/*

 * Copyright (c) 2020 Red Hat, Inc.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 * 

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

 * 02110-1301, USA. 

 *

 * $Id: //eng/vdo-releases/aluminum/src/c++/vdo/base/trace.c#1 $

 */

#include "trace.h"

#include "logger.h"

#include "stringUtils.h"

#include "timeUtils.h"

TRACE_LOCATION_SECTION TraceLocationRecord baseTraceLocation[] = {

  {

    .function = "<none>",

    .line     = 0,

  },

};

/**********************************************************************/

void addTraceRecord(Trace *trace, TraceLocation location)

{

  if (trace->used < NUM_TRACE_RECORDS) {

    TraceRecord *record = &trace->records[trace->used];

    trace->used++;

    record->when     = nowUsec();

    record->tid      = getThreadId();

    record->location = location - baseTraceLocation;

  }

}

/*

 * The record display format used is a comma-separated list, each item

 * containing: optional function name; "@" + timestamp with seconds

 * and microseconds for the first record; if not the first record, "+"

 * and offset in microseconds from previous timestamp.

 *

 * If the buffer's too small, it'll end with an ellipsis.

 */

void formatTrace(Trace  *trace,

                 char   *buffer,

                 size_t  bufferLength,

                 size_t *msgLen)

{

  if (trace == NULL) {

    return;

  }

  memset(buffer, 0, bufferLength);

  char *buf = buffer;

  char *bufferEnd = buffer + bufferLength - 1;

  if (trace->used > 0) {

    TraceRecord *record = &trace->records[0];

    TraceLocationRecord *location = baseTraceLocation + record->location;

    snprintf(buf, bufferEnd - buf, "Trace[%s@%llu.%06llu",

             location->function, record->when / 1000000,

             record->when % 1000000);

    buf += strlen(buf);

    for (unsigned int i = 1; i < trace->used; i++) {

      TraceRecord *prev = record;

      record++;

      snprintf(buf, bufferEnd - buf, ",");

      buf += strlen(buf);

      location = baseTraceLocation + record->location;

      unsigned long timeDiff = record->when - prev->when;

      snprintf(buf, bufferEnd - buf, "%s+%lu",

               location->function, timeDiff);

      buf += strlen(buf);

    }

    if (bufferLength > 7) {

      if (buffer[bufferLength-5] != '\0') {

        // too long

        strcpy(buffer+bufferLength-5, "...]");

      } else {

        strcpy(buf, "]");

      }

    }

  }

  *msgLen = (buf - buffer);

}