wztsv.h

/**
 * The MIT License (MIT)
 * Copyright (c) 2016-2017 Wanding.Zhou@vai.org
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:

 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * usage:
 * tsv_t *tsv = tsv_open("input.tsv");
 * while (tsv_read(tsv)) {
 *   for (i=0; i < tsv->n; ++i) printf("\t|%s", tsv->fields[i]);
 *   printf("\n");
 * }
 * tsv_close(tsv);
**/

#include <string.h>
#include <stdlib.h>
#include <zlib.h>
#include "wzio.h"

typedef struct tsv_t {
   char **fields;
   size_t n, m;                  /* number of fields, and allocated */
   gzFile fp;
   int finished;
   int line_max;
   char *line;
} tsv_t;

static inline tsv_t *tsv_open(char *fn) {
   tsv_t *tsv = calloc(1, sizeof(tsv_t));
   tsv->fp = wzopen(fn);
   tsv->fields = NULL;
   tsv->line_max = 10000;
   tsv->line = calloc(tsv->line_max, sizeof(char));
   tsv->finished = 0;
   return tsv;
}

/* tsv_close release the memory */
static inline void tsv_close(tsv_t *tsv) {
   unsigned i;
   for (i = 0; i < tsv->m; ++i)
      free(tsv->fields[i]);
   free(tsv->fields);
   free(tsv->line);
   gzclose(tsv->fp);
   free(tsv);
}

static inline void __tsv_clear_fields(tsv_t *tsv) {
   tsv->n = 0;
}

/* i is 0-based */
static inline void __tsv_set_field(tsv_t *tsv, int i, const char *s) {
   tsv->fields[i] = realloc(tsv->fields[i], strlen(s)+1);
   strcpy(tsv->fields[i], s);
}

static inline void __tsv_append_field(tsv_t *tsv, const char *s) {
   if (tsv->n == tsv->m) {
      tsv->fields = realloc(tsv->fields, (++tsv->m)*sizeof(char*));
      /* the newly incremented memory is always initialized */
      tsv->fields[tsv->m-1] = NULL;
   }
   __tsv_set_field(tsv, tsv->n++, s);
}

static inline char *tsv_field(tsv_t *tsv, unsigned k) {
   if (k < tsv->n)
      return tsv->fields[k];
   else
      return NULL;
}

static inline int tsv_is_blankline(tsv_t *tsv) {
   if (tsv->line[0] == '\0') return 1;
   else return 0;
}

#define tsv_num_fields(tsv) (tsv)->n

/* return NULL when done */
static inline int tsv_read(tsv_t *tsv) {
   if (tsv->finished)
      return 0;

   char *tok;
   char *line_null = tsv->line; // point to the terminating NULL
   *line_null = '\0';
   char *tmp = NULL;

   while (1) {
      int c = gzgetc(tsv->fp);
      if (c == '\n' || c == EOF) { /* process current line */

         __tsv_clear_fields(tsv);
         if (line_null == tsv->line) { // empty line
            if (c == EOF) tsv->finished = 1;
            break;
         }

         // keep original line
         tmp = realloc(tmp, strlen(tsv->line) + 1);
         strcpy(tmp, tsv->line);
         
         tok = strtok(tmp, "\t");
         while (tok != NULL) {
            __tsv_append_field(tsv, tok);
            tok = strtok(NULL, "\t");
         }
         if (c == EOF)
            tsv->finished = 1;
         break;
      } else {                    /* read line */
         if (line_null >= tsv->line + tsv->line_max) { // reaches max
            tsv->line_max <<= 1;
            int line_len = line_null - tsv->line;
            tsv->line = realloc(tsv->line, tsv->line_max);
            line_null = tsv->line + line_len;
         }
         *line_null++ = c;
         *line_null = '\0';
      }
   }

   free(tmp);

   return 1;
}