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<?xml version="1.0" encoding="latin1" ?>
<!DOCTYPE erlref SYSTEM "erlref.dtd">

<erlref>
  <header>
    <copyright>
      <year>2002</year><year>2009</year>
      <holder>Ericsson AB. All Rights Reserved.</holder>
    </copyright>
    <legalnotice>
      The contents of this file are subject to the Erlang Public License,
      Version 1.1, (the "License"); you may not use this file except in
      compliance with the License. You should have received a copy of the
      Erlang Public License along with this software. If not, it can be
      retrieved online at http://www.erlang.org/.
    
      Software distributed under the License is distributed on an "AS IS"
      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
      the License for the specific language governing rights and limitations
      under the License.
    
    </legalnotice>

    <title>et_selector</title>
    <prepared>H&aring;kan Mattsson</prepared>
    <responsible>H&aring;kan Mattsson</responsible>
    <docno></docno>
    <approved>H&aring;kan Mattsson</approved>
    <checked></checked>
    <date></date>
    <rev>%VSN%</rev>
  </header>
  <module>et_selector</module>
  <modulesummary>Define event transforms and trace patterns</modulesummary>
  <description>
    <p></p>
  </description>
  <funcs>
    <func>
      <name>make_pattern(RawPattern) -> TracePattern</name>
      <fsummary>Makes a trace pattern suitable to feed change_pattern/1</fsummary>
      <type>
        <v>RawPattern = detail_level()</v>
        <v>TracePattern = erlang_trace_pattern_match_spec()</v>
        <v>detail_level() = min | max | integer(X) when X =&lt; 0, X >= 100</v>
      </type>
      <desc>
        <p>Makes a trace pattern suitable to feed change_pattern/1</p>
        <p>Min detail level deactivates tracing of calls to phone_home/4,5</p>
        <p>Max detail level activates tracing of all calls to phone_home/4,5</p>
        <p>integer(X) detail level activates tracing of all calls to
          phone_home/4,5 whose detail level argument is lesser than X.</p>
        <p>See also erlang:trace_pattern/2 for more info about its match_spec()</p>
      </desc>
    </func>
    <func>
      <name>change_pattern(Pattern) -> ok</name>
      <fsummary>Activates/deactivates tracing by changing the current trace pattern</fsummary>
      <type>
        <v>Pattern = detail_level() | empty_match_spec() | erlang_trace_pattern_match_spec()</v>
        <v>detail_level() = min | max | integer(X) when X =&lt;0, X >= 100</v>
        <v>empty_match_spec() = [] </v>
      </type>
      <desc>
        <p>Activates/deactivates tracing by changing the current trace pattern.</p>
        <p>Min detail level deactivates tracing of calls to phone_home/4,5</p>
        <p>Max detail level activates tracing of all calls to phone_home/4,5</p>
        <p>integer(X) detail level activates tracing of all calls to
          phone_home/4,5 whose detail level argument is lesser than X.</p>
        <p>An empty match spec deactivates tracing of calls to phone_home/4,5</p>
        <p>Other match specs activates tracing of calls to phone_home/4,5
          accordingly with erlang:trace_pattern/2.</p>
      </desc>
    </func>
    <func>
      <name>parse_event(Mod, ValidTraceData) -> false | true | {true, Event}</name>
      <fsummary>Transforms trace data and makes an event record out of it</fsummary>
      <type>
        <v>Mod = module_name() | undefined &lt;v>module_name() = atom() &lt;v>ValidTraceData = erlang_trace_data() | record(event)</v>
        <v>erlang_trace_data() = {trace, Pid, Label, Info} |  {trace, Pid, Label, Info, Extra} |  {trace_ts, Pid, Label, Info, ReportedTS} |  {trace_ts, Pid, Label, Info, Extra, ReportedTS} |  {seq_trace, Label, Info} |  {seq_trace, Label, Info, ReportedTS} |  {drop, NumberOfDroppedItems}</v>
      </type>
      <desc>
        <p>Transforms trace data and makes an event record out of it.</p>
        <p>See erlang:trace/3 for more info about the semantics of
          the trace data.</p>
        <p>An event record consists of the following fields:
          detail_level - Noise has a high level as opposed to essentials.
          trace_ts     - Time when the trace was generated.
          Same as event_ts if omitted in trace data.
          event_ts     - Time when the event record was created.
          from         - From actor, such as sender of a message.
          to           - To actor, such as receiver of message.
          label        - Label intended to provide a brief event summary.
          contents     - All nitty gritty details of the event.</p>
        <p>See et:phone_home/4 and et:phone_home/5 for details.</p>
        <p>Returns: 
          {true, Event} - where Event is an #event{} record representing the
          trace data
          true          - means that the trace data already is an event
          record and that it is valid as it is.
          No transformation is needed.
          false         - means that the trace data is uninteresting and
          should be dropped</p>
      </desc>
    </func>
  </funcs>
  
</erlref>