Ejemplo n.º 1
0
/*********************************************************************
 * ms_readtracelist_selection:
 *
 * This routine will open and read all Mini-SEED records in specified
 * file and populate a trace list.  This routine is thread safe.
 *
 * If reclen is <= 0 the length of every record is automatically
 * detected.
 *
 * If a Selections list is supplied it will be used to limit which
 * records are added to the trace list.
 *
 * Returns MS_NOERROR and populates an MSTraceList struct at *ppmstl
 * on successful read, otherwise returns a libmseed error code (listed
 * in libmseed.h).
 *********************************************************************/
int
ms_readtracelist_selection (MSTraceList **ppmstl, const char *msfile,
                            int reclen, double timetol, double sampratetol,
                            Selections *selections, flag dataquality,
                            flag skipnotdata, flag dataflag, flag verbose)
{
  MSRecord *msr     = 0;
  MSFileParam *msfp = 0;
  int retcode;

  if (!ppmstl)
    return MS_GENERROR;

  /* Initialize MSTraceList if needed */
  if (!*ppmstl)
  {
    *ppmstl = mstl_init (*ppmstl);

    if (!*ppmstl)
      return MS_GENERROR;
  }

  /* Loop over the input file */
  while ((retcode = ms_readmsr_main (&msfp, &msr, msfile, reclen, NULL, NULL,
                                     skipnotdata, dataflag, NULL, verbose)) == MS_NOERROR)
  {
    /* Test against selections if supplied */
    if (selections)
    {
      char srcname[50];
      hptime_t endtime;

      msr_srcname (msr, srcname, 1);
      endtime = msr_endtime (msr);

      if (ms_matchselect (selections, srcname, msr->starttime, endtime, NULL) == NULL)
      {
        continue;
      }
    }

    /* Add to trace list */
    mstl_addmsr (*ppmstl, msr, dataquality, 1, timetol, sampratetol);
  }

  /* Reset return code to MS_NOERROR on successful read by ms_readmsr() */
  if (retcode == MS_ENDOFFILE)
    retcode = MS_NOERROR;

  ms_readmsr_main (&msfp, &msr, NULL, 0, NULL, NULL, 0, 0, NULL, 0);

  return retcode;
} /* End of ms_readtracelist_selection() */
Ejemplo n.º 2
0
// Function that reads from a MiniSEED binary file from a char buffer and
// returns a LinkedIDList.
LinkedIDList *
readMSEEDBuffer (char *mseed, int buflen, Selections *selections, flag
                 unpack_data, int reclen, flag verbose, flag details,
                 int header_byteorder, long (*allocData) (int, char),
                 void (*diag_print) (char*), void (*log_print) (char*))
{
    int retcode = 0;
    int retval = 0;
    flag swapflag = 0;

    // current offset of mseed char pointer
    int offset = 0;

    // Unpack without reading the data first
    flag dataflag = 0;

    // the timing_qual of BLK 1001
    uint8_t timing_qual = 0xFF;

    // the calibration type, availability of BLK 300, 310, 320, 390, 395
    int8_t calibration_type = -1;

    // Init all the pointers to NULL. Most compilers should do this anyway.
    LinkedIDList * idListHead = NULL;
    LinkedIDList * idListCurrent = NULL;
    LinkedIDList * idListLast = NULL;
    MSRecord *msr = NULL;
    ContinuousSegment * segmentCurrent = NULL;
    hptime_t lastgap = 0;
    hptime_t hptimetol = 0;
    hptime_t nhptimetol = 0;
    long data_offset;
    LinkedRecordList *recordHead = NULL;
    LinkedRecordList *recordPrevious = NULL;
    LinkedRecordList *recordCurrent = NULL;
    int datasize;
    int record_count = 0;

    // A negative verbosity suppressed as much as possible.
    if (verbose < 0) {
        ms_loginit(&empty_print, NULL, &empty_print, NULL);
    }
    else {
        ms_loginit(log_print, "INFO: ", diag_print, "ERROR: ");
    }

    if (header_byteorder >= 0) {
        // Enforce little endian.
        if (header_byteorder == 0) {
            MS_UNPACKHEADERBYTEORDER(0);
        }
        // Enforce big endian.
        else {
            MS_UNPACKHEADERBYTEORDER(1);
        }
    }
    else {
        MS_UNPACKHEADERBYTEORDER(-1);
    }

    //
    // Read all records and save them in a linked list.
    //
    while (offset < buflen) {
        msr = msr_init(NULL);
        if ( msr == NULL ) {
            ms_log (2, "readMSEEDBuffer(): Error initializing msr\n");
            return NULL;
        }
        if (verbose > 1) {
            ms_log(0, "readMSEEDBuffer(): calling msr_parse with "
                      "mseed+offset=%d+%d, buflen=%d, reclen=%d, dataflag=%d, verbose=%d\n",
                      mseed, offset, buflen, reclen, dataflag, verbose);
        }

        // If the record length is given, make sure at least that amount of data is available.
        if (reclen != -1) {
            if (offset + reclen > buflen) {
                ms_log(1, "readMSEEDBuffer(): Last reclen exceeds buflen, skipping.\n");
                msr_free(&msr);
                break;
            }
        }
        // Otherwise assume the smallest possible record length and assure that enough
        // data is present.
        else {
            if (offset + 256 > buflen) {
                ms_log(1, "readMSEEDBuffer(): Last record only has %i byte(s) which "
                          "is not enough to constitute a full SEED record. Corrupt data? "
                          "Record will be skipped.\n", buflen - offset);
                msr_free(&msr);
                break;
            }
        }

        // Pass (buflen - offset) because msr_parse() expects only a single record. This
        // way libmseed can take care to not overstep bounds.
        retcode = msr_parse ( (mseed+offset), buflen - offset, &msr, reclen, dataflag, verbose);
        if (retcode != MS_NOERROR) {
            switch ( retcode ) {
                case MS_ENDOFFILE:
                    ms_log(1, "readMSEEDBuffer(): Unexpected end of file when "
                              "parsing record starting at offset %d. The rest "
                              "of the file will not be read.\n", offset);
                    break;
                case MS_GENERROR:
                    ms_log(1, "readMSEEDBuffer(): Generic error when parsing "
                              "record starting at offset %d. The rest of the "
                              "file will not be read.\n", offset);
                    break;
                case MS_NOTSEED:
                    ms_log(1, "readMSEEDBuffer(): Record starting at offset "
                              "%d is not valid SEED. The rest of the file "
                              "will not be read.\n", offset);
                    break;
                case MS_WRONGLENGTH:
                    ms_log(1, "readMSEEDBuffer(): Length of data read was not "
                              "correct when parsing record starting at "
                              "offset %d. The rest of the file will not be "
                              "read.\n", offset);
                    break;
                case MS_OUTOFRANGE:
                    ms_log(1, "readMSEEDBuffer(): SEED record length out of "
                              "range for record starting at offset %d. The "
                              "rest of the file will not be read.\n", offset);
                    break;
                case MS_UNKNOWNFORMAT:
                    ms_log(1, "readMSEEDBuffer(): Unknown data encoding "
                              "format for record starting at offset %d. The "
                              "rest of the file will not be read.\n", offset);
                    break;
                case MS_STBADCOMPFLAG:
                    ms_log(1, "readMSEEDBuffer(): Invalid STEIM compression "
                              "flag(s) in record starting at offset %d. The "
                              "rest of the file will not be read.\n", offset);
                    break;
                default:
                    ms_log(1, "readMSEEDBuffer(): Unknown error '%d' in "
                              "record starting at offset %d. The rest of the "
                              "file will not be read.\n", retcode, offset);
                    break;
            }
            msr_free(&msr);
            break;
        }
        if (offset + msr->reclen > buflen) {
            ms_log(1, "readMSEEDBuffer(): Last msr->reclen exceeds buflen, skipping.\n");
            msr_free(&msr);
            break;
        }

        // Test against selections if supplied
        if ( selections ) {
            char srcname[50];
            hptime_t endtime;
            msr_srcname (msr, srcname, 1);
            endtime = msr_endtime (msr);
            if ( ms_matchselect (selections, srcname, msr->starttime, endtime, NULL) == NULL ) {
                // Add the record length for the next iteration
                offset += msr->reclen;
                // Free record.
                msr_free(&msr);
                continue;
            }
        }
        record_count += 1;

        recordCurrent = lrl_init ();
        // Append to linked record list if one exists.
        if ( recordHead != NULL ) {
            recordPrevious->next = recordCurrent;
            recordCurrent->previous = recordPrevious;
            recordCurrent->next = NULL;
            recordPrevious = recordCurrent;
        }
        // Otherwise create a new one.
        else {
            recordHead = recordCurrent;
            recordCurrent->previous = NULL;
            recordPrevious = recordCurrent;
        }
        recordCurrent->record = msr;

        // Determine the byte order swapflag only for the very first record.
        // The byte order should not change within the file.
        // XXX: Maybe check for every record?
        if (swapflag <= 0) {
            // Returns 0 if the host is little endian, otherwise 1.
            flag bigendianhost = ms_bigendianhost();
            // Set the swapbyteflag if it is needed.
            if ( msr->Blkt1000 != 0) {
                /* If BE host and LE data need swapping */
                if ( bigendianhost && msr->byteorder == 0 ) {
                    swapflag = 1;
                }
                /* If LE host and BE data (or bad byte order value) need swapping */
                if ( !bigendianhost && msr->byteorder > 0 ) {
                    swapflag = 1;
                }
            }
        }

        // Actually unpack the data if the flag is not set.
        if (unpack_data != 0) {
            retval = msr_unpack_data (msr, swapflag, verbose);
        }

        if ( retval > 0 ) {
            msr->numsamples = retval;
        }

        // Add the record length for the next iteration
        offset += msr->reclen;
    }

    // Return empty id list if no records could be found.
    if (record_count == 0) {
        idListHead = lil_init();
        return idListHead;
    }


    // All records that match the selection are now stored in a LinkedRecordList
    // that starts at recordHead. The next step is to sort them by matching ids
    // and then by time.
    recordCurrent = recordHead;
    while (recordCurrent != NULL) {
        // Check if the ID of the record is already available and if not create a
        // new one.
        // Start with the last id as it is most likely to be the correct one.
        idListCurrent = idListLast;
        while (idListCurrent != NULL) {
            if (strcmp(idListCurrent->network, recordCurrent->record->network) == 0 &&
                strcmp(idListCurrent->station, recordCurrent->record->station) == 0 &&
                strcmp(idListCurrent->location, recordCurrent->record->location) == 0 &&
                strcmp(idListCurrent->channel, recordCurrent->record->channel) == 0 &&
                idListCurrent->dataquality == recordCurrent->record->dataquality) {
                break;
            }
            else {
                idListCurrent = idListCurrent->previous;
            }
        }

        // Create a new id list if one is needed.
        if (idListCurrent == NULL) {
            idListCurrent = lil_init();
            idListCurrent->previous = idListLast;
            if (idListLast != NULL) {
                idListLast->next = idListCurrent;
            }
            idListLast = idListCurrent;
            if (idListHead == NULL) {
                idListHead = idListCurrent;
            }

            // Set the IdList attributes.
            strcpy(idListCurrent->network, recordCurrent->record->network);
            strcpy(idListCurrent->station, recordCurrent->record->station);
            strcpy(idListCurrent->location, recordCurrent->record->location);
            strcpy(idListCurrent->channel, recordCurrent->record->channel);
            idListCurrent->dataquality = recordCurrent->record->dataquality;
        }

        // Now check if the current record fits exactly to the end of the last
        // segment of the current id. If not create a new segment. Therefore
        // if records with the same id are in wrong order a new segment will be
        // created. This is on purpose.
        segmentCurrent = idListCurrent->lastSegment;
        if (segmentCurrent != NULL) {
            hptimetol = (hptime_t) (0.5 * segmentCurrent->hpdelta);
            nhptimetol = ( hptimetol ) ? -hptimetol : 0;
            lastgap = recordCurrent->record->starttime - segmentCurrent->endtime - segmentCurrent->hpdelta;
        }
        if (details == 1) {
            /* extract information on calibration BLKs */
            calibration_type = -1;
            if (recordCurrent->record->blkts) {
                BlktLink *cur_blkt = recordCurrent->record->blkts;
                while (cur_blkt) {
                    switch (cur_blkt->blkt_type) {
                    case 300:
                        calibration_type = 1;
                        break;
                    case 310:
                        calibration_type = 2;
                        break;
                    case 320:
                        calibration_type = 3;
                        break;
                    case 390:
                        calibration_type = 4;
                        break;
                    case 395:
                        calibration_type = -2;
                        break;
                    default:
                        break;
                    }
                    cur_blkt = cur_blkt->next;
                }
            }
            /* extract information based on timing quality */
            timing_qual = 0xFF;
            if (recordCurrent->record->Blkt1001 != 0) {
                timing_qual = recordCurrent->record->Blkt1001->timing_qual;
            }
        }
        if ( segmentCurrent != NULL &&
             segmentCurrent->sampletype == recordCurrent->record->sampletype &&
             // Test the default sample rate tolerance: abs(1-sr1/sr2) < 0.0001
             MS_ISRATETOLERABLE (segmentCurrent->samprate, recordCurrent->record->samprate) &&
             // Check if the times are within the time tolerance
             lastgap <= hptimetol && lastgap >= nhptimetol &&
             segmentCurrent->timing_qual == timing_qual &&
             segmentCurrent->calibration_type == calibration_type) {
            recordCurrent->previous = segmentCurrent->lastRecord;
            segmentCurrent->lastRecord = segmentCurrent->lastRecord->next = recordCurrent;
            segmentCurrent->samplecnt += recordCurrent->record->samplecnt;
            segmentCurrent->endtime = msr_endtime(recordCurrent->record);
        }
        // Otherwise create a new segment and add the current record.
        else {
            segmentCurrent = seg_init();
            segmentCurrent->previous = idListCurrent->lastSegment;
            if (idListCurrent->lastSegment != NULL) {
                idListCurrent->lastSegment->next = segmentCurrent;
            }
            else {
                idListCurrent->firstSegment = segmentCurrent;
            }
            idListCurrent->lastSegment = segmentCurrent;

            segmentCurrent->starttime = recordCurrent->record->starttime;
            segmentCurrent->endtime = msr_endtime(recordCurrent->record);
            segmentCurrent->samprate = recordCurrent->record->samprate;
            segmentCurrent->sampletype = recordCurrent->record->sampletype;
            segmentCurrent->samplecnt = recordCurrent->record->samplecnt;
            // Calculate high-precision sample period
            segmentCurrent->hpdelta = (hptime_t) (( recordCurrent->record->samprate ) ?
                           (HPTMODULUS / recordCurrent->record->samprate) : 0.0);
            segmentCurrent->timing_qual = timing_qual;
            segmentCurrent->calibration_type = calibration_type;
            segmentCurrent->firstRecord = segmentCurrent->lastRecord = recordCurrent;
            recordCurrent->previous = NULL;
        }
        recordPrevious = recordCurrent->next;
        recordCurrent->next = NULL;
        recordCurrent = recordPrevious;
    }


    // Now loop over all segments, combine the records and free the msr
    // structures.
    idListCurrent = idListHead;
    while (idListCurrent != NULL)
    {
        segmentCurrent = idListCurrent->firstSegment;

        while (segmentCurrent != NULL) {
            if (segmentCurrent->datasamples) {
                free(segmentCurrent->datasamples);
            }
            // Allocate data via a callback function.
            if (unpack_data != 0) {
                segmentCurrent->datasamples = (void *) allocData(segmentCurrent->samplecnt, segmentCurrent->sampletype);
            }

            // Loop over all records, write the data to the buffer and free the msr structures.
            recordCurrent = segmentCurrent->firstRecord;
            data_offset = (long)(segmentCurrent->datasamples);
            while (recordCurrent != NULL) {
                datasize = recordCurrent->record->samplecnt * ms_samplesize(recordCurrent->record->sampletype);
                memcpy((void *)data_offset, recordCurrent->record->datasamples, datasize);
                // Free the record.
                msr_free(&(recordCurrent->record));
                // Increase the data_offset and the record.
                data_offset += (long)datasize;
                recordCurrent = recordCurrent->next;
            }

            segmentCurrent = segmentCurrent->next;
        }
        idListCurrent = idListCurrent->next;
    }
    return idListHead;
}
Ejemplo n.º 3
0
// Function that reads from a MiniSEED binary file from a char buffer and
// returns a LinkedIDList.
LinkedIDList *
readMSEEDBuffer (char *mseed, int buflen, Selections *selections, flag
                 unpack_data, int reclen, flag verbose, flag details,
                 int header_byteorder, long long (*allocData) (int, char),
                 void (*diag_print) (char*), void (*log_print) (char*))
{
    int retcode = 0;
    int retval = 0;
    flag swapflag = 0;
    flag bigendianhost = ms_bigendianhost();

    // current offset of mseed char pointer
    int offset = 0;

    // Unpack without reading the data first
    flag dataflag = 0;

    // the timing_qual of BLK 1001
    uint8_t timing_qual = 0xFF;

    // the calibration type, availability of BLK 300, 310, 320, 390, 395
    int8_t calibration_type = -1;

    // Init all the pointers to NULL. Most compilers should do this anyway.
    LinkedIDList * idListHead = NULL;
    LinkedIDList * idListCurrent = NULL;
    LinkedIDList * idListLast = NULL;
    MSRecord *msr = NULL;
    ContinuousSegment * segmentCurrent = NULL;
    hptime_t lastgap = 0;
    hptime_t hptimetol = 0;
    hptime_t nhptimetol = 0;
    long long data_offset;
    LinkedRecordList *recordHead = NULL;
    LinkedRecordList *recordPrevious = NULL;
    LinkedRecordList *recordCurrent = NULL;
    int datasize;
    int record_count = 0;

    // A negative verbosity suppresses as much as possible.
    if (verbose < 0) {
        ms_loginit(&empty_print, NULL, &empty_print, NULL);
    }
    else {
        ms_loginit(log_print, "INFO: ", diag_print, "ERROR: ");
    }

    if (header_byteorder >= 0) {
        // Enforce little endian.
        if (header_byteorder == 0) {
            MS_UNPACKHEADERBYTEORDER(0);
        }
        // Enforce big endian.
        else {
            MS_UNPACKHEADERBYTEORDER(1);
        }
    }
    else {
        MS_UNPACKHEADERBYTEORDER(-1);
    }

    // Read all records and save them in a linked list.
    while (offset < buflen) {
        msr = msr_init(NULL);
        if ( msr == NULL ) {
            ms_log (2, "readMSEEDBuffer(): Error initializing msr\n");
            return NULL;
        }
        if (verbose > 1) {
            ms_log(0, "readMSEEDBuffer(): calling msr_parse with "
                      "mseed+offset=%d+%d, buflen=%d, reclen=%d, dataflag=%d, verbose=%d\n",
                      mseed, offset, buflen, reclen, dataflag, verbose);
        }

        // If the record length is given, make sure at least that amount of data is available.
        if (reclen != -1) {
            if (offset + reclen > buflen) {
                ms_log(1, "readMSEEDBuffer(): Last reclen exceeds buflen, skipping.\n");
                msr_free(&msr);
                break;
            }
        }
        // Otherwise assume the smallest possible record length and assure that enough
        // data is present.
        else {
            if (offset + MINRECLEN > buflen) {
                ms_log(1, "readMSEEDBuffer(): Last record only has %i byte(s) which "
                          "is not enough to constitute a full SEED record. Corrupt data? "
                          "Record will be skipped.\n", buflen - offset);
                msr_free(&msr);
                break;
            }
        }

        // Skip empty or noise records.
        if (OBSPY_ISVALIDBLANK(mseed + offset)) {
            offset += MINRECLEN;
            continue;
        }

        // Pass (buflen - offset) because msr_parse() expects only a single record. This
        // way libmseed can take care to not overstep bounds.
        // Return values:
        //   0 : Success, populates the supplied MSRecord.
        //  >0 : Data record detected but not enough data is present, the
        //       return value is a hint of how many more bytes are needed.
        //  <0 : libmseed error code (listed in libmseed.h) is returned.
        retcode = msr_parse ((mseed+offset), buflen - offset, &msr, reclen, dataflag, verbose);
        // Handle error.
        if (retcode < 0) {
            log_error(retcode, offset);
            msr_free(&msr);
            break;
        }
        // msr_parse() returns > 0 if a data record has been detected but the buffer either has not enough
        // data (this cannot happen with ObsPy's logic) or the last record has no Blockette 1000 and it cannot
        // determine the record length because there is no next record (this can happen in ObsPy) - handle that
        // case by just calling msr_parse() with an explicit record length set.
        else if ( retcode > 0 && retcode < (buflen - offset)) {

            // Check if the remaining bytes can exactly make up a record length.
            int r_bytes = buflen - offset;
            float exp = log10((float)r_bytes) / log10(2.0);
            if ((fmodf(exp, 1.0) < 0.0000001) && ((int)roundf_(exp) >= 7) && ((int)roundf_(exp) <= 256)) {

                retcode = msr_parse((mseed + offset), buflen - offset, &msr, r_bytes, dataflag, verbose);

                if ( retcode != 0 ) {
                    log_error(retcode, offset);
                    msr_free(&msr);
                    break;
                }

            }
            else {
                msr_free(&msr);
                break;
            }
        }

        if (offset + msr->reclen > buflen) {
            ms_log(1, "readMSEEDBuffer(): Last msr->reclen exceeds buflen, skipping.\n");
            msr_free(&msr);
            break;
        }

        // Test against selections if supplied
        if ( selections ) {
            char srcname[50];
            hptime_t endtime;
            msr_srcname (msr, srcname, 1);
            endtime = msr_endtime (msr);
            if ( ms_matchselect (selections, srcname, msr->starttime, endtime, NULL) == NULL ) {
                // Add the record length for the next iteration
                offset += msr->reclen;
                // Free record.
                msr_free(&msr);
                continue;
            }
        }
        record_count += 1;

        recordCurrent = lrl_init ();
        // Append to linked record list if one exists.
        if ( recordHead != NULL ) {
            recordPrevious->next = recordCurrent;
            recordCurrent->previous = recordPrevious;
            recordCurrent->next = NULL;
            recordPrevious = recordCurrent;
        }
        // Otherwise create a new one.
        else {
            recordHead = recordCurrent;
            recordCurrent->previous = NULL;
            recordPrevious = recordCurrent;
        }
        recordCurrent->record = msr;


        // Figure out if the byte-order of the data has to be swapped.
        swapflag = 0;
        // If blockette 1000 is present, use it.
        if ( msr->Blkt1000 != 0) {
            /* If BE host and LE data need swapping */
            if ( bigendianhost && msr->byteorder == 0 ) {
                swapflag = 1;
            }
            /* If LE host and BE data (or bad byte order value) need swapping */
            if ( !bigendianhost && msr->byteorder > 0 ) {
                swapflag = 1;
            }
        }
        // Otherwise assume the data has the same byte order as the header.
        // This needs to be done on the raw header bytes as libmseed only returns
        // header fields in the native byte order.
        else {
            unsigned char* _t = (unsigned char*)mseed + offset + 20;
            unsigned int year = _t[0] | _t[1] << 8;
            unsigned int day = _t[2] | _t[3] << 8;
            // Swap data if header needs to be swapped.
            if (!MS_ISVALIDYEARDAY(year, day)) {
                swapflag = 1;
            }
        }

        // Actually unpack the data if the flag is not set and if the data
        // offset is valid.
        if ((unpack_data != 0) && (msr->fsdh->data_offset >= 48) &&
            (msr->fsdh->data_offset < msr->reclen) &&
            (msr->samplecnt > 0)) {
            retval = msr_unpack_data (msr, swapflag, verbose);
        }

        if ( retval > 0 ) {
            msr->numsamples = retval;
        }

        if ( msr->fsdh->start_time.fract > 9999 ) {
            ms_log(1, "readMSEEDBuffer(): Record with offset=%d has a "
                      "fractional second (.0001 seconds) of %d. This is not "
                      "strictly valid but will be interpreted as one or more "
                      "additional seconds.",
                      offset, msr->fsdh->start_time.fract);
        }

        // Add the record length for the next iteration
        offset += msr->reclen;
    }

    // Return empty id list if no records could be found.
    if (record_count == 0) {
        idListHead = lil_init();
        return idListHead;
    }


    // All records that match the selection are now stored in a LinkedRecordList
    // that starts at recordHead. The next step is to sort them by matching ids
    // and then by time.
    recordCurrent = recordHead;
    while (recordCurrent != NULL) {
        // Check if the ID of the record is already available and if not create a
        // new one.
        // Start with the last id as it is most likely to be the correct one.
        idListCurrent = idListLast;
        while (idListCurrent != NULL) {
            if (strcmp(idListCurrent->network, recordCurrent->record->network) == 0 &&
                strcmp(idListCurrent->station, recordCurrent->record->station) == 0 &&
                strcmp(idListCurrent->location, recordCurrent->record->location) == 0 &&
                strcmp(idListCurrent->channel, recordCurrent->record->channel) == 0 &&
                idListCurrent->dataquality == recordCurrent->record->dataquality) {
                break;
            }
            else {
                idListCurrent = idListCurrent->previous;
            }
        }

        // Create a new id list if one is needed.
        if (idListCurrent == NULL) {
            idListCurrent = lil_init();
            idListCurrent->previous = idListLast;
            if (idListLast != NULL) {
                idListLast->next = idListCurrent;
            }
            idListLast = idListCurrent;
            if (idListHead == NULL) {
                idListHead = idListCurrent;
            }

            // Set the IdList attributes.
            strcpy(idListCurrent->network, recordCurrent->record->network);
            strcpy(idListCurrent->station, recordCurrent->record->station);
            strcpy(idListCurrent->location, recordCurrent->record->location);
            strcpy(idListCurrent->channel, recordCurrent->record->channel);
            idListCurrent->dataquality = recordCurrent->record->dataquality;
        }

        // Now check if the current record fits exactly to the end of the last
        // segment of the current id. If not create a new segment. Therefore
        // if records with the same id are in wrong order a new segment will be
        // created. This is on purpose.
        segmentCurrent = idListCurrent->lastSegment;
        if (segmentCurrent != NULL) {
            hptimetol = (hptime_t) (0.5 * segmentCurrent->hpdelta);
            nhptimetol = ( hptimetol ) ? -hptimetol : 0;
            lastgap = recordCurrent->record->starttime - segmentCurrent->endtime - segmentCurrent->hpdelta;
        }
        if (details == 1) {
            /* extract information on calibration BLKs */
            calibration_type = -1;
            if (recordCurrent->record->blkts) {
                BlktLink *cur_blkt = recordCurrent->record->blkts;
                while (cur_blkt) {
                    switch (cur_blkt->blkt_type) {
                    case 300:
                        calibration_type = 1;
                        break;
                    case 310:
                        calibration_type = 2;
                        break;
                    case 320:
                        calibration_type = 3;
                        break;
                    case 390:
                        calibration_type = 4;
                        break;
                    case 395:
                        calibration_type = -2;
                        break;
                    default:
                        break;
                    }
                    cur_blkt = cur_blkt->next;
                }
            }
            /* extract information based on timing quality */
            timing_qual = 0xFF;
            if (recordCurrent->record->Blkt1001 != 0) {
                timing_qual = recordCurrent->record->Blkt1001->timing_qual;
            }
        }
        if ( segmentCurrent != NULL &&

             // This is important for zero data record coupled with not unpacking
             // the data. It needs to be split in two places: Before the zero data
             // record and after it.
             recordCurrent->record->samplecnt > 0 && segmentCurrent->samplecnt > 0 &&

             segmentCurrent->sampletype == recordCurrent->record->sampletype &&
             // Test the default sample rate tolerance: abs(1-sr1/sr2) < 0.0001
             MS_ISRATETOLERABLE (segmentCurrent->samprate, recordCurrent->record->samprate) &&
             // Check if the times are within the time tolerance
             lastgap <= hptimetol && lastgap >= nhptimetol &&
             segmentCurrent->timing_qual == timing_qual &&
             segmentCurrent->calibration_type == calibration_type) {
            recordCurrent->previous = segmentCurrent->lastRecord;
            segmentCurrent->lastRecord = segmentCurrent->lastRecord->next = recordCurrent;
            segmentCurrent->samplecnt += recordCurrent->record->samplecnt;
            segmentCurrent->endtime = msr_endtime(recordCurrent->record);
        }
        // Otherwise create a new segment and add the current record.
        else {
            segmentCurrent = seg_init();
            segmentCurrent->previous = idListCurrent->lastSegment;
            if (idListCurrent->lastSegment != NULL) {
                idListCurrent->lastSegment->next = segmentCurrent;
            }
            else {
                idListCurrent->firstSegment = segmentCurrent;
            }
            idListCurrent->lastSegment = segmentCurrent;

            segmentCurrent->starttime = recordCurrent->record->starttime;
            segmentCurrent->endtime = msr_endtime(recordCurrent->record);
            segmentCurrent->samprate = recordCurrent->record->samprate;
            segmentCurrent->sampletype = recordCurrent->record->sampletype;
            segmentCurrent->samplecnt = recordCurrent->record->samplecnt;
            // Calculate high-precision sample period
            segmentCurrent->hpdelta = (hptime_t) (( recordCurrent->record->samprate ) ?
                           (HPTMODULUS / recordCurrent->record->samprate) : 0.0);
            segmentCurrent->timing_qual = timing_qual;
            segmentCurrent->calibration_type = calibration_type;
            segmentCurrent->firstRecord = segmentCurrent->lastRecord = recordCurrent;
            recordCurrent->previous = NULL;
        }
        recordPrevious = recordCurrent->next;
        recordCurrent->next = NULL;
        recordCurrent = recordPrevious;
    }


    // Now loop over all segments, combine the records and free the msr
    // structures.
    idListCurrent = idListHead;
    while (idListCurrent != NULL)
    {
        segmentCurrent = idListCurrent->firstSegment;

        while (segmentCurrent != NULL) {
            if (segmentCurrent->datasamples) {
                free(segmentCurrent->datasamples);
            }
            // Allocate data via a callback function.
            if (unpack_data != 0) {
                segmentCurrent->datasamples = (void *) allocData(segmentCurrent->samplecnt, segmentCurrent->sampletype);
            }

            // Loop over all records, write the data to the buffer and free the msr structures.
            recordCurrent = segmentCurrent->firstRecord;
            data_offset = (long long)(segmentCurrent->datasamples);
            while (recordCurrent != NULL) {
                datasize = recordCurrent->record->samplecnt * ms_samplesize(recordCurrent->record->sampletype);
                memcpy((void *)data_offset, recordCurrent->record->datasamples, datasize);
                // Free the record.
                msr_free(&(recordCurrent->record));
                // Increase the data_offset and the record.
                data_offset += (long long)datasize;
                recordCurrent = recordCurrent->next;
            }

            segmentCurrent = segmentCurrent->next;
        }
        idListCurrent = idListCurrent->next;
    }
    return idListHead;
}
Ejemplo n.º 4
0
/**********************************************************************
 * ms_readmsr_main:
 *
 * This routine will open and read, with subsequent calls, all
 * Mini-SEED records in specified file.
 *
 * All static file reading parameters are stored in a MSFileParam
 * struct and returned (via a pointer to a pointer) for the calling
 * routine to use in subsequent calls.  A MSFileParam struct will be
 * allocated if necessary.  This routine is thread safe and can be
 * used to read multiple files in parallel as long as the file reading
 * parameters are managed appropriately.
 *
 * If reclen is 0 or negative the length of every record is
 * automatically detected.  For auto detection of record length the
 * record must include a 1000 blockette or be followed by a valid
 * record header or end of file.
 *
 * If *fpos is not NULL it will be updated to reflect the file
 * position (offset from the beginning in bytes) from where the
 * returned record was read.  As a special case, if *fpos is not NULL
 * and the value it points to is less than 0 this will be interpreted
 * as a (positive) starting offset from which to begin reading data;
 * this feature does not work with packed files.
 *
 * If *last is not NULL it will be set to 1 when the last record in
 * the file is being returned, otherwise it will be 0.
 *
 * If the skipnotdata flag is true any data chunks read that do not
 * have valid data record indicators (D, R, Q, M, etc.) will be skipped.
 *
 * dataflag will be passed directly to msr_unpack().
 *
 * If a Selections list is supplied it will be used to determine when
 * a section of data in a packed file may be skipped, packed files are
 * internal to the IRIS DMC.
 *
 * After reading all the records in a file the controlling program
 * should call it one last time with msfile set to NULL.  This will
 * close the file and free allocated memory.
 *
 * Returns MS_NOERROR and populates an MSRecord struct at *ppmsr on
 * successful read, returns MS_ENDOFFILE on EOF, otherwise returns a
 * libmseed error code (listed in libmseed.h) and *ppmsr is set to
 * NULL.
 *********************************************************************/
int
ms_readmsr_main (MSFileParam **ppmsfp, MSRecord **ppmsr, const char *msfile,
                 int reclen, off_t *fpos, int *last, flag skipnotdata,
                 flag dataflag, Selections *selections, flag verbose)
{
  MSFileParam *msfp;
  off_t packdatasize = 0;
  int packskipsize;
  int parseval  = 0;
  int readsize  = 0;
  int readcount = 0;
  int retcode   = MS_NOERROR;

  if (!ppmsr)
    return MS_GENERROR;

  if (!ppmsfp)
    return MS_GENERROR;

  msfp = *ppmsfp;

  /* Initialize the file read parameters if needed */
  if (!msfp)
  {
    msfp = (MSFileParam *)malloc (sizeof (MSFileParam));

    if (msfp == NULL)
    {
      ms_log (2, "ms_readmsr_main(): Cannot allocate memory for MSFP\n");
      return MS_GENERROR;
    }

    /* Redirect the supplied pointer to the allocated params */
    *ppmsfp = msfp;

    msfp->fp            = NULL;
    msfp->filename[0]   = '\0';
    msfp->rawrec        = NULL;
    msfp->readlen       = 0;
    msfp->readoffset    = 0;
    msfp->packtype      = 0;
    msfp->packhdroffset = 0;
    msfp->filepos       = 0;
    msfp->filesize      = 0;
    msfp->recordcount   = 0;
  }

  /* When cleanup is requested */
  if (msfile == NULL)
  {
    msr_free (ppmsr);

    if (msfp->fp != NULL)
      fclose (msfp->fp);

    if (msfp->rawrec != NULL)
      free (msfp->rawrec);

    /* If the file parameters are the global parameters reset them */
    if (*ppmsfp == &gMSFileParam)
    {
      gMSFileParam.fp            = NULL;
      gMSFileParam.filename[0]   = '\0';
      gMSFileParam.rawrec        = NULL;
      gMSFileParam.readlen       = 0;
      gMSFileParam.readoffset    = 0;
      gMSFileParam.packtype      = 0;
      gMSFileParam.packhdroffset = 0;
      gMSFileParam.filepos       = 0;
      gMSFileParam.filesize      = 0;
      gMSFileParam.recordcount   = 0;
    }
    /* Otherwise free the MSFileParam */
    else
    {
      free (*ppmsfp);
      *ppmsfp = NULL;
    }

    return MS_NOERROR;
  }

  /* Allocate reading buffer */
  if (msfp->rawrec == NULL)
  {
    if (!(msfp->rawrec = (char *)malloc (MAXRECLEN)))
    {
      ms_log (2, "ms_readmsr_main(): Cannot allocate memory for read buffer\n");
      return MS_GENERROR;
    }
  }

  /* Sanity check: track if we are reading the same file */
  if (msfp->fp && strncmp (msfile, msfp->filename, sizeof (msfp->filename)))
  {
    ms_log (2, "ms_readmsr_main() called with a different file name without being reset\n");

    /* Close previous file and reset needed variables */
    if (msfp->fp != NULL)
      fclose (msfp->fp);

    msfp->fp            = NULL;
    msfp->readlen       = 0;
    msfp->readoffset    = 0;
    msfp->packtype      = 0;
    msfp->packhdroffset = 0;
    msfp->filepos       = 0;
    msfp->filesize      = 0;
    msfp->recordcount   = 0;
  }

  /* Open the file if needed, redirect to stdin if file is "-" */
  if (msfp->fp == NULL)
  {
    /* Store the filename for tracking */
    strncpy (msfp->filename, msfile, sizeof (msfp->filename) - 1);
    msfp->filename[sizeof (msfp->filename) - 1] = '\0';

    if (strcmp (msfile, "-") == 0)
    {
      msfp->fp = stdin;
    }
    else
    {
      if ((msfp->fp = fopen (msfile, "rb")) == NULL)
      {
        ms_log (2, "Cannot open file: %s (%s)\n", msfile, strerror (errno));
        msr_free (ppmsr);

        return MS_GENERROR;
      }
      else
      {
        /* Determine file size */
        struct stat sbuf;

        if (fstat (fileno (msfp->fp), &sbuf))
        {
          ms_log (2, "Cannot open file: %s (%s)\n", msfile, strerror (errno));
          msr_free (ppmsr);

          return MS_GENERROR;
        }

        msfp->filesize = sbuf.st_size;
      }
    }
  }

  /* Seek to a specified offset if requested */
  if (fpos != NULL && *fpos < 0)
  {
    /* Only try to seek in real files, not stdin */
    if (msfp->fp != stdin)
    {
      if (lmp_fseeko (msfp->fp, *fpos * -1, SEEK_SET))
      {
        ms_log (2, "Cannot seek in file: %s (%s)\n", msfile, strerror (errno));

        return MS_GENERROR;
      }

      msfp->filepos    = *fpos * -1;
      msfp->readlen    = 0;
      msfp->readoffset = 0;
    }
  }

  /* Zero the last record indicator */
  if (last)
    *last = 0;

  /* Read data and search for records */
  for (;;)
  {
    /* Read more data into buffer if not at EOF and buffer has less than MINRECLEN
       * or more data is needed for the current record detected in buffer. */
    if (!feof (msfp->fp) && (MSFPBUFLEN (msfp) < MINRECLEN || parseval > 0))
    {
      /* Reset offsets if no unprocessed data in buffer */
      if (MSFPBUFLEN (msfp) <= 0)
      {
        msfp->readlen    = 0;
        msfp->readoffset = 0;
      }
      /* Otherwise shift existing data to beginning of buffer */
      else if (msfp->readoffset > 0)
      {
        ms_shift_msfp (msfp, msfp->readoffset);
      }

      /* Determine read size */
      readsize = (MAXRECLEN - msfp->readlen);

      /* Read data into record buffer */
      readcount = ms_fread (msfp->rawrec + msfp->readlen, 1, readsize, msfp->fp);

      if (readcount != readsize)
      {
        if (!feof (msfp->fp))
        {
          ms_log (2, "Short read of %d bytes starting from %" PRId64 "\n",
                  readsize, msfp->filepos);
          retcode = MS_GENERROR;
          break;
        }
      }

      /* Update read buffer length */
      msfp->readlen += readcount;

      /* File position corresponding to start of buffer; not strictly necessary */
      if (msfp->fp != stdin)
        msfp->filepos = lmp_ftello (msfp->fp) - msfp->readlen;
    }

    /* Test for packed file signature at the beginning of the file */
    if (msfp->filepos == 0 && *(MSFPREADPTR (msfp)) == 'P' && MSFPBUFLEN (msfp) >= 48)
    {
      msfp->packtype = 0;

      /* Determine pack type, the negative pack type indicates initial header */
      if (!memcmp ("PED", MSFPREADPTR (msfp), 3))
        msfp->packtype = -1;
      else if (!memcmp ("PSD", MSFPREADPTR (msfp), 3))
        msfp->packtype = -2;
      else if (!memcmp ("PLC", MSFPREADPTR (msfp), 3))
        msfp->packtype = -6;
      else if (!memcmp ("PQI", MSFPREADPTR (msfp), 3))
        msfp->packtype = -7;
      else if (!memcmp ("PLS", MSFPREADPTR (msfp), 3))
        msfp->packtype = -8;

      if (verbose > 0)
        ms_log (1, "Detected packed file (%3.3s: type %d)\n", MSFPREADPTR (msfp), -msfp->packtype);
    }

    /* Read pack headers, initial and subsequent headers including (ignored) chksum values */
    if (msfp->packtype && (msfp->packtype < 0 || msfp->filepos == msfp->packhdroffset) && MSFPBUFLEN (msfp) >= 48)
    {
      char hdrstr[30];
      int64_t datasize;

      /* Determine bytes to skip before header: either initial ID block or type-specific chksum block */
      packskipsize = (msfp->packtype < 0) ? 10 : packtypes[msfp->packtype][2];

      if (msfp->packtype < 0)
        msfp->packtype = -msfp->packtype;

      /* Read pack length from pack header accounting for bytes that should be skipped */
      memset (hdrstr, 0, sizeof (hdrstr));
      memcpy (hdrstr, MSFPREADPTR (msfp) + (packtypes[msfp->packtype][0] + packskipsize - packtypes[msfp->packtype][1]),
              packtypes[msfp->packtype][1]);
      sscanf (hdrstr, " %" SCNd64, &datasize);
      packdatasize = (off_t)datasize;

      /* Next pack header = File position + skipsize + header size + data size
	   * This offset is actually to the data block chksum which is skipped by the logic above,
	   * the next pack header should directly follow the chksum. */
      msfp->packhdroffset = msfp->filepos + packskipsize + packtypes[msfp->packtype][0] + packdatasize;

      if (verbose > 1)
        ms_log (1, "Read packed file header at offset %" PRId64 " (%d bytes follow), chksum offset: %" PRId64 "\n",
                (msfp->filepos + packskipsize), packdatasize,
                msfp->packhdroffset);

      /* Shift buffer to new reading offset (aligns records in buffer) */
      ms_shift_msfp (msfp, msfp->readoffset + (packskipsize + packtypes[msfp->packtype][0]));
    } /* End of packed header processing */

    /* Check for match if selections are supplied and pack header was read, */
    /* only when enough data is in buffer and not reading from stdin pipe */
    if (selections && msfp->packtype && packdatasize && MSFPBUFLEN (msfp) >= 48 && msfp->fp != stdin)
    {
      char srcname[100];

      ms_recsrcname (MSFPREADPTR (msfp), srcname, 1);

      if (!ms_matchselect (selections, srcname, HPTERROR, HPTERROR, NULL))
      {
        /* Update read position if next section is in buffer */
        if (MSFPBUFLEN (msfp) >= (msfp->packhdroffset - msfp->filepos))
        {
          if (verbose > 1)
          {
            ms_log (1, "Skipping (jump) packed section for %s (%d bytes) starting at offset %" PRId64 "\n",
                    srcname, (msfp->packhdroffset - msfp->filepos), msfp->filepos);
          }

          msfp->readoffset += (msfp->packhdroffset - msfp->filepos);
          msfp->filepos = msfp->packhdroffset;
          packdatasize  = 0;
        }

        /* Otherwise seek to next pack header and reset reading position */
        else
        {
          if (verbose > 1)
          {
            ms_log (1, "Skipping (seek) packed section for %s (%d bytes) starting at offset %" PRId64 "\n",
                    srcname, (msfp->packhdroffset - msfp->filepos), msfp->filepos);
          }

          if (lmp_fseeko (msfp->fp, msfp->packhdroffset, SEEK_SET))
          {
            ms_log (2, "Cannot seek in file: %s (%s)\n", msfile, strerror (errno));

            return MS_GENERROR;
            break;
          }

          msfp->filepos    = msfp->packhdroffset;
          msfp->readlen    = 0;
          msfp->readoffset = 0;
          packdatasize     = 0;
        }

        /* Return to top of loop for proper pack header handling */
        continue;
      }
    } /* End of selection processing */

    /* Attempt to parse record from buffer */
    if (MSFPBUFLEN (msfp) >= MINRECLEN)
    {
      int parselen = MSFPBUFLEN (msfp);

      /* Limit the parse length to offset of pack header if present in the buffer */
      if (msfp->packhdroffset && msfp->packhdroffset < (msfp->filepos + MSFPBUFLEN (msfp)))
        parselen = msfp->packhdroffset - msfp->filepos;

      parseval = msr_parse (MSFPREADPTR (msfp), parselen, ppmsr, reclen, dataflag, verbose);

      /* Record detected and parsed */
      if (parseval == 0)
      {
        if (verbose > 1)
          ms_log (1, "Read record length of %d bytes\n", (*ppmsr)->reclen);

        /* Test if this is the last record if file size is known (not pipe) */
        if (last && msfp->filesize)
          if ((msfp->filesize - (msfp->filepos + (*ppmsr)->reclen)) < MINRECLEN)
            *last = 1;

        /* Return file position for this record */
        if (fpos)
          *fpos = msfp->filepos;

        /* Update reading offset, file position and record count */
        msfp->readoffset += (*ppmsr)->reclen;
        msfp->filepos += (*ppmsr)->reclen;
        msfp->recordcount++;

        retcode = MS_NOERROR;
        break;
      }
      else if (parseval < 0)
      {
        /* Skip non-data if requested */
        if (skipnotdata)
        {
          if (verbose > 1)
          {
            if (MS_ISVALIDBLANK ((char *)MSFPREADPTR (msfp)))
              ms_log (1, "Skipped %d bytes of blank/noise record at byte offset %" PRId64 "\n",
                      MINRECLEN, msfp->filepos);
            else
              ms_log (1, "Skipped %d bytes of non-data record at byte offset %" PRId64 "\n",
                      MINRECLEN, msfp->filepos);
          }

          /* Skip MINRECLEN bytes, update reading offset and file position */
          msfp->readoffset += MINRECLEN;
          msfp->filepos += MINRECLEN;
        }
        /* Parsing errors */
        else
        {
          ms_log (2, "Cannot detect record at byte offset %" PRId64 ": %s\n",
                  msfp->filepos, msfile);

          /* Print common errors and raw details if verbose */
          ms_parse_raw (MSFPREADPTR (msfp), MSFPBUFLEN (msfp), verbose, -1);

          retcode = parseval;
          break;
        }
      }
      else /* parseval > 0 (found record but need more data) */
      {
        /* Determine implied record length if needed */
        int32_t impreclen = reclen;

        /* Check for parse hints that are larger than MAXRECLEN */
        if ((MSFPBUFLEN (msfp) + parseval) > MAXRECLEN)
        {
          if (skipnotdata)
          {
            /* Skip MINRECLEN bytes, update reading offset and file position */
            msfp->readoffset += MINRECLEN;
            msfp->filepos += MINRECLEN;
          }
          else
          {
            retcode = MS_OUTOFRANGE;
            break;
          }
        }

        /* Pack header check, if pack header offset is within buffer */
        else if (impreclen <= 0 && msfp->packhdroffset &&
                 msfp->packhdroffset < (msfp->filepos + MSFPBUFLEN (msfp)))
        {
          impreclen = msfp->packhdroffset - msfp->filepos;

          /* Check that record length is within range and a power of 2.
		   * Power of two if (X & (X - 1)) == 0 */
          if (impreclen >= MINRECLEN && impreclen <= MAXRECLEN &&
              (impreclen & (impreclen - 1)) == 0)
          {
            /* Set the record length implied by the next pack header */
            reclen = impreclen;
          }
          else
          {
            ms_log (1, "Implied record length (%d) is invalid\n", impreclen);

            retcode = MS_NOTSEED;
            break;
          }
        }

        /* End of file check */
        else if (impreclen <= 0 && feof (msfp->fp))
        {
          impreclen = msfp->filesize - msfp->filepos;

          /* Check that record length is within range and a power of 2.
		   * Power of two if (X & (X - 1)) == 0 */
          if (impreclen >= MINRECLEN && impreclen <= MAXRECLEN &&
              (impreclen & (impreclen - 1)) == 0)
          {
            /* Set the record length implied by the end of the file */
            reclen = impreclen;
          }
          /* Otherwise a trucated record */
          else
          {
            if (verbose)
            {
              if (msfp->filesize)
                ms_log (1, "Truncated record at byte offset %" PRId64 ", filesize %d: %s\n",
                        msfp->filepos, msfp->filesize, msfile);
              else
                ms_log (1, "Truncated record at byte offset %" PRId64 "\n",
                        msfp->filepos);
            }

            retcode = MS_ENDOFFILE;
            break;
          }
        }
      }
    } /* End of record detection */

    /* Finished when within MINRECLEN from EOF and buffer less than MINRECLEN */
    if ((msfp->filesize - msfp->filepos) < MINRECLEN && MSFPBUFLEN (msfp) < MINRECLEN)
    {
      if (msfp->recordcount == 0 && msfp->packtype == 0)
      {
        if (verbose > 0)
          ms_log (2, "%s: No data records read, not SEED?\n", msfile);
        retcode = MS_NOTSEED;
      }
      else
      {
        retcode = MS_ENDOFFILE;
      }

      break;
    }
  } /* End of reading, record detection and parsing loop */

  /* Cleanup target MSRecord if returning an error */
  if (retcode != MS_NOERROR)
  {
    msr_free (ppmsr);
  }

  return retcode;
} /* End of ms_readmsr_main() */
Ejemplo n.º 5
0
// Function that reads from a MiniSEED binary file from a char buffer and
// returns a LinkedIDList.
LinkedIDList *
readMSEEDBuffer (char *mseed, int buflen, Selections *selections, flag
                 unpack_data, int reclen, flag verbose, flag details,
                 long (*allocData) (int, char))
{
    int retcode = 0;
    int retval = 0;
    flag swapflag = 0;

    // current offset of mseed char pointer
    int offset = 0;

    // Unpack without reading the data first
    flag dataflag = 0;

    // the timing_qual of BLK 1001
    uint8_t timing_qual = 0xFF;

    // the calibration type, availability of BLK 300, 310, 320, 390, 395
    int8_t calibration_type = -1;

    // Init all the pointers to NULL. Most compilers should do this anyway.
    LinkedIDList * idListHead = NULL;
    LinkedIDList * idListCurrent = NULL;
    LinkedIDList * idListLast = NULL;
    MSRecord *msr = NULL;
    ContinuousSegment * segmentCurrent = NULL;
    hptime_t lastgap;
    hptime_t hptimetol;
    hptime_t nhptimetol;
    long data_offset;
    LinkedRecordList *recordHead = NULL;
    LinkedRecordList *recordPrevious = NULL;
    LinkedRecordList *recordCurrent = NULL;
    int datasize;


    //
    // Read all records and save them in a linked list.
    //
    int record_count = 0;
    while (offset < buflen) {
        msr = msr_init(NULL);
        retcode = msr_parse ( (mseed+offset), buflen, &msr, reclen, dataflag, verbose);
        if ( ! (retcode == MS_NOERROR)) {
            msr_free(&msr);
            break;
        }

        // Test against selections if supplied
        if ( selections ) {
            char srcname[50];
            hptime_t endtime;
            msr_srcname (msr, srcname, 1);
            endtime = msr_endtime (msr);
            if ( ms_matchselect (selections, srcname, msr->starttime, endtime, NULL) == NULL ) {
                // Add the record length for the next iteration
                offset += msr->reclen;
                // Free record.
                msr_free(&msr);
                continue;
            }
        }
        record_count += 1;

        recordCurrent = lrl_init ();
        // Append to linked record list if one exists.
        if ( recordHead != NULL ) {
            recordPrevious->next = recordCurrent;
            recordCurrent->previous = recordPrevious;
            recordCurrent->next = NULL;
            recordPrevious = recordCurrent;
        }
        // Otherwise create a new one.
        else {
            recordHead = recordCurrent;
            recordCurrent->previous = NULL;
            recordPrevious = recordCurrent;
        }
        recordCurrent->record = msr;

        // Determine the byteorder swapflag only for the very first record. The byteorder
        // should not change within the file.
        // XXX: Maybe check for every record?
        if (swapflag <= 0) {
            // Returns 0 if the host is little endian, otherwise 1.
            flag bigendianhost = ms_bigendianhost();
            // Set the swapbyteflag if it is needed.
            if ( msr->Blkt1000 != 0) {
                /* If BE host and LE data need swapping */
                if ( bigendianhost && msr->byteorder == 0 ) {
                    swapflag = 1;
                }
                /* If LE host and BE data (or bad byte order value) need swapping */
                if ( !bigendianhost && msr->byteorder > 0 ) {
                    swapflag = 1;
                }
            }
        }

        // Actually unpack the data if the flag is not set.
        if (unpack_data != 0) {
            retval = msr_unpack_data (msr, swapflag, verbose);
        }

        if ( retval > 0 ) {
            msr->numsamples = retval;
        }

        // Add the record length for the next iteration
        offset += msr->reclen;
    }

    // Return empty id list if no records could be found.
    if (record_count == 0) {
        idListHead = lil_init();
        return idListHead;
    }


    // All records that match the selection are now stored in a LinkedRecordList
    // that starts at recordHead. The next step is to sort them by matching ids
    // and then by time.
    recordCurrent = recordHead;
    while (recordCurrent != NULL) {
        // Check if the ID of the record is already available and if not create a
        // new one.
        // Start with the last id as it is most likely to be the correct one.
        idListCurrent = idListLast;
        while (idListCurrent != NULL) {
            if (strcmp(idListCurrent->network, recordCurrent->record->network) == 0 &&
                strcmp(idListCurrent->station, recordCurrent->record->station) == 0 &&
                strcmp(idListCurrent->location, recordCurrent->record->location) == 0 &&
                strcmp(idListCurrent->channel, recordCurrent->record->channel) == 0 &&
                idListCurrent->dataquality == recordCurrent->record->dataquality) {
                break;
            }
            else {
                idListCurrent = idListCurrent->previous;
            }
        }

        // Create a new id list if one is needed.
        if (idListCurrent == NULL) {
            idListCurrent = lil_init();
            idListCurrent->previous = idListLast;
            if (idListLast != NULL) {
                idListLast->next = idListCurrent;
            }
            idListLast = idListCurrent;
            if (idListHead == NULL) {
                idListHead = idListCurrent;
            }

            // Set the IdList attributes.
            strcpy(idListCurrent->network, recordCurrent->record->network);
            strcpy(idListCurrent->station, recordCurrent->record->station);
            strcpy(idListCurrent->location, recordCurrent->record->location);
            strcpy(idListCurrent->channel, recordCurrent->record->channel);
            idListCurrent->dataquality = recordCurrent->record->dataquality;
        }

        // Now check if the current record fits exactly to the end of the last
        // segment of the current id. If not create a new segment. Therefore
        // if records with the same id are in wrong order a new segment will be
        // created. This is on purpose.
        segmentCurrent = idListCurrent->lastSegment;
        if (segmentCurrent != NULL) {
            hptimetol = (hptime_t) (0.5 * segmentCurrent->hpdelta);
            nhptimetol = ( hptimetol ) ? -hptimetol : 0;
            lastgap = recordCurrent->record->starttime - segmentCurrent->endtime - segmentCurrent->hpdelta;
        }
        if (details == 1) {
            /* extract information on calibration BLKs */
            calibration_type = -1;
            if (recordCurrent->record->blkts) {
                BlktLink *cur_blkt = recordCurrent->record->blkts;
                while (cur_blkt) {
                    switch (cur_blkt->blkt_type) {
                    case 300:
                        calibration_type = 1;
                        break;
                    case 310:
                        calibration_type = 2;
                        break;
                    case 320:
                        calibration_type = 3;
                        break;
                    case 390:
                        calibration_type = 4;
                        break;
                    case 395:
                        calibration_type = -2;
                        break;
                    default:
                        break;
                    }
                    cur_blkt = cur_blkt->next;
                }
            }
            /* extract information based on timing quality */
            timing_qual = 0xFF;
            if (recordCurrent->record->Blkt1001 != 0) {
                timing_qual = recordCurrent->record->Blkt1001->timing_qual;
            }
        }
        if ( segmentCurrent != NULL &&
             segmentCurrent->sampletype == recordCurrent->record->sampletype &&
             // Test the default sample rate tolerance: abs(1-sr1/sr2) < 0.0001
             MS_ISRATETOLERABLE (segmentCurrent->samprate, recordCurrent->record->samprate) &&
             // Check if the times are within the time tolerance
             lastgap <= hptimetol && lastgap >= nhptimetol &&
             segmentCurrent->timing_qual == timing_qual &&
             segmentCurrent->calibration_type == calibration_type) {
            recordCurrent->previous = segmentCurrent->lastRecord;
            segmentCurrent->lastRecord = segmentCurrent->lastRecord->next = recordCurrent;
            segmentCurrent->samplecnt += recordCurrent->record->samplecnt;
            segmentCurrent->endtime = msr_endtime(recordCurrent->record);
        }
        // Otherwise create a new segment and add the current record.
        else {
            segmentCurrent = seg_init();
            segmentCurrent->previous = idListCurrent->lastSegment;
            if (idListCurrent->lastSegment != NULL) {
                idListCurrent->lastSegment->next = segmentCurrent;
            }
            else {
                idListCurrent->firstSegment = segmentCurrent;
            }
            idListCurrent->lastSegment = segmentCurrent;

            segmentCurrent->starttime = recordCurrent->record->starttime;
            segmentCurrent->endtime = msr_endtime(recordCurrent->record);
            segmentCurrent->samprate = recordCurrent->record->samprate;
            segmentCurrent->sampletype = recordCurrent->record->sampletype;
            segmentCurrent->samplecnt = recordCurrent->record->samplecnt;
            // Calculate high-precision sample period
            segmentCurrent->hpdelta = (hptime_t) (( recordCurrent->record->samprate ) ?
                           (HPTMODULUS / recordCurrent->record->samprate) : 0.0);
            segmentCurrent->timing_qual = timing_qual;
            segmentCurrent->calibration_type = calibration_type;
            segmentCurrent->firstRecord = segmentCurrent->lastRecord = recordCurrent;
            recordCurrent->previous = NULL;
        }
        recordPrevious = recordCurrent->next;
        recordCurrent->next = NULL;
        recordCurrent = recordPrevious;
    }


    // Now loop over all segments, combine the records and free the msr
    // structures.
    idListCurrent = idListHead;
    while (idListCurrent != NULL)
    {
        segmentCurrent = idListCurrent->firstSegment;

        while (segmentCurrent != NULL) {
            if (segmentCurrent->datasamples) {
                free(segmentCurrent->datasamples);
            }
            // Allocate data via a callback function.
            if (unpack_data != 0) {
                segmentCurrent->datasamples = (void *) allocData(segmentCurrent->samplecnt, segmentCurrent->sampletype);
            }

            // Loop over all records, write the data to the buffer and free the msr structures.
            recordCurrent = segmentCurrent->firstRecord;
            data_offset = (long)(segmentCurrent->datasamples);
            while (recordCurrent != NULL) {
                datasize = recordCurrent->record->samplecnt * ms_samplesize(recordCurrent->record->sampletype);
                memcpy((void *)data_offset, recordCurrent->record->datasamples, datasize);
                // Free the record.
                msr_free(&(recordCurrent->record));
                // Increase the data_offset and the record.
                data_offset += (long)datasize;
                recordCurrent = recordCurrent->next;
            }

            segmentCurrent = segmentCurrent->next;
        }
        idListCurrent = idListCurrent->next;
    }
    return idListHead;
}