/**
* Remove a file from the cache. Called after it has been removed from its ArchiveHandler.
*
* @param item The ArchiveStoreItem to remove.
*/
synchronized void removeCachedItem(ArchiveStoreItem item) {
long size = item.spaceUsed();
storedData.removeKey(item.key);
// Hard disk space limit = remove it here.
// Soft disk space limit would be to remove it outside the lock.
// Soft disk space limit = we go over the limit significantly when we
// are overloaded.
cachedData -= size;
if (logMINOR) Logger.minor(this, "removeCachedItem: " + item);
item.close();
}
/**
* Get a cached, previously extracted, file from an archive.
*
* @param key The key used to fetch the archive.
* @param filename The name of the file within the archive.
* @return A Bucket containing the data requested, or null.
* @throws ArchiveFailureException
*/
public Bucket getCached(FreenetURI key, String filename) throws ArchiveFailureException {
if (logMINOR) Logger.minor(this, "Fetch cached: " + key + ' ' + filename);
ArchiveKey k = new ArchiveKey(key, filename);
ArchiveStoreItem asi = null;
synchronized (this) {
asi = storedData.get(k);
if (asi == null) return null;
// Promote to top of LRU
storedData.push(k, asi);
}
if (logMINOR) Logger.minor(this, "Found data");
return asi.getReaderBucket();
}
/**
* Add a store element.
*
* @param callbackName If set, the name of the file for which we must call the callback if this
* file happens to match.
* @param gotElement Flag indicating whether we've already found the file for the callback. If so
* we must not call it again.
* @param callback Callback to be called if we do find it. We must getReaderBucket() before adding
* the data to the LRU, otherwise it may be deleted before it reaches the client.
* @throws ArchiveFailureException If a failure occurred resulting in the data not being readable.
* Only happens if callback != null.
*/
private ArchiveStoreItem addStoreElement(
ArchiveStoreContext ctx,
FreenetURI key,
String name,
Bucket temp,
MutableBoolean gotElement,
String callbackName,
ArchiveExtractCallback callback,
ClientContext context)
throws ArchiveFailureException {
RealArchiveStoreItem element = new RealArchiveStoreItem(ctx, key, name, temp);
element.addToContext();
if (logMINOR)
Logger.minor(
this,
"Adding store element: "
+ element
+ " ( "
+ key
+ ' '
+ name
+ " size "
+ element.spaceUsed()
+ " )");
ArchiveStoreItem oldItem;
// Let it throw, if it does something is drastically wrong
Bucket matchBucket = null;
if ((!gotElement.value) && name.equals(callbackName)) {
matchBucket = element.getReaderBucket();
}
synchronized (this) {
oldItem = storedData.get(element.key);
storedData.push(element.key, element);
cachedData += element.spaceUsed();
if (oldItem != null) {
cachedData -= oldItem.spaceUsed();
if (logMINOR)
Logger.minor(this, "Dropping old store element from archive cache: " + oldItem);
oldItem.close();
}
}
if (matchBucket != null) {
callback.gotBucket(matchBucket, context);
gotElement.value = true;
}
return element;
}
/**
* Add an error element to the cache. This happens when a single file in the archive is invalid
* (usually because it is too large).
*
* @param ctx The ArchiveStoreContext which must be notified about this element's creation.
* @param key The key from which the archive was fetched.
* @param name The name of the file within the archive.
* @param error The error message to be included on the eventual exception thrown, if anyone tries
* to extract the data for this element.
*/
private void addErrorElement(
ArchiveStoreContext ctx, FreenetURI key, String name, String error, boolean tooBig) {
ErrorArchiveStoreItem element = new ErrorArchiveStoreItem(ctx, key, name, error, tooBig);
element.addToContext();
if (logMINOR)
Logger.minor(this, "Adding error element: " + element + " for " + key + ' ' + name);
ArchiveStoreItem oldItem;
synchronized (this) {
oldItem = storedData.get(element.key);
storedData.push(element.key, element);
if (oldItem != null) {
oldItem.close();
cachedData -= oldItem.spaceUsed();
if (logMINOR)
Logger.minor(this, "Dropping old store element from archive cache: " + oldItem);
}
}
}
/** Drop any stored data beyond the limit. Call synchronized on storedData. */
private void trimStoredData() {
synchronized (this) {
while (true) {
ArchiveStoreItem item;
if (cachedData <= maxCachedData && storedData.size() <= maxCachedElements) return;
if (storedData.isEmpty()) {
// Race condition? cachedData out of sync?
Logger.error(
this,
"storedData is empty but still over limit: cachedData="
+ cachedData
+ " / "
+ maxCachedData);
return;
}
item = storedData.popValue();
long space = item.spaceUsed();
cachedData -= space;
// Hard limits = delete file within lock, soft limits = delete outside of lock
// Here we use a hard limit
if (logMINOR)
Logger.minor(
this,
"Dropping "
+ item
+ " : cachedData="
+ cachedData
+ " of "
+ maxCachedData
+ " stored items : "
+ storedData.size()
+ " of "
+ maxCachedElements);
item.close();
}
}
}
