Package org.aspectj.org.eclipse.jdt.internal.core.nd.db

Class ModificationLog

java.lang.Object

org.aspectj.org.eclipse.jdt.internal.core.nd.db.ModificationLog

public class ModificationLog
extends Object

Records a record of every modification to the database, in a circular buffer of fixed size. Whenever anything writes to the database, the log records the address and size of the write, along with a call stack describing what was going on at the time of the write. The actual bytes written to the database are not recorded. In addition to writes, it also records every invocation of malloc and free.

Given a memory address range, we can trace the log backwards to find everything that ever happened to that address range since the start of the log.

"call stacks" don't use java call stacks. They use explicit tags that are pushed and popped at the start and end of operations related to modifying the database.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ModificationLog.MemoryAccessLog	Contains a log of events related to a specific range of database addresses, in reverse chronological order.
static class	ModificationLog.MemoryOperation	Represents a single entry in a ModificationLog.MemoryAccessLog.
static class	ModificationLog.Tag	Used to attach messages to events in the log.

Field Summary

Fields

Modifier and Type	Field	Description
static byte	FREE_OPERATION
static byte	MALLOC_OPERATION
static byte	POP_OPERATION
static byte	PUSH_OPERATION
static byte	WRITE_OPERATION

Constructor Summary

Constructors

Constructor	Description
ModificationLog(int size)

Method Summary

Modifier and Type	Method	Description
void	clear()
static ModificationLog.Tag	createTag(String tagName)
boolean	enabled()
void	end(ModificationLog.Tag tag)
int	getBufferEntries()
ModificationLog.MemoryAccessLog	getReportFor(long address, int size)	Returns information about the last write to the given address range
long	getWriteCount()
static void	indent(StringBuilder builder, int indent)
void	printLog(int count)
void	recordFree(long address, int size)
void	recordMalloc(long address, int size)
void	recordWrite(long address, int size)
void	setBufferSize(int megs)
void	start(ModificationLog.Tag tag)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

PUSH_OPERATION

public static final byte PUSH_OPERATION

See Also:

Constant Field Values

POP_OPERATION

public static final byte POP_OPERATION

See Also:

Constant Field Values

WRITE_OPERATION

public static final byte WRITE_OPERATION

See Also:

Constant Field Values

MALLOC_OPERATION

public static final byte MALLOC_OPERATION

See Also:

Constant Field Values

FREE_OPERATION

public static final byte FREE_OPERATION

See Also:

Constant Field Values

Constructor Details

ModificationLog

public ModificationLog(int size)

Method Details

clear

public void clear()

getBufferEntries

public int getBufferEntries()

setBufferSize

public void setBufferSize(int megs)

indent

public static void indent(StringBuilder builder,
 int indent)

enabled

public boolean enabled()

start

public void start(ModificationLog.Tag tag)

end

public void end(ModificationLog.Tag tag)

recordWrite

public void recordWrite(long address,
 int size)

recordMalloc

public void recordMalloc(long address,
 int size)

recordFree

public void recordFree(long address,
 int size)

printLog

public void printLog(int count)

getWriteCount

public long getWriteCount()

getReportFor

public ModificationLog.MemoryAccessLog getReportFor(long address,
 int size)

Returns information about the last write to the given address range

createTag

public static ModificationLog.Tag createTag(String tagName)