diff --git a/community/io/src/main/java/org/neo4j/io/pagecache/tracing/cursor/PageCursorCounters.java b/community/io/src/main/java/org/neo4j/io/pagecache/tracing/cursor/PageCursorCounters.java new file mode 100644 index 000000000000..a1828bdb72f9 --- /dev/null +++ b/community/io/src/main/java/org/neo4j/io/pagecache/tracing/cursor/PageCursorCounters.java @@ -0,0 +1,52 @@ +/* + * Copyright (c) 2002-2017 "Neo Technology," + * Network Engine for Objects in Lund AB [http://neotechnology.com] + * + * This file is part of Neo4j. + * + * Neo4j is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ +package org.neo4j.io.pagecache.tracing.cursor; + +/** + * Expose information from page cache about particular page cursor events. + * + * Exposed counters are relevant only for particular cursor and do not represent global page cache wide picture. + * + * @see PageCursorCounters + * @see PageCursorTracer + */ +public interface PageCursorCounters +{ + /** + * @return The number of page faults observed thus far. + */ + long faults(); + + /** + * @return The number of page pins observed thus far. + */ + long pins(); + + /** + * @return The number of page unpins observed thus far. + */ + long unpins(); + + /** + * @return The sum total of bytes read in through page faults thus far. + */ + long bytesRead(); + +} diff --git a/community/io/src/main/java/org/neo4j/io/pagecache/tracing/cursor/PageCursorTracer.java b/community/io/src/main/java/org/neo4j/io/pagecache/tracing/cursor/PageCursorTracer.java index 42ca2f8871f1..caf17a7a4aed 100644 --- a/community/io/src/main/java/org/neo4j/io/pagecache/tracing/cursor/PageCursorTracer.java +++ b/community/io/src/main/java/org/neo4j/io/pagecache/tracing/cursor/PageCursorTracer.java @@ -23,8 +23,16 @@ import org.neo4j.io.pagecache.tracing.PageCacheTracer; import org.neo4j.io.pagecache.tracing.PinEvent; -//:TODO javadoc -public interface PageCursorTracer +/** + * Event tracer for page cursors. + * + * Performs event tracing related to particular page cursors and expose simple counters around them. + * Since events of each particular page cursor are part of whole page cache events, each particular page cursor + * tracer will eventually report them to global page cache counters/tracers. + * + * @see PageCursorTracer + */ +public interface PageCursorTracer extends PageCursorCounters { PageCursorTracer NULL = new PageCursorTracer() @@ -72,29 +80,8 @@ public void reportEvents() } }; - /** - * @return The number of page faults observed thus far. - */ - long faults(); - - /** - * @return The number of page pins observed thus far. - */ - long pins(); - - /** - * @return The number of page unpins observed thus far. - */ - long unpins(); - - /** - * @return The sum total of bytes read in through page faults thus far. - */ - long bytesRead(); - PinEvent beginPin( boolean writeLock, long filePageId, PageSwapper swapper ); - // TODO:: methods that glue current tracer to page cache tracer can be avoided? void init( PageCacheTracer tracer ); void reportEvents(); diff --git a/community/kernel/src/main/java/org/neo4j/kernel/impl/api/KernelStatement.java b/community/kernel/src/main/java/org/neo4j/kernel/impl/api/KernelStatement.java index 1d8392ec1e3e..8a00f5e13054 100644 --- a/community/kernel/src/main/java/org/neo4j/kernel/impl/api/KernelStatement.java +++ b/community/kernel/src/main/java/org/neo4j/kernel/impl/api/KernelStatement.java @@ -24,7 +24,7 @@ import org.neo4j.graphdb.NotInTransactionException; import org.neo4j.graphdb.TransactionTerminatedException; -import org.neo4j.io.pagecache.tracing.cursor.PageCursorTracer; +import org.neo4j.io.pagecache.tracing.cursor.PageCursorCounters; import org.neo4j.kernel.api.DataWriteOperations; import org.neo4j.kernel.api.query.ExecutingQuery; import org.neo4j.kernel.api.ProcedureCallOperations; @@ -53,14 +53,14 @@ *
    *
  1. Construct {@link KernelStatement} when {@link KernelTransactionImplementation} is constructed
    2. *
  2. For every transaction...
    3. - *
  3. Call {@link #initialize(StatementLocks, StatementOperationParts, PageCursorTracer)} which makes this instance + *
  4. Call {@link #initialize(StatementLocks, StatementOperationParts, PageCursorCounters)} which makes this instance * full available and ready to use. Call when the {@link KernelTransactionImplementation} is initialized.
    5. *
  5. Alternate {@link #acquire()} / {@link #close()} when acquiring / closing a statement for the transaction... * Temporarily asymmetric number of calls to {@link #acquire()} / {@link #close()} is supported, although in * the end an equal number of calls must have been issued.
    6. *
  6. To be safe call {@link #forceClose()} at the end of a transaction to force a close of the statement, * even if there are more than one current call to {@link #acquire()}. This instance is now again ready - * to be {@link #initialize(StatementLocks, StatementOperationParts, PageCursorTracer) initialized} and used for the transaction + * to be {@link #initialize(StatementLocks, StatementOperationParts, PageCursorCounters)} initialized} and used for the transaction * instance again, when it's initialized.
    7. *
*/ @@ -72,7 +72,7 @@ public class KernelStatement implements TxStateHolder, Statement private final KernelTransactionImplementation transaction; private final OperationsFacade facade; private StatementLocks statementLocks; - private PageCursorTracer pageCursorTracer; + private PageCursorCounters pageCursorCounters; private int referenceCount; private volatile ExecutingQueryList executingQueryList; private final LockTracer systemLockTracer; @@ -186,10 +186,10 @@ void assertOpen() } public void initialize( StatementLocks statementLocks, StatementOperationParts operationParts, - PageCursorTracer pageCursorTracer ) + PageCursorCounters pageCursorCounters ) { this.statementLocks = statementLocks; - this.pageCursorTracer = pageCursorTracer; + this.pageCursorCounters = pageCursorCounters; facade.initialize( operationParts ); } @@ -204,9 +204,9 @@ public LockTracer lockTracer() return tracer == null ? systemLockTracer : systemLockTracer.combine( tracer ); } - public PageCursorTracer getPageCursorTracer() + public PageCursorCounters getPageCursorCounters() { - return pageCursorTracer; + return pageCursorCounters; } public final void acquire()