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1
5 package org.h2.command;
6
7 import java.io.IOException  ;
8 import java.sql.SQLException ;
9
10 import org.h2.engine.Constants;
11 import org.h2.engine.SessionInterface;
12 import org.h2.engine.SessionRemote;
13 import org.h2.expression.ParameterInterface;
14 import org.h2.expression.ParameterRemote;
15 import org.h2.message.Trace;
16 import org.h2.result.ResultInterface;
17 import org.h2.result.ResultRemote;
18 import org.h2.util.ObjectArray;
19 import org.h2.value.Transfer;
20
21 public class CommandRemote implements CommandInterface {
22
23 private SessionRemote session;
24 private ObjectArray transferList;
25 private int id;
26 private boolean isQuery;
27 private boolean readonly;
28 private ObjectArray parameters;
29 private Trace trace;
30 private String sql;
31 private int paramCount;
32
33 private void prepare(SessionRemote session) throws SQLException {
34 id = session.getNextId();
35 paramCount = 0;
36 for(int i=0; i<transferList.size(); i++) {
37 try {
38 Transfer transfer = (Transfer) transferList.get(i);
39 session.traceOperation("SESSION_PREPARE", id);
40 transfer.writeInt(SessionRemote.SESSION_PREPARE).writeInt(id).writeString(sql);
41 session.done(transfer);
42 isQuery = transfer.readBoolean();
43 readonly = transfer.readBoolean();
44 paramCount = transfer.readInt();
45 } catch(IOException e) {
46 session.removeServer(i);
47 }
48 }
49 }
50
51 public CommandRemote(SessionRemote session, ObjectArray transferList, String sql) throws SQLException {
52 this.transferList = transferList;
53 trace = session.getTrace();
54 this.sql = sql;
55 parameters = new ObjectArray();
56 prepare(session);
57 for(int i=0; i<paramCount; i++) {
58 parameters.add(new ParameterRemote(i));
59 }
60 this.session = session;
62 }
63
64 public boolean isQuery() {
65 return isQuery;
66 }
67
68 public ObjectArray getParameters() {
69 return parameters;
70 }
71
72 public ResultInterface executeQuery(int maxRows, boolean scrollable) throws SQLException {
73 checkParameters();
74 synchronized(session) {
75 session.checkClosed();
76 if(id <= session.getCurrentId() - Constants.SERVER_CACHED_OBJECTS) {
77 prepare(session);
79 }
80 int objectId = session.getNextId();
81 ResultRemote result = null;
82 for(int i=0; i<transferList.size(); i++) {
83 Transfer transfer = (Transfer) transferList.get(i);
84 try {
85 session.traceOperation("COMMAND_EXECUTE_QUERY", id);
87 transfer.writeInt(SessionRemote.COMMAND_EXECUTE_QUERY).writeInt(id).writeInt(objectId).writeInt(maxRows);
88 int readRows;
89 if(session.isClustered() || scrollable) {
90 readRows = Integer.MAX_VALUE;
91 } else {
92 readRows = Constants.SERVER_SMALL_RESULTSET_SIZE;
93 }
94 transfer.writeInt(readRows);
95 sendParameters(transfer);
96 session.done(transfer);
97 int columnCount = transfer.readInt();
98 if(result != null) {
99 result.close();
100 result = null;
101 }
102 result = new ResultRemote(session, transfer, objectId, columnCount, readRows);
103 if(readonly) {
104 break;
105 }
106 } catch(IOException e) {
107 session.removeServer(i);
108 }
109 }
110 session.autoCommitIfCluster();
111 return result;
112 }
113 }
114
115 public int executeUpdate() throws SQLException {
116 checkParameters();
117 synchronized(session) {
118 session.checkClosed();
119 if(id <= session.getCurrentId() - Constants.SERVER_CACHED_OBJECTS) {
120 prepare(session);
122 }
123 int updateCount = 0;
124 boolean autoCommit = false;
125 for(int i=0; i<transferList.size(); i++) {
126 try {
127 Transfer transfer = (Transfer) transferList.get(i);
128 session.traceOperation("COMMAND_EXECUTE_UPDATE", id);
129 transfer.writeInt(SessionRemote.COMMAND_EXECUTE_UPDATE).writeInt(id);
130 sendParameters(transfer);
131 session.done(transfer);
132 updateCount = transfer.readInt();
133 autoCommit = transfer.readBoolean();
134 } catch(IOException e) {
135 session.removeServer(i);
136 }
137 }
138 session.setAutoCommit(autoCommit);
139 session.autoCommitIfCluster();
140 return updateCount;
141 }
142 }
143
144 private void checkParameters() throws SQLException {
145 int len = parameters.size();
146 for(int i=0; i<len; i++) {
147 ParameterInterface p = (ParameterInterface)parameters.get(i);
148 p.checkSet();
149 }
150 }
151
152 private void sendParameters(Transfer transfer) throws IOException , SQLException {
153 int len = parameters.size();
154 transfer.writeInt(len);
155 for(int i=0; i<len; i++) {
156 ParameterInterface p = (ParameterInterface)parameters.get(i);
157 transfer.writeValue(p.getParamValue());
158 }
159 }
160
161 public SessionInterface getSession() {
162 return session;
163 }
164
165 public void close() {
166 if(session == null || session.isClosed()) {
167 return;
168 }
169 synchronized(session) {
170 for(int i=0; i<transferList.size(); i++) {
171 try {
172 Transfer transfer = (Transfer) transferList.get(i);
173 session.traceOperation("COMMAND_CLOSE", id);
174 transfer.writeInt(SessionRemote.COMMAND_CLOSE).writeInt(id);
175 } catch (IOException e) {
176 trace.error("close", e);
178 }
179 }
180 session = null;
181 }
182 }
183
184
191 public void cancel() {
192 }
194
195 }
196 |
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