1 | /* |
2 | * Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0, |
3 | * and the EPL 1.0 (http://h2database.com/html/license.html). |
4 | * Initial Developer: H2 Group |
5 | */ |
6 | package org.h2.command; |
7 | |
8 | import java.io.IOException; |
9 | import java.util.ArrayList; |
10 | import org.h2.engine.SessionRemote; |
11 | import org.h2.engine.SysProperties; |
12 | import org.h2.expression.ParameterInterface; |
13 | import org.h2.expression.ParameterRemote; |
14 | import org.h2.message.DbException; |
15 | import org.h2.message.Trace; |
16 | import org.h2.result.ResultInterface; |
17 | import org.h2.result.ResultRemote; |
18 | import org.h2.util.New; |
19 | import org.h2.value.Transfer; |
20 | import org.h2.value.Value; |
21 | |
22 | /** |
23 | * Represents the client-side part of a SQL statement. |
24 | * This class is not used in embedded mode. |
25 | */ |
26 | public class CommandRemote implements CommandInterface { |
27 | |
28 | private final ArrayList<Transfer> transferList; |
29 | private final ArrayList<ParameterInterface> parameters; |
30 | private final Trace trace; |
31 | private final String sql; |
32 | private final int fetchSize; |
33 | private SessionRemote session; |
34 | private int id; |
35 | private boolean isQuery; |
36 | private boolean readonly; |
37 | private final int created; |
38 | |
39 | public CommandRemote(SessionRemote session, |
40 | ArrayList<Transfer> transferList, String sql, int fetchSize) { |
41 | this.transferList = transferList; |
42 | trace = session.getTrace(); |
43 | this.sql = sql; |
44 | parameters = New.arrayList(); |
45 | prepare(session, true); |
46 | // set session late because prepare might fail - in this case we don't |
47 | // need to close the object |
48 | this.session = session; |
49 | this.fetchSize = fetchSize; |
50 | created = session.getLastReconnect(); |
51 | } |
52 | |
53 | private void prepare(SessionRemote s, boolean createParams) { |
54 | id = s.getNextId(); |
55 | for (int i = 0, count = 0; i < transferList.size(); i++) { |
56 | try { |
57 | Transfer transfer = transferList.get(i); |
58 | if (createParams) { |
59 | s.traceOperation("SESSION_PREPARE_READ_PARAMS", id); |
60 | transfer. |
61 | writeInt(SessionRemote.SESSION_PREPARE_READ_PARAMS). |
62 | writeInt(id).writeString(sql); |
63 | } else { |
64 | s.traceOperation("SESSION_PREPARE", id); |
65 | transfer.writeInt(SessionRemote.SESSION_PREPARE). |
66 | writeInt(id).writeString(sql); |
67 | } |
68 | s.done(transfer); |
69 | isQuery = transfer.readBoolean(); |
70 | readonly = transfer.readBoolean(); |
71 | int paramCount = transfer.readInt(); |
72 | if (createParams) { |
73 | parameters.clear(); |
74 | for (int j = 0; j < paramCount; j++) { |
75 | ParameterRemote p = new ParameterRemote(j); |
76 | p.readMetaData(transfer); |
77 | parameters.add(p); |
78 | } |
79 | } |
80 | } catch (IOException e) { |
81 | s.removeServer(e, i--, ++count); |
82 | } |
83 | } |
84 | } |
85 | |
86 | @Override |
87 | public boolean isQuery() { |
88 | return isQuery; |
89 | } |
90 | |
91 | @Override |
92 | public ArrayList<ParameterInterface> getParameters() { |
93 | return parameters; |
94 | } |
95 | |
96 | private void prepareIfRequired() { |
97 | if (session.getLastReconnect() != created) { |
98 | // in this case we need to prepare again in every case |
99 | id = Integer.MIN_VALUE; |
100 | } |
101 | session.checkClosed(); |
102 | if (id <= session.getCurrentId() - SysProperties.SERVER_CACHED_OBJECTS) { |
103 | // object is too old - we need to prepare again |
104 | prepare(session, false); |
105 | } |
106 | } |
107 | |
108 | @Override |
109 | public ResultInterface getMetaData() { |
110 | synchronized (session) { |
111 | if (!isQuery) { |
112 | return null; |
113 | } |
114 | int objectId = session.getNextId(); |
115 | ResultRemote result = null; |
116 | for (int i = 0, count = 0; i < transferList.size(); i++) { |
117 | prepareIfRequired(); |
118 | Transfer transfer = transferList.get(i); |
119 | try { |
120 | session.traceOperation("COMMAND_GET_META_DATA", id); |
121 | transfer.writeInt(SessionRemote.COMMAND_GET_META_DATA). |
122 | writeInt(id).writeInt(objectId); |
123 | session.done(transfer); |
124 | int columnCount = transfer.readInt(); |
125 | result = new ResultRemote(session, transfer, objectId, |
126 | columnCount, Integer.MAX_VALUE); |
127 | break; |
128 | } catch (IOException e) { |
129 | session.removeServer(e, i--, ++count); |
130 | } |
131 | } |
132 | session.autoCommitIfCluster(); |
133 | return result; |
134 | } |
135 | } |
136 | |
137 | @Override |
138 | public ResultInterface executeQuery(int maxRows, boolean scrollable) { |
139 | checkParameters(); |
140 | synchronized (session) { |
141 | int objectId = session.getNextId(); |
142 | ResultRemote result = null; |
143 | for (int i = 0, count = 0; i < transferList.size(); i++) { |
144 | prepareIfRequired(); |
145 | Transfer transfer = transferList.get(i); |
146 | try { |
147 | session.traceOperation("COMMAND_EXECUTE_QUERY", id); |
148 | transfer.writeInt(SessionRemote.COMMAND_EXECUTE_QUERY). |
149 | writeInt(id).writeInt(objectId).writeInt(maxRows); |
150 | int fetch; |
151 | if (session.isClustered() || scrollable) { |
152 | fetch = Integer.MAX_VALUE; |
153 | } else { |
154 | fetch = fetchSize; |
155 | } |
156 | transfer.writeInt(fetch); |
157 | sendParameters(transfer); |
158 | session.done(transfer); |
159 | int columnCount = transfer.readInt(); |
160 | if (result != null) { |
161 | result.close(); |
162 | result = null; |
163 | } |
164 | result = new ResultRemote(session, transfer, objectId, columnCount, fetch); |
165 | if (readonly) { |
166 | break; |
167 | } |
168 | } catch (IOException e) { |
169 | session.removeServer(e, i--, ++count); |
170 | } |
171 | } |
172 | session.autoCommitIfCluster(); |
173 | session.readSessionState(); |
174 | return result; |
175 | } |
176 | } |
177 | |
178 | @Override |
179 | public int executeUpdate() { |
180 | checkParameters(); |
181 | synchronized (session) { |
182 | int updateCount = 0; |
183 | boolean autoCommit = false; |
184 | for (int i = 0, count = 0; i < transferList.size(); i++) { |
185 | prepareIfRequired(); |
186 | Transfer transfer = transferList.get(i); |
187 | try { |
188 | session.traceOperation("COMMAND_EXECUTE_UPDATE", id); |
189 | transfer.writeInt(SessionRemote.COMMAND_EXECUTE_UPDATE).writeInt(id); |
190 | sendParameters(transfer); |
191 | session.done(transfer); |
192 | updateCount = transfer.readInt(); |
193 | autoCommit = transfer.readBoolean(); |
194 | } catch (IOException e) { |
195 | session.removeServer(e, i--, ++count); |
196 | } |
197 | } |
198 | session.setAutoCommitFromServer(autoCommit); |
199 | session.autoCommitIfCluster(); |
200 | session.readSessionState(); |
201 | return updateCount; |
202 | } |
203 | } |
204 | |
205 | private void checkParameters() { |
206 | for (ParameterInterface p : parameters) { |
207 | p.checkSet(); |
208 | } |
209 | } |
210 | |
211 | private void sendParameters(Transfer transfer) throws IOException { |
212 | int len = parameters.size(); |
213 | transfer.writeInt(len); |
214 | for (ParameterInterface p : parameters) { |
215 | transfer.writeValue(p.getParamValue()); |
216 | } |
217 | } |
218 | |
219 | @Override |
220 | public void close() { |
221 | if (session == null || session.isClosed()) { |
222 | return; |
223 | } |
224 | synchronized (session) { |
225 | session.traceOperation("COMMAND_CLOSE", id); |
226 | for (Transfer transfer : transferList) { |
227 | try { |
228 | transfer.writeInt(SessionRemote.COMMAND_CLOSE).writeInt(id); |
229 | } catch (IOException e) { |
230 | trace.error(e, "close"); |
231 | } |
232 | } |
233 | } |
234 | session = null; |
235 | try { |
236 | for (ParameterInterface p : parameters) { |
237 | Value v = p.getParamValue(); |
238 | if (v != null) { |
239 | v.close(); |
240 | } |
241 | } |
242 | } catch (DbException e) { |
243 | trace.error(e, "close"); |
244 | } |
245 | parameters.clear(); |
246 | } |
247 | |
248 | /** |
249 | * Cancel this current statement. |
250 | */ |
251 | @Override |
252 | public void cancel() { |
253 | session.cancelStatement(id); |
254 | } |
255 | |
256 | @Override |
257 | public String toString() { |
258 | return sql + Trace.formatParams(getParameters()); |
259 | } |
260 | |
261 | @Override |
262 | public int getCommandType() { |
263 | return UNKNOWN; |
264 | } |
265 | |
266 | } |