Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
/*
* Copyright 2016 Google LLC
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google LLC nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.google.api.gax.paging;
import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
import com.google.api.core.ApiFunction;
import com.google.api.core.ApiFuture;
import com.google.api.core.ApiFutures;
import com.google.api.core.InternalApi;
import com.google.api.gax.rpc.ApiExceptions;
import com.google.api.gax.rpc.PageContext;
import com.google.common.base.Strings;
import com.google.common.collect.AbstractIterator;
import com.google.common.collect.Iterables;
import java.util.Iterator;
/** Partial implementation of {@link AsyncPage}. */
public abstract class AbstractPage<
RequestT,
ResponseT,
ResourceT,
PageT extends AbstractPage>
implements AsyncPage {
private final PageContext context;
private final ResponseT response;
protected AbstractPage(PageContext context, ResponseT response) {
this.context = context;
this.response = response;
}
protected abstract PageT createPage(
PageContext context, ResponseT response);
@InternalApi("Visible for testing")
public ApiFuture createPageAsync(
final PageContext context,
ApiFuture futureResponse) {
return ApiFutures.transform(
futureResponse,
new ApiFunction() {
@Override
public PageT apply(ResponseT input) {
return createPage(context, input);
}
},
directExecutor());
}
@Override
public boolean hasNextPage() {
return !getNextPageToken().equals(context.getPageDescriptor().emptyToken());
}
@Override
public String getNextPageToken() {
return Strings.nullToEmpty(context.getPageDescriptor().extractNextToken(response));
}
@Override
public PageT getNextPage() {
return getNextPageImpl(null);
}
public PageT getNextPage(int pageSize) {
return getNextPageImpl(pageSize);
}
@Override
public ApiFuture getNextPageAsync() {
if (hasNextPage()) {
RequestT request =
context.getPageDescriptor().injectToken(context.getRequest(), getNextPageToken());
final PageContext nextContext = context.withRequest(request);
return createPageAsync(nextContext, callApi(nextContext));
} else {
return ApiFutures.immediateFuture(null);
}
}
private PageT getNextPageImpl(Integer pageSize) {
if (hasNextPage()) {
RequestT request =
context.getPageDescriptor().injectToken(context.getRequest(), getNextPageToken());
if (pageSize != null) {
request = context.getPageDescriptor().injectPageSize(request, pageSize);
}
PageContext nextContext = context.withRequest(request);
ResponseT response = ApiExceptions.callAndTranslateApiException(callApi(nextContext));
return createPage(nextContext, response);
} else {
return null;
}
}
private ApiFuture callApi(PageContext nextContext) {
return nextContext
.getCallable()
.futureCall(nextContext.getRequest(), nextContext.getCallContext());
}
@Override
public Iterable iterateAll() {
return new Iterable() {
@Override
public Iterator iterator() {
return new AllResourcesIterator();
}
};
}
@Override
public Iterable getValues() {
return context.getPageDescriptor().extractResources(response);
}
public ResponseT getResponse() {
return response;
}
public RequestT getRequest() {
return context.getRequest();
}
public int getPageElementCount() {
return Iterables.size(context.getPageDescriptor().extractResources(response));
}
PageContext getContext() {
return context;
}
private class AllResourcesIterator extends AbstractIterator {
private AbstractPage currentPage;
private Iterator currentIterator;
private AllResourcesIterator() {
this.currentPage = AbstractPage.this;
this.currentIterator = this.currentPage.getValues().iterator();
}
@Override
protected ResourceT computeNext() {
while (true) {
if (currentIterator.hasNext()) {
return currentIterator.next();
}
currentPage = currentPage.getNextPage();
if (currentPage == null) {
return endOfData();
}
currentIterator = currentPage.getValues().iterator();
}
}
}
}