Java Cursor.getPrev方法代碼示例

本文整理匯總了Java中com.sleepycat.je.Cursor.getPrev方法的典型用法代碼示例。如果您正苦於以下問題：Java Cursor.getPrev方法的具體用法？Java Cursor.getPrev怎麽用？Java Cursor.getPrev使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。您也可以進一步了解該方法所在類com.sleepycat.je.Cursor的用法示例。

在下文中一共展示了Cursor.getPrev方法的6個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的Java代碼示例。

示例1: examineGTEBucket

import com.sleepycat.je.Cursor; //導入方法依賴的package包/類
/**
 * Find a bucket that is GTE the target, and sees if that bucket is
 * the owner. If it is not the owner look at the previous bucket. 
 * @return null if no GTE bucket was found.
 */
private VLSNBucket examineGTEBucket(VLSN target, Cursor cursor) {

    /* getSearchKeyRange will return a bucket >= target if one exists */
    DatabaseEntry key = new DatabaseEntry();
    DatabaseEntry data = new DatabaseEntry();
    LongBinding.longToEntry(target.getSequence(), key);
    OperationStatus status =
        cursor.getSearchKeyRange(key, data, LockMode.DEFAULT);

    if (status == OperationStatus.SUCCESS) {
        VLSNBucket bucket = VLSNBucket.readFromDatabase(data);
        if (bucket.owns(target)) {
            return bucket;
        }

        /*
         * The bucket we found is > than our target. Look at the
         * previous one.
         */
        status = cursor.getPrev(key, data, LockMode.DEFAULT);
        if (isValidBucket(status, key)) {
            VLSNBucket prevBucket = VLSNBucket.readFromDatabase(data);
            if (prevBucket.owns(target)) {
                return prevBucket;
            }
        }

        /*
         * There is no bucket that owns this target, return the greater
         * one.
         */
        return bucket;
    } 

    /* No bucket at a key >= the target. */
    return null;
}

開發者ID:prat0318，項目名稱:dbms，代碼行數:43，代碼來源:VLSNIndex.java

示例2: positionBeforeOrEqual

import com.sleepycat.je.Cursor; //導入方法依賴的package包/類
private boolean positionBeforeOrEqual(Cursor cursor,
                                      VLSN vlsn,
                                      DatabaseEntry key,
                                      DatabaseEntry data)
    throws DatabaseException {

    LongBinding.longToEntry(vlsn.getSequence(), key);
    VLSNBucket bucket = null;

    /* getSearchKeyRange will give us a bucket >= Y. */
    OperationStatus status =
        cursor.getSearchKeyRange(key, data, LockMode.DEFAULT);

    if (status == OperationStatus.SUCCESS) {
        bucket = VLSNBucket.readFromDatabase(data);
        if (bucket.owns(vlsn)) {
            return true;
        }

        /* The bucket we found is > than our VLSN. Get the previous one. */
        status = cursor.getPrev(key, data, LockMode.DEFAULT);
        if (isValidBucket(status, key)) {
            return true;
        }

        /* Hey, nothing else in the database. */
        return false;
    }
    /*
     * There was no bucket >= Y. Let's find the last bucket in this
     * database then. It should be a bucket that's < Y.
     */
    status =  cursor.getLast(key, data, LockMode.DEFAULT);
    if (isValidBucket(status, key)) {
        return true;
    }

    return false;
}

開發者ID:prat0318，項目名稱:dbms，代碼行數:40，代碼來源:VLSNIndex.java

示例3: testGetPrev_Success

import com.sleepycat.je.Cursor; //導入方法依賴的package包/類
public void testGetPrev_Success()
    throws DatabaseException, InterruptedException {

    openEnv(false);
    DatabaseEntry key = new DatabaseEntry();
    DatabaseEntry data = new DatabaseEntry();
    OperationStatus status;

    /* Insert key 1 and 3. */
    insert(1);
    insert(3);

    /* getPrev returns key 1. */
    Transaction readerTxn = env.beginTransaction(null, txnConfig);
    Cursor cursor = db.openCursor(readerTxn, null);
    assertEquals(OperationStatus.SUCCESS, searchKey(cursor, 3));
    status = cursor.getPrev(key, data, null);
    assertEquals(OperationStatus.SUCCESS, status);
    assertEquals(1, IntegerBinding.entryToInt(key));

    /* Insertions before current position are never blocked. */
    try {
        insert(0);
    } catch (DeadlockException e) {
        fail();
    }

    /* Insert key 2 in a writer thread. */
    startInsert(2);

    /*
     * If serializable, getPrev should return key 1 again; otherwise
     * getPrev should see key 2.
     */
    assertEquals(OperationStatus.SUCCESS, searchKey(cursor, 3));
    status = cursor.getPrev(key, data, null);
    assertEquals(OperationStatus.SUCCESS, status);
    if (txnSerializable) {
        assertEquals(1, IntegerBinding.entryToInt(key));
    } else {
        assertEquals(2, IntegerBinding.entryToInt(key));
    }

    /* Close reader to allow writer to finish. */
    cursor.close();
    readerTxn.commitNoSync();
    waitForInsert();

    /* getPrev returns key 2. */
    readerTxn = env.beginTransaction(null, txnConfig);
    cursor = db.openCursor(readerTxn, null);
    assertEquals(OperationStatus.SUCCESS, searchKey(cursor, 3));
    status = cursor.getPrev(key, data, null);
    assertEquals(OperationStatus.SUCCESS, status);
    assertEquals(2, IntegerBinding.entryToInt(key));
    cursor.close();
    readerTxn.commit();

    closeEnv();
}

開發者ID:nologic，項目名稱:nabs，代碼行數:61，代碼來源:PhantomTest.java

示例4: testGetPrev_Success_Dup

import com.sleepycat.je.Cursor; //導入方法依賴的package包/類
public void testGetPrev_Success_Dup()
    throws DatabaseException, InterruptedException {

    openEnv(true);
    DatabaseEntry key = new DatabaseEntry();
    DatabaseEntry data = new DatabaseEntry();
    OperationStatus status;

    /* Insert dups. */
    insert(1, 1);
    insert(1, 3);

    /* getPrev returns {1,1}. */
    Transaction readerTxn = env.beginTransaction(null, txnConfig);
    Cursor cursor = db.openCursor(readerTxn, null);
    assertEquals(OperationStatus.SUCCESS, searchBoth(cursor, 1, 3));
    status = cursor.getPrev(key, data, null);
    assertEquals(OperationStatus.SUCCESS, status);
    assertEquals(1, IntegerBinding.entryToInt(key));
    assertEquals(1, IntegerBinding.entryToInt(data));

    /* Insertions before current position are never blocked. */
    try {
        insert(1, 0);
    } catch (DeadlockException e) {
        fail();
    }

    /* Insert {1,2} in a writer thread. */
    startInsert(1, 2);

    /*
     * If serializable, getPrev should return {1,1} again; otherwise
     * getPrev should see {1,2}.
     */
    assertEquals(OperationStatus.SUCCESS, searchBoth(cursor, 1, 3));
    status = cursor.getPrev(key, data, null);
    assertEquals(OperationStatus.SUCCESS, status);
    if (txnSerializable) {
        assertEquals(1, IntegerBinding.entryToInt(key));
        assertEquals(1, IntegerBinding.entryToInt(data));
    } else {
        assertEquals(1, IntegerBinding.entryToInt(key));
        assertEquals(2, IntegerBinding.entryToInt(data));
    }

    /* Close reader to allow writer to finish. */
    cursor.close();
    readerTxn.commitNoSync();
    waitForInsert();

    /* getPrev returns {1,2}. */
    readerTxn = env.beginTransaction(null, txnConfig);
    cursor = db.openCursor(readerTxn, null);
    assertEquals(OperationStatus.SUCCESS, searchBoth(cursor, 1, 3));
    status = cursor.getPrev(key, data, null);
    assertEquals(OperationStatus.SUCCESS, status);
    assertEquals(1, IntegerBinding.entryToInt(key));
    assertEquals(2, IntegerBinding.entryToInt(data));
    cursor.close();
    readerTxn.commit();

    closeEnv();
}

開發者ID:nologic，項目名稱:nabs，代碼行數:65，代碼來源:PhantomTest.java

示例5: testGetPrev_NotFound

import com.sleepycat.je.Cursor; //導入方法依賴的package包/類
public void testGetPrev_NotFound()
    throws DatabaseException, InterruptedException {

    openEnv(false);
    DatabaseEntry key = new DatabaseEntry();
    DatabaseEntry data = new DatabaseEntry();
    OperationStatus status;

    /* Insert key 2. */
    insert(2);

    /* getPrev returns NOTFOUND. */
    Transaction readerTxn = env.beginTransaction(null, txnConfig);
    Cursor cursor = db.openCursor(readerTxn, null);
    assertEquals(OperationStatus.SUCCESS, searchKey(cursor, 2));
    status = cursor.getPrev(key, data, null);
    assertEquals(OperationStatus.NOTFOUND, status);

    /* Insert key 1 in a writer thread. */
    startInsert(1);

    /*
     * If serializable, getPrev should return NOTFOUND again; otherwise
     * getPrev should see key 1.
     */
    assertEquals(OperationStatus.SUCCESS, searchKey(cursor, 2));
    status = cursor.getPrev(key, data, null);
    if (txnSerializable) {
        assertEquals(OperationStatus.NOTFOUND, status);
    } else {
        assertEquals(OperationStatus.SUCCESS, status);
        assertEquals(1, IntegerBinding.entryToInt(key));
    }

    /* Close reader to allow writer to finish. */
    cursor.close();
    readerTxn.commitNoSync();
    waitForInsert();

    /* getPrev returns key 1. */
    readerTxn = env.beginTransaction(null, txnConfig);
    cursor = db.openCursor(readerTxn, null);
    assertEquals(OperationStatus.SUCCESS, searchKey(cursor, 2));
    status = cursor.getPrev(key, data, null);
    assertEquals(OperationStatus.SUCCESS, status);
    assertEquals(1, IntegerBinding.entryToInt(key));
    cursor.close();
    readerTxn.commit();

    closeEnv();
}

開發者ID:nologic，項目名稱:nabs，代碼行數:52，代碼來源:PhantomTest.java

示例6: testGetPrev_NotFound_Dup

import com.sleepycat.je.Cursor; //導入方法依賴的package包/類
public void testGetPrev_NotFound_Dup()
    throws DatabaseException, InterruptedException {

    openEnv(true);
    DatabaseEntry key = new DatabaseEntry();
    DatabaseEntry data = new DatabaseEntry();
    OperationStatus status;

    /* Insert dups. */
    insert(2, 2);
    insert(2, 3);

    /* getPrev returns NOTFOUND. */
    Transaction readerTxn = env.beginTransaction(null, txnConfig);
    Cursor cursor = db.openCursor(readerTxn, null);
    assertEquals(OperationStatus.SUCCESS, searchBoth(cursor, 2, 2));
    status = cursor.getPrev(key, data, null);
    assertEquals(OperationStatus.NOTFOUND, status);

    /* Insert {2,1} in a writer thread. */
    startInsert(2, 1);

    /*
     * If serializable, getPrev should return NOTFOUND again; otherwise
     * getPrev should see {2,1}.
     */
    assertEquals(OperationStatus.SUCCESS, searchBoth(cursor, 2, 2));
    status = cursor.getPrev(key, data, null);
    if (txnSerializable) {
        assertEquals(OperationStatus.NOTFOUND, status);
    } else {
        assertEquals(OperationStatus.SUCCESS, status);
        assertEquals(2, IntegerBinding.entryToInt(key));
        assertEquals(1, IntegerBinding.entryToInt(data));
    }

    /* Close reader to allow writer to finish. */
    cursor.close();
    readerTxn.commitNoSync();
    waitForInsert();

    /* getPrev returns {2,1}. */
    readerTxn = env.beginTransaction(null, txnConfig);
    cursor = db.openCursor(readerTxn, null);
    assertEquals(OperationStatus.SUCCESS, searchBoth(cursor, 2, 2));
    status = cursor.getPrev(key, data, null);
    assertEquals(OperationStatus.SUCCESS, status);
    assertEquals(2, IntegerBinding.entryToInt(key));
    assertEquals(1, IntegerBinding.entryToInt(data));
    cursor.close();
    readerTxn.commit();

    closeEnv();
}

開發者ID:nologic，項目名稱:nabs，代碼行數:55，代碼來源:PhantomTest.java

注：本文中的com.sleepycat.je.Cursor.getPrev方法示例由純淨天空整理自Github/MSDocs等開源代碼及文檔管理平台，相關代碼片段篩選自各路編程大神貢獻的開源項目，源碼版權歸原作者所有，傳播和使用請參考對應項目的License；未經允許，請勿轉載。