/**
* Copyright (C) 2014-2017 Regents of the University of California.
* @author: Jeff Thompson <jefft0@remap.ucla.edu>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
* A copy of the GNU Lesser General Public License is in the file COPYING.
*/
package net.named_data.jndn.util;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.logging.Level;
import java.util.logging.Logger;
import net.named_data.jndn.Data;
import net.named_data.jndn.Face;
import net.named_data.jndn.ForwardingFlags;
import net.named_data.jndn.Interest;
import net.named_data.jndn.InterestFilter;
import net.named_data.jndn.Name;
import net.named_data.jndn.OnInterestCallback;
import net.named_data.jndn.OnRegisterFailed;
import net.named_data.jndn.OnRegisterSuccess;
import net.named_data.jndn.encoding.WireFormat;
import net.named_data.jndn.security.SecurityException;
/**
* A MemoryContentCache holds a set of Data packets and answers an Interest to
* return the correct Data packet. The cache is periodically cleaned up to
* remove each stale Data packet based on its FreshnessPeriod (if it has one).
* @note This class is an experimental feature. See the API docs for more detail at
* http://named-data.net/doc/ndn-ccl-api/memory-content-cache.html .
*/
public class MemoryContentCache implements OnInterestCallback {
/**
* Create a new MemoryContentCache to use the given Face.
* @param face The Face to use to call registerPrefix and setInterestFilter,
* and which will call this object's OnInterest callback.
* @param cleanupIntervalMilliseconds The interval in milliseconds
* between each check to clean up stale content in the cache. If this is a
* large number, then effectively the stale content will not be removed from
* the cache.
*/
public MemoryContentCache(Face face, double cleanupIntervalMilliseconds)
{
face_ = face;
cleanupIntervalMilliseconds_ = cleanupIntervalMilliseconds;
construct();
}
/**
* Create a new MemoryContentCache to use the given Face, with a default
* cleanupIntervalMilliseconds of 1000.0 milliseconds.
* @param face The Face to use to call registerPrefix and setInterestFilter,
* and which will call this object's OnInterest callback.
*/
public MemoryContentCache(Face face)
{
face_ = face;
cleanupIntervalMilliseconds_ = 1000.0;
construct();
}
private void
construct()
{
nextCleanupTime_ = Common.getNowMilliseconds() + cleanupIntervalMilliseconds_;
storePendingInterestCallback_ = new OnInterestCallback() {
public void onInterest
(Name localPrefix, Interest localInterest, Face localFace,
long localInterestFilterId, InterestFilter localFilter)
{
storePendingInterest(localInterest, localFace);
}
};
}
/**
* Call registerPrefix on the Face given to the constructor so that this
* MemoryContentCache will answer interests whose name has the prefix.
* Alternatively, if the Face's registerPrefix has already been called, then
* you can call this object's setInterestFilter.
* @param prefix The Name for the prefix to register. This copies the Name.
* @param onRegisterFailed If register prefix fails for any reason, this
* calls onRegisterFailed.onRegisterFailed(prefix).
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @param onRegisterSuccess This calls
* onRegisterSuccess.onRegisterSuccess(prefix, registeredPrefixId) when this
* receives a success message from the forwarder. If onRegisterSuccess is null,
* this does not use it.
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @param onDataNotFound If a data packet for an interest is not found in the
* cache, this forwards the interest by calling
* onDataNotFound.onInterest(prefix, interest, face, interestFilterId, filter).
* Your callback can find the Data packet for the interest and call
* face.putData(data). If your callback cannot find the Data packet, it can
* optionally call storePendingInterest(interest, face) to store the pending
* interest in this object to be satisfied by a later call to add(data). If
* you want to automatically store all pending interests, you can simply use
* getStorePendingInterest() for onDataNotFound. If onDataNotFound is null,
* this does not use it.
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @param flags See Face.registerPrefix.
* @param wireFormat See Face.registerPrefix.
* @throws IOException For I/O error in sending the registration request.
* @throws SecurityException If signing a command interest for NFD and cannot
* find the private key for the certificateName.
*/
public final void
registerPrefix
(Name prefix, OnRegisterFailed onRegisterFailed,
OnRegisterSuccess onRegisterSuccess, OnInterestCallback onDataNotFound,
ForwardingFlags flags, WireFormat wireFormat)
throws IOException, SecurityException
{
if (onDataNotFound != null)
onDataNotFoundForPrefix_.put(prefix.toUri(), onDataNotFound);
long registeredPrefixId = face_.registerPrefix
(prefix, this, onRegisterFailed, onRegisterSuccess, flags, wireFormat);
registeredPrefixIdList_.add(registeredPrefixId);
}
/**
* Call registerPrefix on the Face given to the constructor so that this
* MemoryContentCache will answer interests whose name has the prefix.
* Alternatively, if the Face's registerPrefix has already been called, then
* you can call this object's setInterestFilter.
* This uses the default WireFormat.getDefaultWireFormat().
* @param prefix The Name for the prefix to register. This copies the Name.
* @param onRegisterFailed If register prefix fails for any reason, this
* calls onRegisterFailed.onRegisterFailed(prefix).
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @param onRegisterSuccess This calls
* onRegisterSuccess.onRegisterSuccess(prefix, registeredPrefixId) when this
* receives a success message from the forwarder. If onRegisterSuccess is null,
* this does not use it.
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @param onDataNotFound If a data packet for an interest is not found in the
* cache, this forwards the interest by calling
* onInterest.onInterest(prefix, interest, face, interestFilterId, filter).
* Your callback can find the Data packet for the interest and call
* face.putData(data). If your callback cannot find the Data packet, it can
* optionally call storePendingInterest(interest, face) to store the pending
* interest in this object to be satisfied by a later call to add(data). If
* you want to automatically store all pending interests, you can simply use
* getStorePendingInterest() for onDataNotFound. If onDataNotFound is null,
* this does not use it.
* @param flags See Face.registerPrefix.
* @throws IOException For I/O error in sending the registration request.
* @throws SecurityException If signing a command interest for NFD and cannot
* find the private key for the certificateName.
*/
public final void
registerPrefix
(Name prefix, OnRegisterFailed onRegisterFailed,
OnRegisterSuccess onRegisterSuccess, OnInterestCallback onDataNotFound,
ForwardingFlags flags) throws IOException, SecurityException
{
registerPrefix
(prefix, onRegisterFailed, onRegisterSuccess, onDataNotFound, flags,
WireFormat.getDefaultWireFormat());
}
/**
* Call registerPrefix on the Face given to the constructor so that this
* MemoryContentCache will answer interests whose name has the prefix.
* Alternatively, if the Face's registerPrefix has already been called, then
* you can call this object's setInterestFilter.
* This uses the default WireFormat.getDefaultWireFormat().
* Use default ForwardingFlags.
* @param prefix The Name for the prefix to register. This copies the Name.
* @param onRegisterFailed If register prefix fails for any reason, this
* calls onRegisterFailed.onRegisterFailed(prefix).
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @param onRegisterSuccess This calls
* onRegisterSuccess.onRegisterSuccess(prefix, registeredPrefixId) when this
* receives a success message from the forwarder. If onRegisterSuccess is null,
* this does not use it.
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @param onDataNotFound If a data packet for an interest is not found in the
* cache, this forwards the interest by calling
* onDataNotFound.onInterest(prefix, interest, face, interestFilterId, filter).
* Your callback can find the Data packet for the interest and call
* face.putData(data). If your callback cannot find the Data packet, it can
* optionally call storePendingInterest(interest, face) to store the pending
* interest in this object to be satisfied by a later call to add(data). If
* you want to automatically store all pending interests, you can simply use
* getStorePendingInterest() for onDataNotFound. If onDataNotFound is null,
* this does not use it.
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @throws IOException For I/O error in sending the registration request.
* @throws SecurityException If signing a command interest for NFD and cannot
* find the private key for the certificateName.
*/
public final void
registerPrefix
(Name prefix, OnRegisterFailed onRegisterFailed,
OnRegisterSuccess onRegisterSuccess, OnInterestCallback onDataNotFound)
throws IOException, SecurityException
{
registerPrefix
(prefix, onRegisterFailed, onRegisterSuccess, onDataNotFound,
new ForwardingFlags(), WireFormat.getDefaultWireFormat());
}
/**
* Call registerPrefix on the Face given to the constructor so that this
* MemoryContentCache will answer interests whose name has the prefix.
* Alternatively, if the Face's registerPrefix has already been called, then
* you can call this object's setInterestFilter.
* Do not call a callback if a data packet is not found in the cache.
* This uses the default WireFormat.getDefaultWireFormat().
* Use default ForwardingFlags.
* @param prefix The Name for the prefix to register. This copies the Name.
* @param onRegisterFailed If register prefix fails for any reason, this
* calls onRegisterFailed.onRegisterFailed(prefix).
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @param onRegisterSuccess This calls
* onRegisterSuccess.onRegisterSuccess(prefix, registeredPrefixId) when this
* receives a success message from the forwarder. If onRegisterSuccess is null,
* this does not use it.
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @throws IOException For I/O error in sending the registration request.
* @throws SecurityException If signing a command interest for NFD and cannot
* find the private key for the certificateName.
*/
public final void
registerPrefix(Name prefix, OnRegisterFailed onRegisterFailed,
OnRegisterSuccess onRegisterSuccess)
throws IOException, SecurityException
{
registerPrefix
(prefix, onRegisterFailed, onRegisterSuccess, null, new ForwardingFlags(),
WireFormat.getDefaultWireFormat());
}
/**
* Call registerPrefix on the Face given to the constructor so that this
* MemoryContentCache will answer interests whose name has the prefix.
* Alternatively, if the Face's registerPrefix has already been called, then
* you can call this object's setInterestFilter.
* @param prefix The Name for the prefix to register. This copies the Name.
* @param onRegisterFailed If register prefix fails for any reason, this
* calls onRegisterFailed.onRegisterFailed(prefix).
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @param onDataNotFound If a data packet for an interest is not found in the
* cache, this forwards the interest by calling
* onDataNotFound.onInterest(prefix, interest, face, interestFilterId, filter).
* Your callback can find the Data packet for the interest and call
* face.putData(data). If your callback cannot find the Data packet, it can
* optionally call storePendingInterest(interest, face) to store the pending
* interest in this object to be satisfied by a later call to add(data). If
* you want to automatically store all pending interests, you can simply use
* getStorePendingInterest() for onDataNotFound. If onDataNotFound is null,
* this does not use it.
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @param flags See Face.registerPrefix.
* @param wireFormat See Face.registerPrefix.
* @throws IOException For I/O error in sending the registration request.
* @throws SecurityException If signing a command interest for NFD and cannot
* find the private key for the certificateName.
*/
public final void
registerPrefix
(Name prefix, OnRegisterFailed onRegisterFailed, OnInterestCallback onDataNotFound,
ForwardingFlags flags, WireFormat wireFormat) throws IOException, SecurityException
{
registerPrefix
(prefix, onRegisterFailed, null, onDataNotFound, flags, wireFormat);
}
/**
* Call registerPrefix on the Face given to the constructor so that this
* MemoryContentCache will answer interests whose name has the prefix.
* Alternatively, if the Face's registerPrefix has already been called, then
* you can call this object's setInterestFilter.
* This uses the default WireFormat.getDefaultWireFormat().
* @param prefix The Name for the prefix to register. This copies the Name.
* @param onRegisterFailed If register prefix fails for any reason, this
* calls onRegisterFailed.onRegisterFailed(prefix).
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @param onDataNotFound If a data packet for an interest is not found in the
* cache, this forwards the interest by calling
* onDataNotFound.onInterest(prefix, interest, face, interestFilterId, filter).
* Your callback can find the Data packet for the interest and call
* face.putData(data). If your callback cannot find the Data packet, it can
* optionally call storePendingInterest(interest, face) to store the pending
* interest in this object to be satisfied by a later call to add(data). If
* you want to automatically store all pending interests, you can simply use
* getStorePendingInterest() for onDataNotFound. If onDataNotFound is null,
* this does not use it.
* @param flags See Face.registerPrefix.
* @throws IOException For I/O error in sending the registration request.
* @throws SecurityException If signing a command interest for NFD and cannot
* find the private key for the certificateName.
*/
public final void
registerPrefix
(Name prefix, OnRegisterFailed onRegisterFailed, OnInterestCallback onDataNotFound,
ForwardingFlags flags) throws IOException, SecurityException
{
registerPrefix
(prefix, onRegisterFailed, onDataNotFound, flags,
WireFormat.getDefaultWireFormat());
}
/**
* Call registerPrefix on the Face given to the constructor so that this
* MemoryContentCache will answer interests whose name has the prefix.
* Alternatively, if the Face's registerPrefix has already been called, then
* you can call this object's setInterestFilter.
* This uses the default WireFormat.getDefaultWireFormat().
* Use default ForwardingFlags.
* @param prefix The Name for the prefix to register. This copies the Name.
* @param onRegisterFailed If register prefix fails for any reason, this
* calls onRegisterFailed.onRegisterFailed(prefix).
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @param onDataNotFound If a data packet for an interest is not found in the
* cache, this forwards the interest by calling
* onDataNotFound.onInterest(prefix, interest, face, interestFilterId, filter).
* Your callback can find the Data packet for the interest and call
* face.putData(data). If your callback cannot find the Data packet, it can
* optionally call storePendingInterest(interest, face) to store the pending
* interest in this object to be satisfied by a later call to add(data). If
* you want to automatically store all pending interests, you can simply use
* getStorePendingInterest() for onDataNotFound. If onDataNotFound is null,
* this does not use it.
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @throws IOException For I/O error in sending the registration request.
* @throws SecurityException If signing a command interest for NFD and cannot
* find the private key for the certificateName.
*/
public final void
registerPrefix
(Name prefix, OnRegisterFailed onRegisterFailed, OnInterestCallback onDataNotFound)
throws IOException, SecurityException
{
registerPrefix
(prefix, onRegisterFailed, onDataNotFound, new ForwardingFlags(),
WireFormat.getDefaultWireFormat());
}
/**
* Call registerPrefix on the Face given to the constructor so that this
* MemoryContentCache will answer interests whose name matches the filter.
* Alternatively, if the Face's registerPrefix has already been called, then
* you can call this object's setInterestFilter.
* Do not call a callback if a data packet is not found in the cache.
* This uses the default WireFormat.getDefaultWireFormat().
* Use default ForwardingFlags.
* @param prefix The Name for the prefix to register. This copies the Name.
* @param onRegisterFailed If register prefix fails for any reason, this
* calls onRegisterFailed.onRegisterFailed(prefix).
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
* @throws IOException For I/O error in sending the registration request.
* @throws SecurityException If signing a command interest for NFD and cannot
* find the private key for the certificateName.
*/
public final void
registerPrefix(Name prefix, OnRegisterFailed onRegisterFailed)
throws IOException, SecurityException
{
registerPrefix
(prefix, onRegisterFailed, null, new ForwardingFlags(),
WireFormat.getDefaultWireFormat());
}
/**
* Call setInterestFilter on the Face given to the constructor so that this
* MemoryContentCache will answer interests whose name matches the filter.
* @param filter The InterestFilter with a prefix and optional regex filter
* used to match the name of an incoming Interest. This makes a copy of filter.
* @param onDataNotFound If a data packet for an interest is not found in the
* cache, this forwards the interest by calling
* onDataNotFound.onInterest(prefix, interest, face, interestFilterId, filter).
* Your callback can find the Data packet for the interest and call
* face.putData(data). Note: If you call setInterestFilter multiple times where
* filter.getPrefix() is the same, it is undetermined which onDataNotFound
* will be called. If your callback cannot find the Data packet, it can
* optionally call storePendingInterest(interest, face) to store the pending
* interest in this object to be satisfied by a later call to add(data). If
* you want to automatically store all pending interests, you can simply use
* getStorePendingInterest() for onDataNotFound. If onDataNotFound is null,
* this does not use it.
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
*/
public final void
setInterestFilter(InterestFilter filter, OnInterestCallback onDataNotFound)
{
if (onDataNotFound != null)
onDataNotFoundForPrefix_.put(filter.getPrefix().toUri(), onDataNotFound);
long interestFilterId = face_.setInterestFilter(filter, this);
interestFilterIdList_.add(interestFilterId);
}
/**
* Call setInterestFilter on the Face given to the constructor so that this
* MemoryContentCache will answer interests whose name has the prefix.
* Do not call a callback if a data packet is not found in the cache.
* @param filter The InterestFilter with a prefix and optional regex filter
* used to match the name of an incoming Interest. This makes a copy of filter.
*/
public final void
setInterestFilter(InterestFilter filter)
{
setInterestFilter(filter, null);
}
/**
* Call setInterestFilter on the Face given to the constructor so that this
* MemoryContentCache will answer interests whose name has the prefix.
* @param prefix The Name prefix used to match the name of an incoming
* Interest. This copies the Name.
* @param onDataNotFound If a data packet for an interest is not found in the
* cache, this forwards the interest by calling
* onDataNotFound.onInterest(prefix, interest, face, interestFilterId, filter).
* Your callback can find the Data packet for the interest and call
* face.putData(data). Note: If you call setInterestFilter multiple times where
* filter.getPrefix() is the same, it is undetermined which onDataNotFound
* will be called. If your callback cannot find the Data packet, it can
* optionally call storePendingInterest(interest, face) to store the pending
* interest in this object to be satisfied by a later call to add(data). If
* you want to automatically store all pending interests, you can simply use
* getStorePendingInterest() for onDataNotFound. If onDataNotFound is null,
* this does not use it.
* NOTE: The library will log any exceptions thrown by this callback, but for
* better error handling the callback should catch and properly handle any
* exceptions.
*/
public final void
setInterestFilter(Name prefix, OnInterestCallback onDataNotFound)
{
if (onDataNotFound != null)
onDataNotFoundForPrefix_.put(prefix.toUri(), onDataNotFound);
long interestFilterId = face_.setInterestFilter(prefix, this);
interestFilterIdList_.add(interestFilterId);
}
/**
* Call setInterestFilter on the Face given to the constructor so that this
* MemoryContentCache will answer interests whose name has the prefix.
* Do not call a callback if a data packet is not found in the cache.
* @param prefix The Name prefix used to match the name of an incoming
* Interest. This copies the Name.
*/
public final void
setInterestFilter(Name prefix)
{
setInterestFilter(prefix, null);
}
/**
* Call Face.unsetInterestFilter and Face.removeRegisteredPrefix for all the
* prefixes given to the setInterestFilter and registerPrefix method on this
* MemoryContentCache object so that it will not receive interests any more.
* You can call this if you want to "shut down" this MemoryContentCache while
* your application is still running.
*/
public final void
unregisterAll()
{
for (int i = 0; i < interestFilterIdList_.size(); ++i)
face_.unsetInterestFilter((long)interestFilterIdList_.get(i));
interestFilterIdList_.clear();
for (int i = 0; i < registeredPrefixIdList_.size(); ++i)
face_.removeRegisteredPrefix((long)registeredPrefixIdList_.get(i));
registeredPrefixIdList_.clear();
// Also clear each onDataNotFoundForPrefix given to registerPrefix.
onDataNotFoundForPrefix_.clear();
}
/**
* Add the Data packet to the cache so that it is available to use to
* answer interests. If data.getMetaInfo().getFreshnessPeriod() is not
* negative, set the staleness time to now plus
* data.getMetaInfo().getFreshnessPeriod(), which is checked during cleanup to
* remove stale content. This also checks if cleanupIntervalMilliseconds
* milliseconds have passed and removes stale content from the cache. After
* removing stale content, remove timed-out pending interests from
* storePendingInterest(), then if the added Data packet satisfies any
* interest, send it through the face and remove the interest from the pending
* interest table.
* @param data The Data packet object to put in the cache. This copies the
* fields from the object.
*/
public final void
add(Data data)
{
doCleanup();
if (data.getMetaInfo().getFreshnessPeriod() >= 0.0) {
// The content will go stale, so use staleTimeCache_.
StaleTimeContent content = new StaleTimeContent(data);
// Insert into staleTimeCache, sorted on content.staleTimeMilliseconds.
// Search from the back since we expect it to go there.
int i = staleTimeCache_.size() - 1;
while (i >= 0) {
if (staleTimeCache_.get(i).getStaleTimeMilliseconds() <=
content.getStaleTimeMilliseconds())
break;
--i;
}
// Element i is the greatest less than or equal to
// content.staleTimeMilliseconds, so insert after it.
staleTimeCache_.add(i + 1, content);
}
else
// The data does not go stale, so use noStaleTimeCache_.
noStaleTimeCache_.add(new Content(data));
// Remove timed-out interests and check if the data packet matches any
// pending interest.
// Go backwards through the list so we can erase entries.
double nowMilliseconds = Common.getNowMilliseconds();
for (int i = pendingInterestTable_.size() - 1; i >= 0; --i) {
PendingInterest pendingInterest = pendingInterestTable_.get(i);
if (pendingInterest.isTimedOut(nowMilliseconds)) {
pendingInterestTable_.remove(i);
continue;
}
if (pendingInterest.getInterest().matchesName(data.getName())) {
try {
// Send to the same face from the original call to onInterest.
// wireEncode returns the cached encoding if available.
pendingInterest.getFace().send(data.wireEncode());
} catch (IOException ex) {
Logger.getLogger(MemoryContentCache.class.getName()).log(Level.SEVERE,
ex.getMessage());
return;
}
// The pending interest is satisfied, so remove it.
pendingInterestTable_.remove(i);
}
}
}
/**
* Store an interest from an OnInterest callback in the internal pending
* interest table (normally because there is no Data packet available yet to
* satisfy the interest). add(data) will check if the added Data packet
* satisfies any pending interest and send it through the face.
* @param interest The Interest for which we don't have a Data packet yet. You
* should not modify the interest after calling this.
* @param face The Face with the connection which received the interest. This
* comes from the OnInterest callback.
*/
public final void
storePendingInterest(Interest interest, Face face)
{
pendingInterestTable_.add(new PendingInterest(interest, face));
}
/**
* Return a callback to use for onDataNotFound in registerPrefix which simply
* calls storePendingInterest() to store the interest that doesn't match a
* Data packet. add(data) will check if the added Data packet satisfies any
* pending interest and send it.
* @return A callback to use for onDataNotFound in registerPrefix().
*/
public final OnInterestCallback
getStorePendingInterest()
{
return storePendingInterestCallback_;
}
public final void
onInterest
(Name prefix, Interest interest, Face face, long interestFilterId,
InterestFilter filter)
{
doCleanup();
Name.Component selectedComponent = null;
Blob selectedEncoding = null;
// We need to iterate over both arrays.
int totalSize = staleTimeCache_.size() + noStaleTimeCache_.size();
for (int i = 0; i < totalSize; ++i) {
Content content;
if (i < staleTimeCache_.size())
content = staleTimeCache_.get(i);
else
// We have iterated over the first array. Get from the second.
content = noStaleTimeCache_.get(i - staleTimeCache_.size());
if (interest.matchesName(content.getName())) {
if (interest.getChildSelector() < 0) {
// No child selector, so send the first match that we have found.
try {
face.send(content.getDataEncoding());
} catch (IOException ex) {
Logger.getLogger(MemoryContentCache.class.getName()).log(Level.SEVERE, null, ex);
}
return;
}
else {
// Update selectedEncoding based on the child selector.
Name.Component component;
if (content.getName().size() > interest.getName().size())
component = content.getName().get(interest.getName().size());
else
component = emptyComponent_;
boolean gotBetterMatch = false;
if (selectedEncoding == null)
// Save the first match.
gotBetterMatch = true;
else {
if (interest.getChildSelector() == 0) {
// Leftmost child.
if (component.compare(selectedComponent) < 0)
gotBetterMatch = true;
}
else {
// Rightmost child.
if (component.compare(selectedComponent) > 0)
gotBetterMatch = true;
}
}
if (gotBetterMatch) {
selectedComponent = component;
selectedEncoding = content.getDataEncoding();
}
}
}
}
if (selectedEncoding != null) {
// We found the leftmost or rightmost child.
try {
face.send(selectedEncoding);
} catch (IOException ex) {
Logger.getLogger(MemoryContentCache.class.getName()).log(Level.SEVERE, null, ex);
}
}
else {
// Call the onDataNotFound callback (if defined).
Object onDataNotFound = onDataNotFoundForPrefix_.get(prefix.toUri());
if (onDataNotFound != null) {
try {
((OnInterestCallback)onDataNotFound).onInterest
(prefix, interest, face, interestFilterId, filter);
} catch (Throwable ex) {
logger_.log(Level.SEVERE, "Error in onDataNotFound", ex);
}
}
}
}
/**
* Content is a private class to hold the name and encoding for each entry
* in the cache. This base class is for a Data packet without a
* FreshnessPeriod.
*/
private class Content {
/**
* Create a new Content entry to hold data's name and wire encoding.
* @param data The Data packet whose name and wire encoding are copied.
*/
public Content(Data data)
{
// wireEncode returns the cached encoding if available.
name_ = data.getName();
dataEncoding_ = data.wireEncode();
}
public final Name
getName() { return name_; }
public final Blob
getDataEncoding() { return dataEncoding_; }
private final Name name_;
private final Blob dataEncoding_;
}
/**
* StaleTimeContent extends Content to include the staleTimeMilliseconds
* for when this entry should be cleaned up from the cache.
*/
private class StaleTimeContent extends Content {
/**
* Create a new StaleTimeContent to hold data's name and wire encoding
* as well as the staleTimeMilliseconds which is now plus
* data.getMetaInfo().getFreshnessPeriod().
* @param data The Data packet whose name and wire encoding are copied.
*/
public StaleTimeContent(Data data)
{
// wireEncode returns the cached encoding if available.
super(data);
// Set up staleTimeMilliseconds_.
staleTimeMilliseconds_ = Common.getNowMilliseconds() +
data.getMetaInfo().getFreshnessPeriod();
}
/**
* Check if this content is stale.
* @param nowMilliseconds The current time in milliseconds from
* Common.getNowMilliseconds().
* @return True if this content is stale, otherwise false.
*/
public final boolean
isStale(double nowMilliseconds)
{
return staleTimeMilliseconds_ <= nowMilliseconds;
}
public final double
getStaleTimeMilliseconds() { return staleTimeMilliseconds_; }
private final double staleTimeMilliseconds_; /**< The time when the content
becomse stale in milliseconds according to Common.getNowMilliseconds() */
}
/**
* A PendingInterest holds an interest which onInterest received but could
* not satisfy. When we add a new data packet to the cache, we will also check
* if it satisfies a pending interest.
*/
private static class PendingInterest {
/**
* Create a new PendingInterest and set the timeoutTime_ based on the current
* time and the interest lifetime.
* @param interest The interest.
* @param face The face from the onInterest callback. If the
* interest is satisfied later by a new data packet, we will send the data
* packet to the face.
*/
public PendingInterest(Interest interest, Face face)
{
interest_ = interest;
face_ = face;
// Set up timeoutTimeMilliseconds_.
if (interest_.getInterestLifetimeMilliseconds() >= 0.0)
timeoutTimeMilliseconds_ = Common.getNowMilliseconds() +
interest_.getInterestLifetimeMilliseconds();
else
// No timeout.
timeoutTimeMilliseconds_ = -1.0;
}
/**
* Return the interest given to the constructor.
*/
public final Interest
getInterest() { return interest_; }
/**
* Return the face given to the constructor.
*/
public final Face
getFace() { return face_; }
/**
* Check if this interest is timed out.
* @param nowMilliseconds The current time in milliseconds from
* Common.getNowMilliseconds.
* @return True if this interest timed out, otherwise false.
*/
public final boolean
isTimedOut(double nowMilliseconds)
{
return timeoutTimeMilliseconds_ >= 0.0 && nowMilliseconds >= timeoutTimeMilliseconds_;
}
private final Interest interest_;
private final Face face_;
private final double timeoutTimeMilliseconds_; /**< The time when the
* interest times out in milliseconds according to ndn_getNowMilliseconds,
* or -1 for no timeout. */
}
/**
* Check if now is greater than nextCleanupTime_ and, if so, remove stale
* content from staleTimeCache_ and reset nextCleanupTime_ based on
* cleanupIntervalMilliseconds_. Since add(Data) does a sorted insert into
* staleTimeCache_, the check for stale data is quick and does not require
* searching the entire staleTimeCache_.
*/
private void
doCleanup()
{
double now = Common.getNowMilliseconds();
if (now >= nextCleanupTime_) {
// staleTimeCache_ is sorted on staleTimeMilliseconds_, so we only need to
// erase the stale entries at the front, then quit.
while (staleTimeCache_.size() > 0 && staleTimeCache_.get(0).isStale(now))
staleTimeCache_.remove(0);
nextCleanupTime_ = now + cleanupIntervalMilliseconds_;
}
}
private final Face face_;
private final double cleanupIntervalMilliseconds_;
private double nextCleanupTime_;
// Use HashMap without generics so it works with older Java compilers.
private final HashMap onDataNotFoundForPrefix_ =
new HashMap(); /**< The map key is the prefix.toUri().
* The value is the OnInterest callback. */
// Use ArrayList without generics so it works with older Java compilers.
private final ArrayList<Long> interestFilterIdList_ = new ArrayList<Long>();
private final ArrayList<Long> registeredPrefixIdList_ = new ArrayList<Long>();
private final ArrayList<Content> noStaleTimeCache_ = new ArrayList<Content>();
private final ArrayList<StaleTimeContent> staleTimeCache_ =
new ArrayList<StaleTimeContent>();
private final Name.Component emptyComponent_ = new Name.Component();
private final ArrayList<PendingInterest> pendingInterestTable_ =
new ArrayList<PendingInterest>();
private OnInterestCallback storePendingInterestCallback_;
private static final Logger logger_ = Logger.getLogger(MemoryContentCache.class.getName());
}