cassandra-server
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A thin Javascript wrapper around Apache Cassandra to provide out of the box server support
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<div class="subTitle">org.apache.cassandra.service.pager</div>
<h2 title="Interface QueryPager" class="title">Interface QueryPager</h2>
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<dt>All Known Subinterfaces:</dt>
<dd><a href="../../../../../org/apache/cassandra/service/pager/SinglePartitionPager.html" title="interface in org.apache.cassandra.service.pager">SinglePartitionPager</a></dd>
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<dt>All Known Implementing Classes:</dt>
<dd><a href="../../../../../org/apache/cassandra/service/pager/NamesQueryPager.html" title="class in org.apache.cassandra.service.pager">NamesQueryPager</a>, <a href="../../../../../org/apache/cassandra/service/pager/RangeNamesQueryPager.html" title="class in org.apache.cassandra.service.pager">RangeNamesQueryPager</a>, <a href="../../../../../org/apache/cassandra/service/pager/RangeSliceQueryPager.html" title="class in org.apache.cassandra.service.pager">RangeSliceQueryPager</a>, <a href="../../../../../org/apache/cassandra/service/pager/SliceQueryPager.html" title="class in org.apache.cassandra.service.pager">SliceQueryPager</a></dd>
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<pre>public interface <span class="strong">QueryPager</span></pre>
<div class="block">Perform a query, paging it by page of a given size.
This is essentially an iterator of pages. Each call to fetchPage() will
return the next page (i.e. the next list of rows) and isExhausted()
indicates whether there is more page to fetch. The pageSize will
either be in term of cells or in term of CQL3 row, depending on the
parameters of the command we page.
Please note that the pager might page within rows, so there is no guarantee
that successive pages won't return the same row (though with different
columns every time).
Also, there is no guarantee that fetchPage() won't return an empty list,
even if isExhausted() return false (but it is guaranteed to return an empty
list *if* isExhausted() return true). Indeed, isExhausted() does *not*
trigger a query so in some (fairly rare) case we might not know the paging
is done even though it is.</div>
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<th class="colFirst" scope="col">Modifier and Type</th>
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<td class="colFirst"><code>java.util.List<<a href="../../../../../org/apache/cassandra/db/Row.html" title="class in org.apache.cassandra.db">Row</a>></code></td>
<td class="colLast"><code><strong><a href="../../../../../org/apache/cassandra/service/pager/QueryPager.html#fetchPage(int)">fetchPage</a></strong>(int pageSize)</code>
<div class="block">Fetches the next page.</div>
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<td class="colFirst"><code>boolean</code></td>
<td class="colLast"><code><strong><a href="../../../../../org/apache/cassandra/service/pager/QueryPager.html#isExhausted()">isExhausted</a></strong>()</code>
<div class="block">Whether or not this pager is exhausted, i.e.</div>
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<td class="colFirst"><code>int</code></td>
<td class="colLast"><code><strong><a href="../../../../../org/apache/cassandra/service/pager/QueryPager.html#maxRemaining()">maxRemaining</a></strong>()</code>
<div class="block">The maximum number of cells/CQL3 row that we may still have to return.</div>
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<td class="colFirst"><code><a href="../../../../../org/apache/cassandra/service/pager/PagingState.html" title="class in org.apache.cassandra.service.pager">PagingState</a></code></td>
<td class="colLast"><code><strong><a href="../../../../../org/apache/cassandra/service/pager/QueryPager.html#state()">state</a></strong>()</code>
<div class="block">Get the current state of the pager.</div>
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<h4>fetchPage</h4>
<pre>java.util.List<<a href="../../../../../org/apache/cassandra/db/Row.html" title="class in org.apache.cassandra.db">Row</a>> fetchPage(int pageSize)
throws <a href="../../../../../org/apache/cassandra/exceptions/RequestValidationException.html" title="class in org.apache.cassandra.exceptions">RequestValidationException</a>,
<a href="../../../../../org/apache/cassandra/exceptions/RequestExecutionException.html" title="class in org.apache.cassandra.exceptions">RequestExecutionException</a></pre>
<div class="block">Fetches the next page.</div>
<dl><dt><span class="strong">Parameters:</span></dt><dd><code>pageSize</code> - the maximum number of elements to return in the next page.</dd>
<dt><span class="strong">Returns:</span></dt><dd>the page of result.</dd>
<dt><span class="strong">Throws:</span></dt>
<dd><code><a href="../../../../../org/apache/cassandra/exceptions/RequestValidationException.html" title="class in org.apache.cassandra.exceptions">RequestValidationException</a></code></dd>
<dd><code><a href="../../../../../org/apache/cassandra/exceptions/RequestExecutionException.html" title="class in org.apache.cassandra.exceptions">RequestExecutionException</a></code></dd></dl>
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<h4>isExhausted</h4>
<pre>boolean isExhausted()</pre>
<div class="block">Whether or not this pager is exhausted, i.e. whether or not a call to
fetchPage may return more result.</div>
<dl><dt><span class="strong">Returns:</span></dt><dd>whether the pager is exhausted.</dd></dl>
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<h4>maxRemaining</h4>
<pre>int maxRemaining()</pre>
<div class="block">The maximum number of cells/CQL3 row that we may still have to return.
In other words, that's the initial user limit minus what we've already
returned (note that it's not how many we *will* return, just the upper
limit on it).</div>
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<h4>state</h4>
<pre><a href="../../../../../org/apache/cassandra/service/pager/PagingState.html" title="class in org.apache.cassandra.service.pager">PagingState</a> state()</pre>
<div class="block">Get the current state of the pager. The state can allow to restart the
paging on another host from where we are at this point.</div>
<dl><dt><span class="strong">Returns:</span></dt><dd>the current paging state. Will return null if paging is at the
beginning. If the pager is exhausted, the result is undefined.</dd></dl>
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