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<h1>Source code for apache_beam.io.avroio</h1><div class="highlight"><pre>
<span></span><span class="c1">#</span>
<span class="c1"># Licensed to the Apache Software Foundation (ASF) under one or more</span>
<span class="c1"># contributor license agreements. See the NOTICE file distributed with</span>
<span class="c1"># this work for additional information regarding copyright ownership.</span>
<span class="c1"># The ASF licenses this file to You under the Apache License, Version 2.0</span>
<span class="c1"># (the &quot;License&quot;); you may not use this file except in compliance with</span>
<span class="c1"># 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, software</span>
<span class="c1"># distributed under the License is distributed on an &quot;AS IS&quot; BASIS,</span>
<span class="c1"># WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.</span>
<span class="c1"># See the License for the specific language governing permissions and</span>
<span class="c1"># limitations under the License.</span>
<span class="c1">#</span>
<span class="sd">&quot;&quot;&quot;``PTransforms`` for reading from and writing to Avro files.</span>
<span class="sd">Provides two read ``PTransform``s, ``ReadFromAvro`` and ``ReadAllFromAvro``,</span>
<span class="sd">that produces a ``PCollection`` of records.</span>
<span class="sd">Each record of this ``PCollection`` will contain a single record read from</span>
<span class="sd">an Avro file. Records that are of simple types will be mapped into</span>
<span class="sd">corresponding Python types. Records that are of Avro type &#39;RECORD&#39; will be</span>
<span class="sd">mapped to Python dictionaries that comply with the schema contained in the</span>
<span class="sd">Avro file that contains those records. In this case, keys of each dictionary</span>
<span class="sd">will contain the corresponding field names and will be of type ``string``</span>
<span class="sd">while the values of the dictionary will be of the type defined in the</span>
<span class="sd">corresponding Avro schema.</span>
<span class="sd">For example, if schema of the Avro file is the following.</span>
<span class="sd">{&quot;namespace&quot;: &quot;example.avro&quot;,&quot;type&quot;: &quot;record&quot;,&quot;name&quot;: &quot;User&quot;,&quot;fields&quot;:</span>
<span class="sd">[{&quot;name&quot;: &quot;name&quot;, &quot;type&quot;: &quot;string&quot;},</span>
<span class="sd">{&quot;name&quot;: &quot;favorite_number&quot;, &quot;type&quot;: [&quot;int&quot;, &quot;null&quot;]},</span>
<span class="sd">{&quot;name&quot;: &quot;favorite_color&quot;, &quot;type&quot;: [&quot;string&quot;, &quot;null&quot;]}]}</span>
<span class="sd">Then records generated by read transforms will be dictionaries of the</span>
<span class="sd">following form.</span>
<span class="sd">{u&#39;name&#39;: u&#39;Alyssa&#39;, u&#39;favorite_number&#39;: 256, u&#39;favorite_color&#39;: None}).</span>
<span class="sd">Additionally, this module provides a write ``PTransform`` ``WriteToAvro``</span>
<span class="sd">that can be used to write a given ``PCollection`` of Python objects to an</span>
<span class="sd">Avro file.</span>
<span class="sd">&quot;&quot;&quot;</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">import</span> <span class="nn">io</span>
<span class="kn">import</span> <span class="nn">os</span>
<span class="kn">import</span> <span class="nn">sys</span>
<span class="kn">import</span> <span class="nn">warnings</span>
<span class="kn">import</span> <span class="nn">zlib</span>
<span class="kn">from</span> <span class="nn">builtins</span> <span class="k">import</span> <span class="nb">object</span>
<span class="kn">from</span> <span class="nn">functools</span> <span class="k">import</span> <span class="n">partial</span>
<span class="kn">import</span> <span class="nn">avro</span>
<span class="kn">from</span> <span class="nn">avro</span> <span class="k">import</span> <span class="n">io</span> <span class="k">as</span> <span class="n">avroio</span>
<span class="kn">from</span> <span class="nn">avro</span> <span class="k">import</span> <span class="n">datafile</span>
<span class="kn">from</span> <span class="nn">fastavro.read</span> <span class="k">import</span> <span class="n">block_reader</span>
<span class="kn">from</span> <span class="nn">fastavro.write</span> <span class="k">import</span> <span class="n">Writer</span>
<span class="kn">import</span> <span class="nn">apache_beam</span> <span class="k">as</span> <span class="nn">beam</span>
<span class="kn">from</span> <span class="nn">apache_beam.io</span> <span class="k">import</span> <span class="n">filebasedsink</span>
<span class="kn">from</span> <span class="nn">apache_beam.io</span> <span class="k">import</span> <span class="n">filebasedsource</span>
<span class="kn">from</span> <span class="nn">apache_beam.io</span> <span class="k">import</span> <span class="n">iobase</span>
<span class="kn">from</span> <span class="nn">apache_beam.io.filesystem</span> <span class="k">import</span> <span class="n">CompressionTypes</span>
<span class="kn">from</span> <span class="nn">apache_beam.io.iobase</span> <span class="k">import</span> <span class="n">Read</span>
<span class="kn">from</span> <span class="nn">apache_beam.transforms</span> <span class="k">import</span> <span class="n">PTransform</span>
<span class="c1"># pylint: disable=wrong-import-order, wrong-import-position, ungrouped-imports</span>
<span class="k">try</span><span class="p">:</span>
<span class="kn">from</span> <span class="nn">avro.schema</span> <span class="k">import</span> <span class="n">Parse</span> <span class="c1"># avro-python3 library for python3</span>
<span class="k">except</span> <span class="ne">ImportError</span><span class="p">:</span>
<span class="kn">from</span> <span class="nn">avro.schema</span> <span class="k">import</span> <span class="n">parse</span> <span class="k">as</span> <span class="n">Parse</span> <span class="c1"># avro library for python2</span>
<span class="c1"># pylint: enable=wrong-import-order, wrong-import-position, ungrouped-imports</span>
<span class="n">__all__</span> <span class="o">=</span> <span class="p">[</span><span class="s1">&#39;ReadFromAvro&#39;</span><span class="p">,</span> <span class="s1">&#39;ReadAllFromAvro&#39;</span><span class="p">,</span> <span class="s1">&#39;WriteToAvro&#39;</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">_use_fastavro</span><span class="p">():</span>
<span class="k">return</span> <span class="n">sys</span><span class="o">.</span><span class="n">version_info</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">&gt;=</span> <span class="mi">3</span>
<div class="viewcode-block" id="ReadFromAvro"><a class="viewcode-back" href="../../../apache_beam.io.avroio.html#apache_beam.io.avroio.ReadFromAvro">[docs]</a><span class="k">class</span> <span class="nc">ReadFromAvro</span><span class="p">(</span><span class="n">PTransform</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;A :class:`~apache_beam.transforms.ptransform.PTransform` for reading avro</span>
<span class="sd"> files.&quot;&quot;&quot;</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">file_pattern</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">min_bundle_size</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">validate</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span>
<span class="n">use_fastavro</span><span class="o">=</span><span class="n">_use_fastavro</span><span class="p">()):</span>
<span class="sd">&quot;&quot;&quot;Initializes :class:`ReadFromAvro`.</span>
<span class="sd"> Uses source :class:`~apache_beam.io._AvroSource` to read a set of Avro</span>
<span class="sd"> files defined by a given file pattern.</span>
<span class="sd"> If ``/mypath/myavrofiles*`` is a file-pattern that points to a set of Avro</span>
<span class="sd"> files, a :class:`~apache_beam.pvalue.PCollection` for the records in</span>
<span class="sd"> these Avro files can be created in the following manner.</span>
<span class="sd"> .. testcode::</span>
<span class="sd"> with beam.Pipeline() as p:</span>
<span class="sd"> records = p | &#39;Read&#39; &gt;&gt; beam.io.ReadFromAvro(&#39;/mypath/myavrofiles*&#39;)</span>
<span class="sd"> .. NOTE: We&#39;re not actually interested in this error; but if we get here,</span>
<span class="sd"> it means that the way of calling this transform hasn&#39;t changed.</span>
<span class="sd"> .. testoutput::</span>
<span class="sd"> :hide:</span>
<span class="sd"> Traceback (most recent call last):</span>
<span class="sd"> ...</span>
<span class="sd"> IOError: No files found based on the file pattern</span>
<span class="sd"> Each record of this :class:`~apache_beam.pvalue.PCollection` will contain</span>
<span class="sd"> a single record read from a source. Records that are of simple types will be</span>
<span class="sd"> mapped into corresponding Python types. Records that are of Avro type</span>
<span class="sd"> ``RECORD`` will be mapped to Python dictionaries that comply with the schema</span>
<span class="sd"> contained in the Avro file that contains those records. In this case, keys</span>
<span class="sd"> of each dictionary will contain the corresponding field names and will be of</span>
<span class="sd"> type :class:`str` while the values of the dictionary will be of the type</span>
<span class="sd"> defined in the corresponding Avro schema.</span>
<span class="sd"> For example, if schema of the Avro file is the following. ::</span>
<span class="sd"> {</span>
<span class="sd"> &quot;namespace&quot;: &quot;example.avro&quot;,</span>
<span class="sd"> &quot;type&quot;: &quot;record&quot;,</span>
<span class="sd"> &quot;name&quot;: &quot;User&quot;,</span>
<span class="sd"> &quot;fields&quot;: [</span>
<span class="sd"> {&quot;name&quot;: &quot;name&quot;,</span>
<span class="sd"> &quot;type&quot;: &quot;string&quot;},</span>
<span class="sd"> {&quot;name&quot;: &quot;favorite_number&quot;,</span>
<span class="sd"> &quot;type&quot;: [&quot;int&quot;, &quot;null&quot;]},</span>
<span class="sd"> {&quot;name&quot;: &quot;favorite_color&quot;,</span>
<span class="sd"> &quot;type&quot;: [&quot;string&quot;, &quot;null&quot;]}</span>
<span class="sd"> ]</span>
<span class="sd"> }</span>
<span class="sd"> Then records generated by :class:`~apache_beam.io._AvroSource` will be</span>
<span class="sd"> dictionaries of the following form. ::</span>
<span class="sd"> {u&#39;name&#39;: u&#39;Alyssa&#39;, u&#39;favorite_number&#39;: 256, u&#39;favorite_color&#39;: None}).</span>
<span class="sd"> Args:</span>
<span class="sd"> file_pattern (str): the file glob to read</span>
<span class="sd"> min_bundle_size (int): the minimum size in bytes, to be considered when</span>
<span class="sd"> splitting the input into bundles.</span>
<span class="sd"> validate (bool): flag to verify that the files exist during the pipeline</span>
<span class="sd"> creation time.</span>
<span class="sd"> use_fastavro (bool); when set, use the `fastavro` library for IO, which</span>
<span class="sd"> is significantly faster, and will likely become the default</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="k">if</span> <span class="n">sys</span><span class="o">.</span><span class="n">version_info</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">&gt;=</span> <span class="mi">3</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">use_fastavro</span><span class="p">:</span>
<span class="n">warnings</span><span class="o">.</span><span class="n">warn</span><span class="p">(</span><span class="s2">&quot;Due to a known issue in avro-python3 package, it is &quot;</span>
<span class="s2">&quot;recommended to use fastavro with Beam Avro IO on &quot;</span>
<span class="s2">&quot;Python 3 until BEAM-6522 is addressed.&quot;</span><span class="p">)</span>
<span class="nb">super</span><span class="p">(</span><span class="n">ReadFromAvro</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="bp">self</span><span class="o">.</span><span class="n">_source</span> <span class="o">=</span> <span class="n">_create_avro_source</span><span class="p">(</span>
<span class="n">file_pattern</span><span class="p">,</span>
<span class="n">min_bundle_size</span><span class="p">,</span>
<span class="n">validate</span><span class="o">=</span><span class="n">validate</span><span class="p">,</span>
<span class="n">use_fastavro</span><span class="o">=</span><span class="n">use_fastavro</span>
<span class="p">)</span>
<div class="viewcode-block" id="ReadFromAvro.expand"><a class="viewcode-back" href="../../../apache_beam.io.avroio.html#apache_beam.io.avroio.ReadFromAvro.expand">[docs]</a> <span class="k">def</span> <span class="nf">expand</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">pvalue</span><span class="p">):</span>
<span class="k">return</span> <span class="n">pvalue</span><span class="o">.</span><span class="n">pipeline</span> <span class="o">|</span> <span class="n">Read</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_source</span><span class="p">)</span></div>
<div class="viewcode-block" id="ReadFromAvro.display_data"><a class="viewcode-back" href="../../../apache_beam.io.avroio.html#apache_beam.io.avroio.ReadFromAvro.display_data">[docs]</a> <span class="k">def</span> <span class="nf">display_data</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">{</span><span class="s1">&#39;source_dd&#39;</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">_source</span><span class="p">}</span></div></div>
<div class="viewcode-block" id="ReadAllFromAvro"><a class="viewcode-back" href="../../../apache_beam.io.avroio.html#apache_beam.io.avroio.ReadAllFromAvro">[docs]</a><span class="k">class</span> <span class="nc">ReadAllFromAvro</span><span class="p">(</span><span class="n">PTransform</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;A ``PTransform`` for reading ``PCollection`` of Avro files.</span>
<span class="sd"> Uses source &#39;_AvroSource&#39; to read a ``PCollection`` of Avro files or</span>
<span class="sd"> file patterns and produce a ``PCollection`` of Avro records.</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="n">DEFAULT_DESIRED_BUNDLE_SIZE</span> <span class="o">=</span> <span class="mi">64</span> <span class="o">*</span> <span class="mi">1024</span> <span class="o">*</span> <span class="mi">1024</span> <span class="c1"># 64MB</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">min_bundle_size</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">desired_bundle_size</span><span class="o">=</span><span class="n">DEFAULT_DESIRED_BUNDLE_SIZE</span><span class="p">,</span>
<span class="n">use_fastavro</span><span class="o">=</span><span class="n">_use_fastavro</span><span class="p">(),</span>
<span class="n">label</span><span class="o">=</span><span class="s1">&#39;ReadAllFiles&#39;</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;Initializes ``ReadAllFromAvro``.</span>
<span class="sd"> Args:</span>
<span class="sd"> min_bundle_size: the minimum size in bytes, to be considered when</span>
<span class="sd"> splitting the input into bundles.</span>
<span class="sd"> desired_bundle_size: the desired size in bytes, to be considered when</span>
<span class="sd"> splitting the input into bundles.</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="k">if</span> <span class="n">sys</span><span class="o">.</span><span class="n">version_info</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">&gt;=</span> <span class="mi">3</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">use_fastavro</span><span class="p">:</span>
<span class="n">warnings</span><span class="o">.</span><span class="n">warn</span><span class="p">(</span><span class="s2">&quot;Due to a known issue in avro-python3 package, it is &quot;</span>
<span class="s2">&quot;recommended to use fastavro with Beam Avro IO on &quot;</span>
<span class="s2">&quot;Python 3 until BEAM-6522 is addressed.&quot;</span><span class="p">)</span>
<span class="n">source_from_file</span> <span class="o">=</span> <span class="n">partial</span><span class="p">(</span>
<span class="n">_create_avro_source</span><span class="p">,</span>
<span class="n">min_bundle_size</span><span class="o">=</span><span class="n">min_bundle_size</span><span class="p">,</span>
<span class="n">use_fastavro</span><span class="o">=</span><span class="n">use_fastavro</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_read_all_files</span> <span class="o">=</span> <span class="n">filebasedsource</span><span class="o">.</span><span class="n">ReadAllFiles</span><span class="p">(</span>
<span class="kc">True</span><span class="p">,</span> <span class="n">CompressionTypes</span><span class="o">.</span><span class="n">AUTO</span><span class="p">,</span> <span class="n">desired_bundle_size</span><span class="p">,</span> <span class="n">min_bundle_size</span><span class="p">,</span>
<span class="n">source_from_file</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">label</span> <span class="o">=</span> <span class="n">label</span>
<div class="viewcode-block" id="ReadAllFromAvro.expand"><a class="viewcode-back" href="../../../apache_beam.io.avroio.html#apache_beam.io.avroio.ReadAllFromAvro.expand">[docs]</a> <span class="k">def</span> <span class="nf">expand</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">pvalue</span><span class="p">):</span>
<span class="k">return</span> <span class="n">pvalue</span> <span class="o">|</span> <span class="bp">self</span><span class="o">.</span><span class="n">label</span> <span class="o">&gt;&gt;</span> <span class="bp">self</span><span class="o">.</span><span class="n">_read_all_files</span></div></div>
<span class="k">class</span> <span class="nc">_AvroUtils</span><span class="p">(</span><span class="nb">object</span><span class="p">):</span>
<span class="nd">@staticmethod</span>
<span class="k">def</span> <span class="nf">read_meta_data_from_file</span><span class="p">(</span><span class="n">f</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;Reads metadata from a given Avro file.</span>
<span class="sd"> Args:</span>
<span class="sd"> f: Avro file to read.</span>
<span class="sd"> Returns:</span>
<span class="sd"> a tuple containing the codec, schema, and the sync marker of the Avro</span>
<span class="sd"> file.</span>
<span class="sd"> Raises:</span>
<span class="sd"> ValueError: if the file does not start with the byte sequence defined in</span>
<span class="sd"> the specification.</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="k">if</span> <span class="n">f</span><span class="o">.</span><span class="n">tell</span><span class="p">()</span> <span class="o">&gt;</span> <span class="mi">0</span><span class="p">:</span>
<span class="n">f</span><span class="o">.</span><span class="n">seek</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
<span class="n">decoder</span> <span class="o">=</span> <span class="n">avroio</span><span class="o">.</span><span class="n">BinaryDecoder</span><span class="p">(</span><span class="n">f</span><span class="p">)</span>
<span class="n">header</span> <span class="o">=</span> <span class="n">avroio</span><span class="o">.</span><span class="n">DatumReader</span><span class="p">()</span><span class="o">.</span><span class="n">read_data</span><span class="p">(</span><span class="n">datafile</span><span class="o">.</span><span class="n">META_SCHEMA</span><span class="p">,</span>
<span class="n">datafile</span><span class="o">.</span><span class="n">META_SCHEMA</span><span class="p">,</span> <span class="n">decoder</span><span class="p">)</span>
<span class="k">if</span> <span class="n">header</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s1">&#39;magic&#39;</span><span class="p">)</span> <span class="o">!=</span> <span class="n">datafile</span><span class="o">.</span><span class="n">MAGIC</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">&#39;Not an Avro file. File header should start with </span><span class="si">%s</span><span class="s1"> but&#39;</span>
<span class="s1">&#39;started with </span><span class="si">%s</span><span class="s1"> instead.&#39;</span>
<span class="o">%</span> <span class="p">(</span><span class="n">datafile</span><span class="o">.</span><span class="n">MAGIC</span><span class="p">,</span> <span class="n">header</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s1">&#39;magic&#39;</span><span class="p">)))</span>
<span class="n">meta</span> <span class="o">=</span> <span class="n">header</span><span class="p">[</span><span class="s1">&#39;meta&#39;</span><span class="p">]</span>
<span class="k">if</span> <span class="n">datafile</span><span class="o">.</span><span class="n">CODEC_KEY</span> <span class="ow">in</span> <span class="n">meta</span><span class="p">:</span>
<span class="n">codec</span> <span class="o">=</span> <span class="n">meta</span><span class="p">[</span><span class="n">datafile</span><span class="o">.</span><span class="n">CODEC_KEY</span><span class="p">]</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">codec</span> <span class="o">=</span> <span class="sa">b</span><span class="s1">&#39;null&#39;</span>
<span class="n">schema_string</span> <span class="o">=</span> <span class="n">meta</span><span class="p">[</span><span class="n">datafile</span><span class="o">.</span><span class="n">SCHEMA_KEY</span><span class="p">]</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">&#39;utf-8&#39;</span><span class="p">)</span>
<span class="n">sync_marker</span> <span class="o">=</span> <span class="n">header</span><span class="p">[</span><span class="s1">&#39;sync&#39;</span><span class="p">]</span>
<span class="k">return</span> <span class="n">codec</span><span class="p">,</span> <span class="n">schema_string</span><span class="p">,</span> <span class="n">sync_marker</span>
<span class="nd">@staticmethod</span>
<span class="k">def</span> <span class="nf">read_block_from_file</span><span class="p">(</span><span class="n">f</span><span class="p">,</span> <span class="n">codec</span><span class="p">,</span> <span class="n">schema</span><span class="p">,</span> <span class="n">expected_sync_marker</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;Reads a block from a given Avro file.</span>
<span class="sd"> Args:</span>
<span class="sd"> f: Avro file to read.</span>
<span class="sd"> codec: The codec to use for block-level decompression.</span>
<span class="sd"> Supported codecs: &#39;null&#39;, &#39;deflate&#39;, &#39;snappy&#39;</span>
<span class="sd"> schema: Avro Schema definition represented as JSON string.</span>
<span class="sd"> expected_sync_marker: Avro synchronization marker. If the block&#39;s sync</span>
<span class="sd"> marker does not match with this parameter then ValueError is thrown.</span>
<span class="sd"> Returns:</span>
<span class="sd"> A single _AvroBlock.</span>
<span class="sd"> Raises:</span>
<span class="sd"> ValueError: If the block cannot be read properly because the file doesn&#39;t</span>
<span class="sd"> match the specification.</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="n">offset</span> <span class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">tell</span><span class="p">()</span>
<span class="n">decoder</span> <span class="o">=</span> <span class="n">avroio</span><span class="o">.</span><span class="n">BinaryDecoder</span><span class="p">(</span><span class="n">f</span><span class="p">)</span>
<span class="n">num_records</span> <span class="o">=</span> <span class="n">decoder</span><span class="o">.</span><span class="n">read_long</span><span class="p">()</span>
<span class="n">block_size</span> <span class="o">=</span> <span class="n">decoder</span><span class="o">.</span><span class="n">read_long</span><span class="p">()</span>
<span class="n">block_bytes</span> <span class="o">=</span> <span class="n">decoder</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="n">block_size</span><span class="p">)</span>
<span class="n">sync_marker</span> <span class="o">=</span> <span class="n">decoder</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">expected_sync_marker</span><span class="p">))</span>
<span class="k">if</span> <span class="n">sync_marker</span> <span class="o">!=</span> <span class="n">expected_sync_marker</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">&#39;Unexpected sync marker (actual &quot;</span><span class="si">%s</span><span class="s1">&quot; vs expected &quot;</span><span class="si">%s</span><span class="s1">&quot;). &#39;</span>
<span class="s1">&#39;Maybe the underlying avro file is corrupted?&#39;</span>
<span class="o">%</span> <span class="p">(</span><span class="n">sync_marker</span><span class="p">,</span> <span class="n">expected_sync_marker</span><span class="p">))</span>
<span class="n">size</span> <span class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">tell</span><span class="p">()</span> <span class="o">-</span> <span class="n">offset</span>
<span class="k">return</span> <span class="n">_AvroBlock</span><span class="p">(</span><span class="n">block_bytes</span><span class="p">,</span> <span class="n">num_records</span><span class="p">,</span> <span class="n">codec</span><span class="p">,</span> <span class="n">schema</span><span class="p">,</span> <span class="n">offset</span><span class="p">,</span> <span class="n">size</span><span class="p">)</span>
<span class="nd">@staticmethod</span>
<span class="k">def</span> <span class="nf">advance_file_past_next_sync_marker</span><span class="p">(</span><span class="n">f</span><span class="p">,</span> <span class="n">sync_marker</span><span class="p">):</span>
<span class="n">buf_size</span> <span class="o">=</span> <span class="mi">10000</span>
<span class="n">data</span> <span class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="n">buf_size</span><span class="p">)</span>
<span class="k">while</span> <span class="n">data</span><span class="p">:</span>
<span class="n">pos</span> <span class="o">=</span> <span class="n">data</span><span class="o">.</span><span class="n">find</span><span class="p">(</span><span class="n">sync_marker</span><span class="p">)</span>
<span class="k">if</span> <span class="n">pos</span> <span class="o">&gt;=</span> <span class="mi">0</span><span class="p">:</span>
<span class="c1"># Adjusting the current position to the ending position of the sync</span>
<span class="c1"># marker.</span>
<span class="n">backtrack</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="n">data</span><span class="p">)</span> <span class="o">-</span> <span class="n">pos</span> <span class="o">-</span> <span class="nb">len</span><span class="p">(</span><span class="n">sync_marker</span><span class="p">)</span>
<span class="n">f</span><span class="o">.</span><span class="n">seek</span><span class="p">(</span><span class="o">-</span><span class="mi">1</span> <span class="o">*</span> <span class="n">backtrack</span><span class="p">,</span> <span class="n">os</span><span class="o">.</span><span class="n">SEEK_CUR</span><span class="p">)</span>
<span class="k">return</span> <span class="kc">True</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">if</span> <span class="n">f</span><span class="o">.</span><span class="n">tell</span><span class="p">()</span> <span class="o">&gt;=</span> <span class="nb">len</span><span class="p">(</span><span class="n">sync_marker</span><span class="p">):</span>
<span class="c1"># Backtracking in case we partially read the sync marker during the</span>
<span class="c1"># previous read. We only have to backtrack if there are at least</span>
<span class="c1"># len(sync_marker) bytes before current position. We only have to</span>
<span class="c1"># backtrack (len(sync_marker) - 1) bytes.</span>
<span class="n">f</span><span class="o">.</span><span class="n">seek</span><span class="p">(</span><span class="o">-</span><span class="mi">1</span> <span class="o">*</span> <span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">sync_marker</span><span class="p">)</span> <span class="o">-</span> <span class="mi">1</span><span class="p">),</span> <span class="n">os</span><span class="o">.</span><span class="n">SEEK_CUR</span><span class="p">)</span>
<span class="n">data</span> <span class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="n">buf_size</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_create_avro_source</span><span class="p">(</span><span class="n">file_pattern</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span>
<span class="n">min_bundle_size</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">validate</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span>
<span class="n">use_fastavro</span><span class="o">=</span><span class="n">_use_fastavro</span><span class="p">()):</span>
<span class="k">return</span> \
<span class="n">_FastAvroSource</span><span class="p">(</span>
<span class="n">file_pattern</span><span class="o">=</span><span class="n">file_pattern</span><span class="p">,</span>
<span class="n">min_bundle_size</span><span class="o">=</span><span class="n">min_bundle_size</span><span class="p">,</span>
<span class="n">validate</span><span class="o">=</span><span class="n">validate</span>
<span class="p">)</span> \
<span class="k">if</span> <span class="n">use_fastavro</span> \
<span class="k">else</span> \
<span class="n">_AvroSource</span><span class="p">(</span>
<span class="n">file_pattern</span><span class="o">=</span><span class="n">file_pattern</span><span class="p">,</span>
<span class="n">min_bundle_size</span><span class="o">=</span><span class="n">min_bundle_size</span><span class="p">,</span>
<span class="n">validate</span><span class="o">=</span><span class="n">validate</span>
<span class="p">)</span>
<span class="k">class</span> <span class="nc">_AvroBlock</span><span class="p">(</span><span class="nb">object</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;Represents a block of an Avro file.&quot;&quot;&quot;</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">block_bytes</span><span class="p">,</span> <span class="n">num_records</span><span class="p">,</span> <span class="n">codec</span><span class="p">,</span> <span class="n">schema_string</span><span class="p">,</span>
<span class="n">offset</span><span class="p">,</span> <span class="n">size</span><span class="p">):</span>
<span class="c1"># Decompress data early on (if needed) and thus decrease the number of</span>
<span class="c1"># parallel copies of the data in memory at any given time during block</span>
<span class="c1"># iteration.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_decompressed_block_bytes</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_decompress_bytes</span><span class="p">(</span><span class="n">block_bytes</span><span class="p">,</span> <span class="n">codec</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_num_records</span> <span class="o">=</span> <span class="n">num_records</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_schema</span> <span class="o">=</span> <span class="n">Parse</span><span class="p">(</span><span class="n">schema_string</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_offset</span> <span class="o">=</span> <span class="n">offset</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">=</span> <span class="n">size</span>
<span class="k">def</span> <span class="nf">size</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span>
<span class="k">def</span> <span class="nf">offset</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_offset</span>
<span class="nd">@staticmethod</span>
<span class="k">def</span> <span class="nf">_decompress_bytes</span><span class="p">(</span><span class="n">data</span><span class="p">,</span> <span class="n">codec</span><span class="p">):</span>
<span class="k">if</span> <span class="n">codec</span> <span class="o">==</span> <span class="sa">b</span><span class="s1">&#39;null&#39;</span><span class="p">:</span>
<span class="k">return</span> <span class="n">data</span>
<span class="k">elif</span> <span class="n">codec</span> <span class="o">==</span> <span class="sa">b</span><span class="s1">&#39;deflate&#39;</span><span class="p">:</span>
<span class="c1"># zlib.MAX_WBITS is the window size. &#39;-&#39; sign indicates that this is</span>
<span class="c1"># raw data (without headers). See zlib and Avro documentations for more</span>
<span class="c1"># details.</span>
<span class="k">return</span> <span class="n">zlib</span><span class="o">.</span><span class="n">decompress</span><span class="p">(</span><span class="n">data</span><span class="p">,</span> <span class="o">-</span><span class="n">zlib</span><span class="o">.</span><span class="n">MAX_WBITS</span><span class="p">)</span>
<span class="k">elif</span> <span class="n">codec</span> <span class="o">==</span> <span class="sa">b</span><span class="s1">&#39;snappy&#39;</span><span class="p">:</span>
<span class="c1"># Snappy is an optional avro codec.</span>
<span class="c1"># See Snappy and Avro documentation for more details.</span>
<span class="k">try</span><span class="p">:</span>
<span class="kn">import</span> <span class="nn">snappy</span>
<span class="k">except</span> <span class="ne">ImportError</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">&#39;python-snappy does not seem to be installed.&#39;</span><span class="p">)</span>
<span class="c1"># Compressed data includes a 4-byte CRC32 checksum which we verify.</span>
<span class="c1"># We take care to avoid extra copies of data while slicing large objects</span>
<span class="c1"># by use of a memoryview.</span>
<span class="n">result</span> <span class="o">=</span> <span class="n">snappy</span><span class="o">.</span><span class="n">decompress</span><span class="p">(</span><span class="nb">memoryview</span><span class="p">(</span><span class="n">data</span><span class="p">)[:</span><span class="o">-</span><span class="mi">4</span><span class="p">])</span>
<span class="n">avroio</span><span class="o">.</span><span class="n">BinaryDecoder</span><span class="p">(</span><span class="n">io</span><span class="o">.</span><span class="n">BytesIO</span><span class="p">(</span><span class="n">data</span><span class="p">[</span><span class="o">-</span><span class="mi">4</span><span class="p">:]))</span><span class="o">.</span><span class="n">check_crc32</span><span class="p">(</span><span class="n">result</span><span class="p">)</span>
<span class="k">return</span> <span class="n">result</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="s1">&#39;Unknown codec: </span><span class="si">%r</span><span class="s1">&#39;</span> <span class="o">%</span> <span class="n">codec</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">num_records</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_num_records</span>
<span class="k">def</span> <span class="nf">records</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">decoder</span> <span class="o">=</span> <span class="n">avroio</span><span class="o">.</span><span class="n">BinaryDecoder</span><span class="p">(</span>
<span class="n">io</span><span class="o">.</span><span class="n">BytesIO</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_decompressed_block_bytes</span><span class="p">))</span>
<span class="n">writer_schema</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_schema</span>
<span class="n">reader_schema</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_schema</span>
<span class="n">reader</span> <span class="o">=</span> <span class="n">avroio</span><span class="o">.</span><span class="n">DatumReader</span><span class="p">(</span><span class="n">writer_schema</span><span class="p">,</span> <span class="n">reader_schema</span><span class="p">)</span>
<span class="n">current_record</span> <span class="o">=</span> <span class="mi">0</span>
<span class="k">while</span> <span class="n">current_record</span> <span class="o">&lt;</span> <span class="bp">self</span><span class="o">.</span><span class="n">_num_records</span><span class="p">:</span>
<span class="k">yield</span> <span class="n">reader</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="n">decoder</span><span class="p">)</span>
<span class="n">current_record</span> <span class="o">+=</span> <span class="mi">1</span>
<span class="k">class</span> <span class="nc">_AvroSource</span><span class="p">(</span><span class="n">filebasedsource</span><span class="o">.</span><span class="n">FileBasedSource</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;A source for reading Avro files.</span>
<span class="sd"> ``_AvroSource`` is implemented using the file-based source framework available</span>
<span class="sd"> in module &#39;filebasedsource&#39;. Hence please refer to module &#39;filebasedsource&#39;</span>
<span class="sd"> to fully understand how this source implements operations common to all</span>
<span class="sd"> file-based sources such as file-pattern expansion and splitting into bundles</span>
<span class="sd"> for parallel processing.</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="k">def</span> <span class="nf">read_records</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">file_name</span><span class="p">,</span> <span class="n">range_tracker</span><span class="p">):</span>
<span class="n">next_block_start</span> <span class="o">=</span> <span class="o">-</span><span class="mi">1</span>
<span class="k">def</span> <span class="nf">split_points_unclaimed</span><span class="p">(</span><span class="n">stop_position</span><span class="p">):</span>
<span class="k">if</span> <span class="n">next_block_start</span> <span class="o">&gt;=</span> <span class="n">stop_position</span><span class="p">:</span>
<span class="c1"># Next block starts at or after the suggested stop position. Hence</span>
<span class="c1"># there will not be split points to be claimed for the range ending at</span>
<span class="c1"># suggested stop position.</span>
<span class="k">return</span> <span class="mi">0</span>
<span class="k">return</span> <span class="n">iobase</span><span class="o">.</span><span class="n">RangeTracker</span><span class="o">.</span><span class="n">SPLIT_POINTS_UNKNOWN</span>
<span class="n">range_tracker</span><span class="o">.</span><span class="n">set_split_points_unclaimed_callback</span><span class="p">(</span><span class="n">split_points_unclaimed</span><span class="p">)</span>
<span class="n">start_offset</span> <span class="o">=</span> <span class="n">range_tracker</span><span class="o">.</span><span class="n">start_position</span><span class="p">()</span>
<span class="k">if</span> <span class="n">start_offset</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">start_offset</span> <span class="o">=</span> <span class="mi">0</span>
<span class="k">with</span> <span class="bp">self</span><span class="o">.</span><span class="n">open_file</span><span class="p">(</span><span class="n">file_name</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="n">codec</span><span class="p">,</span> <span class="n">schema_string</span><span class="p">,</span> <span class="n">sync_marker</span> <span class="o">=</span> \
<span class="n">_AvroUtils</span><span class="o">.</span><span class="n">read_meta_data_from_file</span><span class="p">(</span><span class="n">f</span><span class="p">)</span>
<span class="c1"># We have to start at current position if previous bundle ended at the</span>
<span class="c1"># end of a sync marker.</span>
<span class="n">start_offset</span> <span class="o">=</span> <span class="nb">max</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">start_offset</span> <span class="o">-</span> <span class="nb">len</span><span class="p">(</span><span class="n">sync_marker</span><span class="p">))</span>
<span class="n">f</span><span class="o">.</span><span class="n">seek</span><span class="p">(</span><span class="n">start_offset</span><span class="p">)</span>
<span class="n">_AvroUtils</span><span class="o">.</span><span class="n">advance_file_past_next_sync_marker</span><span class="p">(</span><span class="n">f</span><span class="p">,</span> <span class="n">sync_marker</span><span class="p">)</span>
<span class="n">next_block_start</span> <span class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">tell</span><span class="p">()</span>
<span class="k">while</span> <span class="n">range_tracker</span><span class="o">.</span><span class="n">try_claim</span><span class="p">(</span><span class="n">next_block_start</span><span class="p">):</span>
<span class="n">block</span> <span class="o">=</span> <span class="n">_AvroUtils</span><span class="o">.</span><span class="n">read_block_from_file</span><span class="p">(</span><span class="n">f</span><span class="p">,</span> <span class="n">codec</span><span class="p">,</span> <span class="n">schema_string</span><span class="p">,</span>
<span class="n">sync_marker</span><span class="p">)</span>
<span class="n">next_block_start</span> <span class="o">=</span> <span class="n">block</span><span class="o">.</span><span class="n">offset</span><span class="p">()</span> <span class="o">+</span> <span class="n">block</span><span class="o">.</span><span class="n">size</span><span class="p">()</span>
<span class="k">for</span> <span class="n">record</span> <span class="ow">in</span> <span class="n">block</span><span class="o">.</span><span class="n">records</span><span class="p">():</span>
<span class="k">yield</span> <span class="n">record</span>
<span class="k">class</span> <span class="nc">_FastAvroSource</span><span class="p">(</span><span class="n">filebasedsource</span><span class="o">.</span><span class="n">FileBasedSource</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;A source for reading Avro files using the `fastavro` library.</span>
<span class="sd"> ``_FastAvroSource`` is implemented using the file-based source framework</span>
<span class="sd"> available in module &#39;filebasedsource&#39;. Hence please refer to module</span>
<span class="sd"> &#39;filebasedsource&#39; to fully understand how this source implements operations</span>
<span class="sd"> common to all file-based sources such as file-pattern expansion and splitting</span>
<span class="sd"> into bundles for parallel processing.</span>
<span class="sd"> TODO: remove ``_AvroSource`` in favor of using ``_FastAvroSource``</span>
<span class="sd"> everywhere once it has been more widely tested</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="k">def</span> <span class="nf">read_records</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">file_name</span><span class="p">,</span> <span class="n">range_tracker</span><span class="p">):</span>
<span class="n">next_block_start</span> <span class="o">=</span> <span class="o">-</span><span class="mi">1</span>
<span class="k">def</span> <span class="nf">split_points_unclaimed</span><span class="p">(</span><span class="n">stop_position</span><span class="p">):</span>
<span class="k">if</span> <span class="n">next_block_start</span> <span class="o">&gt;=</span> <span class="n">stop_position</span><span class="p">:</span>
<span class="c1"># Next block starts at or after the suggested stop position. Hence</span>
<span class="c1"># there will not be split points to be claimed for the range ending at</span>
<span class="c1"># suggested stop position.</span>
<span class="k">return</span> <span class="mi">0</span>
<span class="k">return</span> <span class="n">iobase</span><span class="o">.</span><span class="n">RangeTracker</span><span class="o">.</span><span class="n">SPLIT_POINTS_UNKNOWN</span>
<span class="n">range_tracker</span><span class="o">.</span><span class="n">set_split_points_unclaimed_callback</span><span class="p">(</span><span class="n">split_points_unclaimed</span><span class="p">)</span>
<span class="n">start_offset</span> <span class="o">=</span> <span class="n">range_tracker</span><span class="o">.</span><span class="n">start_position</span><span class="p">()</span>
<span class="k">if</span> <span class="n">start_offset</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">start_offset</span> <span class="o">=</span> <span class="mi">0</span>
<span class="k">with</span> <span class="bp">self</span><span class="o">.</span><span class="n">open_file</span><span class="p">(</span><span class="n">file_name</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="n">blocks</span> <span class="o">=</span> <span class="n">block_reader</span><span class="p">(</span><span class="n">f</span><span class="p">)</span>
<span class="n">sync_marker</span> <span class="o">=</span> <span class="n">blocks</span><span class="o">.</span><span class="n">_header</span><span class="p">[</span><span class="s1">&#39;sync&#39;</span><span class="p">]</span>
<span class="c1"># We have to start at current position if previous bundle ended at the</span>
<span class="c1"># end of a sync marker.</span>
<span class="n">start_offset</span> <span class="o">=</span> <span class="nb">max</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">start_offset</span> <span class="o">-</span> <span class="nb">len</span><span class="p">(</span><span class="n">sync_marker</span><span class="p">))</span>
<span class="n">f</span><span class="o">.</span><span class="n">seek</span><span class="p">(</span><span class="n">start_offset</span><span class="p">)</span>
<span class="n">_AvroUtils</span><span class="o">.</span><span class="n">advance_file_past_next_sync_marker</span><span class="p">(</span><span class="n">f</span><span class="p">,</span> <span class="n">sync_marker</span><span class="p">)</span>
<span class="n">next_block_start</span> <span class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">tell</span><span class="p">()</span>
<span class="k">while</span> <span class="n">range_tracker</span><span class="o">.</span><span class="n">try_claim</span><span class="p">(</span><span class="n">next_block_start</span><span class="p">):</span>
<span class="n">block</span> <span class="o">=</span> <span class="nb">next</span><span class="p">(</span><span class="n">blocks</span><span class="p">)</span>
<span class="n">next_block_start</span> <span class="o">=</span> <span class="n">block</span><span class="o">.</span><span class="n">offset</span> <span class="o">+</span> <span class="n">block</span><span class="o">.</span><span class="n">size</span>
<span class="k">for</span> <span class="n">record</span> <span class="ow">in</span> <span class="n">block</span><span class="p">:</span>
<span class="k">yield</span> <span class="n">record</span>
<div class="viewcode-block" id="WriteToAvro"><a class="viewcode-back" href="../../../apache_beam.io.avroio.html#apache_beam.io.avroio.WriteToAvro">[docs]</a><span class="k">class</span> <span class="nc">WriteToAvro</span><span class="p">(</span><span class="n">beam</span><span class="o">.</span><span class="n">transforms</span><span class="o">.</span><span class="n">PTransform</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;A ``PTransform`` for writing avro files.&quot;&quot;&quot;</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">file_path_prefix</span><span class="p">,</span>
<span class="n">schema</span><span class="p">,</span>
<span class="n">codec</span><span class="o">=</span><span class="s1">&#39;deflate&#39;</span><span class="p">,</span>
<span class="n">file_name_suffix</span><span class="o">=</span><span class="s1">&#39;&#39;</span><span class="p">,</span>
<span class="n">num_shards</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">shard_name_template</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span>
<span class="n">mime_type</span><span class="o">=</span><span class="s1">&#39;application/x-avro&#39;</span><span class="p">,</span>
<span class="n">use_fastavro</span><span class="o">=</span><span class="n">_use_fastavro</span><span class="p">()):</span>
<span class="sd">&quot;&quot;&quot;Initialize a WriteToAvro transform.</span>
<span class="sd"> Args:</span>
<span class="sd"> file_path_prefix: The file path to write to. The files written will begin</span>
<span class="sd"> with this prefix, followed by a shard identifier (see num_shards), and</span>
<span class="sd"> end in a common extension, if given by file_name_suffix. In most cases,</span>
<span class="sd"> only this argument is specified and num_shards, shard_name_template, and</span>
<span class="sd"> file_name_suffix use default values.</span>
<span class="sd"> schema: The schema to use, as returned by avro.schema.Parse</span>
<span class="sd"> codec: The codec to use for block-level compression. Any string supported</span>
<span class="sd"> by the Avro specification is accepted (for example &#39;null&#39;).</span>
<span class="sd"> file_name_suffix: Suffix for the files written.</span>
<span class="sd"> num_shards: The number of files (shards) used for output. If not set, the</span>
<span class="sd"> service will decide on the optimal number of shards.</span>
<span class="sd"> Constraining the number of shards is likely to reduce</span>
<span class="sd"> the performance of a pipeline. Setting this value is not recommended</span>
<span class="sd"> unless you require a specific number of output files.</span>
<span class="sd"> shard_name_template: A template string containing placeholders for</span>
<span class="sd"> the shard number and shard count. When constructing a filename for a</span>
<span class="sd"> particular shard number, the upper-case letters &#39;S&#39; and &#39;N&#39; are</span>
<span class="sd"> replaced with the 0-padded shard number and shard count respectively.</span>
<span class="sd"> This argument can be &#39;&#39; in which case it behaves as if num_shards was</span>
<span class="sd"> set to 1 and only one file will be generated. The default pattern used</span>
<span class="sd"> is &#39;-SSSSS-of-NNNNN&#39; if None is passed as the shard_name_template.</span>
<span class="sd"> mime_type: The MIME type to use for the produced files, if the filesystem</span>
<span class="sd"> supports specifying MIME types.</span>
<span class="sd"> use_fastavro: when set, use the `fastavro` library for IO</span>
<span class="sd"> Returns:</span>
<span class="sd"> A WriteToAvro transform usable for writing.</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_sink</span> <span class="o">=</span> \
<span class="n">_create_avro_sink</span><span class="p">(</span>
<span class="n">file_path_prefix</span><span class="p">,</span>
<span class="n">schema</span><span class="p">,</span>
<span class="n">codec</span><span class="p">,</span>
<span class="n">file_name_suffix</span><span class="p">,</span>
<span class="n">num_shards</span><span class="p">,</span>
<span class="n">shard_name_template</span><span class="p">,</span>
<span class="n">mime_type</span><span class="p">,</span>
<span class="n">use_fastavro</span>
<span class="p">)</span>
<div class="viewcode-block" id="WriteToAvro.expand"><a class="viewcode-back" href="../../../apache_beam.io.avroio.html#apache_beam.io.avroio.WriteToAvro.expand">[docs]</a> <span class="k">def</span> <span class="nf">expand</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">pcoll</span><span class="p">):</span>
<span class="k">return</span> <span class="n">pcoll</span> <span class="o">|</span> <span class="n">beam</span><span class="o">.</span><span class="n">io</span><span class="o">.</span><span class="n">iobase</span><span class="o">.</span><span class="n">Write</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_sink</span><span class="p">)</span></div>
<div class="viewcode-block" id="WriteToAvro.display_data"><a class="viewcode-back" href="../../../apache_beam.io.avroio.html#apache_beam.io.avroio.WriteToAvro.display_data">[docs]</a> <span class="k">def</span> <span class="nf">display_data</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">{</span><span class="s1">&#39;sink_dd&#39;</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">_sink</span><span class="p">}</span></div></div>
<span class="k">def</span> <span class="nf">_create_avro_sink</span><span class="p">(</span><span class="n">file_path_prefix</span><span class="p">,</span>
<span class="n">schema</span><span class="p">,</span>
<span class="n">codec</span><span class="p">,</span>
<span class="n">file_name_suffix</span><span class="p">,</span>
<span class="n">num_shards</span><span class="p">,</span>
<span class="n">shard_name_template</span><span class="p">,</span>
<span class="n">mime_type</span><span class="p">,</span>
<span class="n">use_fastavro</span><span class="p">):</span>
<span class="k">return</span> \
<span class="n">_FastAvroSink</span><span class="p">(</span>
<span class="n">file_path_prefix</span><span class="p">,</span>
<span class="n">schema</span><span class="p">,</span>
<span class="n">codec</span><span class="p">,</span>
<span class="n">file_name_suffix</span><span class="p">,</span>
<span class="n">num_shards</span><span class="p">,</span>
<span class="n">shard_name_template</span><span class="p">,</span>
<span class="n">mime_type</span>
<span class="p">)</span> \
<span class="k">if</span> <span class="n">use_fastavro</span> \
<span class="k">else</span> \
<span class="n">_AvroSink</span><span class="p">(</span>
<span class="n">file_path_prefix</span><span class="p">,</span>
<span class="n">schema</span><span class="p">,</span>
<span class="n">codec</span><span class="p">,</span>
<span class="n">file_name_suffix</span><span class="p">,</span>
<span class="n">num_shards</span><span class="p">,</span>
<span class="n">shard_name_template</span><span class="p">,</span>
<span class="n">mime_type</span>
<span class="p">)</span>
<span class="k">class</span> <span class="nc">_BaseAvroSink</span><span class="p">(</span><span class="n">filebasedsink</span><span class="o">.</span><span class="n">FileBasedSink</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;A base for a sink for avro files. &quot;&quot;&quot;</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">file_path_prefix</span><span class="p">,</span>
<span class="n">schema</span><span class="p">,</span>
<span class="n">codec</span><span class="p">,</span>
<span class="n">file_name_suffix</span><span class="p">,</span>
<span class="n">num_shards</span><span class="p">,</span>
<span class="n">shard_name_template</span><span class="p">,</span>
<span class="n">mime_type</span><span class="p">):</span>
<span class="nb">super</span><span class="p">(</span><span class="n">_BaseAvroSink</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">file_path_prefix</span><span class="p">,</span>
<span class="n">file_name_suffix</span><span class="o">=</span><span class="n">file_name_suffix</span><span class="p">,</span>
<span class="n">num_shards</span><span class="o">=</span><span class="n">num_shards</span><span class="p">,</span>
<span class="n">shard_name_template</span><span class="o">=</span><span class="n">shard_name_template</span><span class="p">,</span>
<span class="n">coder</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span>
<span class="n">mime_type</span><span class="o">=</span><span class="n">mime_type</span><span class="p">,</span>
<span class="c1"># Compression happens at the block level using the supplied codec, and</span>
<span class="c1"># not at the file level.</span>
<span class="n">compression_type</span><span class="o">=</span><span class="n">CompressionTypes</span><span class="o">.</span><span class="n">UNCOMPRESSED</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_schema</span> <span class="o">=</span> <span class="n">schema</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_codec</span> <span class="o">=</span> <span class="n">codec</span>
<span class="k">def</span> <span class="nf">display_data</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">res</span> <span class="o">=</span> <span class="nb">super</span><span class="p">(</span><span class="n">_BaseAvroSink</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">display_data</span><span class="p">()</span>
<span class="n">res</span><span class="p">[</span><span class="s1">&#39;codec&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="nb">str</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_codec</span><span class="p">)</span>
<span class="n">res</span><span class="p">[</span><span class="s1">&#39;schema&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="nb">str</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_schema</span><span class="p">)</span>
<span class="k">return</span> <span class="n">res</span>
<span class="k">class</span> <span class="nc">_AvroSink</span><span class="p">(</span><span class="n">_BaseAvroSink</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;A sink for avro files using Avro. &quot;&quot;&quot;</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="n">temp_path</span><span class="p">):</span>
<span class="n">file_handle</span> <span class="o">=</span> <span class="nb">super</span><span class="p">(</span><span class="n">_AvroSink</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="n">temp_path</span><span class="p">)</span>
<span class="k">return</span> <span class="n">avro</span><span class="o">.</span><span class="n">datafile</span><span class="o">.</span><span class="n">DataFileWriter</span><span class="p">(</span>
<span class="n">file_handle</span><span class="p">,</span> <span class="n">avro</span><span class="o">.</span><span class="n">io</span><span class="o">.</span><span class="n">DatumWriter</span><span class="p">(),</span> <span class="bp">self</span><span class="o">.</span><span class="n">_schema</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_codec</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">write_record</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">writer</span><span class="p">,</span> <span class="n">value</span><span class="p">):</span>
<span class="n">writer</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">value</span><span class="p">)</span>
<span class="k">class</span> <span class="nc">_FastAvroSink</span><span class="p">(</span><span class="n">_BaseAvroSink</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;A sink for avro files using FastAvro. &quot;&quot;&quot;</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="n">temp_path</span><span class="p">):</span>
<span class="n">file_handle</span> <span class="o">=</span> <span class="nb">super</span><span class="p">(</span><span class="n">_FastAvroSink</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="n">temp_path</span><span class="p">)</span>
<span class="k">return</span> <span class="n">Writer</span><span class="p">(</span><span class="n">file_handle</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_schema</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_codec</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">write_record</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">writer</span><span class="p">,</span> <span class="n">value</span><span class="p">):</span>
<span class="n">writer</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">value</span><span class="p">)</span>
<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="n">writer</span><span class="p">):</span>
<span class="n">writer</span><span class="o">.</span><span class="n">flush</span><span class="p">()</span>
<span class="n">writer</span><span class="o">.</span><span class="n">fo</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
</pre></div>
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