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1 package com.quadcap.sql;
2
3
40
41 import java.io.Externalizable  ;
42 import java.io.IOException ;
43 import java.io.ObjectInput ;
44 import java.io.ObjectOutput ;
45
46 import java.sql.SQLException ;
47
48 import com.quadcap.sql.file.BlockFile;
49
50 import com.quadcap.sql.index.Btree;
51
52 import com.quadcap.util.Debug;
53 import com.quadcap.util.Util;
54
55
60 public abstract class ModIndexEntry extends LogStep implements Externalizable {
61 transient Btree index;
62 transient Constraint constraint;
63
64 String tableName;
65 String constraintName;
66
67 byte[] key;
68
69
72 public ModIndexEntry() {}
73
74 public ModIndexEntry(Session session, Constraint constraint, byte[] key) {
75 super(session);
76 this.constraint = constraint;
77 this.key = key;
78 }
79
80 Btree getIndex(Session session) throws IOException {
81 if (index == null) {
82 Database db = session.getDatabase();
83 if (constraint == null) {
84 Table table = (Table)db.getRelation(tableName);
85 constraint = table.getConstraint(constraintName);
86 if (constraint == null) {
87 throw new RuntimeException ("No constraint: " +
88 constraintName);
89 }
90 }
91 index = constraint.getIndex(db);
92 if (index == null) {
93 throw new RuntimeException ("No index for table: " + tableName);
94 }
95 }
96 return index;
97 }
98
99 abstract public void redo(Session session)
100 throws IOException , SQLException
101 ;
102
103 abstract public void undo(Session session)
104 throws IOException , SQLException
105 ;
106
107 public void prepare(Session session) throws IOException {}
108
109 public void readExternal(ObjectInput in)
110 throws IOException , ClassNotFoundException
111 {
112 super.readExternal(in);
113 tableName = (String )in.readObject();
114 constraintName = (String )in.readObject();
115 int cnt = in.readInt();
116 key = new byte[cnt];
117 in.read(key);
118 }
119
120 public void writeExternal(ObjectOutput out) throws IOException {
121 super.writeExternal(out);
122 if (tableName == null) {
123 tableName = constraint.getTable().getName();
124 constraintName = constraint.getName();
125 }
126 out.writeObject(tableName);
127 out.writeObject(constraintName);
128 out.writeInt(key.length);
129 out.write(key);
130 }
131
132 public String toString() {
134 StringBuffer sb = new StringBuffer (super.toString());
135 sb.append(" ModIndexEntry(");
136 sb.append(Util.hexBytes(key));
137 sb.append(')');
138 return sb.toString();
139 }
140 }
142
143
144 |
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