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<h1>Source code for mxnet.recordio</h1><div class="highlight"><pre>
<span></span><span class="c1"># Licensed to the Apache Software Foundation (ASF) under one</span>
<span class="c1"># or more contributor license agreements. See the NOTICE file</span>
<span class="c1"># distributed with this work for additional information</span>
<span class="c1"># regarding copyright ownership. The ASF licenses this file</span>
<span class="c1"># to you under the Apache License, Version 2.0 (the</span>
<span class="c1"># "License"); you may not use this file except in compliance</span>
<span class="c1"># with the License. You may obtain a copy of the License at</span>
<span class="c1">#</span>
<span class="c1"># http://www.apache.org/licenses/LICENSE-2.0</span>
<span class="c1">#</span>
<span class="c1"># Unless required by applicable law or agreed to in writing,</span>
<span class="c1"># software distributed under the License is distributed on an</span>
<span class="c1"># "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY</span>
<span class="c1"># KIND, either express or implied. See the License for the</span>
<span class="c1"># specific language governing permissions and limitations</span>
<span class="c1"># under the License.</span>
<span class="sd">"""Read and write for the RecordIO data format."""</span>
<span class="kn">from</span> <span class="nn">__future__</span> <span class="k">import</span> <span class="n">absolute_import</span>
<span class="kn">from</span> <span class="nn">collections</span> <span class="k">import</span> <span class="n">namedtuple</span>
<span class="kn">from</span> <span class="nn">multiprocessing</span> <span class="k">import</span> <span class="n">current_process</span>
<span class="kn">import</span> <span class="nn">ctypes</span>
<span class="kn">import</span> <span class="nn">struct</span>
<span class="kn">import</span> <span class="nn">numbers</span>
<span class="kn">import</span> <span class="nn">numpy</span> <span class="k">as</span> <span class="nn">np</span>
<span class="kn">from</span> <span class="nn">.base</span> <span class="k">import</span> <span class="n">_LIB</span>
<span class="kn">from</span> <span class="nn">.base</span> <span class="k">import</span> <span class="n">RecordIOHandle</span>
<span class="kn">from</span> <span class="nn">.base</span> <span class="k">import</span> <span class="n">check_call</span>
<span class="kn">from</span> <span class="nn">.base</span> <span class="k">import</span> <span class="n">c_str</span>
<span class="k">try</span><span class="p">:</span>
<span class="kn">import</span> <span class="nn">cv2</span>
<span class="k">except</span> <span class="ne">ImportError</span><span class="p">:</span>
<span class="n">cv2</span> <span class="o">=</span> <span class="kc">None</span>
<div class="viewcode-block" id="MXRecordIO"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.MXRecordIO">[docs]</a><span class="k">class</span> <span class="nc">MXRecordIO</span><span class="p">(</span><span class="nb">object</span><span class="p">):</span>
<span class="sd">"""Reads/writes `RecordIO` data format, supporting sequential read and write.</span>
<span class="sd"> Examples</span>
<span class="sd"> ---------</span>
<span class="sd"> >>> record = mx.recordio.MXRecordIO('tmp.rec', 'w')</span>
<span class="sd"> <mxnet.recordio.MXRecordIO object at 0x10ef40ed0></span>
<span class="sd"> >>> for i in range(5):</span>
<span class="sd"> ... record.write('record_%d'%i)</span>
<span class="sd"> >>> record.close()</span>
<span class="sd"> >>> record = mx.recordio.MXRecordIO('tmp.rec', 'r')</span>
<span class="sd"> >>> for i in range(5):</span>
<span class="sd"> ... item = record.read()</span>
<span class="sd"> ... print(item)</span>
<span class="sd"> record_0</span>
<span class="sd"> record_1</span>
<span class="sd"> record_2</span>
<span class="sd"> record_3</span>
<span class="sd"> record_4</span>
<span class="sd"> >>> record.close()</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> uri : string</span>
<span class="sd"> Path to the record file.</span>
<span class="sd"> flag : string</span>
<span class="sd"> 'w' for write or 'r' for read.</span>
<span class="sd"> """</span>
<span class="k">def</span> <span class="nf">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">uri</span><span class="p">,</span> <span class="n">flag</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">uri</span> <span class="o">=</span> <span class="n">c_str</span><span class="p">(</span><span class="n">uri</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">handle</span> <span class="o">=</span> <span class="n">RecordIOHandle</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">flag</span> <span class="o">=</span> <span class="n">flag</span>
<span class="bp">self</span><span class="o">.</span><span class="n">pid</span> <span class="o">=</span> <span class="kc">None</span>
<span class="bp">self</span><span class="o">.</span><span class="n">is_open</span> <span class="o">=</span> <span class="kc">False</span>
<span class="bp">self</span><span class="o">.</span><span class="n">open</span><span class="p">()</span>
<div class="viewcode-block" id="MXRecordIO.open"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.MXRecordIO.open">[docs]</a> <span class="k">def</span> <span class="nf">open</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""Opens the record file."""</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">flag</span> <span class="o">==</span> <span class="s2">"w"</span><span class="p">:</span>
<span class="n">check_call</span><span class="p">(</span><span class="n">_LIB</span><span class="o">.</span><span class="n">MXRecordIOWriterCreate</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">uri</span><span class="p">,</span> <span class="n">ctypes</span><span class="o">.</span><span class="n">byref</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">handle</span><span class="p">)))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">writable</span> <span class="o">=</span> <span class="kc">True</span>
<span class="k">elif</span> <span class="bp">self</span><span class="o">.</span><span class="n">flag</span> <span class="o">==</span> <span class="s2">"r"</span><span class="p">:</span>
<span class="n">check_call</span><span class="p">(</span><span class="n">_LIB</span><span class="o">.</span><span class="n">MXRecordIOReaderCreate</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">uri</span><span class="p">,</span> <span class="n">ctypes</span><span class="o">.</span><span class="n">byref</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">handle</span><span class="p">)))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">writable</span> <span class="o">=</span> <span class="kc">False</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s2">"Invalid flag </span><span class="si">%s</span><span class="s2">"</span><span class="o">%</span><span class="bp">self</span><span class="o">.</span><span class="n">flag</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">pid</span> <span class="o">=</span> <span class="n">current_process</span><span class="p">()</span><span class="o">.</span><span class="n">pid</span>
<span class="bp">self</span><span class="o">.</span><span class="n">is_open</span> <span class="o">=</span> <span class="kc">True</span></div>
<span class="k">def</span> <span class="nf">__del__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">__getstate__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""Override pickling behavior."""</span>
<span class="c1"># pickling pointer is not allowed</span>
<span class="n">is_open</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_open</span>
<span class="bp">self</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
<span class="n">d</span> <span class="o">=</span> <span class="nb">dict</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="vm">__dict__</span><span class="p">)</span>
<span class="n">d</span><span class="p">[</span><span class="s1">'is_open'</span><span class="p">]</span> <span class="o">=</span> <span class="n">is_open</span>
<span class="n">uri</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">uri</span><span class="o">.</span><span class="n">value</span>
<span class="k">try</span><span class="p">:</span>
<span class="n">uri</span> <span class="o">=</span> <span class="n">uri</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">'utf-8'</span><span class="p">)</span>
<span class="k">except</span> <span class="ne">AttributeError</span><span class="p">:</span>
<span class="k">pass</span>
<span class="k">del</span> <span class="n">d</span><span class="p">[</span><span class="s1">'handle'</span><span class="p">]</span>
<span class="n">d</span><span class="p">[</span><span class="s1">'uri'</span><span class="p">]</span> <span class="o">=</span> <span class="n">uri</span>
<span class="k">return</span> <span class="n">d</span>
<span class="k">def</span> <span class="nf">__setstate__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">d</span><span class="p">):</span>
<span class="sd">"""Restore from pickled."""</span>
<span class="bp">self</span><span class="o">.</span><span class="vm">__dict__</span> <span class="o">=</span> <span class="n">d</span>
<span class="n">is_open</span> <span class="o">=</span> <span class="n">d</span><span class="p">[</span><span class="s1">'is_open'</span><span class="p">]</span>
<span class="bp">self</span><span class="o">.</span><span class="n">is_open</span> <span class="o">=</span> <span class="kc">False</span>
<span class="bp">self</span><span class="o">.</span><span class="n">handle</span> <span class="o">=</span> <span class="n">RecordIOHandle</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">uri</span> <span class="o">=</span> <span class="n">c_str</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">uri</span><span class="p">)</span>
<span class="k">if</span> <span class="n">is_open</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">open</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">_check_pid</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">allow_reset</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="sd">"""Check process id to ensure integrity, reset if in new process."""</span>
<span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">pid</span> <span class="o">==</span> <span class="n">current_process</span><span class="p">()</span><span class="o">.</span><span class="n">pid</span><span class="p">:</span>
<span class="k">if</span> <span class="n">allow_reset</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">reset</span><span class="p">()</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">RuntimeError</span><span class="p">(</span><span class="s2">"Forbidden operation in multiple processes"</span><span class="p">)</span>
<div class="viewcode-block" id="MXRecordIO.close"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.MXRecordIO.close">[docs]</a> <span class="k">def</span> <span class="nf">close</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""Closes the record file."""</span>
<span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_open</span><span class="p">:</span>
<span class="k">return</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">writable</span><span class="p">:</span>
<span class="n">check_call</span><span class="p">(</span><span class="n">_LIB</span><span class="o">.</span><span class="n">MXRecordIOWriterFree</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">handle</span><span class="p">))</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">check_call</span><span class="p">(</span><span class="n">_LIB</span><span class="o">.</span><span class="n">MXRecordIOReaderFree</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">handle</span><span class="p">))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">is_open</span> <span class="o">=</span> <span class="kc">False</span>
<span class="bp">self</span><span class="o">.</span><span class="n">pid</span> <span class="o">=</span> <span class="kc">None</span></div>
<div class="viewcode-block" id="MXRecordIO.reset"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.MXRecordIO.reset">[docs]</a> <span class="k">def</span> <span class="nf">reset</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""Resets the pointer to first item.</span>
<span class="sd"> If the record is opened with 'w', this function will truncate the file to empty.</span>
<span class="sd"> Examples</span>
<span class="sd"> ---------</span>
<span class="sd"> >>> record = mx.recordio.MXRecordIO('tmp.rec', 'r')</span>
<span class="sd"> >>> for i in range(2):</span>
<span class="sd"> ... item = record.read()</span>
<span class="sd"> ... print(item)</span>
<span class="sd"> record_0</span>
<span class="sd"> record_1</span>
<span class="sd"> >>> record.reset() # Pointer is reset.</span>
<span class="sd"> >>> print(record.read()) # Started reading from start again.</span>
<span class="sd"> record_0</span>
<span class="sd"> >>> record.close()</span>
<span class="sd"> """</span>
<span class="bp">self</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">open</span><span class="p">()</span></div>
<div class="viewcode-block" id="MXRecordIO.write"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.MXRecordIO.write">[docs]</a> <span class="k">def</span> <span class="nf">write</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">buf</span><span class="p">):</span>
<span class="sd">"""Inserts a string buffer as a record.</span>
<span class="sd"> Examples</span>
<span class="sd"> ---------</span>
<span class="sd"> >>> record = mx.recordio.MXRecordIO('tmp.rec', 'w')</span>
<span class="sd"> >>> for i in range(5):</span>
<span class="sd"> ... record.write('record_%d'%i)</span>
<span class="sd"> >>> record.close()</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> buf : string (python2), bytes (python3)</span>
<span class="sd"> Buffer to write.</span>
<span class="sd"> """</span>
<span class="k">assert</span> <span class="bp">self</span><span class="o">.</span><span class="n">writable</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_check_pid</span><span class="p">(</span><span class="n">allow_reset</span><span class="o">=</span><span class="kc">False</span><span class="p">)</span>
<span class="n">check_call</span><span class="p">(</span><span class="n">_LIB</span><span class="o">.</span><span class="n">MXRecordIOWriterWriteRecord</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">handle</span><span class="p">,</span>
<span class="n">ctypes</span><span class="o">.</span><span class="n">c_char_p</span><span class="p">(</span><span class="n">buf</span><span class="p">),</span>
<span class="n">ctypes</span><span class="o">.</span><span class="n">c_size_t</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">buf</span><span class="p">))))</span></div>
<div class="viewcode-block" id="MXRecordIO.read"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.MXRecordIO.read">[docs]</a> <span class="k">def</span> <span class="nf">read</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""Returns record as a string.</span>
<span class="sd"> Examples</span>
<span class="sd"> ---------</span>
<span class="sd"> >>> record = mx.recordio.MXRecordIO('tmp.rec', 'r')</span>
<span class="sd"> >>> for i in range(5):</span>
<span class="sd"> ... item = record.read()</span>
<span class="sd"> ... print(item)</span>
<span class="sd"> record_0</span>
<span class="sd"> record_1</span>
<span class="sd"> record_2</span>
<span class="sd"> record_3</span>
<span class="sd"> record_4</span>
<span class="sd"> >>> record.close()</span>
<span class="sd"> Returns</span>
<span class="sd"> ----------</span>
<span class="sd"> buf : string</span>
<span class="sd"> Buffer read.</span>
<span class="sd"> """</span>
<span class="k">assert</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">writable</span>
<span class="c1"># trying to implicitly read from multiple processes is forbidden,</span>
<span class="c1"># there's no elegant way to handle unless lock is introduced</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_check_pid</span><span class="p">(</span><span class="n">allow_reset</span><span class="o">=</span><span class="kc">False</span><span class="p">)</span>
<span class="n">buf</span> <span class="o">=</span> <span class="n">ctypes</span><span class="o">.</span><span class="n">c_char_p</span><span class="p">()</span>
<span class="n">size</span> <span class="o">=</span> <span class="n">ctypes</span><span class="o">.</span><span class="n">c_size_t</span><span class="p">()</span>
<span class="n">check_call</span><span class="p">(</span><span class="n">_LIB</span><span class="o">.</span><span class="n">MXRecordIOReaderReadRecord</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">handle</span><span class="p">,</span>
<span class="n">ctypes</span><span class="o">.</span><span class="n">byref</span><span class="p">(</span><span class="n">buf</span><span class="p">),</span>
<span class="n">ctypes</span><span class="o">.</span><span class="n">byref</span><span class="p">(</span><span class="n">size</span><span class="p">)))</span>
<span class="k">if</span> <span class="n">buf</span><span class="p">:</span>
<span class="n">buf</span> <span class="o">=</span> <span class="n">ctypes</span><span class="o">.</span><span class="n">cast</span><span class="p">(</span><span class="n">buf</span><span class="p">,</span> <span class="n">ctypes</span><span class="o">.</span><span class="n">POINTER</span><span class="p">(</span><span class="n">ctypes</span><span class="o">.</span><span class="n">c_char</span><span class="o">*</span><span class="n">size</span><span class="o">.</span><span class="n">value</span><span class="p">))</span>
<span class="k">return</span> <span class="n">buf</span><span class="o">.</span><span class="n">contents</span><span class="o">.</span><span class="n">raw</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">return</span> <span class="kc">None</span></div></div>
<div class="viewcode-block" id="MXIndexedRecordIO"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.MXIndexedRecordIO">[docs]</a><span class="k">class</span> <span class="nc">MXIndexedRecordIO</span><span class="p">(</span><span class="n">MXRecordIO</span><span class="p">):</span>
<span class="sd">"""Reads/writes `RecordIO` data format, supporting random access.</span>
<span class="sd"> Examples</span>
<span class="sd"> ---------</span>
<span class="sd"> >>> for i in range(5):</span>
<span class="sd"> ... record.write_idx(i, 'record_%d'%i)</span>
<span class="sd"> >>> record.close()</span>
<span class="sd"> >>> record = mx.recordio.MXIndexedRecordIO('tmp.idx', 'tmp.rec', 'r')</span>
<span class="sd"> >>> record.read_idx(3)</span>
<span class="sd"> record_3</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> idx_path : str</span>
<span class="sd"> Path to the index file.</span>
<span class="sd"> uri : str</span>
<span class="sd"> Path to the record file. Only supports seekable file types.</span>
<span class="sd"> flag : str</span>
<span class="sd"> 'w' for write or 'r' for read.</span>
<span class="sd"> key_type : type</span>
<span class="sd"> Data type for keys.</span>
<span class="sd"> """</span>
<span class="k">def</span> <span class="nf">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">idx_path</span><span class="p">,</span> <span class="n">uri</span><span class="p">,</span> <span class="n">flag</span><span class="p">,</span> <span class="n">key_type</span><span class="o">=</span><span class="nb">int</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">idx_path</span> <span class="o">=</span> <span class="n">idx_path</span>
<span class="bp">self</span><span class="o">.</span><span class="n">idx</span> <span class="o">=</span> <span class="p">{}</span>
<span class="bp">self</span><span class="o">.</span><span class="n">keys</span> <span class="o">=</span> <span class="p">[]</span>
<span class="bp">self</span><span class="o">.</span><span class="n">key_type</span> <span class="o">=</span> <span class="n">key_type</span>
<span class="bp">self</span><span class="o">.</span><span class="n">fidx</span> <span class="o">=</span> <span class="kc">None</span>
<span class="nb">super</span><span class="p">(</span><span class="n">MXIndexedRecordIO</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="fm">__init__</span><span class="p">(</span><span class="n">uri</span><span class="p">,</span> <span class="n">flag</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">open</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="nb">super</span><span class="p">(</span><span class="n">MXIndexedRecordIO</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">open</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">idx</span> <span class="o">=</span> <span class="p">{}</span>
<span class="bp">self</span><span class="o">.</span><span class="n">keys</span> <span class="o">=</span> <span class="p">[]</span>
<span class="bp">self</span><span class="o">.</span><span class="n">fidx</span> <span class="o">=</span> <span class="nb">open</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">idx_path</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">flag</span><span class="p">)</span>
<span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">writable</span><span class="p">:</span>
<span class="k">for</span> <span class="n">line</span> <span class="ow">in</span> <span class="nb">iter</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">fidx</span><span class="o">.</span><span class="n">readline</span><span class="p">,</span> <span class="s1">''</span><span class="p">):</span>
<span class="n">line</span> <span class="o">=</span> <span class="n">line</span><span class="o">.</span><span class="n">strip</span><span class="p">()</span><span class="o">.</span><span class="n">split</span><span class="p">(</span><span class="s1">'</span><span class="se">\t</span><span class="s1">'</span><span class="p">)</span>
<span class="n">key</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">key_type</span><span class="p">(</span><span class="n">line</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span>
<span class="bp">self</span><span class="o">.</span><span class="n">idx</span><span class="p">[</span><span class="n">key</span><span class="p">]</span> <span class="o">=</span> <span class="nb">int</span><span class="p">(</span><span class="n">line</span><span class="p">[</span><span class="mi">1</span><span class="p">])</span>
<span class="bp">self</span><span class="o">.</span><span class="n">keys</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">key</span><span class="p">)</span>
<div class="viewcode-block" id="MXIndexedRecordIO.close"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.MXIndexedRecordIO.close">[docs]</a> <span class="k">def</span> <span class="nf">close</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""Closes the record file."""</span>
<span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_open</span><span class="p">:</span>
<span class="k">return</span>
<span class="nb">super</span><span class="p">(</span><span class="n">MXIndexedRecordIO</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">fidx</span><span class="o">.</span><span class="n">close</span><span class="p">()</span></div>
<span class="k">def</span> <span class="nf">__getstate__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""Override pickling behavior."""</span>
<span class="n">d</span> <span class="o">=</span> <span class="nb">super</span><span class="p">(</span><span class="n">MXIndexedRecordIO</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__getstate__</span><span class="p">()</span>
<span class="n">d</span><span class="p">[</span><span class="s1">'fidx'</span><span class="p">]</span> <span class="o">=</span> <span class="kc">None</span>
<span class="k">return</span> <span class="n">d</span>
<div class="viewcode-block" id="MXIndexedRecordIO.seek"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.MXIndexedRecordIO.seek">[docs]</a> <span class="k">def</span> <span class="nf">seek</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">idx</span><span class="p">):</span>
<span class="sd">"""Sets the current read pointer position.</span>
<span class="sd"> This function is internally called by `read_idx(idx)` to find the current</span>
<span class="sd"> reader pointer position. It doesn't return anything."""</span>
<span class="k">assert</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">writable</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_check_pid</span><span class="p">(</span><span class="n">allow_reset</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="n">pos</span> <span class="o">=</span> <span class="n">ctypes</span><span class="o">.</span><span class="n">c_size_t</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">idx</span><span class="p">[</span><span class="n">idx</span><span class="p">])</span>
<span class="n">check_call</span><span class="p">(</span><span class="n">_LIB</span><span class="o">.</span><span class="n">MXRecordIOReaderSeek</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">handle</span><span class="p">,</span> <span class="n">pos</span><span class="p">))</span></div>
<div class="viewcode-block" id="MXIndexedRecordIO.tell"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.MXIndexedRecordIO.tell">[docs]</a> <span class="k">def</span> <span class="nf">tell</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""Returns the current position of write head.</span>
<span class="sd"> Examples</span>
<span class="sd"> ---------</span>
<span class="sd"> >>> record = mx.recordio.MXIndexedRecordIO('tmp.idx', 'tmp.rec', 'w')</span>
<span class="sd"> >>> print(record.tell())</span>
<span class="sd"> 0</span>
<span class="sd"> >>> for i in range(5):</span>
<span class="sd"> ... record.write_idx(i, 'record_%d'%i)</span>
<span class="sd"> ... print(record.tell())</span>
<span class="sd"> 16</span>
<span class="sd"> 32</span>
<span class="sd"> 48</span>
<span class="sd"> 64</span>
<span class="sd"> 80</span>
<span class="sd"> """</span>
<span class="k">assert</span> <span class="bp">self</span><span class="o">.</span><span class="n">writable</span>
<span class="n">pos</span> <span class="o">=</span> <span class="n">ctypes</span><span class="o">.</span><span class="n">c_size_t</span><span class="p">()</span>
<span class="n">check_call</span><span class="p">(</span><span class="n">_LIB</span><span class="o">.</span><span class="n">MXRecordIOWriterTell</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">handle</span><span class="p">,</span> <span class="n">ctypes</span><span class="o">.</span><span class="n">byref</span><span class="p">(</span><span class="n">pos</span><span class="p">)))</span>
<span class="k">return</span> <span class="n">pos</span><span class="o">.</span><span class="n">value</span></div>
<div class="viewcode-block" id="MXIndexedRecordIO.read_idx"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.MXIndexedRecordIO.read_idx">[docs]</a> <span class="k">def</span> <span class="nf">read_idx</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">idx</span><span class="p">):</span>
<span class="sd">"""Returns the record at given index.</span>
<span class="sd"> Examples</span>
<span class="sd"> ---------</span>
<span class="sd"> >>> record = mx.recordio.MXIndexedRecordIO('tmp.idx', 'tmp.rec', 'w')</span>
<span class="sd"> >>> for i in range(5):</span>
<span class="sd"> ... record.write_idx(i, 'record_%d'%i)</span>
<span class="sd"> >>> record.close()</span>
<span class="sd"> >>> record = mx.recordio.MXIndexedRecordIO('tmp.idx', 'tmp.rec', 'r')</span>
<span class="sd"> >>> record.read_idx(3)</span>
<span class="sd"> record_3</span>
<span class="sd"> """</span>
<span class="bp">self</span><span class="o">.</span><span class="n">seek</span><span class="p">(</span><span class="n">idx</span><span class="p">)</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">read</span><span class="p">()</span></div>
<div class="viewcode-block" id="MXIndexedRecordIO.write_idx"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.MXIndexedRecordIO.write_idx">[docs]</a> <span class="k">def</span> <span class="nf">write_idx</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">idx</span><span class="p">,</span> <span class="n">buf</span><span class="p">):</span>
<span class="sd">"""Inserts input record at given index.</span>
<span class="sd"> Examples</span>
<span class="sd"> ---------</span>
<span class="sd"> >>> for i in range(5):</span>
<span class="sd"> ... record.write_idx(i, 'record_%d'%i)</span>
<span class="sd"> >>> record.close()</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> idx : int</span>
<span class="sd"> Index of a file.</span>
<span class="sd"> buf :</span>
<span class="sd"> Record to write.</span>
<span class="sd"> """</span>
<span class="n">key</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">key_type</span><span class="p">(</span><span class="n">idx</span><span class="p">)</span>
<span class="n">pos</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">tell</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">buf</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">fidx</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s1">'</span><span class="si">%s</span><span class="se">\t</span><span class="si">%d</span><span class="se">\n</span><span class="s1">'</span><span class="o">%</span><span class="p">(</span><span class="nb">str</span><span class="p">(</span><span class="n">key</span><span class="p">),</span> <span class="n">pos</span><span class="p">))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">idx</span><span class="p">[</span><span class="n">key</span><span class="p">]</span> <span class="o">=</span> <span class="n">pos</span>
<span class="bp">self</span><span class="o">.</span><span class="n">keys</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">key</span><span class="p">)</span></div></div>
<span class="n">IRHeader</span> <span class="o">=</span> <span class="n">namedtuple</span><span class="p">(</span><span class="s1">'HEADER'</span><span class="p">,</span> <span class="p">[</span><span class="s1">'flag'</span><span class="p">,</span> <span class="s1">'label'</span><span class="p">,</span> <span class="s1">'id'</span><span class="p">,</span> <span class="s1">'id2'</span><span class="p">])</span>
<span class="sd">"""An alias for HEADER. Used to store metadata (e.g. labels) accompanying a record.</span>
<span class="sd">See mxnet.recordio.pack and mxnet.recordio.pack_img for example uses.</span>
<span class="sd">Parameters</span>
<span class="sd">----------</span>
<span class="sd"> flag : int</span>
<span class="sd"> Available for convenience, can be set arbitrarily.</span>
<span class="sd"> label : float or an array of float</span>
<span class="sd"> Typically used to store label(s) for a record.</span>
<span class="sd"> id: int</span>
<span class="sd"> Usually a unique id representing record.</span>
<span class="sd"> id2: int</span>
<span class="sd"> Higher order bits of the unique id, should be set to 0 (in most cases).</span>
<span class="sd">"""</span>
<span class="n">_IR_FORMAT</span> <span class="o">=</span> <span class="s1">'IfQQ'</span>
<span class="n">_IR_SIZE</span> <span class="o">=</span> <span class="n">struct</span><span class="o">.</span><span class="n">calcsize</span><span class="p">(</span><span class="n">_IR_FORMAT</span><span class="p">)</span>
<div class="viewcode-block" id="pack"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.pack">[docs]</a><span class="k">def</span> <span class="nf">pack</span><span class="p">(</span><span class="n">header</span><span class="p">,</span> <span class="n">s</span><span class="p">):</span>
<span class="sd">"""Pack a string into MXImageRecord.</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> header : IRHeader</span>
<span class="sd"> Header of the image record.</span>
<span class="sd"> ``header.label`` can be a number or an array. See more detail in ``IRHeader``.</span>
<span class="sd"> s : str</span>
<span class="sd"> Raw image string to be packed.</span>
<span class="sd"> Returns</span>
<span class="sd"> -------</span>
<span class="sd"> s : str</span>
<span class="sd"> The packed string.</span>
<span class="sd"> Examples</span>
<span class="sd"> --------</span>
<span class="sd"> >>> label = 4 # label can also be a 1-D array, for example: label = [1,2,3]</span>
<span class="sd"> >>> id = 2574</span>
<span class="sd"> >>> header = mx.recordio.IRHeader(0, label, id, 0)</span>
<span class="sd"> >>> with open(path, 'r') as file:</span>
<span class="sd"> ... s = file.read()</span>
<span class="sd"> >>> packed_s = mx.recordio.pack(header, s)</span>
<span class="sd"> """</span>
<span class="n">header</span> <span class="o">=</span> <span class="n">IRHeader</span><span class="p">(</span><span class="o">*</span><span class="n">header</span><span class="p">)</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">header</span><span class="o">.</span><span class="n">label</span><span class="p">,</span> <span class="n">numbers</span><span class="o">.</span><span class="n">Number</span><span class="p">):</span>
<span class="n">header</span> <span class="o">=</span> <span class="n">header</span><span class="o">.</span><span class="n">_replace</span><span class="p">(</span><span class="n">flag</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">label</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">asarray</span><span class="p">(</span><span class="n">header</span><span class="o">.</span><span class="n">label</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">np</span><span class="o">.</span><span class="n">float32</span><span class="p">)</span>
<span class="n">header</span> <span class="o">=</span> <span class="n">header</span><span class="o">.</span><span class="n">_replace</span><span class="p">(</span><span class="n">flag</span><span class="o">=</span><span class="n">label</span><span class="o">.</span><span class="n">size</span><span class="p">,</span> <span class="n">label</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">s</span> <span class="o">=</span> <span class="n">label</span><span class="o">.</span><span class="n">tostring</span><span class="p">()</span> <span class="o">+</span> <span class="n">s</span>
<span class="n">s</span> <span class="o">=</span> <span class="n">struct</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">_IR_FORMAT</span><span class="p">,</span> <span class="o">*</span><span class="n">header</span><span class="p">)</span> <span class="o">+</span> <span class="n">s</span>
<span class="k">return</span> <span class="n">s</span></div>
<div class="viewcode-block" id="unpack"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.unpack">[docs]</a><span class="k">def</span> <span class="nf">unpack</span><span class="p">(</span><span class="n">s</span><span class="p">):</span>
<span class="sd">"""Unpack a MXImageRecord to string.</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> s : str</span>
<span class="sd"> String buffer from ``MXRecordIO.read``.</span>
<span class="sd"> Returns</span>
<span class="sd"> -------</span>
<span class="sd"> header : IRHeader</span>
<span class="sd"> Header of the image record.</span>
<span class="sd"> s : str</span>
<span class="sd"> Unpacked string.</span>
<span class="sd"> Examples</span>
<span class="sd"> --------</span>
<span class="sd"> >>> record = mx.recordio.MXRecordIO('test.rec', 'r')</span>
<span class="sd"> >>> item = record.read()</span>
<span class="sd"> >>> header, s = mx.recordio.unpack(item)</span>
<span class="sd"> >>> header</span>
<span class="sd"> HEADER(flag=0, label=14.0, id=20129312, id2=0)</span>
<span class="sd"> """</span>
<span class="n">header</span> <span class="o">=</span> <span class="n">IRHeader</span><span class="p">(</span><span class="o">*</span><span class="n">struct</span><span class="o">.</span><span class="n">unpack</span><span class="p">(</span><span class="n">_IR_FORMAT</span><span class="p">,</span> <span class="n">s</span><span class="p">[:</span><span class="n">_IR_SIZE</span><span class="p">]))</span>
<span class="n">s</span> <span class="o">=</span> <span class="n">s</span><span class="p">[</span><span class="n">_IR_SIZE</span><span class="p">:]</span>
<span class="k">if</span> <span class="n">header</span><span class="o">.</span><span class="n">flag</span> <span class="o">></span> <span class="mi">0</span><span class="p">:</span>
<span class="n">header</span> <span class="o">=</span> <span class="n">header</span><span class="o">.</span><span class="n">_replace</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="n">np</span><span class="o">.</span><span class="n">frombuffer</span><span class="p">(</span><span class="n">s</span><span class="p">,</span> <span class="n">np</span><span class="o">.</span><span class="n">float32</span><span class="p">,</span> <span class="n">header</span><span class="o">.</span><span class="n">flag</span><span class="p">))</span>
<span class="n">s</span> <span class="o">=</span> <span class="n">s</span><span class="p">[</span><span class="n">header</span><span class="o">.</span><span class="n">flag</span><span class="o">*</span><span class="mi">4</span><span class="p">:]</span>
<span class="k">return</span> <span class="n">header</span><span class="p">,</span> <span class="n">s</span></div>
<div class="viewcode-block" id="unpack_img"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.unpack_img">[docs]</a><span class="k">def</span> <span class="nf">unpack_img</span><span class="p">(</span><span class="n">s</span><span class="p">,</span> <span class="n">iscolor</span><span class="o">=-</span><span class="mi">1</span><span class="p">):</span>
<span class="sd">"""Unpack a MXImageRecord to image.</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> s : str</span>
<span class="sd"> String buffer from ``MXRecordIO.read``.</span>
<span class="sd"> iscolor : int</span>
<span class="sd"> Image format option for ``cv2.imdecode``.</span>
<span class="sd"> Returns</span>
<span class="sd"> -------</span>
<span class="sd"> header : IRHeader</span>
<span class="sd"> Header of the image record.</span>
<span class="sd"> img : numpy.ndarray</span>
<span class="sd"> Unpacked image.</span>
<span class="sd"> Examples</span>
<span class="sd"> --------</span>
<span class="sd"> >>> record = mx.recordio.MXRecordIO('test.rec', 'r')</span>
<span class="sd"> >>> item = record.read()</span>
<span class="sd"> >>> header, img = mx.recordio.unpack_img(item)</span>
<span class="sd"> >>> header</span>
<span class="sd"> HEADER(flag=0, label=14.0, id=20129312, id2=0)</span>
<span class="sd"> >>> img</span>
<span class="sd"> array([[[ 23, 27, 45],</span>
<span class="sd"> [ 28, 32, 50],</span>
<span class="sd"> ...,</span>
<span class="sd"> [ 36, 40, 59],</span>
<span class="sd"> [ 35, 39, 58]],</span>
<span class="sd"> ...,</span>
<span class="sd"> [[ 91, 92, 113],</span>
<span class="sd"> [ 97, 98, 119],</span>
<span class="sd"> ...,</span>
<span class="sd"> [168, 169, 167],</span>
<span class="sd"> [166, 167, 165]]], dtype=uint8)</span>
<span class="sd"> """</span>
<span class="n">header</span><span class="p">,</span> <span class="n">s</span> <span class="o">=</span> <span class="n">unpack</span><span class="p">(</span><span class="n">s</span><span class="p">)</span>
<span class="n">img</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">frombuffer</span><span class="p">(</span><span class="n">s</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">np</span><span class="o">.</span><span class="n">uint8</span><span class="p">)</span>
<span class="k">assert</span> <span class="n">cv2</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span>
<span class="n">img</span> <span class="o">=</span> <span class="n">cv2</span><span class="o">.</span><span class="n">imdecode</span><span class="p">(</span><span class="n">img</span><span class="p">,</span> <span class="n">iscolor</span><span class="p">)</span>
<span class="k">return</span> <span class="n">header</span><span class="p">,</span> <span class="n">img</span></div>
<div class="viewcode-block" id="pack_img"><a class="viewcode-back" href="../../api/python/io/io.html#mxnet.recordio.pack_img">[docs]</a><span class="k">def</span> <span class="nf">pack_img</span><span class="p">(</span><span class="n">header</span><span class="p">,</span> <span class="n">img</span><span class="p">,</span> <span class="n">quality</span><span class="o">=</span><span class="mi">95</span><span class="p">,</span> <span class="n">img_fmt</span><span class="o">=</span><span class="s1">'.jpg'</span><span class="p">):</span>
<span class="sd">"""Pack an image into ``MXImageRecord``.</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> header : IRHeader</span>
<span class="sd"> Header of the image record.</span>
<span class="sd"> ``header.label`` can be a number or an array. See more detail in ``IRHeader``.</span>
<span class="sd"> img : numpy.ndarray</span>
<span class="sd"> Image to be packed.</span>
<span class="sd"> quality : int</span>
<span class="sd"> Quality for JPEG encoding in range 1-100, or compression for PNG encoding in range 1-9.</span>
<span class="sd"> img_fmt : str</span>
<span class="sd"> Encoding of the image (.jpg for JPEG, .png for PNG).</span>
<span class="sd"> Returns</span>
<span class="sd"> -------</span>
<span class="sd"> s : str</span>
<span class="sd"> The packed string.</span>
<span class="sd"> Examples</span>
<span class="sd"> --------</span>
<span class="sd"> >>> label = 4 # label can also be a 1-D array, for example: label = [1,2,3]</span>
<span class="sd"> >>> id = 2574</span>
<span class="sd"> >>> header = mx.recordio.IRHeader(0, label, id, 0)</span>
<span class="sd"> >>> img = cv2.imread('test.jpg')</span>
<span class="sd"> >>> packed_s = mx.recordio.pack_img(header, img)</span>
<span class="sd"> """</span>
<span class="k">assert</span> <span class="n">cv2</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span>
<span class="n">jpg_formats</span> <span class="o">=</span> <span class="p">[</span><span class="s1">'.JPG'</span><span class="p">,</span> <span class="s1">'.JPEG'</span><span class="p">]</span>
<span class="n">png_formats</span> <span class="o">=</span> <span class="p">[</span><span class="s1">'.PNG'</span><span class="p">]</span>
<span class="n">encode_params</span> <span class="o">=</span> <span class="kc">None</span>
<span class="k">if</span> <span class="n">img_fmt</span><span class="o">.</span><span class="n">upper</span><span class="p">()</span> <span class="ow">in</span> <span class="n">jpg_formats</span><span class="p">:</span>
<span class="n">encode_params</span> <span class="o">=</span> <span class="p">[</span><span class="n">cv2</span><span class="o">.</span><span class="n">IMWRITE_JPEG_QUALITY</span><span class="p">,</span> <span class="n">quality</span><span class="p">]</span>
<span class="k">elif</span> <span class="n">img_fmt</span><span class="o">.</span><span class="n">upper</span><span class="p">()</span> <span class="ow">in</span> <span class="n">png_formats</span><span class="p">:</span>
<span class="n">encode_params</span> <span class="o">=</span> <span class="p">[</span><span class="n">cv2</span><span class="o">.</span><span class="n">IMWRITE_PNG_COMPRESSION</span><span class="p">,</span> <span class="n">quality</span><span class="p">]</span>
<span class="n">ret</span><span class="p">,</span> <span class="n">buf</span> <span class="o">=</span> <span class="n">cv2</span><span class="o">.</span><span class="n">imencode</span><span class="p">(</span><span class="n">img_fmt</span><span class="p">,</span> <span class="n">img</span><span class="p">,</span> <span class="n">encode_params</span><span class="p">)</span>
<span class="k">assert</span> <span class="n">ret</span><span class="p">,</span> <span class="s1">'failed to encode image'</span>
<span class="k">return</span> <span class="n">pack</span><span class="p">(</span><span class="n">header</span><span class="p">,</span> <span class="n">buf</span><span class="o">.</span><span class="n">tostring</span><span class="p">())</span></div>
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