io.github.whippetdb.db.internal

Class DbProxy

java.lang.Object

io.github.whippetdb.db.internal.DbProxy

All Implemented Interfaces:

Db

public class DbProxy
extends java.lang.Object
implements Db

Nested Class Summary

Nested classes/interfaces inherited from interface io.github.whippetdb.db.api.Db

Db.PutHandler<T>, Db.ScanHandler, Db.SeekHandler<T>, Db.Type

Constructor Summary

Constructors

Constructor and Description
DbProxy(Db parent)

Method Summary

Modifier and Type	Method and Description
long	allocatedSize() Total allocated memory for this db, file or RAM.
void	close() Close the backing file.
void	commit() Mark the end of transaction.
void	discard() Discard changes after last commit
void	flush() Immediately persist the commited transations.
java.lang.Integer	keySize() Key size, non-null indicates that this db has fixed-size keys.
java.lang.Integer	maxKeySize() Max key size, if known.
java.lang.Integer	maxValueSize() Max value size, if known.
<T> T	put(MemIO key, long keyOff, int keyLen, Db.PutHandler<T> handler) Insert or visit a value for a key.
void	scan(Db.ScanHandler handler)
<T> T	seek(MemIO key, long keyOff, int keyLen, Db.SeekHandler<T> handler) Visit a value for a key.
java.lang.Integer	valueSize() Value size, non-null indicates that this db has fixed-size values.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.github.whippetdb.db.api.Db

clear, delete, put, put, seek, seek

Constructor Detail

DbProxy

public DbProxy(Db parent)

Method Detail

commit

public void commit()

Description copied from interface: Db

Mark the end of transaction. In general, the transaction is NOT immediately persisted. The immediate durability may be enabled by DbBuilder flags.

Specified by:

commit in interface Db

flush

public void flush()

Description copied from interface: Db

Immediately persist the commited transations.

Specified by:

flush in interface Db

close

public void close()

Description copied from interface: Db

Close the backing file. If journaling is enabled, persist all transactions to the main file and delete the transaction log.

Specified by:

close in interface Db

keySize

public java.lang.Integer keySize()

Description copied from interface: Db

Key size, non-null indicates that this db has fixed-size keys. If present, keyLen parameter in seek()/put()/delete() is ignored.

Specified by:

keySize in interface Db

maxKeySize

public java.lang.Integer maxKeySize()

Description copied from interface: Db

Max key size, if known. If present, keyLen parameter in seek()/put()/delete() is checked against it.

Specified by:

maxKeySize in interface Db

valueSize

public java.lang.Integer valueSize()

Description copied from interface: Db

Value size, non-null indicates that this db has fixed-size values.

Specified by:

valueSize in interface Db

maxValueSize

public java.lang.Integer maxValueSize()

Description copied from interface: Db

Max value size, if known. If present, operations on value in seek()/put() are checked against it.

Specified by:

maxValueSize in interface Db

seek

public <T> T seek(MemIO key,
                  long keyOff,
                  int keyLen,
                  Db.SeekHandler<T> handler)

Description copied from interface: Db

Visit a value for a key. If the key doesn't exist, a handler will receive null arguments. A handler is allowed to change the value on the fly. If the db has fixed-size keys: - keyLen is ignored (the db will use the size it knows). If the db has fixed-size values: - reading/writing is checked against this size, - initially value is filled by zeros, all changes are persistent. If the db has variable-size keys: - keyLen is respected, - if maxKeySize is present, keyLen is checked against it. If the db has variable-size values: - value may be cast to MemDataBuffer and resized - reading/writing follow the rules for MemDataBuffer - if maxValueSize is present, reading/writing/resizing is checked against it

Specified by:

seek in interface Db

Parameters:

key - - key memory

keyOff - - key start

keyLen - - key length

handler - - value handler

put

public <T> T put(MemIO key,
                 long keyOff,
                 int keyLen,
                 Db.PutHandler<T> handler)

Description copied from interface: Db

Insert or visit a value for a key. The boolean parameter of a handler indicates whether the key was just inserted. The value is always non-null. A handler is allowed to change the value on the fly. If the db has fixed-size keys: - keyLen is ignored (the db will use the size it knows). If the db has fixed-size values: - reading/writing is checked against this size, - initially value is filled by zeros, all changes are persistent. If the db has variable-size keys: - keyLen is respected, - if maxKeySize is present, keyLen is checked against it. If the db has variable-size values: - value may be cast to MemDataBuffer and resized, - reading/writing follow the rules for MemDataBuffer, - initially value is empty (zero-size), all changes are persistent, - if maxValueSize is present, reading/writing/resizing is checked against it.

Specified by:

put in interface Db

Parameters:

key - - key memory

keyOff - - actual key start

keyLen - - actual key length

allocatedSize

public long allocatedSize()

Description copied from interface: Db

Total allocated memory for this db, file or RAM.

Specified by:

allocatedSize in interface Db

scan

public void scan(Db.ScanHandler handler)

Specified by:

scan in interface Db

discard

public void discard()

Description copied from interface: Db

Discard changes after last commit

Specified by:

discard in interface Db