/** * A PageProviderIMpl * * <p>TODO: this may be moved entirely into PagingStore as there's an one-to-one relationship here * However I want to keep this isolated as much as possible during development * * @author <a href="mailto:[email protected]">Clebert Suconic</a> */ public class PageCursorProviderImpl implements PageCursorProvider { // Constants ----------------------------------------------------- private static final Logger log = Logger.getLogger(PageCursorProviderImpl.class); boolean isTrace = log.isTraceEnabled(); // Attributes ---------------------------------------------------- private final PagingStore pagingStore; private final StorageManager storageManager; // This is the same executor used at the PageStoreImpl. One Executor per pageStore private final Executor executor; private final SoftValueHashMap<Long, PageCache> softCache; private final ConcurrentMap<Long, PageSubscription> activeCursors = new ConcurrentHashMap<Long, PageSubscription>(); // Static -------------------------------------------------------- // Constructors -------------------------------------------------- public PageCursorProviderImpl( final PagingStore pagingStore, final StorageManager storageManager, final Executor executor, final int maxCacheSize) { this.pagingStore = pagingStore; this.storageManager = storageManager; this.executor = executor; this.softCache = new SoftValueHashMap<Long, PageCache>(maxCacheSize); } // Public -------------------------------------------------------- public PagingStore getAssociatedStore() { return pagingStore; } public synchronized PageSubscription createSubscription( long cursorID, Filter filter, boolean persistent) { if (log.isDebugEnabled()) { log.debug( this.pagingStore.getAddress() + " creating subscription " + cursorID + " with filter " + filter, new Exception("trace")); } PageSubscription activeCursor = activeCursors.get(cursorID); if (activeCursor != null) { throw new IllegalStateException("Cursor " + cursorID + " had already been created"); } activeCursor = new PageSubscriptionImpl( this, pagingStore, storageManager, executor, filter, cursorID, persistent); activeCursors.put(cursorID, activeCursor); return activeCursor; } /* (non-Javadoc) * @see org.hornetq.core.paging.cursor.PageCursorProvider#createCursor() */ public synchronized PageSubscription getSubscription(long cursorID) { return activeCursors.get(cursorID); } public PagedMessage getMessage(final PagePosition pos) throws Exception { PageCache cache = getPageCache(pos); if (pos.getMessageNr() >= cache.getNumberOfMessages()) { // sanity check, this should never happen unless there's a bug throw new IllegalStateException("Invalid messageNumber passed = " + pos + " on " + cache); } return cache.getMessage(pos.getMessageNr()); } public PagedReference newReference( final PagePosition pos, final PagedMessage msg, final PageSubscription subscription) { return new PagedReferenceImpl(pos, msg, subscription); } /** * No need to synchronize this method since the private getPageCache will have a synchronized call */ public PageCache getPageCache(PagePosition pos) { return getPageCache(pos.getPageNr()); } public PageCache getPageCache(final long pageId) { try { boolean needToRead = false; PageCache cache = null; synchronized (softCache) { if (pageId > pagingStore.getCurrentWritingPage()) { return null; } cache = softCache.get(pageId); if (cache == null) { if (!pagingStore.checkPageFileExists((int) pageId)) { return null; } cache = createPageCache(pageId); needToRead = true; // anyone reading from this cache will have to wait reading to finish first // we also want only one thread reading this cache cache.lock(); if (isTrace) { log.trace("adding " + pageId + " into cursor = " + this.pagingStore.getAddress()); } softCache.put(pageId, cache); } } // Reading is done outside of the synchronized block, however // the page stays locked until the entire reading is finished if (needToRead) { Page page = null; try { page = pagingStore.createPage((int) pageId); storageManager.beforePageRead(); page.open(); List<PagedMessage> pgdMessages = page.read(storageManager); cache.setMessages(pgdMessages.toArray(new PagedMessage[pgdMessages.size()])); } finally { try { if (page != null) { page.close(); } } catch (Throwable ignored) { } storageManager.afterPageRead(); cache.unlock(); } } return cache; } catch (Exception e) { throw new RuntimeException( "Couldn't complete paging due to an IO Exception on Paging - " + e.getMessage(), e); } } public void addPageCache(PageCache cache) { synchronized (softCache) { softCache.put(cache.getPageId(), cache); } } public int getCacheMaxSize() { return softCache.getMaxEelements(); } public void setCacheMaxSize(final int size) { softCache.setMaxElements(size); } public int getCacheSize() { synchronized (softCache) { return softCache.size(); } } public void processReload() throws Exception { for (PageSubscription cursor : this.activeCursors.values()) { cursor.processReload(); } cleanup(); } public void stop() { for (PageSubscription cursor : activeCursors.values()) { cursor.stop(); } Future future = new Future(); executor.execute(future); while (!future.await(10000)) { log.warn("Waiting cursor provider " + this + " to finish executors" + executor); } } public void flushExecutors() { for (PageSubscription cursor : activeCursors.values()) { cursor.flushExecutors(); } Future future = new Future(); executor.execute(future); while (!future.await(10000)) { log.warn("Waiting cursor provider " + this + " to finish executors " + executor); } } public void close(PageSubscription cursor) { activeCursors.remove(cursor.getId()); scheduleCleanup(); } /* (non-Javadoc) * @see org.hornetq.core.paging.cursor.PageCursorProvider#scheduleCleanup() */ public void scheduleCleanup() { executor.execute( new Runnable() { public void run() { storageManager.setContext(storageManager.newSingleThreadContext()); try { cleanup(); } finally { storageManager.clearContext(); } } @Override public String toString() { return "PageCursorProvider:scheduleCleanup()"; } }); } public void cleanup() { ArrayList<Page> depagedPages = new ArrayList<Page>(); while (true) { if (pagingStore.lock(100)) { break; } if (!pagingStore.isStarted()) return; } synchronized (this) { try { if (!pagingStore.isStarted()) { return; } if (pagingStore.getNumberOfPages() == 0) { return; } if (log.isDebugEnabled()) { log.debug("Asserting cleanup for address " + this.pagingStore.getAddress()); } ArrayList<PageSubscription> cursorList = new ArrayList<PageSubscription>(); cursorList.addAll(activeCursors.values()); long minPage = checkMinPage(cursorList); if (minPage == pagingStore.getCurrentWritingPage() && pagingStore.getCurrentPage().getNumberOfMessages() > 0) { boolean complete = true; for (PageSubscription cursor : cursorList) { if (!cursor.isComplete(minPage)) { if (log.isDebugEnabled()) { log.debug("Cursor " + cursor + " was considered incomplete at page " + minPage); } complete = false; break; } else { if (log.isDebugEnabled()) { log.debug("Cursor " + cursor + "was considered **complete** at page " + minPage); } } } if (!pagingStore.isStarted()) { return; } if (complete) { if (log.isDebugEnabled()) { log.debug( "Address " + pagingStore.getAddress() + " is leaving page mode as all messages are consumed and acknowledged from the page store"); } pagingStore.forceAnotherPage(); Page currentPage = pagingStore.getCurrentPage(); storePositions(cursorList, currentPage); pagingStore.stopPaging(); // This has to be called after we stopped paging for (PageSubscription cursor : cursorList) { cursor.scheduleCleanupCheck(); } } } for (long i = pagingStore.getFirstPage(); i < minPage; i++) { Page page = pagingStore.depage(); if (page == null) { break; } depagedPages.add(page); } if (pagingStore.getNumberOfPages() == 0 || pagingStore.getNumberOfPages() == 1 && pagingStore.getCurrentPage().getNumberOfMessages() == 0) { pagingStore.stopPaging(); } else { if (log.isTraceEnabled()) { log.trace( "Couldn't cleanup page on address " + this.pagingStore.getAddress() + " as numberOfPages == " + pagingStore.getNumberOfPages() + " and currentPage.numberOfMessages = " + pagingStore.getCurrentPage().getNumberOfMessages()); } } } catch (Exception ex) { log.warn("Couldn't complete cleanup on paging", ex); return; } finally { pagingStore.unlock(); } } try { for (Page depagedPage : depagedPages) { PageCache cache; PagedMessage[] pgdMessages; synchronized (softCache) { cache = softCache.get((long) depagedPage.getPageId()); } if (isTrace) { log.trace("Removing page " + depagedPage.getPageId() + " from page-cache"); } if (cache == null) { // The page is not on cache any more // We need to read the page-file before deleting it // to make sure we remove any large-messages pending storageManager.beforePageRead(); List<PagedMessage> pgdMessagesList = null; try { depagedPage.open(); pgdMessagesList = depagedPage.read(storageManager); } finally { try { depagedPage.close(); } catch (Exception e) { } storageManager.afterPageRead(); } depagedPage.close(); pgdMessages = pgdMessagesList.toArray(new PagedMessage[pgdMessagesList.size()]); } else { pgdMessages = cache.getMessages(); } depagedPage.delete(pgdMessages); synchronized (softCache) { softCache.remove((long) depagedPage.getPageId()); } } } catch (Exception ex) { log.warn("Couldn't complete cleanup on paging", ex); return; } } /** * @param cursorList * @param currentPage * @throws Exception */ private void storePositions(ArrayList<PageSubscription> cursorList, Page currentPage) throws Exception { try { // First step: Move every cursor to the next bookmarked page (that was just created) for (PageSubscription cursor : cursorList) { cursor.confirmPosition(new PagePositionImpl(currentPage.getPageId(), -1)); } while (!storageManager.waitOnOperations(5000)) { log.warn("Couldn't complete operations on IO context " + storageManager.getContext()); } } finally { for (PageSubscription cursor : cursorList) { cursor.enableAutoCleanup(); } } } public void printDebug() { System.out.println("Debug information for PageCursorProviderImpl:"); for (PageCache cache : softCache.values()) { System.out.println("Cache " + cache); } } // Package protected --------------------------------------------- // Protected ----------------------------------------------------- /* Protected as we may let test cases to instrument the test */ protected PageCacheImpl createPageCache(final long pageId) throws Exception { return new PageCacheImpl(pagingStore.createPage((int) pageId)); } // Private ------------------------------------------------------- /** This method is synchronized because we want it to be atomic with the cursors being used */ private long checkMinPage(List<PageSubscription> cursorList) { long minPage = Long.MAX_VALUE; for (PageSubscription cursor : cursorList) { long firstPage = cursor.getFirstPage(); if (log.isDebugEnabled()) { log.debug( this.pagingStore.getAddress() + " has a cursor " + cursor + " with first page=" + firstPage); } if (firstPage < minPage) { minPage = firstPage; } } if (log.isDebugEnabled()) { log.debug(this.pagingStore.getAddress() + " has minPage=" + minPage); } return minPage; } // Inner classes ------------------------------------------------- }
public void cleanup() {
ArrayList<Page> depagedPages = new ArrayList<Page>();
while (true) {
if (pagingStore.lock(100)) {
break;
}
if (!pagingStore.isStarted()) return;
}
synchronized (this) {
try {
if (!pagingStore.isStarted()) {
return;
}
if (pagingStore.getNumberOfPages() == 0) {
return;
}
if (log.isDebugEnabled()) {
log.debug("Asserting cleanup for address " + this.pagingStore.getAddress());
}
ArrayList<PageSubscription> cursorList = new ArrayList<PageSubscription>();
cursorList.addAll(activeCursors.values());
long minPage = checkMinPage(cursorList);
if (minPage == pagingStore.getCurrentWritingPage()
&& pagingStore.getCurrentPage().getNumberOfMessages() > 0) {
boolean complete = true;
for (PageSubscription cursor : cursorList) {
if (!cursor.isComplete(minPage)) {
if (log.isDebugEnabled()) {
log.debug("Cursor " + cursor + " was considered incomplete at page " + minPage);
}
complete = false;
break;
} else {
if (log.isDebugEnabled()) {
log.debug("Cursor " + cursor + "was considered **complete** at page " + minPage);
}
}
}
if (!pagingStore.isStarted()) {
return;
}
if (complete) {
if (log.isDebugEnabled()) {
log.debug(
"Address "
+ pagingStore.getAddress()
+ " is leaving page mode as all messages are consumed and acknowledged from the page store");
}
pagingStore.forceAnotherPage();
Page currentPage = pagingStore.getCurrentPage();
storePositions(cursorList, currentPage);
pagingStore.stopPaging();
// This has to be called after we stopped paging
for (PageSubscription cursor : cursorList) {
cursor.scheduleCleanupCheck();
}
}
}
for (long i = pagingStore.getFirstPage(); i < minPage; i++) {
Page page = pagingStore.depage();
if (page == null) {
break;
}
depagedPages.add(page);
}
if (pagingStore.getNumberOfPages() == 0
|| pagingStore.getNumberOfPages() == 1
&& pagingStore.getCurrentPage().getNumberOfMessages() == 0) {
pagingStore.stopPaging();
} else {
if (log.isTraceEnabled()) {
log.trace(
"Couldn't cleanup page on address "
+ this.pagingStore.getAddress()
+ " as numberOfPages == "
+ pagingStore.getNumberOfPages()
+ " and currentPage.numberOfMessages = "
+ pagingStore.getCurrentPage().getNumberOfMessages());
}
}
} catch (Exception ex) {
log.warn("Couldn't complete cleanup on paging", ex);
return;
} finally {
pagingStore.unlock();
}
}
try {
for (Page depagedPage : depagedPages) {
PageCache cache;
PagedMessage[] pgdMessages;
synchronized (softCache) {
cache = softCache.get((long) depagedPage.getPageId());
}
if (isTrace) {
log.trace("Removing page " + depagedPage.getPageId() + " from page-cache");
}
if (cache == null) {
// The page is not on cache any more
// We need to read the page-file before deleting it
// to make sure we remove any large-messages pending
storageManager.beforePageRead();
List<PagedMessage> pgdMessagesList = null;
try {
depagedPage.open();
pgdMessagesList = depagedPage.read(storageManager);
} finally {
try {
depagedPage.close();
} catch (Exception e) {
}
storageManager.afterPageRead();
}
depagedPage.close();
pgdMessages = pgdMessagesList.toArray(new PagedMessage[pgdMessagesList.size()]);
} else {
pgdMessages = cache.getMessages();
}
depagedPage.delete(pgdMessages);
synchronized (softCache) {
softCache.remove((long) depagedPage.getPageId());
}
}
} catch (Exception ex) {
log.warn("Couldn't complete cleanup on paging", ex);
return;
}
}
