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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, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  package org.apache.hadoop.hbase;
20  
21  import org.apache.hadoop.classification.InterfaceAudience;
22  import org.apache.hadoop.classification.InterfaceStability;
23  import org.apache.hadoop.hbase.KeyValue.KVComparator;
24  import org.apache.hadoop.hbase.util.Bytes;
25  
26  import java.nio.ByteBuffer;
27  import java.util.Arrays;
28  import java.util.Set;
29  import java.util.concurrent.CopyOnWriteArraySet;
30  
31  /**
32   * Immutable POJO class for representing a table name.
33   * Which is of the form:
34   * <table namespace>:<table qualifier>
35   *
36   * Two special namespaces:
37   *
38   * 1. hbase - system namespace, used to contain hbase internal tables
39   * 2. default - tables with no explicit specified namespace will
40   * automatically fall into this namespace.
41   *
42   * ie
43   *
44   * a) foo:bar, means namespace=foo and qualifier=bar
45   * b) bar, means namespace=default and qualifier=bar
46   * c) default:bar, means namespace=default and qualifier=bar
47   *
48   *  <p>
49   * Internally, in this class, we cache the instances to limit the number of objects and
50   *  make the "equals" faster. We try to minimize the number of objects created of
51   *  the number of array copy to check if we already have an instance of this TableName. The code
52   *  is not optimize for a new instance creation but is optimized to check for existence.
53   * </p>
54   */
55  @InterfaceAudience.Public
56  @InterfaceStability.Evolving
57  public final class TableName implements Comparable<TableName> {
58  
59    /** See {@link #createTableNameIfNecessary(ByteBuffer, ByteBuffer)} */
60    private static final Set<TableName> tableCache = new CopyOnWriteArraySet<TableName>();
61  
62    /** Namespace delimiter */
63    //this should always be only 1 byte long
64    public final static char NAMESPACE_DELIM = ':';
65  
66    // A non-capture group so that this can be embedded.
67    // regex is a bit more complicated to support nuance of tables
68    // in default namespace
69    //Allows only letters, digits and '_'
70    public static final String VALID_NAMESPACE_REGEX =
71        "(?:[a-zA-Z_0-9]+)";
72    //Allows only letters, digits, '_', '-' and '.'
73    public static final String VALID_TABLE_QUALIFIER_REGEX =
74        "(?:[a-zA-Z_0-9][a-zA-Z_0-9-.]*)";
75    //Concatenation of NAMESPACE_REGEX and TABLE_QUALIFIER_REGEX,
76    //with NAMESPACE_DELIM as delimiter
77    public static final String VALID_USER_TABLE_REGEX =
78        "(?:(?:(?:"+VALID_NAMESPACE_REGEX+"\\"+NAMESPACE_DELIM+")?)" +
79           "(?:"+VALID_TABLE_QUALIFIER_REGEX+"))";
80  
81    /** The hbase:meta table's name. */
82    public static final TableName META_TABLE_NAME =
83        valueOf(NamespaceDescriptor.SYSTEM_NAMESPACE_NAME_STR, "meta");
84  
85    /** The Namespace table's name. */
86    public static final TableName NAMESPACE_TABLE_NAME =
87        valueOf(NamespaceDescriptor.SYSTEM_NAMESPACE_NAME_STR, "namespace");
88  
89    public static final String OLD_META_STR = ".META.";
90    public static final String OLD_ROOT_STR = "-ROOT-";
91  
92  
93  
94    /**
95     * TableName for old -ROOT- table. It is used to read/process old WALs which have
96     * ROOT edits.
97     */
98    public static final TableName OLD_ROOT_TABLE_NAME = getADummyTableName(OLD_ROOT_STR);
99    /**
100    * TableName for old .META. table. Used in testing.
101    */
102   public static final TableName OLD_META_TABLE_NAME = getADummyTableName(OLD_META_STR);
103 
104   private final byte[] name;
105   private final String nameAsString;
106   private final byte[] namespace;
107   private final String namespaceAsString;
108   private final byte[] qualifier;
109   private final String qualifierAsString;
110   private final boolean systemTable;
111   private final int hashCode;
112 
113   /**
114    * Check passed byte array, "tableName", is legal user-space table name.
115    * @return Returns passed <code>tableName</code> param
116    * @throws IllegalArgumentException if passed a tableName is null or
117    * is made of other than 'word' characters or underscores: i.e.
118    * <code>[a-zA-Z_0-9.-:]</code>. The ':' is used to delimit the namespace
119    * from the table name and can be used for nothing else.
120    *
121    * Namespace names can only contain 'word' characters
122    * <code>[a-zA-Z_0-9]</code> or '_'
123    *
124    * Qualifier names can only contain 'word' characters
125    * <code>[a-zA-Z_0-9]</code> or '_', '.' or '-'.
126    * The name may not start with '.' or '-'.
127    *
128    * Valid fully qualified table names:
129    * foo:bar, namespace=>foo, table=>bar
130    * org:foo.bar, namespace=org, table=>foo.bar
131    */
132   public static byte [] isLegalFullyQualifiedTableName(final byte[] tableName) {
133     if (tableName == null || tableName.length <= 0) {
134       throw new IllegalArgumentException("Name is null or empty");
135     }
136 
137     int namespaceDelimIndex = com.google.common.primitives.Bytes.lastIndexOf(tableName,
138         (byte) NAMESPACE_DELIM);
139     if (namespaceDelimIndex == 0 || namespaceDelimIndex == -1){
140       isLegalTableQualifierName(tableName);
141     } else {
142       isLegalNamespaceName(tableName, 0, namespaceDelimIndex);
143       isLegalTableQualifierName(tableName, namespaceDelimIndex + 1, tableName.length);
144     }
145     return tableName;
146   }
147 
148   public static byte [] isLegalTableQualifierName(final byte[] qualifierName) {
149     isLegalTableQualifierName(qualifierName, 0, qualifierName.length, false);
150     return qualifierName;
151   }
152 
153   public static byte [] isLegalTableQualifierName(final byte[] qualifierName, boolean isSnapshot) {
154     isLegalTableQualifierName(qualifierName, 0, qualifierName.length, isSnapshot);
155     return qualifierName;
156   }
157 
158 
159   /**
160    * Qualifier names can only contain 'word' characters
161    * <code>[a-zA-Z_0-9]</code> or '_', '.' or '-'.
162    * The name may not start with '.' or '-'.
163    *
164    * @param qualifierName byte array containing the qualifier name
165    * @param start start index
166    * @param end end index (exclusive)
167    */
168   public static void isLegalTableQualifierName(final byte[] qualifierName,
169                                                 int start,
170                                                 int end) {
171       isLegalTableQualifierName(qualifierName, start, end, false);
172   }
173 
174   public static void isLegalTableQualifierName(final byte[] qualifierName,
175                                                 int start,
176                                                 int end,
177                                                 boolean isSnapshot) {
178     if(end - start < 1) {
179       throw new IllegalArgumentException(isSnapshot ? "Snapshot" : "Table" + " qualifier must not be empty");
180     }
181 
182     if (qualifierName[start] == '.' || qualifierName[start] == '-') {
183       throw new IllegalArgumentException("Illegal first character <" + qualifierName[0] +
184                                          "> at 0. Namespaces can only start with alphanumeric " +
185                                          "characters': i.e. [a-zA-Z_0-9]: " +
186                                          Bytes.toString(qualifierName));
187     }
188     for (int i = start; i < end; i++) {
189       if (Character.isLetterOrDigit(qualifierName[i]) ||
190           qualifierName[i] == '_' ||
191           qualifierName[i] == '-' ||
192           qualifierName[i] == '.') {
193         continue;
194       }
195       throw new IllegalArgumentException("Illegal character code:" + qualifierName[i] +
196                                          ", <" + (char) qualifierName[i] + "> at " + i +
197                                          ". " + (isSnapshot ? "snapshot" : "User-space table") +
198                                          " qualifiers can only contain " +
199                                          "'alphanumeric characters': i.e. [a-zA-Z_0-9-.]: " +
200                                          Bytes.toString(qualifierName, start, end));
201     }
202   }
203   public static void isLegalNamespaceName(byte[] namespaceName) {
204     isLegalNamespaceName(namespaceName, 0, namespaceName.length);
205   }
206 
207   /**
208    * Valid namespace characters are [a-zA-Z_0-9]
209    */
210   public static void isLegalNamespaceName(byte[] namespaceName, int offset, int length) {
211     for (int i = offset; i < length; i++) {
212       if (Character.isLetterOrDigit(namespaceName[i])|| namespaceName[i] == '_') {
213         continue;
214       }
215       throw new IllegalArgumentException("Illegal character <" + namespaceName[i] +
216         "> at " + i + ". Namespaces can only contain " +
217         "'alphanumeric characters': i.e. [a-zA-Z_0-9]: " + Bytes.toString(namespaceName,
218           offset, length));
219     }
220   }
221 
222   public byte[] getName() {
223     return name;
224   }
225 
226   public String getNameAsString() {
227     return nameAsString;
228   }
229 
230   public byte[] getNamespace() {
231     return namespace;
232   }
233 
234   public String getNamespaceAsString() {
235     return namespaceAsString;
236   }
237 
238   public byte[] getQualifier() {
239     return qualifier;
240   }
241 
242   public String getQualifierAsString() {
243     return qualifierAsString;
244   }
245 
246   public byte[] toBytes() {
247     return name;
248   }
249 
250   public boolean isSystemTable() {
251     return systemTable;
252   }
253 
254   @Override
255   public String toString() {
256     return nameAsString;
257   }
258 
259   /**
260    *
261    * @throws IllegalArgumentException See {@link #valueOf(byte[])}
262    */
263   private TableName(ByteBuffer namespace, ByteBuffer qualifier) throws IllegalArgumentException {
264     this.qualifier = new byte[qualifier.remaining()];
265     qualifier.duplicate().get(this.qualifier);
266     this.qualifierAsString = Bytes.toString(this.qualifier);
267 
268     if (qualifierAsString.equals(OLD_ROOT_STR)) {
269       throw new IllegalArgumentException(OLD_ROOT_STR + " has been deprecated.");
270     }
271     if (qualifierAsString.equals(OLD_META_STR)) {
272       throw new IllegalArgumentException(OLD_META_STR + " no longer exists. The table has been " +
273           "renamed to " + META_TABLE_NAME);
274     }
275 
276     if (Bytes.equals(NamespaceDescriptor.DEFAULT_NAMESPACE_NAME, namespace)) {
277       // Using the same objects: this will make the comparison faster later
278       this.namespace = NamespaceDescriptor.DEFAULT_NAMESPACE_NAME;
279       this.namespaceAsString = NamespaceDescriptor.DEFAULT_NAMESPACE_NAME_STR;
280       this.systemTable = false;
281 
282       // The name does not include the namespace when it's the default one.
283       this.nameAsString = qualifierAsString;
284       this.name = this.qualifier;
285     } else {
286       if (Bytes.equals(NamespaceDescriptor.SYSTEM_NAMESPACE_NAME, namespace)) {
287         this.namespace = NamespaceDescriptor.SYSTEM_NAMESPACE_NAME;
288         this.namespaceAsString = NamespaceDescriptor.SYSTEM_NAMESPACE_NAME_STR;
289         this.systemTable = true;
290       } else {
291         this.namespace = new byte[namespace.remaining()];
292         namespace.duplicate().get(this.namespace);
293         this.namespaceAsString = Bytes.toString(this.namespace);
294         this.systemTable = false;
295       }
296       this.nameAsString = namespaceAsString + NAMESPACE_DELIM + qualifierAsString;
297       this.name = Bytes.toBytes(nameAsString);
298     }
299 
300     this.hashCode = nameAsString.hashCode();
301 
302     isLegalNamespaceName(this.namespace);
303     isLegalTableQualifierName(this.qualifier);
304   }
305 
306   /**
307    * This is only for the old and meta tables.
308    */
309   private TableName(String qualifier) {
310     this.qualifier = Bytes.toBytes(qualifier);
311     this.qualifierAsString = qualifier;
312 
313     this.namespace = NamespaceDescriptor.SYSTEM_NAMESPACE_NAME;
314     this.namespaceAsString = NamespaceDescriptor.SYSTEM_NAMESPACE_NAME_STR;
315     this.systemTable = true;
316 
317     // WARNING: nameAsString is different than name for old meta & root!
318     // This is by design.
319     this.nameAsString = namespaceAsString + NAMESPACE_DELIM + qualifierAsString;
320     this.name = this.qualifier;
321 
322     this.hashCode = nameAsString.hashCode();
323   }
324 
325 
326   /**
327    * Check that the object does not exist already. There are two reasons for creating the objects
328    * only once:
329    * 1) With 100K regions, the table names take ~20MB.
330    * 2) Equals becomes much faster as it's resolved with a reference and an int comparison.
331    */
332   private static TableName createTableNameIfNecessary(ByteBuffer bns, ByteBuffer qns) {
333     for (TableName tn : tableCache) {
334       if (Bytes.equals(tn.getQualifier(), qns) && Bytes.equals(tn.getNamespace(), bns)) {
335         return tn;
336       }
337     }
338 
339     TableName newTable = new TableName(bns, qns);
340     if (tableCache.add(newTable)) {  // Adds the specified element if it is not already present
341       return newTable;
342     }
343 
344     // Someone else added it. Let's find it.
345     for (TableName tn : tableCache) {
346       if (Bytes.equals(tn.getQualifier(), qns) && Bytes.equals(tn.getNamespace(), bns)) {
347         return tn;
348       }
349     }
350     // this should never happen.
351     throw new IllegalStateException(newTable + " was supposed to be in the cache");
352   }
353 
354 
355   /**
356    * It is used to create table names for old META, and ROOT table.
357    * These tables are not really legal tables. They are not added into the cache.
358    * @return a dummy TableName instance (with no validation) for the passed qualifier
359    */
360   private static TableName getADummyTableName(String qualifier) {
361     return new TableName(qualifier);
362   }
363 
364 
365   public static TableName valueOf(String namespaceAsString, String qualifierAsString) {
366     if (namespaceAsString == null || namespaceAsString.length() < 1) {
367       namespaceAsString = NamespaceDescriptor.DEFAULT_NAMESPACE_NAME_STR;
368     }
369 
370     for (TableName tn : tableCache) {
371       if (qualifierAsString.equals(tn.getQualifierAsString()) &&
372           namespaceAsString.equals(tn.getNameAsString())) {
373         return tn;
374       }
375     }
376 
377     return createTableNameIfNecessary(
378         ByteBuffer.wrap(Bytes.toBytes(namespaceAsString)),
379         ByteBuffer.wrap(Bytes.toBytes(qualifierAsString)));
380   }
381 
382 
383   /**
384    * @throws IllegalArgumentException if fullName equals old root or old meta. Some code
385    *  depends on this. The test is buried in the table creation to save on array comparison
386    *  when we're creating a standard table object that will be in the cache.
387    */
388   public static TableName valueOf(byte[] fullName) throws IllegalArgumentException{
389     for (TableName tn : tableCache) {
390       if (Arrays.equals(tn.getName(), fullName)) {
391         return tn;
392       }
393     }
394 
395     int namespaceDelimIndex = com.google.common.primitives.Bytes.lastIndexOf(fullName,
396         (byte) NAMESPACE_DELIM);
397 
398     if (namespaceDelimIndex < 0) {
399       return createTableNameIfNecessary(
400           ByteBuffer.wrap(NamespaceDescriptor.DEFAULT_NAMESPACE_NAME),
401           ByteBuffer.wrap(fullName));
402     } else {
403       return createTableNameIfNecessary(
404           ByteBuffer.wrap(fullName, 0, namespaceDelimIndex),
405           ByteBuffer.wrap(fullName, namespaceDelimIndex + 1,
406               fullName.length - (namespaceDelimIndex + 1)));
407     }
408   }
409 
410 
411   /**
412    * @throws IllegalArgumentException if fullName equals old root or old meta. Some code
413    *  depends on this.
414    */
415   public static TableName valueOf(String name) {
416     for (TableName tn : tableCache) {
417       if (name.equals(tn.getNameAsString())) {
418         return tn;
419       }
420     }
421 
422     int namespaceDelimIndex = name.indexOf(NAMESPACE_DELIM);
423     byte[] nameB = Bytes.toBytes(name);
424 
425     if (namespaceDelimIndex < 0) {
426       return createTableNameIfNecessary(
427           ByteBuffer.wrap(NamespaceDescriptor.DEFAULT_NAMESPACE_NAME),
428           ByteBuffer.wrap(nameB));
429     } else {
430       return createTableNameIfNecessary(
431           ByteBuffer.wrap(nameB, 0, namespaceDelimIndex),
432           ByteBuffer.wrap(nameB, namespaceDelimIndex + 1,
433               nameB.length - (namespaceDelimIndex + 1)));
434     }
435   }
436 
437 
438   public static TableName valueOf(byte[] namespace, byte[] qualifier) {
439     if (namespace == null || namespace.length < 1) {
440       namespace = NamespaceDescriptor.DEFAULT_NAMESPACE_NAME;
441     }
442 
443     for (TableName tn : tableCache) {
444       if (Arrays.equals(tn.getQualifier(), namespace) &&
445           Arrays.equals(tn.getNamespace(), namespace)) {
446         return tn;
447       }
448     }
449 
450     return createTableNameIfNecessary(
451         ByteBuffer.wrap(namespace), ByteBuffer.wrap(qualifier));
452   }
453 
454   public static TableName valueOf(ByteBuffer namespace, ByteBuffer qualifier) {
455     if (namespace == null || namespace.remaining() < 1) {
456       return createTableNameIfNecessary(
457           ByteBuffer.wrap(NamespaceDescriptor.DEFAULT_NAMESPACE_NAME), qualifier);
458     }
459 
460     return createTableNameIfNecessary(namespace, qualifier);
461   }
462 
463   @Override
464   public boolean equals(Object o) {
465     if (this == o) return true;
466     if (o == null || getClass() != o.getClass()) return false;
467 
468     TableName tableName = (TableName) o;
469 
470     return o.hashCode() == hashCode && nameAsString.equals(tableName.nameAsString);
471   }
472 
473   @Override
474   public int hashCode() {
475     return hashCode;
476   }
477 
478   /**
479    * For performance reasons, the ordering is not lexicographic.
480    */
481   @Override
482   public int compareTo(TableName tableName) {
483     if (this == tableName) return 0;
484     if (this.hashCode < tableName.hashCode()) {
485       return -1;
486     }
487     if (this.hashCode > tableName.hashCode()) {
488       return 1;
489     }
490     return this.nameAsString.compareTo(tableName.getNameAsString());
491   }
492 
493   /**
494    * Get the appropriate row comparator for this table.
495    *
496    * @return The comparator.
497    */
498   public KVComparator getRowComparator() {
499      if(TableName.META_TABLE_NAME.equals(this)) {
500       return KeyValue.META_COMPARATOR;
501     }
502     return KeyValue.COMPARATOR;
503   }
504 }