Package com.coyotegulch.jisp
Interface ObjectIndex
- All Known Implementing Classes:
BTreeIndex
,HashIndex
public interface ObjectIndex
ObjectIndex
defines the concept of an index
that associates key
values with references to serializable objects. Concrete subclasses of ObjectIndex
assume that an object's position
(as given by a long
value) is constant,
regardless of the actual meaning of that position. In general, the position represents the * location (file pointer) of a Serializable
object in an IndexedObjectDatabase
. * * Use the IndexedObjectDatabase.attachIndex
method to attach an ObjectIndex
* to a database. A database updates all attached indexes when it writes or removes objects * from its file.
- See Also:
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Method Summary
Modifier and TypeMethodDescriptionlong
Find the position of the object associated with a given key.void
Insert a key into the database, associating a record position with the given key.void
Removes the given key from the index.void
replaceKey
(KeyObject key, long pos) Replace the reference pos for the given key.void
If the key already exists, replace the reference pos for the given key.
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Method Details
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insertKey
Insert a key into the database, associating a record position with the given key. Throws aDuplicateKey
exception if the key already exists.- Parameters:
key
- A key identifying the record to be read.pos
- File position of record associated with key- Throws:
IOException
- when an I/O exception is thrown by an underlying java.io.* classClassNotFoundException
- for a casting error, usually when a persistent object or index does match the expected typeDuplicateKey
- when inserting a duplicate key into an index that does not support duplicates- See Also:
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replaceKey
Replace the reference pos for the given key. Throws aKeyNotFound
exception if the requested key does not exist in the index.- Parameters:
key
- A key identifying the record to be read.pos
- File position of record associated with key- Throws:
IOException
- when an I/O exception is thrown by an underlying java.io.* classClassNotFoundException
- for a casting error, usually when a persistent object or index does match the expected typeKeyNotFound
- when the specified key can not be found in the index- See Also:
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storeKey
If the key already exists, replace the reference pos for the given key. Otherwise, insert a key into the database, associating a record position with the given key.- Parameters:
key
- A key identifying the record to be read.pos
- File position of record associated with key- Throws:
IOException
- when an I/O exception is thrown by an underlying java.io.* classClassNotFoundException
- for a casting error, usually when a persistent object or index does match the expected type- See Also:
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findKey
Find the position of the object associated with a given key.- Parameters:
key
- A key identifying the record to be read.- Returns:
- The position of the record associated with
key
. - Throws:
IOException
- when an I/O exception is thrown by an underlying java.io.* classClassNotFoundException
- for a casting error, usually when a persistent object or index does match the expected typeKeyNotFound
- when the specified key can not be found in the index- See Also:
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removeKey
Removes the given key from the index.- Parameters:
key
- A key identifying the record to be read.- Throws:
IOException
- when an I/O exception is thrown by an underlying java.io.* classClassNotFoundException
- for a casting error, usually when a persistent object or index does match the expected typeKeyNotFound
- when the specified key can not be found in the index- See Also:
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