// Copyright (C) 2009 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.gerrit.sshd;
import com.google.gerrit.server.CurrentUser;
import com.google.gerrit.server.IdentifiedUser;
import com.google.gerrit.server.RequestCleanup;
import com.google.gerrit.server.util.RequestContext;
import com.google.gerrit.server.util.ThreadLocalRequestContext;
import com.google.gerrit.server.util.ThreadLocalRequestScopePropagator;
import com.google.inject.Inject;
import com.google.inject.Key;
import com.google.inject.OutOfScopeException;
import com.google.inject.Provider;
import com.google.inject.Scope;
import java.util.HashMap;
import java.util.Map;
/** Guice scopes for state during an SSH connection. */
class SshScope {
private static final Key<RequestCleanup> RC_KEY =
Key.get(RequestCleanup.class);
class Context implements RequestContext {
private final RequestCleanup cleanup;
private final SshSession session;
private final String commandLine;
private final Map<Key<?>, Object> map;
final long created;
volatile long started;
volatile long finished;
private Context(final SshSession s, final String c, final long at) {
cleanup = new RequestCleanup();
session = s;
commandLine = c;
map = new HashMap<Key<?>, Object>();
map.put(RC_KEY, cleanup);
created = started = finished = at;
}
private Context(Context p, SshSession s, String c) {
this(s, c, p.created);
started = p.started;
finished = p.finished;
}
String getCommandLine() {
return commandLine;
}
SshSession getSession() {
return session;
}
@Override
public CurrentUser getCurrentUser() {
final CurrentUser user = session.getCurrentUser();
if (user instanceof IdentifiedUser) {
return userFactory.create(user.getAccessPath(), //
((IdentifiedUser) user).getAccountId());
}
return user;
}
synchronized <T> T get(Key<T> key, Provider<T> creator) {
@SuppressWarnings("unchecked")
T t = (T) map.get(key);
if (t == null) {
t = creator.get();
map.put(key, t);
}
return t;
}
synchronized Context subContext(SshSession newSession, String newCommandLine) {
Context ctx = new Context(this, newSession, newCommandLine);
cleanup.add(ctx.cleanup);
return ctx;
}
}
static class ContextProvider implements Provider<Context> {
@Override
public Context get() {
return requireContext();
}
}
static class SshSessionProvider implements Provider<SshSession> {
@Override
public SshSession get() {
return requireContext().getSession();
}
}
static class Propagator extends ThreadLocalRequestScopePropagator<Context> {
private final SshScope sshScope;
@Inject
Propagator(SshScope sshScope, ThreadLocalRequestContext local) {
super(REQUEST, current, local);
this.sshScope = sshScope;
}
@Override
protected Context continuingContext(Context ctx) {
// The cleanup is not chained, since the RequestScopePropagator executors
// the Context's cleanup when finished executing.
return sshScope.newContinuingContext(ctx);
}
}
private static final ThreadLocal<Context> current =
new ThreadLocal<Context>();
private static Context requireContext() {
final Context ctx = current.get();
if (ctx == null) {
throw new OutOfScopeException("Not in command/request");
}
return ctx;
}
private final ThreadLocalRequestContext local;
private final IdentifiedUser.RequestFactory userFactory;
@Inject
SshScope(ThreadLocalRequestContext local,
IdentifiedUser.RequestFactory userFactory) {
this.local = local;
this.userFactory = userFactory;
}
Context newContext(SshSession session, String commandLine) {
return new Context(session, commandLine, System.currentTimeMillis());
}
private Context newContinuingContext(Context ctx) {
return new Context(ctx, ctx.getSession(), ctx.getCommandLine());
}
Context set(Context ctx) {
Context old = current.get();
current.set(ctx);
local.setContext(ctx);
return old;
}
/** Returns exactly one instance per command executed. */
static final Scope REQUEST = new Scope() {
public <T> Provider<T> scope(final Key<T> key, final Provider<T> creator) {
return new Provider<T>() {
public T get() {
return requireContext().get(key, creator);
}
@Override
public String toString() {
return String.format("%s[%s]", creator, REQUEST);
}
};
}
@Override
public String toString() {
return "SshScopes.REQUEST";
}
};
}