DatabaseEntry


1   /*-
2    * See the file LICENSE for redistribution information.
3    *
4    * Copyright (c) 2002,2006 Oracle.  All rights reserved.
5    *
6    * $Id: DatabaseEntry.java,v 1.41 2006/12/04 18:47:40 cwl Exp $
7    */
8   
9   package com.sleepycat.je;
10  
11  import com.sleepycat.je.tree.TreeUtils;
12  import com.sleepycat.util.keyrange.KeyRange;
13  
14  /**
15   * Javadoc for this public class is generated
16   * via the doc templates in the doc_src directory.
17   */
18  public class DatabaseEntry {
19  
20      /* Currently, JE stores all data records as byte array */
21      private byte[] data;
22      private int dlen = 0;
23      private int doff = 0;
24      private int offset = 0;
25      private int size = 0;
26      private boolean partial = false; 
27  
28      /* The maximum number of bytes to show when toString() is called. */
29      /* FindBugs - ignore not "final" since a user can set this. */
30      public static int MAX_DUMP_BYTES = 100;
31  
32      public String   toString() {
33      StringBuffer   sb = new StringBuffer  ("<DatabaseEntry");
34      sb.append(" dlen=\"").append(dlen);
35      sb.append("\" doff=\"").append(doff);
36      sb.append("\" doff=\"").append(doff);
37      sb.append("\" offset=\"").append(offset);
38      sb.append("\" size=\"").append(size);
39      sb.append("\" data=\"").append(dumpData());
40      if ((size - 1) > MAX_DUMP_BYTES) {
41          sb.append(" ... ").append((size - MAX_DUMP_BYTES) +
42                        " bytes not shown ");
43      }
44      sb.append("\"/>");
45      return sb.toString();
46      }
47  
48      /*
49       * Constructors
50       */
51  
52      /**
53       * Javadoc for this public method is generated via
54       * the doc templates in the doc_src directory.
55       */
56      public DatabaseEntry() {
57      }
58  
59      /**
60       * Javadoc for this public method is generated via
61       * the doc templates in the doc_src directory.
62       */
63      public DatabaseEntry(byte[] data) {
64          this.data = data;
65          if (data != null) {
66              this.size = data.length;
67          }
68      }
69  
70      /**
71       * Javadoc for this public method is generated via
72       * the doc templates in the doc_src directory.
73       */
74      public DatabaseEntry(byte[] data, int offset, int size) {
75          this.data = data;
76          this.offset = offset;
77          this.size = size;
78      }
79  
80      /*
81       * Accessors
82       */
83  
84      /**
85       * Javadoc for this public method is generated via
86       * the doc templates in the doc_src directory.
87       */
88      public byte[] getData() {
89          return data;
90      }
91  
92      /**
93       * Javadoc for this public method is generated via
94       * the doc templates in the doc_src directory.
95       */
96      public void setData(byte[] data) {
97      this.data = data;
98          offset = 0;
99      size = (data == null) ? 0 : data.length;
100     }
101 
102     /**
103      * Javadoc for this public method is generated via
104      * the doc templates in the doc_src directory.
105      */
106     public void setData(byte[] data, int offset, int size) {
107     this.data = data;
108         this.offset = offset;
109         this.size = size;
110     }
111 
112     /**
113      * Javadoc for this public method is generated via
114      * the doc templates in the doc_src directory.
115      */
116     public void setPartial(int doff, int dlen, boolean partial) {
117         setPartialOffset(doff);
118         setPartialLength(dlen);
119         setPartial(partial);
120     }
121 
122     /**
123      * Javadoc for this public method is generated via
124      * the doc templates in the doc_src directory.
125      */
126     public int getPartialLength() {
127         return dlen;
128     }
129 
130     /**
131      * Javadoc for this public method is generated via
132      * the doc templates in the doc_src directory.
133      */
134     public void setPartialLength(int dlen) {
135         this.dlen = dlen;
136     }
137 
138     /**
139      * Javadoc for this public method is generated via
140      * the doc templates in the doc_src directory.
141      */
142     public int getPartialOffset() {
143         return doff;
144     }
145 
146     /**
147      * Javadoc for this public method is generated via
148      * the doc templates in the doc_src directory.
149      */
150     public void setPartialOffset(int doff) {
151         this.doff = doff;
152     }
153 
154     /**
155      * Javadoc for this public method is generated via
156      * the doc templates in the doc_src directory.
157      */
158     public boolean getPartial() {
159         return partial;
160     }
161 
162     /**
163      * Javadoc for this public method is generated via
164      * the doc templates in the doc_src directory.
165      */
166     public void setPartial(boolean partial) {
167         this.partial = partial;
168     }
169 
170     /**
171      * Javadoc for this public method is generated via
172      * the doc templates in the doc_src directory.
173      */
174     public int getOffset() {
175         return offset;
176     }
177 
178     /**
179      * Javadoc for this public method is generated via
180      * the doc templates in the doc_src directory.
181      */
182     public void setOffset(int offset) {
183         this.offset = offset;
184     }
185 
186     /**
187      * Javadoc for this public method is generated via
188      * the doc templates in the doc_src directory.
189      */
190     public int getSize() {
191         return size;
192     }
193 
194     /**
195      * Javadoc for this public method is generated via
196      * the doc templates in the doc_src directory.
197      */
198     public void setSize(int size) {
199         this.size = size;
200     }
201     
202     /**
203      * Dumps the data as a byte array, for tracing purposes
204      */
205     String   dumpData() {
206         return TreeUtils.dumpByteArray(KeyRange.getByteArray(this,
207                                  MAX_DUMP_BYTES));
208     }
209 
210     /**
211      * Compares the data of two entries for byte-by-byte equality.
212      *
213      * <p>In either entry, if the offset is non-zero or the size is not equal
214      * to the data array length, then only the data bounded by these values is
215      * compared.  The data array length and offset need not be the same in both
216      * entries for them to be considered equal.</p>
217      * 
218      * <p>If the data array is null in one entry, then to be considered equal
219      * both entries must have a null data array.</p>
220      *
221      * <p>If the partial property is set in either entry, then to be considered
222      * equal both entries must have the same partial properties: partial,
223      * partialOffset and partialLength.
224      */
225     public boolean equals(Object   o) {
226         if (!(o instanceof DatabaseEntry)) {
227             return false;
228         }
229         DatabaseEntry e = (DatabaseEntry) o;
230         if (partial || e.partial) {
231             if (partial != e.partial ||
232                 dlen != e.dlen ||
233                 doff != e.doff) {
234                 return false;
235             }
236         }
237         if (data == null && e.data == null) {
238             return true;
239         }
240         if (data == null || e.data == null) {
241             return false;
242         }
243         if (size != e.size) {
244             return false;
245         }
246         for (int i = 0; i < size; i += 1) {
247             if (data[offset + i] != e.data[e.offset + i]) {
248                 return false;
249             }
250         }
251         return true;
252     }
253 
254     /**
255      * Returns a hash code based on the data value.
256      */
257     public int hashCode() {
258         int hash = 0;
259         if (data != null) {
260             for (int i = 0; i < size; i += 1) {
261                 hash += data[offset + i];
262             }
263         }
264         return hash;
265     }
266 }
267
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