1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
<meta name="generator" content="Doxygen 1.8.6"/>
<title>libmspack: mspack_system Struct Reference</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<link href="search/search.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="search/search.js"></script>
<script type="text/javascript">
$(document).ready(function() { searchBox.OnSelectItem(0); });
</script>
<link href="doxygen.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
<tbody>
<tr style="height: 56px;">
<td style="padding-left: 0.5em;">
<div id="projectname">libmspack
</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- end header part -->
<!-- Generated by Doxygen 1.8.6 -->
<script type="text/javascript">
var searchBox = new SearchBox("searchBox", "search",false,'Search');
</script>
<div id="navrow1" class="tabs">
<ul class="tablist">
<li><a href="index.html"><span>Main Page</span></a></li>
<li class="current"><a href="annotated.html"><span>Data Structures</span></a></li>
<li><a href="files.html"><span>Files</span></a></li>
<li>
<div id="MSearchBox" class="MSearchBoxInactive">
<span class="left">
<img id="MSearchSelect" src="search/mag_sel.png"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
alt=""/>
<input type="text" id="MSearchField" value="Search" accesskey="S"
onfocus="searchBox.OnSearchFieldFocus(true)"
onblur="searchBox.OnSearchFieldFocus(false)"
onkeyup="searchBox.OnSearchFieldChange(event)"/>
</span><span class="right">
<a id="MSearchClose" href="javascript:searchBox.CloseResultsWindow()"><img id="MSearchCloseImg" border="0" src="search/close.png" alt=""/></a>
</span>
</div>
</li>
</ul>
</div>
<div id="navrow2" class="tabs2">
<ul class="tablist">
<li><a href="annotated.html"><span>Data Structures</span></a></li>
<li><a href="classes.html"><span>Data Structure Index</span></a></li>
<li><a href="functions.html"><span>Data Fields</span></a></li>
</ul>
</div>
<!-- window showing the filter options -->
<div id="MSearchSelectWindow"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
onkeydown="return searchBox.OnSearchSelectKey(event)">
<a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(0)"><span class="SelectionMark"> </span>All</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(1)"><span class="SelectionMark"> </span>Data Structures</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(2)"><span class="SelectionMark"> </span>Files</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(3)"><span class="SelectionMark"> </span>Functions</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(4)"><span class="SelectionMark"> </span>Variables</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(5)"><span class="SelectionMark"> </span>Macros</a></div>
<!-- iframe showing the search results (closed by default) -->
<div id="MSearchResultsWindow">
<iframe src="javascript:void(0)" frameborder="0"
name="MSearchResults" id="MSearchResults">
</iframe>
</div>
</div><!-- top -->
<div class="header">
<div class="summary">
<a href="#pub-attribs">Data Fields</a> </div>
<div class="headertitle">
<div class="title">mspack_system Struct Reference</div> </div>
</div><!--header-->
<div class="contents">
<p>A structure which abstracts file I/O and memory management.
<a href="structmspack__system.html#details">More...</a></p>
<p><code>#include <<a class="el" href="mspack_8h_source.html">mspack.h</a>></code></p>
<table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="pub-attribs"></a>
Data Fields</h2></td></tr>
<tr class="memitem:a1a85cac5eeb55db6a432fe3824aa04a3"><td class="memItemLeft" align="right" valign="top">struct <a class="el" href="structmspack__file.html">mspack_file</a> *(* </td><td class="memItemRight" valign="bottom"><a class="el" href="structmspack__system.html#a1a85cac5eeb55db6a432fe3824aa04a3">open</a> )(struct <a class="el" href="structmspack__system.html">mspack_system</a> *self, const char *filename, int mode)</td></tr>
<tr class="memdesc:a1a85cac5eeb55db6a432fe3824aa04a3"><td class="mdescLeft"> </td><td class="mdescRight">Opens a file for reading, writing, appending or updating. <a href="#a1a85cac5eeb55db6a432fe3824aa04a3">More...</a><br/></td></tr>
<tr class="separator:a1a85cac5eeb55db6a432fe3824aa04a3"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:a266561cea2dcf8ad60a42c2ac88536c2"><td class="memItemLeft" align="right" valign="top">void(* </td><td class="memItemRight" valign="bottom"><a class="el" href="structmspack__system.html#a266561cea2dcf8ad60a42c2ac88536c2">close</a> )(struct <a class="el" href="structmspack__file.html">mspack_file</a> *file)</td></tr>
<tr class="memdesc:a266561cea2dcf8ad60a42c2ac88536c2"><td class="mdescLeft"> </td><td class="mdescRight">Closes a previously opened file. <a href="#a266561cea2dcf8ad60a42c2ac88536c2">More...</a><br/></td></tr>
<tr class="separator:a266561cea2dcf8ad60a42c2ac88536c2"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ac33dcc54409a7d5da9be475b3938101e"><td class="memItemLeft" align="right" valign="top">int(* </td><td class="memItemRight" valign="bottom"><a class="el" href="structmspack__system.html#ac33dcc54409a7d5da9be475b3938101e">read</a> )(struct <a class="el" href="structmspack__file.html">mspack_file</a> *file, void *buffer, int bytes)</td></tr>
<tr class="memdesc:ac33dcc54409a7d5da9be475b3938101e"><td class="mdescLeft"> </td><td class="mdescRight">Reads a given number of bytes from an open file. <a href="#ac33dcc54409a7d5da9be475b3938101e">More...</a><br/></td></tr>
<tr class="separator:ac33dcc54409a7d5da9be475b3938101e"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ac57fb5944e7726abe2272822fa07a30f"><td class="memItemLeft" align="right" valign="top">int(* </td><td class="memItemRight" valign="bottom"><a class="el" href="structmspack__system.html#ac57fb5944e7726abe2272822fa07a30f">write</a> )(struct <a class="el" href="structmspack__file.html">mspack_file</a> *file, void *buffer, int bytes)</td></tr>
<tr class="memdesc:ac57fb5944e7726abe2272822fa07a30f"><td class="mdescLeft"> </td><td class="mdescRight">Writes a given number of bytes to an open file. <a href="#ac57fb5944e7726abe2272822fa07a30f">More...</a><br/></td></tr>
<tr class="separator:ac57fb5944e7726abe2272822fa07a30f"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:a86ceffde52284d3a57d5d555d7484a03"><td class="memItemLeft" align="right" valign="top">int(* </td><td class="memItemRight" valign="bottom"><a class="el" href="structmspack__system.html#a86ceffde52284d3a57d5d555d7484a03">seek</a> )(struct <a class="el" href="structmspack__file.html">mspack_file</a> *file, off_t offset, int mode)</td></tr>
<tr class="memdesc:a86ceffde52284d3a57d5d555d7484a03"><td class="mdescLeft"> </td><td class="mdescRight">Seeks to a specific file offset within an open file. <a href="#a86ceffde52284d3a57d5d555d7484a03">More...</a><br/></td></tr>
<tr class="separator:a86ceffde52284d3a57d5d555d7484a03"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ae25e8b0ca839867f19041aa20508e548"><td class="memItemLeft" align="right" valign="top">off_t(* </td><td class="memItemRight" valign="bottom"><a class="el" href="structmspack__system.html#ae25e8b0ca839867f19041aa20508e548">tell</a> )(struct <a class="el" href="structmspack__file.html">mspack_file</a> *file)</td></tr>
<tr class="memdesc:ae25e8b0ca839867f19041aa20508e548"><td class="mdescLeft"> </td><td class="mdescRight">Returns the current file position (in bytes) of the given file. <a href="#ae25e8b0ca839867f19041aa20508e548">More...</a><br/></td></tr>
<tr class="separator:ae25e8b0ca839867f19041aa20508e548"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:a612c93482eb01d2b97321015716ea24a"><td class="memItemLeft" align="right" valign="top">void(* </td><td class="memItemRight" valign="bottom"><a class="el" href="structmspack__system.html#a612c93482eb01d2b97321015716ea24a">message</a> )(struct <a class="el" href="structmspack__file.html">mspack_file</a> *file, const char *format,...)</td></tr>
<tr class="memdesc:a612c93482eb01d2b97321015716ea24a"><td class="mdescLeft"> </td><td class="mdescRight">Used to send messages from the library to the user. <a href="#a612c93482eb01d2b97321015716ea24a">More...</a><br/></td></tr>
<tr class="separator:a612c93482eb01d2b97321015716ea24a"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ac70dd55eb6eca7a390e5ae143525f36a"><td class="memItemLeft" align="right" valign="top">void *(* </td><td class="memItemRight" valign="bottom"><a class="el" href="structmspack__system.html#ac70dd55eb6eca7a390e5ae143525f36a">alloc</a> )(struct <a class="el" href="structmspack__system.html">mspack_system</a> *self, size_t bytes)</td></tr>
<tr class="memdesc:ac70dd55eb6eca7a390e5ae143525f36a"><td class="mdescLeft"> </td><td class="mdescRight">Allocates memory. <a href="#ac70dd55eb6eca7a390e5ae143525f36a">More...</a><br/></td></tr>
<tr class="separator:ac70dd55eb6eca7a390e5ae143525f36a"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:aafe460b1ce55ce69be8c16948250f86c"><td class="memItemLeft" align="right" valign="top">void(* </td><td class="memItemRight" valign="bottom"><a class="el" href="structmspack__system.html#aafe460b1ce55ce69be8c16948250f86c">free</a> )(void *ptr)</td></tr>
<tr class="memdesc:aafe460b1ce55ce69be8c16948250f86c"><td class="mdescLeft"> </td><td class="mdescRight">Frees memory. <a href="#aafe460b1ce55ce69be8c16948250f86c">More...</a><br/></td></tr>
<tr class="separator:aafe460b1ce55ce69be8c16948250f86c"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:a22cdc77c82dba0f6c58945c816c2732e"><td class="memItemLeft" align="right" valign="top">void(* </td><td class="memItemRight" valign="bottom"><a class="el" href="structmspack__system.html#a22cdc77c82dba0f6c58945c816c2732e">copy</a> )(void *src, void *dest, size_t bytes)</td></tr>
<tr class="memdesc:a22cdc77c82dba0f6c58945c816c2732e"><td class="mdescLeft"> </td><td class="mdescRight">Copies from one region of memory to another. <a href="#a22cdc77c82dba0f6c58945c816c2732e">More...</a><br/></td></tr>
<tr class="separator:a22cdc77c82dba0f6c58945c816c2732e"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:a8c64d1bd9b6b0ac9455cfde19ccb61b2"><td class="memItemLeft" align="right" valign="top">void * </td><td class="memItemRight" valign="bottom"><a class="el" href="structmspack__system.html#a8c64d1bd9b6b0ac9455cfde19ccb61b2">null_ptr</a></td></tr>
<tr class="memdesc:a8c64d1bd9b6b0ac9455cfde19ccb61b2"><td class="mdescLeft"> </td><td class="mdescRight">A null pointer to mark the end of <a class="el" href="structmspack__system.html" title="A structure which abstracts file I/O and memory management. ">mspack_system</a>. <a href="#a8c64d1bd9b6b0ac9455cfde19ccb61b2">More...</a><br/></td></tr>
<tr class="separator:a8c64d1bd9b6b0ac9455cfde19ccb61b2"><td class="memSeparator" colspan="2"> </td></tr>
</table>
<a name="details" id="details"></a><h2 class="groupheader">Detailed Description</h2>
<div class="textblock"><p>A structure which abstracts file I/O and memory management. </p>
<p>The library always uses the <a class="el" href="structmspack__system.html" title="A structure which abstracts file I/O and memory management. ">mspack_system</a> structure for interaction with the file system and to allocate, free and copy all memory. It also uses it to send literal messages to the library user.</p>
<p>When the library is compiled normally, passing NULL to a compressor or decompressor constructor will result in a default <a class="el" href="structmspack__system.html" title="A structure which abstracts file I/O and memory management. ">mspack_system</a> being used, where all methods are implemented with the standard C library. However, all constructors support being given a custom created <a class="el" href="structmspack__system.html" title="A structure which abstracts file I/O and memory management. ">mspack_system</a> structure, with the library user's own methods. This allows for more abstract interaction, such as reading and writing files directly to memory, or from a network socket or pipe.</p>
<p>Implementors of an <a class="el" href="structmspack__system.html" title="A structure which abstracts file I/O and memory management. ">mspack_system</a> structure should read all documentation entries for every structure member, and write methods which conform to those standards. </p>
</div><h2 class="groupheader">Field Documentation</h2>
<a class="anchor" id="ac70dd55eb6eca7a390e5ae143525f36a"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void*(* mspack_system::alloc)(struct <a class="el" href="structmspack__system.html">mspack_system</a> *self, size_t bytes)</td>
</tr>
</table>
</div><div class="memdoc">
<p>Allocates memory. </p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">self</td><td>a self-referential pointer to the <a class="el" href="structmspack__system.html" title="A structure which abstracts file I/O and memory management. ">mspack_system</a> structure whose <a class="el" href="structmspack__system.html#ac70dd55eb6eca7a390e5ae143525f36a" title="Allocates memory. ">alloc()</a> method is being called. </td></tr>
<tr><td class="paramname">bytes</td><td>the number of bytes to allocate </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>a pointer to the requested number of bytes, or NULL if not enough memory is available </dd></dl>
<dl class="section see"><dt>See Also</dt><dd><a class="el" href="structmspack__system.html#aafe460b1ce55ce69be8c16948250f86c" title="Frees memory. ">free()</a> </dd></dl>
</div>
</div>
<a class="anchor" id="a266561cea2dcf8ad60a42c2ac88536c2"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void(* mspack_system::close)(struct <a class="el" href="structmspack__file.html">mspack_file</a> *file)</td>
</tr>
</table>
</div><div class="memdoc">
<p>Closes a previously opened file. </p>
<p>If any memory was allocated for this particular file handle, it should be freed at this time.</p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">file</td><td>the file to close </td></tr>
</table>
</dd>
</dl>
<dl class="section see"><dt>See Also</dt><dd><a class="el" href="structmspack__system.html#a1a85cac5eeb55db6a432fe3824aa04a3" title="Opens a file for reading, writing, appending or updating. ">open()</a> </dd></dl>
</div>
</div>
<a class="anchor" id="a22cdc77c82dba0f6c58945c816c2732e"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void(* mspack_system::copy)(void *src, void *dest, size_t bytes)</td>
</tr>
</table>
</div><div class="memdoc">
<p>Copies from one region of memory to another. </p>
<p>The regions of memory are guaranteed not to overlap, are usually less than 256 bytes, and may not be aligned. Please note that the source parameter comes before the destination parameter, unlike the standard C function memcpy().</p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">src</td><td>the region of memory to copy from </td></tr>
<tr><td class="paramname">dest</td><td>the region of memory to copy to </td></tr>
<tr><td class="paramname">bytes</td><td>the size of the memory region, in bytes </td></tr>
</table>
</dd>
</dl>
</div>
</div>
<a class="anchor" id="aafe460b1ce55ce69be8c16948250f86c"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void(* mspack_system::free)(void *ptr)</td>
</tr>
</table>
</div><div class="memdoc">
<p>Frees memory. </p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">ptr</td><td>the memory to be freed. </td></tr>
</table>
</dd>
</dl>
<dl class="section see"><dt>See Also</dt><dd><a class="el" href="structmspack__system.html#ac70dd55eb6eca7a390e5ae143525f36a" title="Allocates memory. ">alloc()</a> </dd></dl>
</div>
</div>
<a class="anchor" id="a612c93482eb01d2b97321015716ea24a"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void(* mspack_system::message)(struct <a class="el" href="structmspack__file.html">mspack_file</a> *file, const char *format,...)</td>
</tr>
</table>
</div><div class="memdoc">
<p>Used to send messages from the library to the user. </p>
<p>Occasionally, the library generates warnings or other messages in plain english to inform the human user. These are informational only and can be ignored if not wanted.</p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">file</td><td>may be a file handle returned from <a class="el" href="structmspack__system.html#a1a85cac5eeb55db6a432fe3824aa04a3" title="Opens a file for reading, writing, appending or updating. ">open()</a> if this message pertains to a specific open file, or NULL if not related to a specific file. </td></tr>
<tr><td class="paramname">format</td><td>a printf() style format string. It does NOT include a trailing newline. </td></tr>
</table>
</dd>
</dl>
<dl class="section see"><dt>See Also</dt><dd><a class="el" href="structmspack__system.html#a1a85cac5eeb55db6a432fe3824aa04a3" title="Opens a file for reading, writing, appending or updating. ">open()</a> </dd></dl>
</div>
</div>
<a class="anchor" id="a8c64d1bd9b6b0ac9455cfde19ccb61b2"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void* mspack_system::null_ptr</td>
</tr>
</table>
</div><div class="memdoc">
<p>A null pointer to mark the end of <a class="el" href="structmspack__system.html" title="A structure which abstracts file I/O and memory management. ">mspack_system</a>. </p>
<p>It must equal NULL.</p>
<p>Should the <a class="el" href="structmspack__system.html" title="A structure which abstracts file I/O and memory management. ">mspack_system</a> structure extend in the future, this NULL will be seen, rather than have an invalid method pointer called. </p>
</div>
</div>
<a class="anchor" id="a1a85cac5eeb55db6a432fe3824aa04a3"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">struct <a class="el" href="structmspack__file.html">mspack_file</a>*(* mspack_system::open)(struct <a class="el" href="structmspack__system.html">mspack_system</a> *self, const char *filename, int mode)</td>
</tr>
</table>
</div><div class="memdoc">
<p>Opens a file for reading, writing, appending or updating. </p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">self</td><td>a self-referential pointer to the <a class="el" href="structmspack__system.html" title="A structure which abstracts file I/O and memory management. ">mspack_system</a> structure whose <a class="el" href="structmspack__system.html#a1a85cac5eeb55db6a432fe3824aa04a3" title="Opens a file for reading, writing, appending or updating. ">open()</a> method is being called. If this pointer is required by <a class="el" href="structmspack__system.html#a266561cea2dcf8ad60a42c2ac88536c2" title="Closes a previously opened file. ">close()</a>, <a class="el" href="structmspack__system.html#ac33dcc54409a7d5da9be475b3938101e" title="Reads a given number of bytes from an open file. ">read()</a>, <a class="el" href="structmspack__system.html#ac57fb5944e7726abe2272822fa07a30f" title="Writes a given number of bytes to an open file. ">write()</a>, <a class="el" href="structmspack__system.html#a86ceffde52284d3a57d5d555d7484a03" title="Seeks to a specific file offset within an open file. ">seek()</a> or <a class="el" href="structmspack__system.html#ae25e8b0ca839867f19041aa20508e548" title="Returns the current file position (in bytes) of the given file. ">tell()</a>, it should be stored in the result structure at this time. </td></tr>
<tr><td class="paramname">filename</td><td>the file to be opened. It is passed directly from the library caller without being modified, so it is up to the caller what this parameter actually represents. </td></tr>
<tr><td class="paramname">mode</td><td>one of <a class="el" href="mspack_8h.html#a817255b35e433f4adcf907fc97f9b63f" title="mspack_system::open() mode: open existing file for reading. ">MSPACK_SYS_OPEN_READ</a> (open an existing file for reading), <a class="el" href="mspack_8h.html#a77508ef49eff6a98f39a3b5021c5c51f" title="mspack_system::open() mode: open new file for writing ">MSPACK_SYS_OPEN_WRITE</a> (open a new file for writing), <a class="el" href="mspack_8h.html#ae9f356d2f22c7c236b9bdad87b25b18b" title="mspack_system::open() mode: open existing file for writing ">MSPACK_SYS_OPEN_UPDATE</a> (open an existing file for reading/writing from the start of the file) or <a class="el" href="mspack_8h.html#a05310a4221173aabf06ab99d09d7504e" title="mspack_system::open() mode: open existing file for writing ">MSPACK_SYS_OPEN_APPEND</a> (open an existing file for reading/writing from the end of the file) </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>a pointer to a <a class="el" href="structmspack__file.html" title="A structure which represents an open file handle. ">mspack_file</a> structure. This structure officially contains no members, its true contents are up to the <a class="el" href="structmspack__system.html" title="A structure which abstracts file I/O and memory management. ">mspack_system</a> implementor. It should contain whatever is needed for other <a class="el" href="structmspack__system.html" title="A structure which abstracts file I/O and memory management. ">mspack_system</a> methods to operate. Returning the NULL pointer indicates an error condition. </dd></dl>
<dl class="section see"><dt>See Also</dt><dd><a class="el" href="structmspack__system.html#a266561cea2dcf8ad60a42c2ac88536c2" title="Closes a previously opened file. ">close()</a>, <a class="el" href="structmspack__system.html#ac33dcc54409a7d5da9be475b3938101e" title="Reads a given number of bytes from an open file. ">read()</a>, <a class="el" href="structmspack__system.html#ac57fb5944e7726abe2272822fa07a30f" title="Writes a given number of bytes to an open file. ">write()</a>, <a class="el" href="structmspack__system.html#a86ceffde52284d3a57d5d555d7484a03" title="Seeks to a specific file offset within an open file. ">seek()</a>, <a class="el" href="structmspack__system.html#ae25e8b0ca839867f19041aa20508e548" title="Returns the current file position (in bytes) of the given file. ">tell()</a>, <a class="el" href="structmspack__system.html#a612c93482eb01d2b97321015716ea24a" title="Used to send messages from the library to the user. ">message()</a> </dd></dl>
</div>
</div>
<a class="anchor" id="ac33dcc54409a7d5da9be475b3938101e"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">int(* mspack_system::read)(struct <a class="el" href="structmspack__file.html">mspack_file</a> *file, void *buffer, int bytes)</td>
</tr>
</table>
</div><div class="memdoc">
<p>Reads a given number of bytes from an open file. </p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">file</td><td>the file to read from </td></tr>
<tr><td class="paramname">buffer</td><td>the location where the read bytes should be stored </td></tr>
<tr><td class="paramname">bytes</td><td>the number of bytes to read from the file. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>the number of bytes successfully read (this can be less than the number requested), zero to mark the end of file, or less than zero to indicate an error. </dd></dl>
<dl class="section see"><dt>See Also</dt><dd><a class="el" href="structmspack__system.html#a1a85cac5eeb55db6a432fe3824aa04a3" title="Opens a file for reading, writing, appending or updating. ">open()</a>, <a class="el" href="structmspack__system.html#ac57fb5944e7726abe2272822fa07a30f" title="Writes a given number of bytes to an open file. ">write()</a> </dd></dl>
</div>
</div>
<a class="anchor" id="a86ceffde52284d3a57d5d555d7484a03"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">int(* mspack_system::seek)(struct <a class="el" href="structmspack__file.html">mspack_file</a> *file, off_t offset, int mode)</td>
</tr>
</table>
</div><div class="memdoc">
<p>Seeks to a specific file offset within an open file. </p>
<p>Sometimes the library needs to know the length of a file. It does this by seeking to the end of the file with seek(file, 0, MSPACK_SYS_SEEK_END), then calling <a class="el" href="structmspack__system.html#ae25e8b0ca839867f19041aa20508e548" title="Returns the current file position (in bytes) of the given file. ">tell()</a>. Implementations may want to make a special case for this.</p>
<p>Due to the potentially varying 32/64 bit datatype off_t on some architectures, the <a class="el" href="mspack_8h.html#a3a94be2216dd1e835733acb7c4645fca" title="System self-test function, to ensure both library and calling program can use one another...">MSPACK_SYS_SELFTEST</a> macro MUST be used before using the library. If not, the error caused by the library passing an inappropriate stackframe to <a class="el" href="structmspack__system.html#a86ceffde52284d3a57d5d555d7484a03" title="Seeks to a specific file offset within an open file. ">seek()</a> is subtle and hard to trace.</p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">file</td><td>the file to be seeked </td></tr>
<tr><td class="paramname">offset</td><td>an offset to seek, measured in bytes </td></tr>
<tr><td class="paramname">mode</td><td>one of <a class="el" href="mspack_8h.html#a80228888f03f72c392e138373acfc74e" title="mspack_system::seek() mode: seek relative to start of file ">MSPACK_SYS_SEEK_START</a> (the offset should be measured from the start of the file), <a class="el" href="mspack_8h.html#a9b90c177e3582571d0155c4597f85168" title="mspack_system::seek() mode: seek relative to current offset ">MSPACK_SYS_SEEK_CUR</a> (the offset should be measured from the current file offset) or <a class="el" href="mspack_8h.html#a24e4d3889d52558e7f0c703db94270d6" title="mspack_system::seek() mode: seek relative to end of file ">MSPACK_SYS_SEEK_END</a> (the offset should be measured from the end of the file) </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>zero for success, non-zero for an error </dd></dl>
<dl class="section see"><dt>See Also</dt><dd><a class="el" href="structmspack__system.html#a1a85cac5eeb55db6a432fe3824aa04a3" title="Opens a file for reading, writing, appending or updating. ">open()</a>, <a class="el" href="structmspack__system.html#ae25e8b0ca839867f19041aa20508e548" title="Returns the current file position (in bytes) of the given file. ">tell()</a> </dd></dl>
</div>
</div>
<a class="anchor" id="ae25e8b0ca839867f19041aa20508e548"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">off_t(* mspack_system::tell)(struct <a class="el" href="structmspack__file.html">mspack_file</a> *file)</td>
</tr>
</table>
</div><div class="memdoc">
<p>Returns the current file position (in bytes) of the given file. </p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">file</td><td>the file whose file position is wanted </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>the current file position of the file </dd></dl>
<dl class="section see"><dt>See Also</dt><dd><a class="el" href="structmspack__system.html#a1a85cac5eeb55db6a432fe3824aa04a3" title="Opens a file for reading, writing, appending or updating. ">open()</a>, <a class="el" href="structmspack__system.html#a86ceffde52284d3a57d5d555d7484a03" title="Seeks to a specific file offset within an open file. ">seek()</a> </dd></dl>
</div>
</div>
<a class="anchor" id="ac57fb5944e7726abe2272822fa07a30f"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">int(* mspack_system::write)(struct <a class="el" href="structmspack__file.html">mspack_file</a> *file, void *buffer, int bytes)</td>
</tr>
</table>
</div><div class="memdoc">
<p>Writes a given number of bytes to an open file. </p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">file</td><td>the file to write to </td></tr>
<tr><td class="paramname">buffer</td><td>the location where the written bytes should be read from </td></tr>
<tr><td class="paramname">bytes</td><td>the number of bytes to write to the file. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>the number of bytes successfully written, this can be less than the number requested. Zero or less can indicate an error where no bytes at all could be written. All cases where less bytes were written than requested are considered by the library to be an error. </dd></dl>
<dl class="section see"><dt>See Also</dt><dd><a class="el" href="structmspack__system.html#a1a85cac5eeb55db6a432fe3824aa04a3" title="Opens a file for reading, writing, appending or updating. ">open()</a>, <a class="el" href="structmspack__system.html#ac33dcc54409a7d5da9be475b3938101e" title="Reads a given number of bytes from an open file. ">read()</a> </dd></dl>
</div>
</div>
<hr/>The documentation for this struct was generated from the following file:<ul>
<li><a class="el" href="mspack_8h_source.html">mspack.h</a></li>
</ul>
</div><!-- contents -->
<!-- start footer part -->
<hr class="footer"/><address class="footer"><small>
Generated by  <a href="http://www.doxygen.org/index.html">
<img class="footer" src="doxygen.png" alt="doxygen"/>
</a> 1.8.6
</small></address>
</body>
</html>
|