org.rocksdb

接口 WriteBatchInterface

所有已知实现类:

AbstractWriteBatch, WriteBatch, WriteBatchWithIndex

public interface WriteBatchInterface

Defines the interface for a Write Batch which holds a collection of updates to apply atomically to a DB.

方法概要

限定符和类型	方法和说明
void	clear() Clear all updates buffered in this batch
int	count() Returns the number of updates in the batch.
void	delete(byte[] key) If the database contains a mapping for "key", erase it.
void	delete(java.nio.ByteBuffer key) If column family contains a mapping for "key", erase it.
void	delete(ColumnFamilyHandle columnFamilyHandle, byte[] key) If column family contains a mapping for "key", erase it.
void	delete(ColumnFamilyHandle columnFamilyHandle, java.nio.ByteBuffer key) If column family contains a mapping for "key", erase it.
void	deleteRange(byte[] beginKey, byte[] endKey) Removes the database entries in the range ["beginKey", "endKey"), i.e., including "beginKey" and excluding "endKey". a non-OK status on error.
void	deleteRange(ColumnFamilyHandle columnFamilyHandle, byte[] beginKey, byte[] endKey) Removes the database entries in the range ["beginKey", "endKey"), i.e., including "beginKey" and excluding "endKey". a non-OK status on error.
WriteBatch	getWriteBatch() Get the underlying Write Batch.
void	merge(byte[] key, byte[] value) Merge "value" with the existing value of "key" in the database.
void	merge(ColumnFamilyHandle columnFamilyHandle, byte[] key, byte[] value) Merge "value" with the existing value of "key" in given column family.
void	popSavePoint() Pop the most recent save point.
void	put(byte[] key, byte[] value) Store the mapping "key->value" in the database.
void	put(java.nio.ByteBuffer key, java.nio.ByteBuffer value) Store the mapping "key->value" within given column family.
void	put(ColumnFamilyHandle columnFamilyHandle, byte[] key, byte[] value) Store the mapping "key->value" within given column family.
void	put(ColumnFamilyHandle columnFamilyHandle, java.nio.ByteBuffer key, java.nio.ByteBuffer value) Store the mapping "key->value" within given column family.
void	putLogData(byte[] blob) Append a blob of arbitrary size to the records in this batch.
void	rollbackToSavePoint() Remove all entries in this batch (Put, Merge, Delete, PutLogData) since the most recent call to SetSavePoint() and removes the most recent save point.
void	setMaxBytes(long maxBytes) Set the maximum size of the write batch.
void	setSavePoint() Records the state of the batch for future calls to RollbackToSavePoint().
void	singleDelete(byte[] key) Remove the database entry for key.
void	singleDelete(ColumnFamilyHandle columnFamilyHandle, byte[] key) Remove the database entry for key.

方法详细资料

count

int count()

Returns the number of updates in the batch.

返回:

number of items in WriteBatch

put

void put(byte[] key,
         byte[] value)
  throws RocksDBException

Store the mapping "key->value" in the database.

参数:

key - the specified key to be inserted.

value - the value associated with the specified key.

抛出:

RocksDBException - thrown if error happens in underlying native library.

put

void put(ColumnFamilyHandle columnFamilyHandle,
         byte[] key,
         byte[] value)
  throws RocksDBException

Store the mapping "key->value" within given column family.

参数:

columnFamilyHandle - ColumnFamilyHandle instance

key - the specified key to be inserted.

value - the value associated with the specified key.

抛出:

RocksDBException - thrown if error happens in underlying native library.

put

void put(java.nio.ByteBuffer key,
         java.nio.ByteBuffer value)
  throws RocksDBException

Store the mapping "key->value" within given column family.

参数:

key - the specified key to be inserted. It is using position and limit. Supports direct buffer only.

value - the value associated with the specified key. It is using position and limit. Supports direct buffer only.

抛出:

RocksDBException - thrown if error happens in underlying native library.

put

void put(ColumnFamilyHandle columnFamilyHandle,
         java.nio.ByteBuffer key,
         java.nio.ByteBuffer value)
  throws RocksDBException

Store the mapping "key->value" within given column family.

参数:

columnFamilyHandle - ColumnFamilyHandle instance

key - the specified key to be inserted. It is using position and limit. Supports direct buffer only.

value - the value associated with the specified key. It is using position and limit. Supports direct buffer only.

抛出:

RocksDBException - thrown if error happens in underlying native library.

merge

void merge(byte[] key,
           byte[] value)
    throws RocksDBException

Merge "value" with the existing value of "key" in the database. "key->merge(existing, value)"

参数:

key - the specified key to be merged.

value - the value to be merged with the current value for the specified key.

抛出:

RocksDBException - thrown if error happens in underlying native library.

merge

void merge(ColumnFamilyHandle columnFamilyHandle,
           byte[] key,
           byte[] value)
    throws RocksDBException

Merge "value" with the existing value of "key" in given column family. "key->merge(existing, value)"

参数:

columnFamilyHandle - ColumnFamilyHandle instance

key - the specified key to be merged.

value - the value to be merged with the current value for the specified key.

抛出:

RocksDBException - thrown if error happens in underlying native library.

delete

void delete(byte[] key)
     throws RocksDBException

If the database contains a mapping for "key", erase it. Else do nothing.

参数:

key - Key to delete within database

抛出:

RocksDBException - thrown if error happens in underlying native library.

delete

void delete(ColumnFamilyHandle columnFamilyHandle,
            byte[] key)
     throws RocksDBException

If column family contains a mapping for "key", erase it. Else do nothing.

参数:

columnFamilyHandle - ColumnFamilyHandle instance

key - Key to delete within database

抛出:

RocksDBException - thrown if error happens in underlying native library.

delete

void delete(java.nio.ByteBuffer key)
     throws RocksDBException

If column family contains a mapping for "key", erase it. Else do nothing.

参数:

key - Key to delete within database. It is using position and limit. Supports direct buffer only.

抛出:

RocksDBException - thrown if error happens in underlying native library.

delete

void delete(ColumnFamilyHandle columnFamilyHandle,
            java.nio.ByteBuffer key)
     throws RocksDBException

If column family contains a mapping for "key", erase it. Else do nothing.

参数:

columnFamilyHandle - ColumnFamilyHandle instance

key - Key to delete within database. It is using position and limit. Supports direct buffer only.

抛出:

RocksDBException - thrown if error happens in underlying native library.

singleDelete

@Experimental(value="Performance optimization for a very specific workload")
void singleDelete(byte[] key)
                                                                                        throws RocksDBException

Remove the database entry for key. Requires that the key exists and was not overwritten. It is not an error if the key did not exist in the database.

If a key is overwritten (by calling put(byte[], byte[]) multiple times), then the result of calling SingleDelete() on this key is undefined. SingleDelete() only behaves correctly if there has been only one Put() for this key since the previous call to SingleDelete() for this key.

This feature is currently an experimental performance optimization for a very specific workload. It is up to the caller to ensure that SingleDelete is only used for a key that is not deleted using Delete() or written using Merge(). Mixing SingleDelete operations with Deletes and Merges can result in undefined behavior.

参数:

key - Key to delete within database

抛出:

RocksDBException - thrown if error happens in underlying native library.

singleDelete

@Experimental(value="Performance optimization for a very specific workload")
void singleDelete(ColumnFamilyHandle columnFamilyHandle,
                                                                                               byte[] key)
                                                                                        throws RocksDBException

Remove the database entry for key. Requires that the key exists and was not overwritten. It is not an error if the key did not exist in the database.

If a key is overwritten (by calling put(byte[], byte[]) multiple times), then the result of calling SingleDelete() on this key is undefined. SingleDelete() only behaves correctly if there has been only one Put() for this key since the previous call to SingleDelete() for this key.

This feature is currently an experimental performance optimization for a very specific workload. It is up to the caller to ensure that SingleDelete is only used for a key that is not deleted using Delete() or written using Merge(). Mixing SingleDelete operations with Deletes and Merges can result in undefined behavior.

参数:

columnFamilyHandle - The column family to delete the key from

key - Key to delete within database

抛出:

RocksDBException - thrown if error happens in underlying native library.

deleteRange

void deleteRange(byte[] beginKey,
                 byte[] endKey)
          throws RocksDBException

Removes the database entries in the range ["beginKey", "endKey"), i.e., including "beginKey" and excluding "endKey". a non-OK status on error. It is not an error if no keys exist in the range ["beginKey", "endKey").

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

参数:

beginKey - First key to delete within database (included)

endKey - Last key to delete within database (excluded)

抛出:

RocksDBException - thrown if error happens in underlying native library.

deleteRange

void deleteRange(ColumnFamilyHandle columnFamilyHandle,
                 byte[] beginKey,
                 byte[] endKey)
          throws RocksDBException

Removes the database entries in the range ["beginKey", "endKey"), i.e., including "beginKey" and excluding "endKey". a non-OK status on error. It is not an error if no keys exist in the range ["beginKey", "endKey").

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

参数:

columnFamilyHandle - ColumnFamilyHandle instance

beginKey - First key to delete within database (included)

endKey - Last key to delete within database (excluded)

抛出:

RocksDBException - thrown if error happens in underlying native library.

putLogData

void putLogData(byte[] blob)
         throws RocksDBException

Append a blob of arbitrary size to the records in this batch. The blob will be stored in the transaction log but not in any other file. In particular, it will not be persisted to the SST files. When iterating over this WriteBatch, WriteBatch::Handler::LogData will be called with the contents of the blob as it is encountered. Blobs, puts, deletes, and merges will be encountered in the same order in which they were inserted. The blob will NOT consume sequence number(s) and will NOT increase the count of the batch

Example application: add timestamps to the transaction log for use in replication.

参数:

blob - binary object to be inserted

抛出:

RocksDBException - thrown if error happens in underlying native library.

clear

void clear()

Clear all updates buffered in this batch

setSavePoint

void setSavePoint()

Records the state of the batch for future calls to RollbackToSavePoint(). May be called multiple times to set multiple save points.

rollbackToSavePoint

void rollbackToSavePoint()
                  throws RocksDBException

Remove all entries in this batch (Put, Merge, Delete, PutLogData) since the most recent call to SetSavePoint() and removes the most recent save point.

抛出:

RocksDBException - if there is no previous call to SetSavePoint()

popSavePoint

void popSavePoint()
           throws RocksDBException

Pop the most recent save point.

That is to say that it removes the last save point, which was set by setSavePoint().

抛出:

RocksDBException - If there is no previous call to setSavePoint(), an exception with Status.Code.NotFound will be thrown.

setMaxBytes

void setMaxBytes(long maxBytes)

Set the maximum size of the write batch.

参数:

maxBytes - the maximum size in bytes.

getWriteBatch

WriteBatch getWriteBatch()

Get the underlying Write Batch.

返回:

the underlying WriteBatch.