package com.fasterxml.clustermate.service.store;
import com.fasterxml.storemate.shared.ByteContainer;
import com.fasterxml.storemate.shared.compress.Compression;
import com.fasterxml.storemate.store.Storable;
import com.fasterxml.clustermate.api.EntryKey;
import com.fasterxml.clustermate.api.EntryKeyConverter;
import com.fasterxml.clustermate.api.msg.ItemInfo;
import com.fasterxml.clustermate.api.msg.ListItem;
/**
* Converter used by store for handling conversions between
* low-level {@link Storable} (things stored in StoreMate store),
* and ClusterMate-level {@link StoredEntry} instances.
*<p>
* Custom sub-classing is needed to support additional metadata for
* systems implementations.
*/
public abstract class StoredEntryConverter<K extends EntryKey,
E extends StoredEntry<K>,
/* 15-Feb-2014, tatu: Only now realized that this type parameter is
* pretty much useless; could/should eliminate. But major refactoring
* to get rid of it...
*/
L extends ListItem
>
{
// // // Key conversion
public abstract EntryKeyConverter<K> keyConverter();
// // // Entry conversion
public abstract E entryFromStorable(Storable raw);
public abstract E entryFromStorable(K key, final Storable raw);
public abstract E entryFromStorable(K key, Storable raw,
byte[] buffer, int offset, int length);
/**
* Method for constructing implementation minimal {@link ListItem} instances
* (subtypes) from raw {@link Storable}
*/
public ListItem minimalListItemFromStorable(Storable raw) {
return defaultMinimalListItemFromStorable(raw);
}
/**
* Method for constructing implementation implementation-specific
* full {@link ListItem} instances (subtypes) from raw {@link Storable}
*/
public abstract L fullListItemFromStorable(Storable raw);
/**
* Method for constructing {@link ItemInfo} from raw entry metadata
*/
public ItemInfo itemInfoFromStorable(Storable raw) {
return defaultItemInfoFromStorable(raw);
}
// // // Metadata handling
/**
* Method called to construct "custom metadata" section to be
* used for constructing a new <code>Storable</code> instance.
*/
public abstract ByteContainer createMetadata(long creationTime,
byte lastAccessUpdateMethod,
int minTTLSecs, int maxTTLSecs);
/*
/**********************************************************************
/* Default implementations (mostly for unit tests)
/**********************************************************************
*/
/**
* Helper method that can be used as the baseline implementation for
* {@link #listItemFromStorable(Storable)} by tests.
*/
protected ListItem defaultMinimalListItemFromStorable(Storable raw) {
return new ListItem(raw.getKey(), raw.getContentHash(), raw.getActualUncompressedLength());
}
protected ItemInfo defaultItemInfoFromStorable(Storable raw) {
Compression c = raw.getCompression();
Character compression = (c == null || c == Compression.NONE) ? null
: Character.valueOf(c.asChar());
long compLen = (compression == null) ? -1L : raw.getStorageLength();
StringBuilder sb = new StringBuilder(4);
if (raw.isDeleted()) {
sb.append(ItemInfo.FLAG_DELETED);
}
if (!raw.hasExternalData()) {
sb.append(ItemInfo.FLAG_INLINED);
}
if (raw.isReplicated()) {
sb.append(ItemInfo.FLAG_REPLICA);
}
String flags = (sb.length() == 0) ? "" : sb.toString();
return new ItemInfo(raw.getLastModified(), raw.getActualUncompressedLength(), compLen,
compression, raw.getContentHash(),
flags);
}
}