccessKey(),  68  s3Credentials.getSecretAccessKey());  69 this.s3Service = new RestS3Service(awsCredentials);  70 } catch (S3ServiceException e) {  71 if (e.getCause() instanceof IOException) {  72 throw (IOException) e.getCause();  73  }  74 throw new S3Exception(e);  75  }  76 bucket = new S3Bucket(uri.getHost());  77  78 this.bufferSize = conf.getInt("io.file.buffer.size", 4096);  79  }  80  81 public String getVersion() throws IOException {  82 return FILE_SYSTEM_VERSION_VALUE;  83  }  84  85 private void delete(String key) throws IOException {  86 try {  87  s3Service.deleteObject(bucket, key);  88 } catch (S3ServiceException e) {  89 if (e.getCause() instanceof IOException) {  90 throw (IOException) e.getCause();  91  }  92 throw new S3Exception(e);  93  }  94  }  95  96 public void deleteINode(Path path) throws IOException {  97  delete(pathToKey(path));  98  }  99 100 public void deleteBlock(Block block) throws IOException { 101  delete(blockToKey(block)); 102  } 103 104 public boolean inodeExists(Path path) throws IOException { 105 InputStream in = get(pathToKey(path), true); 106 if (in == null) { 107 return false; 108  } 109  in.close(); 110 return true; 111  } 112 113 public boolean blockExists(long blockId) throws IOException { 114 InputStream in = get(blockToKey(blockId), false); 115 if (in == null) { 116 return false; 117  } 118  in.close(); 119 return true; 120  } 121 122 private InputStream get(String key, boolean checkMetadata) 123 throws IOException { 124 125 try { 126 S3Object object = s3Service.getObject(bucket, key); 127 if (checkMetadata) { 128  checkMetadata(object); 129  } 130 return object.getDataInputStream(); 131 } catch (S3ServiceException e) { 132 if ("NoSuchKey".equals(e.getS3ErrorCode())) { 133 return null; 134  } 135 if (e.getCause() instanceof IOException) { 136 throw (IOException) e.getCause(); 137  } 138 throw new S3Exception(e); 139  } 140  } 141 142 private InputStream get(String key, long byteRangeStart) throws IOException { 143 try { 144 S3Object object = s3Service.getObject(bucket, key, null, null, null, 145 null, byteRangeStart, null); 146 return object.getDataInputStream(); 147 } catch (S3ServiceException e) { 148 if ("NoSuchKey".equals(e.getS3ErrorCode())) { 149 return null; 150  } 151 if (e.getCause() instanceof IOException) { 152 throw (IOException) e.getCause(); 153  } 154 throw new S3Exception(e); 155  } 156  } 157 158 private void checkMetadata(S3Object object) throws S3FileSystemException, 159  S3ServiceException { 160 161 String name = (String) object.getMetadata(FILE_SYSTEM_NAME); 162 if (!FILE_SYSTEM_VALUE.equals(name)) { 163 throw new S3FileSystemException("Not a Hadoop S3 file."); 164  } 165 String type = (String) object.getMetadata(FILE_SYSTEM_TYPE_NAME); 166 if (!FILE_SYSTEM_TYPE_VALUE.equals(type)) { 167 throw new S3FileSystemException("Not a block file."); 168  } 169 String dataVersion = (String) object.getMetadata(FILE_SYSTEM_VERSION_NAME); 170 if (!FILE_SYSTEM_VERSION_VALUE.equals(dataVersion)) { 171 throw new VersionMismatchException(FILE_SYSTEM_VERSION_VALUE, 172  dataVersion); 173  } 174  } 175 176 public INode retrieveINode(Path path) throws IOException { 177 return INode.deserialize(get(pathToKey(path), true)); 178  } 179 180 public File retrieveBlock(Block block, long byteRangeStart) 181 throws IOException { 182 File fileBlock = null; 183 InputStream in = null; 184 OutputStream out = null; 185 try { 186 fileBlock = newBackupFile(); 187 in = get(blockToKey(block), byteRangeStart); 188 out = new BufferedOutputStream(new FileOutputStream(fileBlock)); 189 byte[] buf = new byte[bufferSize]; 190 int numRead; 191 while ((numRead = in.read(buf)) >= 0) { 192 out.write(buf, 0, numRead); 193  } 194 return fileBlock; 195 } catch (IOException e) { 196 // close output stream to file then delete file 197  closeQuietly(out); 198 out = null; // to prevent a second close 199 if (fileBlock != null) { 200  fileBlock.delete(); 201  } 202 throw e; 203 } finally { 204  closeQuietly(out); 205  closeQuietly(in); 206  } 207  } 208 209 private File newBackupFile() throws IOException { 210 File dir = new File(conf.get("fs.s3.buffer.dir")); 211 if (!dir.exists() && !dir.mkdirs()) { 212 throw new IOException("Cannot create S3 buffer directory: " + dir); 213  } 214 File result = File.createTempFile("input-", ".tmp", dir); 215  result.deleteOnExit(); 216 return result; 217  } 218 219 public Set<Path> listSubPaths(Path path) throws IOException { 220 try { 221 String prefix = pathToKey(path); 222 if (!prefix.endsWith(PATH_DELIMITER)) { 223 prefix += PATH_DELIMITER; 224  } 225 S3Object[] objects = s3Service.listObjects(bucket, prefix, PATH_DELIMITER); 226 Set<Path> prefixes = new TreeSet<Path>(); 227 for (int i = 0; i < objects.length; i++) { 228  prefixes.add(keyToPath(objects[i].getKey())); 229  } 230  prefixes.remove(path); 231 return prefixes; 232 } catch (S3ServiceException e) { 233 if (e.getCause() instanceof IOException) { 234 throw (IOException) e.getCause(); 235  } 236 throw new S3Exception(e); 237  } 238  } 239 240 public Set<Path> listDeepSubPaths(Path path) throws IOException { 241 try { 242 String prefix = pathToKey(path); 243 if (!prefix.endsWith(PATH_DELIMITER)) { 244 prefix += PATH_DELIMITER; 245  } 246 S3Object[] objects = s3Service.listObjects(bucket, prefix, null); 247 Set<Path> prefixes = new TreeSet<Path>(); 248 for (int i = 0; i < objects.length; i++) { 249  prefixes.add(keyToPath(objects[i].getKey())); 250  } 251  prefixes.remove(path); 252 return prefixes; 253 } catch (S3ServiceException e) { 254 if (e.getCause() instanceof IOException) { 255 throw (IOException) e.getCause(); 256  } 257 throw new S3Exception(e); 258  } 259  } 260 261 private void put(String key, InputStream in, long length, boolean storeMetadata) 262 throws IOException { 263 264 try { 265 S3Object object = new S3Object(key); 266  object.setDataInputStream(in); 267 object.setContentType("binary/octet-stream"); 268  object.setContentLength(length); 269 if (storeMetadata) { 270  object.addAllMetadata(METADATA); 271  } 272  s3Service.putObject(bucket, object); 273 } catch (S3ServiceException e) { 274 if (e.getCause() instanceof IOException) { 275 throw (IOException) e.getCause(); 276  } 277 throw new S3Exception(e); 278  } 279  } 280 281 public void storeINode(Path path, INode inode) throws IOException { 282 put(pathToKey(path), inode.serialize(), inode.getSerializedLength(), true); 283  } 284 285 public void storeBlock(Block block, File file) throws IOException { 286 BufferedInputStream in = null; 287 try { 288 in = new BufferedInputStream(new FileInputStream(file)); 289 put(blockToKey(block), in, block.getLength(), false); 290 } finally { 291  closeQuietly(in); 292  } 293  } 294 295 private void closeQuietly(Closeable closeable) { 296 if (closeable != null) { 297 try { 298  closeable.close(); 299 } catch (IOException e) { 300 // ignore 301  } 302  } 303  } 304 305 private String pathToKey(Path path) { 306 if (!path.isAbsolute()) { 307 throw new IllegalArgumentException("Path must be absolute: " + path); 308  } 309 return path.toUri().getPath(); 310  } 311 312 private Path keyToPath(String key) { 313 return new Path(key); 314  } 315 316 private String blockToKey(long blockId) { 317 return BLOCK_PREFIX + blockId; 318  } 319 320 private String blockToKey(Block block) { 321 return blockToKey(block.getId()); 322  } 323 324 public void purge() throws IOException { 325 try { 326 S3Object[] objects = s3Service.listObjects(bucket); 327 for (int i = 0; i < objects.length; i++) { 328  s3Service.deleteObject(bucket, objects[i].getKey()); 329  } 330 } catch (S3ServiceException e) { 331 if (e.getCause() instanceof IOException) { 332 throw (IOException) e.getCause(); 333  } 334 throw new S3Exception(e); 335  } 336  } 337 338 public void dump() throws IOException { 339 StringBuilder sb = new StringBuilder("S3 Filesystem, "); 340 sb.append(bucket.getName()).append("\n"); 341 try { 342 S3Object[] objects = s3Service.listObjects(bucket, PATH_DELIMITER, null); 343 for (int i = 0; i < objects.length; i++) { 344 Path path = keyToPath(objects[i].getKey()); 345 sb.append(path).append("\n"); 346 INode m = retrieveINode(path); 347 sb.append("\t").append(m.getFileType()).append("\n"); 348 if (m.getFileType() == FileType.DIRECTORY) { 349 continue; 350  } 351 for (int j = 0; j < m.getBlocks().length; j++) { 352 sb.append("\t").append(m.getBlocks()[j]).append("\n"); 353  } 354  } 355 } catch (S3ServiceException e) { 356 if (e.getCause() instanceof IOException) { 357 throw (IOException) e.getCause(); 358  } 359 throw new S3Exception(e); 360  } 361  System.out.println(sb); 362  } 363 364 }