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<div id="projectname">libaaruformat<span id="projectnumber">&#160;1.0</span>
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<div id="projectbrief">Aaru Data Preservation Suite - Format Library</div>
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<div class="textblock"><code>#include &lt;inttypes.h&gt;</code><br />
<code>#include &lt;stdint.h&gt;</code><br />
<code>#include &lt;stdio.h&gt;</code><br />
<code>#include &lt;stdlib.h&gt;</code><br />
<code>#include &lt;string.h&gt;</code><br />
<code>#include &quot;<a class="el" href="aaruformat_8h_source.html">aaruformat.h</a>&quot;</code><br />
<code>#include &quot;<a class="el" href="erasure__internal_8h_source.html">erasure_internal.h</a>&quot;</code><br />
<code>#include &quot;<a class="el" href="internal_8h_source.html">internal.h</a>&quot;</code><br />
<code>#include &quot;<a class="el" href="log_8h_source.html">log.h</a>&quot;</code><br />
</div>
<p><a href="blocks_2dpm_8c_source.html">Go to the source code of this file.</a></p>
<table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 id="header-func-members" class="groupheader"><a id="func-members" name="func-members"></a>
Functions</h2></td></tr>
<tr class="memitem:a4b9ba209f6722b88a1d21f1ed4ee99c5" id="r_a4b9ba209f6722b88a1d21f1ed4ee99c5"><td class="memItemLeft">uint64_t&#160;</td><td class="memItemRight"><a class="el" href="#a4b9ba209f6722b88a1d21f1ed4ee99c5">dpm_payload_length</a> (const <a class="el" href="structDpmHeader.html">DpmHeader</a> *header)</td></tr>
<tr class="memdesc:a4b9ba209f6722b88a1d21f1ed4ee99c5"><td class="mdescLeft">&#160;</td><td class="mdescRight">Computes the payload length a Data Position Measurement header describes. <br /></td></tr>
<tr class="memitem:ab012bc60295f357069a2d3fc0d36724e" id="r_ab012bc60295f357069a2d3fc0d36724e"><td class="memItemLeft">int32_t&#160;</td><td class="memItemRight"><a class="el" href="#ab012bc60295f357069a2d3fc0d36724e">validate_dpm_block</a> (const uint8_t *data, size_t length)</td></tr>
<tr class="memdesc:ab012bc60295f357069a2d3fc0d36724e"><td class="mdescLeft">&#160;</td><td class="mdescRight">Validates a serialized Data Position Measurement block. <br /></td></tr>
<tr class="memitem:ae2ccc865166ddb1638f1443ac63ef326" id="r_ae2ccc865166ddb1638f1443ac63ef326"><td class="memItemLeft">int32_t&#160;</td><td class="memItemRight"><a class="el" href="#ae2ccc865166ddb1638f1443ac63ef326">recover_dpm_block</a> (<a class="el" href="structaaruformat__context.html">aaruformat_context</a> *ctx)</td></tr>
<tr class="memdesc:ae2ccc865166ddb1638f1443ac63ef326"><td class="mdescLeft">&#160;</td><td class="mdescRight">Recovers a damaged Data Position Measurement block with erasure coding. <br /></td></tr>
<tr class="memitem:aa2692f41f0fe80552c1a2173588f12a9" id="r_aa2692f41f0fe80552c1a2173588f12a9"><td class="memItemLeft">void&#160;</td><td class="memItemRight"><a class="el" href="#aa2692f41f0fe80552c1a2173588f12a9">process_dpm_block</a> (<a class="el" href="structaaruformat__context.html">aaruformat_context</a> *ctx, const <a class="el" href="structIndexEntry.html">IndexEntry</a> *entry)</td></tr>
<tr class="memdesc:aa2692f41f0fe80552c1a2173588f12a9"><td class="mdescLeft">&#160;</td><td class="mdescRight">Processes a Data Position Measurement block from the image stream. <br /></td></tr>
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<a name="doc-func-members" id="doc-func-members"></a><h2 id="header-doc-func-members" class="groupheader">Function Documentation</h2>
<a id="a4b9ba209f6722b88a1d21f1ed4ee99c5" name="a4b9ba209f6722b88a1d21f1ed4ee99c5"></a>
<h2 class="memtitle"><span class="permalink"><a href="#a4b9ba209f6722b88a1d21f1ed4ee99c5">&#9670;&#160;</a></span>dpm_payload_length()</h2>
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<td class="memname">uint64_t dpm_payload_length </td>
<td>(</td>
<td class="paramtype">const <a class="el" href="structDpmHeader.html">DpmHeader</a> *</td> <td class="paramname"><span class="paramname"><em>header</em></span></td><td>)</td>
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<p>Computes the payload length a Data Position Measurement header describes. </p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">header</td><td>DPM block header. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>Payload length in bytes. </dd></dl>
<p class="definition">Definition at line <a class="el" href="blocks_2dpm_8c_source.html#l00036">36</a> of file <a class="el" href="blocks_2dpm_8c_source.html">dpm.c</a>.</p>
<p class="reference">References <a class="el" href="dpm_8h_source.html#l00080">DpmHeader::calibrations</a>, <a class="el" href="blocks_2dpm_8c_source.html#l00036">dpm_payload_length()</a>, <a class="el" href="dpm_8h_source.html#l00079">DpmHeader::entries</a>, and <a class="el" href="dpm_8h_source.html#l00084">DpmHeader::layerEnds</a>.</p>
<p class="reference">Referenced by <a class="el" href="verify_8c_source.html#l00130">aaruf_verify_image()</a>, <a class="el" href="blocks_2dpm_8c_source.html#l00036">dpm_payload_length()</a>, <a class="el" href="blocks_2dpm_8c_source.html#l00148">process_dpm_block()</a>, and <a class="el" href="blocks_2dpm_8c_source.html#l00053">validate_dpm_block()</a>.</p>
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<a id="aa2692f41f0fe80552c1a2173588f12a9" name="aa2692f41f0fe80552c1a2173588f12a9"></a>
<h2 class="memtitle"><span class="permalink"><a href="#aa2692f41f0fe80552c1a2173588f12a9">&#9670;&#160;</a></span>process_dpm_block()</h2>
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<td class="memname">void process_dpm_block </td>
<td>(</td>
<td class="paramtype"><a class="el" href="structaaruformat__context.html">aaruformat_context</a> *</td> <td class="paramname"><span class="paramname"><em>ctx</em></span>, </td>
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<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">const <a class="el" href="structIndexEntry.html">IndexEntry</a> *</td> <td class="paramname"><span class="paramname"><em>entry</em></span>&#160;)</td>
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<p>Processes a Data Position Measurement block from the image stream. </p>
<p>Reads the block pointed to by the index entry, validates it and keeps it, header included, in the context so <a class="el" href="decls_8h.html#a2a5895e15916ffcffec176e7693d618f" title="Retrieves the Data Position Measurement block.">aaruf_get_dpm()</a> can return it. The block is optional: if it cannot be read or is invalid it is ignored and the image opens without it.</p>
<p>On images opened for resume, the loaded block is not marked dirty, so its index entry is kept untouched on close unless <a class="el" href="decls_8h.html#a3fab43f31b8b8c0181e8a9d33f6fcc9d" title="Sets the Data Position Measurement block.">aaruf_set_dpm()</a> or <a class="el" href="decls_8h.html#af44db9fad21942b3521c7e739d398ef9" title="Removes the Data Position Measurement block.">aaruf_clear_dpm()</a> are called.</p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">ctx</td><td>Pointer to the aaruformat context. </td></tr>
<tr><td class="paramname">entry</td><td>Index entry pointing to the block. </td></tr>
</table>
</dd>
</dl>
<p class="definition">Definition at line <a class="el" href="blocks_2dpm_8c_source.html#l00148">148</a> of file <a class="el" href="blocks_2dpm_8c_source.html">dpm.c</a>.</p>
<p class="reference">References <a class="el" href="internal_8h_source.html#l00046">aaruf_fseek()</a>, <a class="el" href="internal_8h_source.html#l00052">aaruf_ftell()</a>, <a class="el" href="errors_8h_source.html#l00082">AARUF_STATUS_OK</a>, <a class="el" href="enums_8h_source.html#l00177">DataPositionMeasurementBlock</a>, <a class="el" href="context_8h_source.html#l00223">aaruformat_context::dpm_block</a>, <a class="el" href="context_8h_source.html#l00224">aaruformat_context::dpm_block_length</a>, <a class="el" href="context_8h_source.html#l00225">aaruformat_context::dpm_damaged_offset</a>, <a class="el" href="blocks_2dpm_8c_source.html#l00036">dpm_payload_length()</a>, <a class="el" href="dpm_8h_source.html#l00079">DpmHeader::entries</a>, <a class="el" href="log_8h_source.html#l00075">FATAL</a>, <a class="el" href="dpm_8h_source.html#l00078">DpmHeader::identifier</a>, <a class="el" href="context_8h_source.html#l00270">aaruformat_context::image_info</a>, <a class="el" href="aaru_8h_source.html#l00937">ImageInfo::ImageSize</a>, <a class="el" href="context_8h_source.html#l00182">aaruformat_context::imageStream</a>, <a class="el" href="dpm_8h_source.html#l00087">DpmHeader::length</a>, <a class="el" href="index_8h_source.html#l00112">IndexEntry::offset</a>, <a class="el" href="blocks_2dpm_8c_source.html#l00148">process_dpm_block()</a>, <a class="el" href="blocks_2dpm_8c_source.html#l00083">recover_dpm_block()</a>, <a class="el" href="log_8h_source.html#l00069">TRACE</a>, and <a class="el" href="blocks_2dpm_8c_source.html#l00053">validate_dpm_block()</a>.</p>
<p class="reference">Referenced by <a class="el" href="open_8c_source.html#l00236">aaruf_open()</a>, and <a class="el" href="blocks_2dpm_8c_source.html#l00148">process_dpm_block()</a>.</p>
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<a id="ae2ccc865166ddb1638f1443ac63ef326" name="ae2ccc865166ddb1638f1443ac63ef326"></a>
<h2 class="memtitle"><span class="permalink"><a href="#ae2ccc865166ddb1638f1443ac63ef326">&#9670;&#160;</a></span>recover_dpm_block()</h2>
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<td class="memname">int32_t recover_dpm_block </td>
<td>(</td>
<td class="paramtype"><a class="el" href="structaaruformat__context.html">aaruformat_context</a> *</td> <td class="paramname"><span class="paramname"><em>ctx</em></span></td><td>)</td>
<td></td>
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<p>Recovers a damaged Data Position Measurement block with erasure coding. </p>
<p>The DPM block is part of the erasure coding metadata group. When it fails to load, its offset is remembered in ctx-&gt;dpm_damaged_offset, and this rebuilds it from the parity, trims the alignment padding the recovered bytes carry, validates it and keeps it in the context. <a class="el" href="decls_8h.html#a5cea94dcb9c08a646f7f7160ec8418de" title="Opens an existing AaruFormat image file.">aaruf_open()</a> loads the erasure coding map before processing the indexed blocks, so this works while opening.</p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">ctx</td><td>Pointer to the aaruformat context. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>AARUF_STATUS_OK if the block was recovered, an error status otherwise. </dd></dl>
<p class="definition">Definition at line <a class="el" href="blocks_2dpm_8c_source.html#l00083">83</a> of file <a class="el" href="blocks_2dpm_8c_source.html">dpm.c</a>.</p>
<p class="reference">References <a class="el" href="errors_8h_source.html#l00046">AARUF_ERROR_CANNOT_READ_BLOCK</a>, <a class="el" href="errors_8h_source.html#l00082">AARUF_STATUS_OK</a>, <a class="el" href="context_8h_source.html#l00223">aaruformat_context::dpm_block</a>, <a class="el" href="context_8h_source.html#l00224">aaruformat_context::dpm_block_length</a>, <a class="el" href="context_8h_source.html#l00225">aaruformat_context::dpm_damaged_offset</a>, <a class="el" href="erasure_8c_source.html#l00909">ec_recover_meta_block()</a>, <a class="el" href="dpm_8h_source.html#l00087">DpmHeader::length</a>, <a class="el" href="blocks_2dpm_8c_source.html#l00083">recover_dpm_block()</a>, <a class="el" href="log_8h_source.html#l00069">TRACE</a>, and <a class="el" href="blocks_2dpm_8c_source.html#l00053">validate_dpm_block()</a>.</p>
<p class="reference">Referenced by <a class="el" href="blocks_2dpm_8c_source.html#l00148">process_dpm_block()</a>, and <a class="el" href="blocks_2dpm_8c_source.html#l00083">recover_dpm_block()</a>.</p>
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<a id="ab012bc60295f357069a2d3fc0d36724e" name="ab012bc60295f357069a2d3fc0d36724e"></a>
<h2 class="memtitle"><span class="permalink"><a href="#ab012bc60295f357069a2d3fc0d36724e">&#9670;&#160;</a></span>validate_dpm_block()</h2>
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<td class="memname">int32_t validate_dpm_block </td>
<td>(</td>
<td class="paramtype">const uint8_t *</td> <td class="paramname"><span class="paramname"><em>data</em></span>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">size_t</td> <td class="paramname"><span class="paramname"><em>length</em></span>&#160;)</td>
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<p>Validates a serialized Data Position Measurement block. </p>
<p>Checks that the buffer holds a <a class="el" href="structDpmHeader.html" title="Header of the Data Position Measurement block.">DpmHeader</a> with the correct identifier, that the payload length matches both the header length field and the counts of layer ends, entries and calibrations, and that the payload CRC64 matches.</p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">data</td><td>Serialized block, header followed by its payload. </td></tr>
<tr><td class="paramname">length</td><td>Length of <code class="param">data</code> in bytes. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>AARUF_STATUS_OK if the block is valid, AARUF_ERROR_INCORRECT_DATA_SIZE if the sizes do not match, AARUF_ERROR_CANNOT_READ_BLOCK if the identifier is wrong, AARUF_ERROR_INVALID_BLOCK_CRC on CRC mismatch. </dd></dl>
<p class="definition">Definition at line <a class="el" href="blocks_2dpm_8c_source.html#l00053">53</a> of file <a class="el" href="blocks_2dpm_8c_source.html">dpm.c</a>.</p>
<p class="reference">References <a class="el" href="crc64_8c_source.html#l00160">aaruf_crc64_data()</a>, <a class="el" href="errors_8h_source.html#l00046">AARUF_ERROR_CANNOT_READ_BLOCK</a>, <a class="el" href="errors_8h_source.html#l00065">AARUF_ERROR_INCORRECT_DATA_SIZE</a>, <a class="el" href="errors_8h_source.html#l00057">AARUF_ERROR_INVALID_BLOCK_CRC</a>, <a class="el" href="errors_8h_source.html#l00082">AARUF_STATUS_OK</a>, <a class="el" href="dpm_8h_source.html#l00088">DpmHeader::crc64</a>, <a class="el" href="enums_8h_source.html#l00177">DataPositionMeasurementBlock</a>, <a class="el" href="blocks_2dpm_8c_source.html#l00036">dpm_payload_length()</a>, <a class="el" href="dpm_8h_source.html#l00078">DpmHeader::identifier</a>, <a class="el" href="dpm_8h_source.html#l00087">DpmHeader::length</a>, and <a class="el" href="blocks_2dpm_8c_source.html#l00053">validate_dpm_block()</a>.</p>
<p class="reference">Referenced by <a class="el" href="dpm_8c_source.html#l00102">aaruf_set_dpm()</a>, <a class="el" href="blocks_2dpm_8c_source.html#l00148">process_dpm_block()</a>, <a class="el" href="blocks_2dpm_8c_source.html#l00083">recover_dpm_block()</a>, and <a class="el" href="blocks_2dpm_8c_source.html#l00053">validate_dpm_block()</a>.</p>
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