RowInputBase


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30  
31  
32  package org.hsqldb.rowio;
33  
34  import java.io.IOException  ;
35  import java.math.BigDecimal  ;
36  import java.sql.Date  ;
37  import java.sql.Time  ;
38  import java.sql.Timestamp  ;
39  
40  import org.hsqldb.HsqlException;
41  import org.hsqldb.Trace;
42  import org.hsqldb.Types;
43  import org.hsqldb.lib.HsqlByteArrayInputStream;
44  import org.hsqldb.types.Binary;
45  
46  /**
47   * Base class for reading the data for a database row in different formats.
48   * Defines the methods that are independent of storage format and declares
49   * the format-dependent methods that subclasses should define.
50   *
51   * @author sqlbob@users (RMP)
52   * @author fredt@users
53   * @version 1.7.2
54   * @since 1.7.0
55   */
56  public abstract class RowInputBase extends HsqlByteArrayInputStream {
57  
58      static final int NO_POS = -1;
59  
60      // fredt - initialisation may be unnecessary as it's done in resetRow()
61      protected int filePos = NO_POS;
62      protected int size;
63  
64      public RowInputBase() {
65          this(new byte[4]);
66      }
67  
68      /**
69       * Constructor takes a complete row
70       */
71      public RowInputBase(byte[] buf) {
72  
73          super(buf);
74  
75          size = buf.length;
76      }
77  
78      public int getPos() {
79  
80          if (filePos == NO_POS) {
81  
82  //                Trace.printSystemOut(Trace.DatabaseRowInput_getPos);
83          }
84  
85          return (filePos);
86      }
87  
88      public int getSize() {
89          return size;
90      }
91  
92  // fredt@users - comment - methods used for node and type data
93      public abstract int readIntData() throws IOException  ;
94  
95      public abstract long readLongData() throws IOException  ;
96  
97      public abstract int readType() throws IOException  ;
98  
99      public abstract String   readString() throws IOException  ;
100 
101 // fredt@users - comment - methods used for SQL types
102     protected abstract boolean checkNull() throws IOException  ;
103 
104     protected abstract String   readChar(int type)
105     throws IOException  , HsqlException;
106 
107     protected abstract Integer   readSmallint()
108     throws IOException  , HsqlException;
109 
110     protected abstract Integer   readInteger()
111     throws IOException  , HsqlException;
112 
113     protected abstract Long   readBigint() throws IOException  , HsqlException;
114 
115     protected abstract Double   readReal(int type)
116     throws IOException  , HsqlException;
117 
118     protected abstract BigDecimal   readDecimal()
119     throws IOException  , HsqlException;
120 
121     protected abstract Boolean   readBit() throws IOException  , HsqlException;
122 
123     protected abstract Time   readTime() throws IOException  , HsqlException;
124 
125     protected abstract Date   readDate() throws IOException  , HsqlException;
126 
127     protected abstract Timestamp   readTimestamp()
128     throws IOException  , HsqlException;
129 
130     protected abstract Object   readOther() throws IOException  , HsqlException;
131 
132     protected abstract Binary readBinary(int type)
133     throws IOException  , HsqlException;
134 
135     /**
136      *  reads row data from a stream using the JDBC types in colTypes
137      *
138      * @param  colTypes
139      * @return
140      * @throws  IOException
141      * @throws  HsqlException
142      */
143     public Object  [] readData(int[] colTypes)
144     throws IOException  , HsqlException {
145 
146         int      l    = colTypes.length;
147         Object  [] data = new Object  [l];
148         Object     o;
149         int      type;
150 
151         for (int i = 0; i < l; i++) {
152             if (checkNull()) {
153                 continue;
154             }
155 
156             o    = null;
157             type = colTypes[i];
158 
159             switch (type) {
160 
161                 case Types.NULL :
162                 case Types.CHAR :
163                 case Types.VARCHAR :
164                 case Types.VARCHAR_IGNORECASE :
165                 case Types.LONGVARCHAR :
166                     o = readChar(type);
167                     break;
168 
169                 case Types.TINYINT :
170                 case Types.SMALLINT :
171                     o = readSmallint();
172                     break;
173 
174                 case Types.INTEGER :
175                     o = readInteger();
176                     break;
177 
178                 case Types.BIGINT :
179                     o = readBigint();
180                     break;
181 
182                 //fredt although REAL is now Double, it is read / written in
183                 //the old format for compatibility
184                 case Types.REAL :
185                 case Types.FLOAT :
186                 case Types.DOUBLE :
187                     o = readReal(type);
188                     break;
189 
190                 case Types.NUMERIC :
191                 case Types.DECIMAL :
192                     o = readDecimal();
193                     break;
194 
195                 case Types.DATE :
196                     o = readDate();
197                     break;
198 
199                 case Types.TIME :
200                     o = readTime();
201                     break;
202 
203                 case Types.TIMESTAMP :
204                     o = readTimestamp();
205                     break;
206 
207                 case Types.BOOLEAN :
208                     o = readBit();
209                     break;
210 
211                 case Types.OTHER :
212                     o = readOther();
213                     break;
214 
215                 case Types.BINARY :
216                 case Types.VARBINARY :
217                 case Types.LONGVARBINARY :
218                     o = readBinary(type);
219                     break;
220 
221                 default :
222                     throw Trace.runtimeError(
223                         Trace.UNSUPPORTED_INTERNAL_OPERATION,
224                         "RowInputBase " + Types.getTypeString(type));
225             }
226 
227             data[i] = o;
228         }
229 
230         return data;
231     }
232 
233     /**
234      *  Used to reset the row, ready for a new row to be written into the
235      *  byte[] buffer by an external routine.
236      *
237      */
238     public void resetRow(int filepos, int rowsize) throws IOException   {
239 
240         mark = 0;
241 
242         reset();
243 
244         if (buf.length < rowsize) {
245             buf = new byte[rowsize];
246         }
247 
248         filePos = filepos;
249         size    = count = rowsize;
250         pos     = 4;
251         buf[0]  = (byte) ((rowsize >>> 24) & 0xFF);
252         buf[1]  = (byte) ((rowsize >>> 16) & 0xFF);
253         buf[2]  = (byte) ((rowsize >>> 8) & 0xFF);
254         buf[3]  = (byte) ((rowsize >>> 0) & 0xFF);
255     }
256 
257     public byte[] getBuffer() {
258         return buf;
259     }
260 
261     public int skipBytes(int n) throws IOException   {
262         throw Trace.runtimeError(Trace.UNSUPPORTED_INTERNAL_OPERATION,
263                                  "RowInputBase");
264     }
265 
266     public String   readLine() throws IOException   {
267         throw Trace.runtimeError(Trace.UNSUPPORTED_INTERNAL_OPERATION,
268                                  "RowInputBase");
269     }
270 }
271
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