| Brian Silverman | 8867871 | 2018-08-04 23:56:48 -0700 | [diff] [blame^] | 1 | <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
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| 4 | (C) Copyright 2002-4 Robert Ramey - http://www.rrsd.com . |
| 5 | Use, modification and distribution is subject to the Boost Software |
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| 13 | <title>Serialization - To Do</title> |
| 14 | </head> |
| 15 | <body link="#0000ff" vlink="#800080"> |
| 16 | <table border="0" cellpadding="7" cellspacing="0" width="100%" summary="header"> |
| 17 | <tr> |
| 18 | <td valign="top" width="300"> |
| 19 | <h3><a href="../../../index.htm"><img height="86" width="277" alt="C++ Boost" src="../../../boost.png" border="0"></a></h3> |
| 20 | </td> |
| 21 | <td valign="top"> |
| 22 | <h1 align="center">Serialization</h1> |
| 23 | <h2 align="center">To Do</h2> |
| 24 | </td> |
| 25 | </tr> |
| 26 | </table> |
| 27 | <hr> |
| 28 | <dl class="index"> |
| 29 | <dt><a href="#portablebinaryarchives">Portable Binary Archives</a></dt> |
| 30 | <dt><a href="#performancetesting">Performance Testing and Profiling</a></dt> |
| 31 | <dt><a href="#backversioning">Back Versioning</a></dt> |
| 32 | <dt><a href="#nortti">Testing for Environments with No RTTI</a></dt> |
| 33 | <dt><a href="new_case_studies.html">Additional Case Studies</a></dt> |
| 34 | </dl> |
| 35 | |
| 36 | These are enhancements that the serialization library needs but have not been done. |
| 37 | Some of these projects, though tricky, are not huge and would be suitable |
| 38 | for someone who has a limited time to spend on them. In particular, they |
| 39 | might be of interest as student projects such as the Google Summer of Code. |
| 40 | |
| 41 | <h2><a name="portablebinaryarchives"></a>Portable Binary Archives</h2> |
| 42 | Currently there is a portable binary archive in the examples directory. |
| 43 | It is not regularly submitted to the exhaustive boost testing regimen |
| 44 | but it is tested occasionally and has been used in production code. |
| 45 | <p> |
| 46 | It's missing the following: |
| 47 | <ul> |
| 48 | <li>Addition of portable floating point types. This is not trivial. In addition to |
| 49 | handling floating point types of varying sizes, It requires |
| 50 | handling invalid floating point numbers (NaNs) in a portable manner. |
| 51 | <li>Integration into the Boost testing regimen similar to the other archive classes. |
| 52 | </ul> |
| 53 | |
| 54 | <h2><a name="performancetesting"></a>Performance Testing and Profiling</h2> |
| 55 | |
| 56 | I've managed to setup performance profiling using the following: |
| 57 | <ul> |
| 58 | <li>current (as I write this) Boost.Build tools. |
| 59 | <li>the gcc compiler. |
| 60 | <li>and a shell script - profile.sh |
| 61 | <li>library_status program from the tools/regression/src directory |
| 62 | </ul> |
| 63 | Invoking profile script produces a |
| 64 | <a href="performance_status.html">table</a> |
| 65 | which shows the results of each test and links to the actual |
| 66 | profile. |
| 67 | <p> |
| 68 | The first thing I did was include some of the serialization library tests. |
| 69 | It became immediately apparent that these tests were totally unsuitable |
| 70 | for performance testing and that new tests needed to be written for this |
| 71 | purpose. These tests would highlight the location of any performance |
| 72 | bottlenecks in the serialization library. Whenever I've subjected my |
| 73 | code in the past to this type of analysis, I've always been surprised |
| 74 | to find bottlenecks in totally unanticipated places and fixing those |
| 75 | has always led to large improvements in performance. I expect that |
| 76 | this project would have a huge impact on the utility of the serialization |
| 77 | library. |
| 78 | |
| 79 | <h2><a name="backversioning"></a>Back Versioning</h2> |
| 80 | |
| 81 | It has been suggested that a useful feature of the library would be |
| 82 | the ability to create "older versions" of archives. Currently, |
| 83 | the library permits one to make programs that are guaranteed |
| 84 | the ability to load archives with classes of a previous version. |
| 85 | But there is no way to save classes in accordance with a |
| 86 | previous version. At first I dismissed this as a huge project |
| 87 | with small demand. A cursory examination of the code revealed |
| 88 | that this would not be very difficult. It would require some |
| 89 | small changes in code and some additional tests. Also it |
| 90 | would require special treatment in the documentation - perhaps |
| 91 | a case study. |
| 92 | |
| 93 | |
| 94 | <h2><a name="nortti"></a>Environments without RTTI</h2> |
| 95 | |
| 96 | I note that some have commented that this library requires RTTI. |
| 97 | This is not strictly true. The examples and almost all the |
| 98 | tests presume the existence of RTTI. But it should be possible |
| 99 | to use the library without it. The example used for testing is an |
| 100 | <code style="white-space: normal">extended_typeinfo</code> |
| 101 | implemenation which presumes that all classes names have been exported. |
| 102 | So, to make this library compatible for platforms without RTTI, |
| 103 | a set of tests, examples and new manual section would have to be created. |
| 104 | |
| 105 | <hr> |
| 106 | <p>Revised 1 November, 2008 |
| 107 | <p><i>© Copyright <a href="http://www.rrsd.com">Robert Ramey</a> 2002-2008. |
| 108 | Distributed under the Boost Software License, Version 1.0. (See |
| 109 | accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| 110 | </i></p> |
| 111 | </body> |
| 112 | </html> |