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Diffstat (limited to 'src/third_party/wiredtiger/examples/java/com/wiredtiger/examples/ex_async.java')
| -rw-r--r-- | src/third_party/wiredtiger/examples/java/com/wiredtiger/examples/ex_async.java | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/src/third_party/wiredtiger/examples/java/com/wiredtiger/examples/ex_async.java b/src/third_party/wiredtiger/examples/java/com/wiredtiger/examples/ex_async.java new file mode 100644 index 00000000000..2e890095b2d --- /dev/null +++ b/src/third_party/wiredtiger/examples/java/com/wiredtiger/examples/ex_async.java @@ -0,0 +1,221 @@ +/*- + * Public Domain 2014-2016 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); + } + } +} |