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/*-
* Public Domain 2014-2017 MongoDB, Inc.
* Public Domain 2008-2014 WiredTiger, Inc.
*
* This is free and unencumbered software released into the public domain.
*
* Anyone is free to copy, modify, publish, use, compile, sell, or
* distribute this software, either in source code form or as a compiled
* binary, for any purpose, commercial or non-commercial, and by any
* means.
*
* In jurisdictions that recognize copyright laws, the author or authors
* of this software dedicate any and all copyright interest in the
* software to the public domain. We make this dedication for the benefit
* of the public at large and to the detriment of our heirs and
* successors. We intend this dedication to be an overt act of
* relinquishment in perpetuity of all present and future rights to this
* software under copyright law.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* ex_async.java
* demonstrates how to use the asynchronous API.
*/
package com.wiredtiger.examples;
import com.wiredtiger.db.*;
import java.io.*;
import java.util.*;
/*! [async example callback implementation] */
class AsyncKeys implements AsyncCallback {
public int numKeys = 0;
public AsyncKeys() {}
public void notifyError(String desc) {
System.err.println("ERROR: notify: " + desc);
}
public int notify(AsyncOp op, int opReturn, int flags) {
/*
* Note: we are careful not to throw any errors here. Any
* exceptions would be swallowed by a native worker thread.
*/
int ret = 0;
try {
/*! [async get type] */
/* Retrieve the operation's type. */
AsyncOpType optype = op.getType();
/*! [async get type] */
/*! [async get identifier] */
/* Retrieve the operation's 64-bit identifier. */
long id = op.getId();
/*! [async get identifier] */
/* If doing a search, retrieve the key/value pair. */
if (optype == AsyncOpType.WT_AOP_SEARCH) {
/*! [async get the operation's string key] */
String key = op.getKeyString();
/*! [async get the operation's string key] */
/*! [async get the operation's string value] */
String value = op.getValueString();
/*! [async get the operation's string value] */
synchronized (this) {
numKeys += 1;
}
System.out.println("Id " + id + " got record: " + key +
" : " + value);
}
}
catch (Exception e) {
System.err.println("ERROR: exception in notify: " + e.toString() +
", opreturn=" + opReturn);
ret = 1;
}
return (ret);
}
}
/*! [async example callback implementation] */
public class ex_async {
public static String home;
public static final int MAX_KEYS = 15;
public static AsyncOp tryAsyncNewOp(Connection conn, String uri,
String config, AsyncCallback cb) throws WiredTigerException
{
WiredTigerException savedwte = null;
for (int tries = 0; tries < 10; tries++)
try {
return conn.async_new_op(uri, config, cb);
}
catch (WiredTigerException wte) {
/*
* If we used up all the handles, pause and retry to
* give the workers a chance to catch up.
*/
System.err.println(
"asynchronous operation handle not available: " + wte);
savedwte = wte;
try {
Thread.sleep(1);
} catch (InterruptedException ie) {
/* not a big problem, continue to retry */
}
}
throw savedwte;
}
public static int
asyncExample()
throws WiredTigerException
{
AsyncOp op;
Connection conn;
Session session;
int i, ret;
String k[] = new String[MAX_KEYS];
String v[] = new String[MAX_KEYS];
/*! [async example callback implementation part 2] */
AsyncKeys asynciface = new AsyncKeys();
/*! [async example callback implementation part 2] */
/*! [async example connection] */
conn = wiredtiger.open(home, "create,cache_size=100MB," +
"async=(enabled=true,ops_max=20,threads=2)");
/*! [async example connection] */
/*! [async example table create] */
session = conn.open_session(null);
ret = session.create("table:async", "key_format=S,value_format=S");
/*! [async example table create] */
/* Insert a set of keys asynchronously. */
for (i = 0; i < MAX_KEYS; i++) {
/*! [async handle allocation] */
op = tryAsyncNewOp(conn, "table:async", null, asynciface);
/*! [async handle allocation] */
/*! [async insert] */
/*
* Set the operation's string key and value, and then do
* an asynchronous insert.
*/
/*! [async set the operation's string key] */
k[i] = "key" + i;
op.putKeyString(k[i]);
/*! [async set the operation's string key] */
/*! [async set the operation's string value] */
v[i] = "value" + i;
op.putValueString(v[i]);
/*! [async set the operation's string value] */
ret = op.insert();
/*! [async insert] */
}
/*! [async flush] */
/* Wait for all outstanding operations to complete. */
ret = conn.async_flush();
/*! [async flush] */
/*! [async compaction] */
/*
* Compact a table asynchronously, limiting the run-time to 5 minutes.
*/
op = tryAsyncNewOp(conn, "table:async", "timeout=300", asynciface);
ret = op.compact();
/*! [async compaction] */
/* Search for the keys we just inserted, asynchronously. */
for (i = 0; i < MAX_KEYS; i++) {
op = tryAsyncNewOp(conn, "table:async", null, asynciface);
/*! [async search] */
/*
* Set the operation's string key and value, and then do
* an asynchronous search.
*/
k[i] = "key" + i;
op.putKeyString(k[i]);
ret = op.search();
/*! [async search] */
}
/*
* Connection close automatically does an async_flush so it will wait
* for all queued search operations to complete.
*/
ret = conn.close(null);
System.out.println("Searched for " + asynciface.numKeys + " keys");
return (ret);
}
public static void
main(String[] argv)
{
try {
System.exit(asyncExample());
}
catch (WiredTigerException wte) {
System.err.println("Exception: " + wte);
wte.printStackTrace();
System.exit(1);
}
}
}
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