| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.iapi.db.OptimizerTrace |
| 4 | |
| 5 | Copyright 2000, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 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 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.iapi.db; |
| 22 | |
| 23 | import org.apache.derby.iapi.sql.conn.LanguageConnectionContext; |
| 24 | import org.apache.derby.iapi.sql.conn.ConnectionUtil; |
| 25 | |
| 26 | /** |
| 27 | <P> |
| 28 | This class provides static methods for controlling the |
| 29 | optimizer tracing in a Cloudscape database. |
| 30 | |
| 31 | <P> |
| 32 | <i> |
| 33 | Cloudscape reserves the right to change, rename, or remove this interface |
| 34 | at any time. </i> |
| 35 | */ |
| 36 | public class OptimizerTrace |
| 37 | { |
| 38 | /** |
| 39 | * Control whether or not optimizer trace is on. |
| 40 | * |
| 41 | * @param onOrOff Whether to turn optimizer trace on (true) or off (false). |
| 42 | * |
| 43 | * @return Whether or not the call was successful. (false will be returned when optimizer tracing is not supported.) |
| 44 | */ |
| 45 | public static boolean setOptimizerTrace(boolean onOrOff) |
| 46 | { |
| 47 | boolean retCode = false; |
| 48 | |
| 49 | try |
| 50 | { |
| 51 | // Get the current language connection context. This is associated |
| 52 | // with the current database. |
| 53 | LanguageConnectionContext lcc = ConnectionUtil.getCurrentLCC(); |
| 54 | retCode = lcc.setOptimizerTrace(onOrOff); |
| 55 | } |
| 56 | catch (Throwable t) |
| 57 | { |
| 58 | // eat all exceptions, simply return false |
| 59 | } |
| 60 | |
| 61 | return retCode; |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * Control whether or not optimizer trace is generated in html. |
| 66 | * |
| 67 | * @param onOrOff Whether or not optimizer trace will be in html (true) or not (false). |
| 68 | * |
| 69 | * @return Whether or not the call was successful. (false will be returned when optimizer tracing is not supported.) |
| 70 | */ |
| 71 | public static boolean setOptimizerTraceHtml(boolean onOrOff) |
| 72 | { |
| 73 | boolean retCode = false; |
| 74 | |
| 75 | try |
| 76 | { |
| 77 | // Get the current language connection context. This is associated |
| 78 | // with the current database. |
| 79 | LanguageConnectionContext lcc = ConnectionUtil.getCurrentLCC(); |
| 80 | retCode = lcc.setOptimizerTraceHtml(onOrOff); |
| 81 | } |
| 82 | catch (Throwable t) |
| 83 | { |
| 84 | // eat all exceptions, simply return false |
| 85 | } |
| 86 | |
| 87 | return retCode; |
| 88 | } |
| 89 | |
| 90 | /** |
| 91 | * Get the optimizer trace output for the last optimized query as a String. If optimizer trace |
| 92 | * html is on, then the String will contain the html tags. |
| 93 | * |
| 94 | * @return The optimizer trace output for the last optimized query as a String. |
| 95 | * Null will be returned if optimizer trace output is off or not supported |
| 96 | * or no trace output was found or an exception occurred. |
| 97 | */ |
| 98 | public static String getOptimizerTraceOutput() |
| 99 | { |
| 100 | String retCode = null; |
| 101 | |
| 102 | try |
| 103 | { |
| 104 | // Get the current language connection context. This is associated |
| 105 | // with the current database. |
| 106 | LanguageConnectionContext lcc = ConnectionUtil.getCurrentLCC(); |
| 107 | retCode = lcc.getOptimizerTraceOutput(); |
| 108 | } |
| 109 | catch (Throwable t) |
| 110 | { |
| 111 | // eat all exceptions, simply return null |
| 112 | } |
| 113 | |
| 114 | return retCode; |
| 115 | } |
| 116 | |
| 117 | /** |
| 118 | * Send the optimizer trace output for the last optimized query to a file with a .html extension. |
| 119 | * If optimizer trace html is on, then the output will contain the html tags. |
| 120 | * |
| 121 | * @param fileName The name of the file to write to. (.html extension will be added.) |
| 122 | * |
| 123 | * @return Whether or not the request was successful. |
| 124 | * false mayl be returned for a number of reasons, including if optimizer trace output is off or not supported |
| 125 | * or no trace output was found or an exception occurred. |
| 126 | */ |
| 127 | public static boolean writeOptimizerTraceOutputHtml(String fileName) |
| 128 | { |
| 129 | boolean retCode = true; |
| 130 | |
| 131 | try |
| 132 | { |
| 133 | String output = getOptimizerTraceOutput(); |
| 134 | //RESOLVEOPTIMIZERTRACE - need to write out the html |
| 135 | } |
| 136 | catch (Throwable t) |
| 137 | { |
| 138 | // eat all exceptions, simply return false |
| 139 | retCode = false; |
| 140 | } |
| 141 | |
| 142 | return retCode; |
| 143 | } |
| 144 | |
| 145 | } |