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Made counter methods and the log method synchronized 

Signed-off-by: Jim Martens <github@2martens.de>
This commit is contained in:
Jim Martens 2017-05-24 15:38:46 +02:00
parent cd7be5eac8
commit 11e3d7074b
1 changed files with 10 additions and 30 deletions
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40
04/src/PersistenceManager.java
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@ -50,9 +50,9 @@ public class PersistenceManager {
*
* @return transaction ID
*/
public int beginTransaction() {
public synchronized int beginTransaction() {
_transactions.put(_nextTransactionNumber, false);
logSimple(_nextTransactionNumber, "BOT");
log(_nextTransactionNumber, -1, "BOT", "");
// return the next transaction number and increase it by one afterwards
return _nextTransactionNumber++;
}
@ -70,7 +70,7 @@ public class PersistenceManager {
// only perform commit actions if transaction isn't commited yet
if (!_transactions.get(taid)) {
_transactions.replace(taid, true);
logSimple(taid, "COMMIT");
log(taid, -1, "COMMIT", "");
}
}
@ -96,7 +96,7 @@ public class PersistenceManager {
_transactionPageBuffer.put(taid, pageIDs);
_pageBuffer.put(pageid, data);
// log changes
int lsn = logWrite(taid, pageid, data);
int lsn = log(taid, pageid, "WRITE", data);
_pageLSN.put(pageid, lsn);
// call persist
persist();
@ -150,42 +150,22 @@ public class PersistenceManager {
}
/**
* Logs a write to the log file.
* Logs to the log file.
*
* @param taid
* affected transaction
* @param pageid
* modified page
* @param data
* written data
* @return log sequence number
*/
private int logWrite(int taid, int pageid, String data) {
try {
FileWriter fw = new FileWriter("../data/log.txt", true);
fw.write("" + _nextLogSequenceNumber + "," + taid + ",WRITE," + pageid + "," + data);
fw.write("\n");
fw.close();
} catch (IOException e) {
e.printStackTrace();
}
return _nextLogSequenceNumber++;
}
/**
* Logs a BOT to the log file.
*
* @param taid
* affected transaction
* modified page or -1 if not relevant
* @param type
* log type
* @param data
* written data or empty string if not relevant
* @return log sequence number
*/
private int logSimple(int taid, String type) {
private synchronized int log(int taid, int pageid, String type, String data) {
try {
FileWriter fw = new FileWriter("../data/log.txt", true);
fw.write("" + _nextLogSequenceNumber + "," + taid + "," + type + "\n");
fw.write("" + _nextLogSequenceNumber + "," + taid + "," + type + "," + pageid + "," + data);
fw.write("\n");
fw.close();
} catch (IOException e) {