1 /*
2 * #%L
3 * GetLastError.java - mongodb-async-driver - Allanbank Consulting, Inc.
4 * %%
5 * Copyright (C) 2011 - 2014 Allanbank Consulting, Inc.
6 * %%
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 * #L%
19 */
20 package com.allanbank.mongodb.client.message;
21
22 import java.io.StringWriter;
23
24 import com.allanbank.mongodb.Durability;
25 import com.allanbank.mongodb.ReadPreference;
26 import com.allanbank.mongodb.bson.Document;
27 import com.allanbank.mongodb.bson.builder.BuilderFactory;
28 import com.allanbank.mongodb.bson.builder.DocumentBuilder;
29 import com.allanbank.mongodb.bson.element.JsonSerializationVisitor;
30 import com.allanbank.mongodb.client.connection.Connection;
31
32 /**
33 * Provides a convenient mechanism for creating a <a href=
34 * "http://www.mongodb.org/display/DOCS/getLastError+Command" >getlasterror</a>
35 * command.
36 * <p>
37 * This is a helper class for retrieving the results of {@link Delete},
38 * {@link Insert}, and {@link Update} commands. Get last error is not a part of
39 * the standard wire protocol but is provided here due to the frequency of
40 * usage.
41 * </p>
42 *
43 * @api.no This class is <b>NOT</b> part of the drivers API. This class may be
44 * mutated in incompatible ways between any two releases of the driver.
45 * @copyright 2011-2013, Allanbank Consulting, Inc., All Rights Reserved
46 */
47 public class GetLastError extends Query {
48
49 /**
50 * Creates the query document for the getlasterror command.
51 *
52 * @param fsync
53 * If true the command waits for an fsync of the data to have
54 * completed.
55 * @param waitForJournal
56 * If true the command waits for the preceding command to have
57 * been written to the journal.
58 * @param w
59 * The replication factor to wait for.
60 * @param wtimeout
61 * The amount of time (in milliseconds) to wait for the write to
62 * finish.
63 * @return The command's query document.
64 */
65 private static Document createQuery(final boolean fsync,
66 final boolean waitForJournal, final int w, final int wtimeout) {
67 final DocumentBuilder builder = BuilderFactory.start();
68 builder.addInteger("getlasterror", 1);
69 if (waitForJournal) {
70 builder.addBoolean("j", waitForJournal);
71 }
72 if (fsync) {
73 builder.addBoolean("fsync", fsync);
74 }
75 if (w >= 1) {
76 builder.addInteger("w", w);
77 }
78 if (wtimeout > 0) {
79 builder.addInteger("wtimeout", wtimeout);
80 }
81 return builder.build();
82 }
83
84 /**
85 * Create a new GetLastError.
86 *
87 * @param dbName
88 * The name of the database.
89 * @param fsync
90 * If true the command waits for an fsync of the data to have
91 * completed.
92 * @param waitForJournal
93 * If true the command waits for the preceding command to have
94 * been written to the journal.
95 * @param w
96 * The replication factor to wait for.
97 * @param wtimeout
98 * The amount of time (in milliseconds) to wait for the write to
99 * finish.
100 */
101 public GetLastError(final String dbName, final boolean fsync,
102 final boolean waitForJournal, final int w, final int wtimeout) {
103 super(dbName, Connection.COMMAND_COLLECTION, createQuery(fsync,
104 waitForJournal, w, wtimeout), /* fields= */null,
105 /* batchSize= */1, /* limit= */1, /* numberToSkip= */0,
106 /* tailable= */false, ReadPreference.PRIMARY,
107 /* noCursorTimeout= */false, /* awaitData= */false,
108 /* exhaust= */false, /* partial= */false);
109 }
110
111 /**
112 * Create a new GetLastError.
113 *
114 * @param dbName
115 * The name of the database.
116 * @param durability
117 * The Durability requested.
118 */
119 public GetLastError(final String dbName, final Durability durability) {
120 super(dbName, Connection.COMMAND_COLLECTION, durability.asDocument(),
121 /* fields= */null, /* batchSize= */1, /* limit= */1,
122 /* numberToSkip= */0, /* tailable= */false, ReadPreference.PRIMARY,
123 /* noCursorTimeout= */false, /* awaitData= */false,
124 /* exhaust= */false, /* partial= */false);
125 }
126
127 /**
128 * {@inheritDoc}
129 * <p>
130 * Overridden to returns the getLastError on a single line.
131 * </p>
132 */
133 @Override
134 public String toString() {
135 final StringWriter sink = new StringWriter();
136
137 final JsonSerializationVisitor visitor = new JsonSerializationVisitor(
138 sink, true);
139 getQuery().accept(visitor);
140
141 return sink.toString();
142 }
143 }