All Superinterfaces:

java.lang.AutoCloseable, java.io.Closeable, java.io.Flushable

All Known Implementing Classes:

DiskStore, MemoryStore
```
public interface Store
extends java.io.Closeable, java.io.Flushable
```
A repository of binary data entries each identified by a string key. Each entry has a metadata block and a data stream. An entry's metadata block and data stream can be accessed by a Store.Viewer and modified by an Store.Editor. An entry can have at most one active editor but can have multiple concurrent viewers. No data written through an editor is visible to subsequently opened viewers unless committed. A viewer sees a consistent snapshot of the entry as perceived at the time it was opened at.
A store may bound its size by automatic eviction of entries, possibly in background. The size bound is not strict. A store's size() might temporarily exceed its bound in case the store is being actively expanded while eviction is in progress. Additionally, a store's size doesn't include the overhead of the underlying filesystem or any metadata the store itself uses for indexing purposes. Thus, a store's maxSize() is not exact and might be slightly exceeded as necessary.
Entries on a store are volatile. It is not guaranteed that an entry can be viewed any time, even if immediately, after it has been committed.
Functions that are expected to be called frequently have two variants: one synchronous, and another asynchronous variant that takes an additional Executor parameter. The former has a default implementation that calls the latter and waits for the result. The executor parameter only expresses caller's preferred asynchronous execution strategy, and may be ignored by the store if seen fit. The executor parameter can be Runnable::run if same-thread execution is preferred.
Store is thread-safe and is suitable for concurrent use.

Nested Class Summary

Nested Classes
Modifier and Type	Interface	Description
`static interface`	`Store.Editor`	Writes an entry's metadata block and data stream.
`static interface`	`Store.EntryReader`	A reader for an entry's data stream.
`static interface`	`Store.EntryWriter`	A writer for an entry's data stream.
`static interface`	`Store.Viewer`	Reads an entry's metadata block and data stream.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`void`	`clear()`	Removes all entries from this store.
`void`	`close()`	Closes this store.
`void`	`dispose()`	Atomically clears and closes this store.
`default java.util.Optional<Store.Editor>`	`edit(java.lang.String key)`	Synchronous variant of `edit(String, Executor)`.
`java.util.concurrent.CompletableFuture<java.util.Optional<Store.Editor>>`	`edit(java.lang.String key, java.util.concurrent.Executor executor)`	Opens an editor for the entry associated with the given key.
`void`	`flush()`	Flushes any indexing data buffered by this store.
`java.util.Iterator<Store.Viewer>`	`iterator()`	Returns an iterator of `Viewers` over the entries in this store.
`long`	`maxSize()`	Returns this store's max size in bytes.
`boolean`	`remove(java.lang.String key)`	Removes the entry associated with the given key.
`default boolean`	`removeAll(java.util.List<java.lang.String> keys)`	Removes all the entries associated with the given keys.
`long`	`size()`	Returns the size in bytes of all entries in this store.
`default java.util.Optional<Store.Viewer>`	`view(java.lang.String key)`	Synchronous variant of `view(String, Executor)`.
`java.util.concurrent.CompletableFuture<java.util.Optional<Store.Viewer>>`	`view(java.lang.String key, java.util.concurrent.Executor executor)`	Opens a viewer for the entry associated with the given key.

- Method Detail
  - maxSize
```
long maxSize()
```
    Returns this store's max size in bytes.
  - view
```
default java.util.Optional<Store.Viewer> view(java.lang.String key)
                                       throws java.io.IOException
```
    Synchronous variant of view(String, Executor).
    
    Throws:
    
    java.lang.IllegalStateException - if closed
    
    java.io.IOException
  - view
```
java.util.concurrent.CompletableFuture<java.util.Optional<Store.Viewer>> view(java.lang.String key,
                                                                              java.util.concurrent.Executor executor)
```
    Opens a viewer for the entry associated with the given key. An empty optional is returned if there's no such entry.
    
    Throws:
    
    java.lang.IllegalStateException - if closed
  - edit
```
default java.util.Optional<Store.Editor> edit(java.lang.String key)
                                       throws java.io.IOException
```
    Synchronous variant of edit(String, Executor).
    
    Throws:
    
    java.lang.IllegalStateException - if closed
    
    java.io.IOException
  - edit
```
java.util.concurrent.CompletableFuture<java.util.Optional<Store.Editor>> edit(java.lang.String key,
                                                                              java.util.concurrent.Executor executor)
```
    Opens an editor for the entry associated with the given key. An empty optional is returned either if there's no such entry, or such entry cannot be edited at the moment.
    
    Throws:
    
    java.lang.IllegalStateException - if closed
  - iterator
```
java.util.Iterator<Store.Viewer> iterator()
                                   throws java.io.IOException
```
    Returns an iterator of Viewers over the entries in this store. The iterator doesn't throw ConcurrentModificationException when the store is asynchronously modified, but there's no guarantee such changes are reflected.
    
    Throws:
    
    java.io.IOException
  - remove
```
@CanIgnoreReturnValue
boolean remove(java.lang.String key)
        throws java.io.IOException
```
    Removes the entry associated with the given key.
    
    Throws:
    
    java.lang.IllegalStateException - if closed
    
    java.io.IOException
  - removeAll
```
@CanIgnoreReturnValue
default boolean removeAll(java.util.List<java.lang.String> keys)
                   throws java.io.IOException
```
    Removes all the entries associated with the given keys.
    
    Throws:
    
    java.lang.IllegalStateException - if closed
    
    java.io.IOException
  - clear
```
void clear()
    throws java.io.IOException
```
    Removes all entries from this store.
    
    Throws:
    
    java.lang.IllegalStateException - if closed
    
    java.io.IOException
  - size
```
long size()
   throws java.io.IOException
```
    Returns the size in bytes of all entries in this store.
    
    Throws:
    
    java.io.IOException
  - dispose
```
void dispose()
      throws java.io.IOException
```
    Atomically clears and closes this store.
    
    Throws:
    
    java.io.IOException
  - close
```
void close()
    throws java.io.IOException
```
    Closes this store. Once the store is closed, all ongoing edits fail, either silently or by throwing an exception, to write or commit anything.
    
    Specified by:
    
    close in interface java.lang.AutoCloseable
    
    Specified by:
    
    close in interface java.io.Closeable
    
    Throws:
    
    java.io.IOException
  - flush
```
void flush()
    throws java.io.IOException
```
    Flushes any indexing data buffered by this store.
    
    Specified by:
    
    flush in interface java.io.Flushable
    
    Throws:
    
    java.lang.IllegalStateException - if the store is closed
    
    java.io.IOException

Interface Store

Nested Class Summary

Method Summary

Method Detail

maxSize

view

view

edit

edit

iterator

remove

removeAll

clear

size

dispose

close

flush