/src/logging-log4cxx/src/main/cpp/jsonlayout.cpp

Source
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <log4cxx/logstring.h>
#include <log4cxx/jsonlayout.h>
#include <log4cxx/spi/loggingevent.h>
#include <log4cxx/level.h>
#include <log4cxx/helpers/optionconverter.h>
#include <log4cxx/helpers/cacheddateformat.h>
#include <log4cxx/helpers/simpledateformat.h>
#include <log4cxx/helpers/stringhelper.h>
#include <log4cxx/helpers/transcoder.h>
#include <log4cxx/private/layout_priv.h>

#include <string.h>

using namespace LOG4CXX_NS;
using namespace LOG4CXX_NS::helpers;
using namespace LOG4CXX_NS::spi;

IMPLEMENT_LOG4CXX_OBJECT(JSONLayout)

struct JSONLayout::JSONLayoutPrivate
{
  JSONLayoutPrivate() :
    locationInfo(false),
    prettyPrint(false),
    ppIndentL1(LOG4CXX_STR("  ")),
    ppIndentL2(LOG4CXX_STR("    ")),
    expectedPatternLength(100),
    threadInfo(false) {}

  // Print no location info by default
  bool locationInfo; //= false
  bool prettyPrint; //= false

  pattern::CachedDateFormat dateFormat
    { std::make_shared<helpers::SimpleDateFormat>(LOG4CXX_STR("yyyy-MM-dd HH:mm:ss,SSS"))
    , pattern::CachedDateFormat::getMaximumCacheValidity(LOG4CXX_STR("yyyy-MM-dd HH:mm:ss,SSS"))
    };

  LogString ppIndentL1;
  LogString ppIndentL2;

  // Expected length of a formatted event excluding the message text
  size_t expectedPatternLength;

  // Thread info is not included by default
  bool threadInfo; //= false
};

JSONLayout::JSONLayout() :
  m_priv(std::make_unique<JSONLayoutPrivate>())
{
}

JSONLayout::~JSONLayout(){}

void JSONLayout::setLocationInfo(bool locationInfoFlag)
{
  m_priv->locationInfo = locationInfoFlag;
}

bool JSONLayout::getLocationInfo() const
{
  return m_priv->locationInfo;
}

void JSONLayout::setPrettyPrint(bool prettyPrintFlag)
{
  m_priv->prettyPrint = prettyPrintFlag;
}

bool JSONLayout::getPrettyPrint() const
{
  return m_priv->prettyPrint;
}

void JSONLayout::setThreadInfo(bool newValue)
{
  m_priv->threadInfo = newValue;
}

bool JSONLayout::getThreadInfo() const
{
  return m_priv->threadInfo;
}

LogString JSONLayout::getContentType() const
{
  return LOG4CXX_STR("application/json");
}

void JSONLayout::activateOptions( LOG4CXX_ACTIVATE_OPTIONS_FORMAL_PARAMETERS )
{
  m_priv->expectedPatternLength = priv::doubledLayoutSize(getFormattedEventCharacterCount());
}

void JSONLayout::setOption(const LogString& option, const LogString& value)
{
  if (StringHelper::equalsIgnoreCase(option,
      LOG4CXX_STR("LOCATIONINFO"), LOG4CXX_STR("locationinfo")))
  {
    setLocationInfo(OptionConverter::toBoolean(value, false));
  }
  else if (StringHelper::equalsIgnoreCase(option,
      LOG4CXX_STR("THREADINFO"), LOG4CXX_STR("threadinfo")))
  {
    setThreadInfo(OptionConverter::toBoolean(value, false));
  }
  else if (StringHelper::equalsIgnoreCase(option,
      LOG4CXX_STR("PRETTYPRINT"), LOG4CXX_STR("prettyprint")))
  {
    setPrettyPrint(OptionConverter::toBoolean(value, false));
  }
}

void JSONLayout::format( LOG4CXX_FORMAT_LAYOUT_FORMAL_PARAMETERS ) const
{
  auto& lsMsg = event->getRenderedMessage();
  priv::reserveFormattedEvent(output, m_priv->expectedPatternLength, lsMsg.size());
  output.append(LOG4CXX_STR("{"));
  output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  if (m_priv->prettyPrint)
  {
    output.append(m_priv->ppIndentL1);
  }

  output.append(LOG4CXX_STR("\"timestamp\": \""));
  m_priv->dateFormat.format(output, event->getTimeStamp());
  output.append(LOG4CXX_STR("\","));
  output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  if (m_priv->threadInfo)
  {
    if (m_priv->prettyPrint)
    {
      output.append(m_priv->ppIndentL1);
    }
    appendQuotedEscapedString(output, LOG4CXX_STR("thread"));
    output.append(LOG4CXX_STR(": "));
    appendQuotedEscapedString(output, event->getThreadName());
    output.append(LOG4CXX_STR(","));
    output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
  }

  if (m_priv->prettyPrint)
  {
    output.append(m_priv->ppIndentL1);
  }

  output.append(LOG4CXX_STR("\"level\": "));
  LogString level;
  event->getLevel()->toString(level);
  appendQuotedEscapedString(output, level);
  output.append(LOG4CXX_STR(","));
  output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  if (m_priv->prettyPrint)
  {
    output.append(m_priv->ppIndentL1);
  }

  output.append(LOG4CXX_STR("\"logger\": "));
  appendQuotedEscapedString(output, event->getLoggerName());
  output.append(LOG4CXX_STR(","));
  output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  if (m_priv->prettyPrint)
  {
    output.append(m_priv->ppIndentL1);
  }

  output.append(LOG4CXX_STR("\"message\": "));
  appendQuotedEscapedString(output, lsMsg);

  appendSerializedMDC(output, event);
  appendSerializedNDC(output, event);

  if (m_priv->locationInfo)
  {
    output.append(LOG4CXX_STR(","));
    output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
    appendSerializedLocationInfo(output, event);
  }

  output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
  output.append(LOG4CXX_STR("}"));
  output.append(LOG4CXX_EOL);
}

void JSONLayout::appendQuotedEscapedString(LogString& buf,
  const LogString& input) const
{
  appendItem(input, buf);
}

void JSONLayout::appendItem(const LogString& input, LogString& buf)
{
  auto toHexDigit = [](int ch) -> int
  {
    return (10 <= ch ? (0x61 - 10) : 0x30) + ch;
  };
  /* add leading quote */
  buf.push_back(0x22);

  auto start = input.begin();
  for (auto nextCodePoint = start; input.end() != nextCodePoint; )
  {
    auto lastCodePoint = nextCodePoint;
    auto ch = Transcoder::decode(input, nextCodePoint);
    if (nextCodePoint == lastCodePoint) // failed to decode input?
    {
      // Skip the undecodable run and keep escaping the remaining input
      // instead of discarding it; the run collapses to one replacement.
      for (++nextCodePoint; nextCodePoint != input.end(); ++nextCodePoint)
      {
        auto probe = nextCodePoint;
        Transcoder::decode(input, probe);
        if (probe != nextCodePoint) // next unit starts a decodable sequence
          break;
      }
      ch = 0xFFFD; // The Unicode replacement character
    }
    else if ((0xD800 <= ch && ch <= 0xDFFF) || 0x10FFFF < ch)
    {
      ch = 0xFFFD; // The Unicode replacement character
    }
    else if (0x22 == ch || 0x5c == ch) // double quote or backslash?
      ;
    else if (0x20 <= ch) // not a control character?
      continue;

    if (start != lastCodePoint)
      buf.append(start, lastCodePoint);
    start = nextCodePoint;
    switch (ch)
    {
      case 0x08:
        /* \b backspace */
        buf.push_back(0x5c);
        buf.push_back('b');
        break;

      case 0x09:
        /* \t tab */
        buf.push_back(0x5c);
        buf.push_back('t');
        break;

      case 0x0a:
        /* \n newline */
        buf.push_back(0x5c);
        buf.push_back('n');
        break;

      case 0x0c:
        /* \f form feed */
        buf.push_back(0x5c);
        buf.push_back('f');
        break;

      case 0x0d:
        /* \r carriage return */
        buf.push_back(0x5c);
        buf.push_back('r');
        break;

      case 0x22:
        /* \" double quote */
        buf.push_back(0x5c);
        buf.push_back(0x22);
        break;

      case 0x5c:
        /* \\ backslash */
        buf.push_back(0x5c);
        buf.push_back(0x5c);
        break;

      default:
        buf.push_back(0x5c);
        buf.push_back(0x75); // 'u'
        buf.push_back(toHexDigit((ch & 0xF000) >> 12));
        buf.push_back(toHexDigit((ch & 0xF00) >> 8));
        buf.push_back(toHexDigit((ch & 0xF0) >> 4));
        buf.push_back(toHexDigit(ch & 0xF));
        break;
    }
  }
  buf.append(start, input.end());

  /* add trailing quote */
  buf.push_back(0x22);
}

void JSONLayout::appendSerializedMDC(LogString& buf,
  const LoggingEventPtr& event) const
{
  LoggingEvent::KeySet keys = event->getMDCKeySet();

  if (keys.empty())
  {
    return;
  }

  buf.append(LOG4CXX_STR(","));
  buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  if (m_priv->prettyPrint)
  {
    buf.append(m_priv->ppIndentL1);
  }

  appendQuotedEscapedString(buf, LOG4CXX_STR("context_map"));
  buf.append(LOG4CXX_STR(": {"));
  buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  for (LoggingEvent::KeySet::iterator it = keys.begin();
    it != keys.end(); ++it)
  {
    if (m_priv->prettyPrint)
    {
      buf.append(m_priv->ppIndentL2);
    }

    appendQuotedEscapedString(buf, *it);
    buf.append(LOG4CXX_STR(": "));
    LogString value;
    event->getMDC(*it, value);
    appendQuotedEscapedString(buf, value);

    /* if this isn't the last k:v pair, we need a comma */
    if (it + 1 != keys.end())
    {
      buf.append(LOG4CXX_STR(","));
      buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
    }
    else
    {
      buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
    }
  }

  if (m_priv->prettyPrint)
  {
    buf.append(m_priv->ppIndentL1);
  }

  buf.append(LOG4CXX_STR("}"));
}

void JSONLayout::appendSerializedNDC(LogString& buf,
  const LoggingEventPtr& event) const
{
  LogString ndcVal;

  if (!event->getNDC(ndcVal))
  {
    return;
  }

  buf.append(LOG4CXX_STR(","));
  buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  if (m_priv->prettyPrint)
  {
    buf.append(m_priv->ppIndentL1);
  }

  appendQuotedEscapedString(buf, LOG4CXX_STR("context_stack"));
  buf.append(LOG4CXX_STR(": ["));
  buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  if (m_priv->prettyPrint)
  {
    buf.append(m_priv->ppIndentL2);
  }

  appendQuotedEscapedString(buf, ndcVal);
  buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  if (m_priv->prettyPrint)
  {
    buf.append(m_priv->ppIndentL1);
  }

  buf.append(LOG4CXX_STR("]"));
}

void JSONLayout::appendSerializedLocationInfo(LogString& buf, const LoggingEventPtr& event) const
{
  if (m_priv->prettyPrint)
  {
    buf.append(m_priv->ppIndentL1);
  }

  appendQuotedEscapedString(buf, LOG4CXX_STR("location_info"));
  buf.append(LOG4CXX_STR(": {"));
  buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
  const LocationInfo& locInfo = event->getLocationInformation();

  if (m_priv->prettyPrint)
  {
    buf.append(m_priv->ppIndentL2);
  }

  appendQuotedEscapedString(buf, LOG4CXX_STR("file"));
  buf.append(LOG4CXX_STR(": "));
  LOG4CXX_DECODE_CHAR(fileName, locInfo.getFileName());
  appendQuotedEscapedString(buf, fileName);
  buf.append(LOG4CXX_STR(","));
  buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  if (m_priv->prettyPrint)
  {
    buf.append(m_priv->ppIndentL2);
  }

  appendQuotedEscapedString(buf, LOG4CXX_STR("line"));
  buf.append(LOG4CXX_STR(": "));
  LogString lineNumber;
  StringHelper::toString(locInfo.getLineNumber(), lineNumber);
  appendQuotedEscapedString(buf, lineNumber);
  buf.append(LOG4CXX_STR(","));
  buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  if (m_priv->prettyPrint)
  {
    buf.append(m_priv->ppIndentL2);
  }

  appendQuotedEscapedString(buf, LOG4CXX_STR("class"));
  buf.append(LOG4CXX_STR(": "));
  LOG4CXX_DECODE_CHAR(className, locInfo.getClassName());
  appendQuotedEscapedString(buf, className);
  buf.append(LOG4CXX_STR(","));
  buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  if (m_priv->prettyPrint)
  {
    buf.append(m_priv->ppIndentL2);
  }

  appendQuotedEscapedString(buf, LOG4CXX_STR("method"));
  buf.append(LOG4CXX_STR(": "));
  LOG4CXX_DECODE_CHAR(methodName, locInfo.getMethodName());
  appendQuotedEscapedString(buf, methodName);
  buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

  if (m_priv->prettyPrint)
  {
    buf.append(m_priv->ppIndentL1);
  }

  buf.append(LOG4CXX_STR("}"));
}

#if LOG4CXX_ABI_VERSION <= 15
void JSONLayout::appendSerializedLocationInfo(LogString& buf,
  const LoggingEventPtr& event, Pool& p) const
{
  appendSerializedLocationInfo(buf, event);
}
#endif

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Created: 2026-06-15 06:23