LedgerHandle (bookkeeper 4.4.0-SNAPSHOT API)

java.lang.Object
- org.apache.bookkeeper.client.LedgerHandle

```
public class LedgerHandle
extends Object
```
Ledger handle contains ledger metadata and is used to access the read and write operations to a ledger.

Field Summary

Fields
Modifier and Type Field and Description

static long INVALID_ENTRY_ID
Invalid entry id.

Fields
Modifier and Type	Field and Description
`static long`	`INVALID_ENTRY_ID` Invalid entry id.

Method Summary

Methods
Modifier and Type	Method and Description
`long`	`addEntry(byte[] data)` Add entry synchronously to an open ledger.
`long`	`addEntry(byte[] data, int offset, int length)` Add entry synchronously to an open ledger.
`void`	`asyncAddEntry(byte[] data, AsyncCallback.AddCallback cb, Object ctx)` Add entry asynchronously to an open ledger.
`void`	`asyncAddEntry(byte[] data, int offset, int length, AsyncCallback.AddCallback cb, Object ctx)` Add entry asynchronously to an open ledger, using an offset and range.
`void`	`asyncClose(AsyncCallback.CloseCallback cb, Object ctx)` Asynchronous close, any adds in flight will return errors.
`void`	`asyncReadEntries(long firstEntry, long lastEntry, AsyncCallback.ReadCallback cb, Object ctx)` Read a sequence of entries asynchronously.
`void`	`asyncReadLastConfirmed(AsyncCallback.ReadLastConfirmedCallback cb, Object ctx)` Obtains asynchronously the last confirmed write from a quorum of bookies.
`void`	`asyncTryReadLastConfirmed(AsyncCallback.ReadLastConfirmedCallback cb, Object ctx)` Obtains asynchronously the last confirmed write from a quorum of bookies.
`void`	`close()` Close this ledger synchronously.
`long`	`getId()` Get the id of the current ledger
`long`	`getLastAddConfirmed()` Get the last confirmed entry id on this ledger.
`long`	`getLastAddPushed()` Get the entry id of the last entry that has been enqueued for addition (but may not have possibly been persited to the ledger)
`byte[]`	`getLedgerKey()` Get the Ledger's key/password.
`long`	`getLength()` Returns the length of the ledger in bytes.
`boolean`	`isClosed()` Has the ledger been closed?
`Enumeration<LedgerEntry>`	`readEntries(long firstEntry, long lastEntry)` Read a sequence of entries synchronously.
`long`	`readLastConfirmed()` Obtains synchronously the last confirmed write from a quorum of bookies.
`long`	`tryReadLastConfirmed()` Obtains synchronously the last confirmed write from a quorum of bookies.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - INVALID_ENTRY_ID
```
public static final long INVALID_ENTRY_ID
```
    Invalid entry id. This value is returned from methods which should return an entry id but there is no valid entry available.
    
    See Also:
    Constant Field Values
- Method Detail
  - getId
```
public long getId()
```
    Get the id of the current ledger
    
    Returns:
    the id of the ledger
  - getLastAddConfirmed
```
public long getLastAddConfirmed()
```
    Get the last confirmed entry id on this ledger. It reads the local state of the ledger handle, which is different from the readLastConfirmed call. In the case the ledger is not closed and the client is a reader, it is necessary to call readLastConfirmed to obtain an estimate of the last add operation that has been confirmed.
    
    Returns:
    the last confirmed entry id or INVALID_ENTRY_ID if no entry has been confirmed
    See Also:
    readLastConfirmed()
  - getLastAddPushed
```
public long getLastAddPushed()
```
    Get the entry id of the last entry that has been enqueued for addition (but may not have possibly been persited to the ledger)
    
    Returns:
    the id of the last entry pushed or INVALID_ENTRY_ID if no entry has been pushed
  - getLedgerKey
```
public byte[] getLedgerKey()
```
    Get the Ledger's key/password.
    
    Returns:
    byte array for the ledger's key/password.
  - getLength
```
public long getLength()
```
    Returns the length of the ledger in bytes.
    
    Returns:
    the length of the ledger in bytes
  - close
```
public void close()
           throws InterruptedException,
                  BKException
```
    Close this ledger synchronously.
    
    Throws:
    
    InterruptedException
    
    BKException
    See Also:
    asyncClose(org.apache.bookkeeper.client.AsyncCallback.CloseCallback, java.lang.Object)
  - asyncClose
```
public void asyncClose(AsyncCallback.CloseCallback cb,
              Object ctx)
```
    Asynchronous close, any adds in flight will return errors. Closing a ledger will ensure that all clients agree on what the last entry of the ledger is. This ensures that, once the ledger has been closed, all reads from the ledger will return the same set of entries.
    
    Parameters:
    cb - callback implementation
    ctx - control object
  - isClosed
```
public boolean isClosed()
```
    Has the ledger been closed?
  - readEntries
```
public Enumeration<LedgerEntry> readEntries(long firstEntry,
                                   long lastEntry)
                                     throws InterruptedException,
                                            BKException
```
    Read a sequence of entries synchronously.
    
    Parameters:
    firstEntry - id of first entry of sequence (included)
    lastEntry - id of last entry of sequence (included)
    
    Throws:
    
    InterruptedException
    
    BKException
  - asyncReadEntries
```
public void asyncReadEntries(long firstEntry,
                    long lastEntry,
                    AsyncCallback.ReadCallback cb,
                    Object ctx)
```
    Read a sequence of entries asynchronously.
    
    Parameters:
    firstEntry - id of first entry of sequence
    lastEntry - id of last entry of sequence
    cb - object implementing read callback interface
    ctx - control object
  - addEntry
```
public long addEntry(byte[] data)
              throws InterruptedException,
                     BKException
```
    Add entry synchronously to an open ledger.
    
    Parameters:
    data - array of bytes to be written to the ledger
    
    Returns:
    the entryId of the new inserted entry
    
    Throws:
    
    InterruptedException
    
    BKException
  - addEntry
```
public long addEntry(byte[] data,
            int offset,
            int length)
              throws InterruptedException,
                     BKException
```
    Add entry synchronously to an open ledger.
    
    Parameters:
    data - array of bytes to be written to the ledger
    offset - offset from which to take bytes from data
    length - number of bytes to take from data
    
    Returns:
    the entryId of the new inserted entry
    
    Throws:
    
    InterruptedException
    
    BKException
  - asyncAddEntry
```
public void asyncAddEntry(byte[] data,
                 AsyncCallback.AddCallback cb,
                 Object ctx)
```
    Add entry asynchronously to an open ledger.
    
    Parameters:
    data - array of bytes to be written
    cb - object implementing callbackinterface
    ctx - some control object
  - asyncAddEntry
```
public void asyncAddEntry(byte[] data,
                 int offset,
                 int length,
                 AsyncCallback.AddCallback cb,
                 Object ctx)
```
    Add entry asynchronously to an open ledger, using an offset and range.
    
    Parameters:
    data - array of bytes to be written
    offset - offset from which to take bytes from data
    length - number of bytes to take from data
    cb - object implementing callbackinterface
    ctx - some control object
    
    Throws:
    
    ArrayIndexOutOfBoundsException - if offset or length is negative or offset and length sum to a value higher than the length of data.
  - asyncReadLastConfirmed
```
public void asyncReadLastConfirmed(AsyncCallback.ReadLastConfirmedCallback cb,
                          Object ctx)
```
    Obtains asynchronously the last confirmed write from a quorum of bookies. This call obtains the the last add confirmed each bookie has received for this ledger and returns the maximum. If the ledger has been closed, the value returned by this call may not correspond to the id of the last entry of the ledger, since it reads the hint of bookies. Consequently, in the case the ledger has been closed, it may return a different value than getLastAddConfirmed, which returns the local value of the ledger handle.
    
    Parameters:
    cb -
    ctx -
    See Also:
    getLastAddConfirmed()
  - asyncTryReadLastConfirmed
```
public void asyncTryReadLastConfirmed(AsyncCallback.ReadLastConfirmedCallback cb,
                             Object ctx)
```
    Obtains asynchronously the last confirmed write from a quorum of bookies. It is similar as asyncTryReadLastConfirmed(org.apache.bookkeeper.client.AsyncCallback.ReadLastConfirmedCallback, Object), but it doesn't wait all the responses from the quorum. It would callback immediately if it received a LAC which is larger than current LAC.
    
    Parameters:
    cb - callback to return read last confirmed
    ctx - callback context
    See Also:
    asyncTryReadLastConfirmed(org.apache.bookkeeper.client.AsyncCallback.ReadLastConfirmedCallback, Object)
  - readLastConfirmed
```
public long readLastConfirmed()
                       throws InterruptedException,
                              BKException
```
    Obtains synchronously the last confirmed write from a quorum of bookies. This call obtains the the last add confirmed each bookie has received for this ledger and returns the maximum. If the ledger has been closed, the value returned by this call may not correspond to the id of the last entry of the ledger, since it reads the hint of bookies. Consequently, in the case the ledger has been closed, it may return a different value than getLastAddConfirmed, which returns the local value of the ledger handle.
    
    Returns:
    The entry id of the last confirmed write or INVALID_ENTRY_ID if no entry has been confirmed
    
    Throws:
    
    InterruptedException
    
    BKException
    See Also:
    getLastAddConfirmed()
  - tryReadLastConfirmed
```
public long tryReadLastConfirmed()
                          throws InterruptedException,
                                 BKException
```
    Obtains synchronously the last confirmed write from a quorum of bookies. It is similar as readLastConfirmed(), but it doesn't wait all the responses from the quorum. It would callback immediately if it received a LAC which is larger than current LAC.
    
    Returns:
    The entry id of the last confirmed write or INVALID_ENTRY_ID if no entry has been confirmed
    
    Throws:
    
    InterruptedException
    
    BKException
    See Also:
    readLastConfirmed()

Class LedgerHandle

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

INVALID_ENTRY_ID

Method Detail

getId

getLastAddConfirmed

getLastAddPushed

getLedgerKey

getLength

close

asyncClose

isClosed

readEntries

asyncReadEntries

addEntry

addEntry

asyncAddEntry

asyncAddEntry

asyncReadLastConfirmed

asyncTryReadLastConfirmed

readLastConfirmed

tryReadLastConfirmed