| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.store.raw.log.CheckpointOperation |
| 4 | |
| 5 | Copyright 1997, 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.store.raw.log; |
| 22 | |
| 23 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 24 | import org.apache.derby.iapi.services.io.Formatable; |
| 25 | import org.apache.derby.iapi.services.io.FormatIdUtil; |
| 26 | import org.apache.derby.iapi.services.io.StoredFormatIds; |
| 27 | import org.apache.derby.catalog.UUID; |
| 28 | |
| 29 | import org.apache.derby.iapi.store.raw.Transaction; |
| 30 | import org.apache.derby.iapi.store.raw.Loggable; |
| 31 | import org.apache.derby.iapi.store.raw.log.LogInstant; |
| 32 | import org.apache.derby.iapi.store.raw.log.LogFactory; |
| 33 | import org.apache.derby.iapi.store.raw.xact.RawTransaction; |
| 34 | |
| 35 | import org.apache.derby.iapi.error.StandardException; |
| 36 | |
| 37 | import org.apache.derby.iapi.services.io.CompressedNumber; |
| 38 | import org.apache.derby.iapi.util.ByteArray; |
| 39 | |
| 40 | import java.io.Externalizable; |
| 41 | import java.io.OutputStream; |
| 42 | import java.io.InputStream; |
| 43 | import java.io.ObjectInput; |
| 44 | import java.io.ObjectOutput; |
| 45 | import java.io.IOException; |
| 46 | import org.apache.derby.iapi.services.io.LimitObjectInput; |
| 47 | |
| 48 | /** |
| 49 | A Log Operation that represents a checkpoint. |
| 50 | @see Loggable |
| 51 | */ |
| 52 | |
| 53 | public class CheckpointOperation implements Loggable |
| 54 | { |
| 55 | |
| 56 | // redo LWM |
| 57 | protected long redoLWM; |
| 58 | |
| 59 | // undo LWM |
| 60 | protected long undoLWM; |
| 61 | |
| 62 | protected Formatable transactionTable; |
| 63 | |
| 64 | public CheckpointOperation(long redoLWM, long undoLWM, Formatable ttab) |
| 65 | { |
| 66 | this.redoLWM = redoLWM; |
| 67 | this.undoLWM = undoLWM; |
| 68 | this.transactionTable = ttab; |
| 69 | } |
| 70 | |
| 71 | /* |
| 72 | * Formatable methods |
| 73 | */ |
| 74 | |
| 75 | // no-arg constructor, required by Formatable |
| 76 | public CheckpointOperation() { super(); } |
| 77 | |
| 78 | public void writeExternal(ObjectOutput out) throws IOException |
| 79 | { |
| 80 | CompressedNumber.writeLong(out, redoLWM); |
| 81 | CompressedNumber.writeLong(out, undoLWM); |
| 82 | // RESOLVE: Following write Not needed, keeping it to avoid upgrade/downgrade issues. |
| 83 | CompressedNumber.writeInt(out, 0); // no other truncation LWM |
| 84 | |
| 85 | if (transactionTable == null) |
| 86 | CompressedNumber.writeInt(out, 0); |
| 87 | else |
| 88 | { |
| 89 | CompressedNumber.writeInt(out, 1); |
| 90 | out.writeObject(transactionTable); |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException |
| 95 | { |
| 96 | redoLWM = CompressedNumber.readLong(in); |
| 97 | undoLWM = CompressedNumber.readLong(in); |
| 98 | |
| 99 | // RESOLVE: Following read Not required, keeping it to avoid upgrade/downgrade issues. |
| 100 | int tsize = CompressedNumber.readInt(in); // is there any truncationLWM? |
| 101 | |
| 102 | int haveTTab = CompressedNumber.readInt(in); |
| 103 | if (haveTTab == 1) |
| 104 | transactionTable = (Formatable)in.readObject(); |
| 105 | else |
| 106 | transactionTable = (Formatable)null; |
| 107 | } |
| 108 | |
| 109 | /** |
| 110 | Return my format identifier. |
| 111 | */ |
| 112 | public int getTypeFormatId() { |
| 113 | return StoredFormatIds.LOGOP_CHECKPOINT; |
| 114 | } |
| 115 | |
| 116 | /** |
| 117 | Loggable methods |
| 118 | */ |
| 119 | |
| 120 | /** |
| 121 | * Nothing to do unless we are rollforward recovery; |
| 122 | * Redoing of checkpoints during rollforward recovery allows us to restart |
| 123 | * the roll-forward recovery from the last checkpoint redone during rollforward recovery, if |
| 124 | * we happen to crash during the roll-forward recovery process. |
| 125 | * Another reason why we need to do this is dropped table stub files |
| 126 | * removed at checkpoint because the containerids may have been reused |
| 127 | * after a checkpoint if the system was rebooted. |
| 128 | */ |
| 129 | public void doMe(Transaction xact, LogInstant instant, LimitObjectInput in) throws StandardException |
| 130 | { |
| 131 | //redo the checkpoint if we are in roll-forward recovery only |
| 132 | if(((RawTransaction)xact).inRollForwardRecovery()) |
| 133 | { |
| 134 | ((RawTransaction)xact).checkpointInRollForwardRecovery(instant, redoLWM); |
| 135 | } |
| 136 | return; |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | the default for prepared log is always null for all the operations |
| 141 | that don't have optionalData. If an operation has optional data, |
| 142 | the operation need to prepare the optional data for this method. |
| 143 | |
| 144 | Checkpoint has no optional data to write out |
| 145 | */ |
| 146 | public ByteArray getPreparedLog() |
| 147 | { |
| 148 | return (ByteArray) null; |
| 149 | } |
| 150 | |
| 151 | /** |
| 152 | Checkpoint does not need to be redone unless |
| 153 | we are doing rollforward recovery. |
| 154 | */ |
| 155 | public boolean needsRedo(Transaction xact) |
| 156 | { |
| 157 | |
| 158 | if(((RawTransaction)xact).inRollForwardRecovery()) |
| 159 | return true; |
| 160 | else |
| 161 | return false; |
| 162 | } |
| 163 | |
| 164 | |
| 165 | /** |
| 166 | Checkpoint has not resource to release |
| 167 | */ |
| 168 | public void releaseResource(Transaction xact) |
| 169 | {} |
| 170 | |
| 171 | /** |
| 172 | Checkpoint is a raw store operation |
| 173 | */ |
| 174 | public int group() |
| 175 | { |
| 176 | return Loggable.RAWSTORE; |
| 177 | } |
| 178 | |
| 179 | /** |
| 180 | Access attributes of the checkpoint record |
| 181 | */ |
| 182 | public long redoLWM() |
| 183 | { |
| 184 | return redoLWM; |
| 185 | } |
| 186 | |
| 187 | public long undoLWM() |
| 188 | { |
| 189 | return undoLWM; |
| 190 | } |
| 191 | |
| 192 | |
| 193 | public Formatable getTransactionTable() |
| 194 | { |
| 195 | return transactionTable; |
| 196 | } |
| 197 | |
| 198 | /** |
| 199 | DEBUG: Print self. |
| 200 | */ |
| 201 | public String toString() |
| 202 | { |
| 203 | if (SanityManager.DEBUG) |
| 204 | { |
| 205 | LogCounter undolwm = new LogCounter(undoLWM); |
| 206 | LogCounter redolwm = new LogCounter(redoLWM); |
| 207 | |
| 208 | StringBuffer str = new StringBuffer(1000) |
| 209 | .append("Checkpoint : \tredoLWM ") |
| 210 | .append(redolwm.toString()) |
| 211 | .append("\n\t\tundoLWM ").append(undolwm.toString()); |
| 212 | |
| 213 | if (transactionTable != null) |
| 214 | { |
| 215 | str.append(transactionTable.toString()); |
| 216 | } |
| 217 | |
| 218 | return str.toString(); |
| 219 | } |
| 220 | else |
| 221 | return null; |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | |
| 226 | |
| 227 | |
| 228 | |
| 229 | |
| 230 | |
| 231 | |
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| 235 | |