/***************************************************************************
 * filespace.c -- a simple mechanism for storing dynamic amounts of data   *
 * in a simple to use, and quick to append-to structure.                   *
 *                                                                         *
 ***********************IMPORTANT NSOCK LICENSE TERMS***********************
 *                                                                         *
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 * LLC This library is free software; you may redistribute and/or          *
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 * may be willing to sell alternative licenses (contact                    *
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 *                                                                         *
 ***************************************************************************/

/* $Id: filespace.c 37640 2019-05-28 21:36:04Z dmiller $ */

#include "nsock_internal.h"
#include "filespace.h"

#include <string.h>

#define FS_INITSIZE_DEFAULT 1024


/* Assumes space for fs has already been allocated */
int filespace_init(struct filespace *fs, int initial_size) {
  memset(fs, 0, sizeof(struct filespace));
  if (initial_size == 0)
    initial_size = FS_INITSIZE_DEFAULT;

  fs->current_alloc = initial_size;
  fs->str = (char *)safe_malloc(fs->current_alloc);
  fs->str[0] = '\0';
  fs->pos = fs->str;
  return 0;
}

int fs_free(struct filespace *fs) {
  if (fs->str)
    free(fs->str);

  fs->current_alloc = fs->current_size = 0;
  fs->pos = fs->str = NULL;
  return 0;
}

/* Concatenate a string to the end of a filespace */
int fs_cat(struct filespace *fs, const char *str, int len) {
  if (len < 0)
    return -1;

  if (len == 0)
    return 0;

  if (fs->current_alloc - fs->current_size < len + 2) {
    char *tmpstr;

    fs->current_alloc = (int)(fs->current_alloc * 1.4 + 1);
    fs->current_alloc += 100 + len;

    tmpstr = (char *)safe_malloc(fs->current_alloc);
    memcpy(tmpstr, fs->str, fs->current_size);

    fs->pos = (fs->pos - fs->str) + tmpstr;

    if (fs->str)
      free(fs->str);

    fs->str = tmpstr;
  }
  memcpy(fs->str + fs->current_size, str, len);

  fs->current_size += len;
  fs->str[fs->current_size] = '\0';
  return 0;
}

