| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.sql.CursorInfo |
| 4 | |
| 5 | Copyright 1999, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.impl.sql; |
| 22 | |
| 23 | import org.apache.derby.iapi.sql.ResultColumnDescriptor; |
| 24 | import org.apache.derby.iapi.sql.execute.ExecCursorTableReference; |
| 25 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 26 | |
| 27 | import org.apache.derby.iapi.services.io.ArrayUtil; |
| 28 | import org.apache.derby.iapi.services.io.StoredFormatIds; |
| 29 | import org.apache.derby.iapi.services.io.FormatIdUtil; |
| 30 | import org.apache.derby.iapi.services.io.Formatable; |
| 31 | |
| 32 | import java.io.ObjectOutput; |
| 33 | import java.io.ObjectInput; |
| 34 | import java.io.IOException; |
| 35 | /** |
| 36 | * A basic holder for information about cursors |
| 37 | * for execution. |
| 38 | * |
| 39 | * @author jamie |
| 40 | */ |
| 41 | public class CursorInfo |
| 42 | implements Formatable |
| 43 | { |
| 44 | |
| 45 | /******************************************************** |
| 46 | ** |
| 47 | ** This class implements Formatable. That means that it |
| 48 | ** can write itself to and from a formatted stream. If |
| 49 | ** you add more fields to this class, make sure that you |
| 50 | ** also write/read them with the writeExternal()/readExternal() |
| 51 | ** methods. |
| 52 | ** |
| 53 | ** If, inbetween releases, you add more fields to this class, |
| 54 | ** then you should bump the version number emitted by the getTypeFormatId() |
| 55 | ** method. |
| 56 | ** |
| 57 | ********************************************************/ |
| 58 | |
| 59 | ExecCursorTableReference targetTable; |
| 60 | ResultColumnDescriptor[] targetColumns; |
| 61 | String[] updateColumns; |
| 62 | int updateMode; |
| 63 | |
| 64 | /** |
| 65 | * Niladic constructor for Formatable |
| 66 | */ |
| 67 | public CursorInfo() |
| 68 | { |
| 69 | } |
| 70 | |
| 71 | /** |
| 72 | * |
| 73 | */ |
| 74 | public CursorInfo |
| 75 | ( |
| 76 | int updateMode, |
| 77 | ExecCursorTableReference targetTable, |
| 78 | ResultColumnDescriptor[] targetColumns, |
| 79 | String[] updateColumns |
| 80 | ) |
| 81 | { |
| 82 | this.updateMode = updateMode; |
| 83 | this.targetTable = targetTable; |
| 84 | this.targetColumns = targetColumns; |
| 85 | this.updateColumns = updateColumns; |
| 86 | } |
| 87 | |
| 88 | ////////////////////////////////////////////// |
| 89 | // |
| 90 | // FORMATABLE |
| 91 | // |
| 92 | ////////////////////////////////////////////// |
| 93 | /** |
| 94 | * Write this object out |
| 95 | * |
| 96 | * @param out write bytes here |
| 97 | * |
| 98 | * @exception IOException thrown on error |
| 99 | */ |
| 100 | public void writeExternal(ObjectOutput out) throws IOException |
| 101 | { |
| 102 | out.writeInt(updateMode); |
| 103 | out.writeObject(targetTable); |
| 104 | ArrayUtil.writeArray(out, targetColumns); |
| 105 | ArrayUtil.writeArray(out, updateColumns); |
| 106 | } |
| 107 | |
| 108 | /** |
| 109 | * Read this object from a stream of stored objects. |
| 110 | * |
| 111 | * @param in read this. |
| 112 | * |
| 113 | * @exception IOException thrown on error |
| 114 | * @exception ClassNotFoundException thrown on error |
| 115 | */ |
| 116 | public void readExternal(ObjectInput in) |
| 117 | throws IOException, ClassNotFoundException |
| 118 | { |
| 119 | updateMode = in.readInt(); |
| 120 | targetTable = (ExecCursorTableReference)in.readObject(); |
| 121 | int len = ArrayUtil.readArrayLength(in); |
| 122 | if (len != 0) |
| 123 | { |
| 124 | targetColumns = new ResultColumnDescriptor[len]; |
| 125 | ArrayUtil.readArrayItems(in, targetColumns); |
| 126 | } |
| 127 | len = ArrayUtil.readArrayLength(in); |
| 128 | if (len != 0) |
| 129 | { |
| 130 | updateColumns = new String[len]; |
| 131 | ArrayUtil.readArrayItems(in, updateColumns); |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | /** |
| 136 | * Get the formatID which corresponds to this class. |
| 137 | * |
| 138 | * @return the formatID of this class |
| 139 | */ |
| 140 | public int getTypeFormatId() { return StoredFormatIds.CURSOR_INFO_V01_ID; } |
| 141 | |
| 142 | public String toString() |
| 143 | { |
| 144 | if (SanityManager.DEBUG) |
| 145 | { |
| 146 | StringBuffer strbuf = new StringBuffer(); |
| 147 | |
| 148 | strbuf.append("CursorInfo"+ |
| 149 | "\n\tupdateMode: "+updateMode+ |
| 150 | "\n\ttargetTable: "+targetTable+ |
| 151 | "\n\tupdateColumns: "); |
| 152 | |
| 153 | if (updateColumns == null) |
| 154 | { |
| 155 | strbuf.append("NULL\n"); |
| 156 | } |
| 157 | else |
| 158 | { |
| 159 | strbuf.append("{"); |
| 160 | for (int i = 0; i < updateColumns.length; i++) |
| 161 | { |
| 162 | if (i > 0) |
| 163 | strbuf.append(","); |
| 164 | strbuf.append(updateColumns[i]); |
| 165 | } |
| 166 | strbuf.append(")\n"); |
| 167 | } |
| 168 | |
| 169 | strbuf.append("\tTargetColumnDescriptors: \n"); |
| 170 | if (targetColumns == null) |
| 171 | { |
| 172 | strbuf.append("NULL"); |
| 173 | } |
| 174 | else |
| 175 | { |
| 176 | for (int i = 0; i < targetColumns.length; i++) |
| 177 | { |
| 178 | strbuf.append(targetColumns[i]); |
| 179 | } |
| 180 | strbuf.append("\n"); |
| 181 | } |
| 182 | return strbuf.toString(); |
| 183 | } |
| 184 | else |
| 185 | { |
| 186 | return ""; |
| 187 | } |
| 188 | } |
| 189 | } |