/*

 * Samba Unix/Linux SMB client library

 *

 * Copyright (C) Gregor Beck 2010

 *

 * 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 3 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, see <http://www.gnu.org/licenses/>.

 */

/**

 * @file   cbuf.c

 * @author Gregor Beck <gb@sernet.de>

 * @date   Aug 2010

 *

 * @brief  A talloced character buffer.

 *

 */

#include "replace.h"

#include "system/locale.h"

#include "cbuf.h"

#include <talloc.h>

#include <assert.h>

#include "lib/util/byteorder.h"

struct cbuf {

  char*  buf;

  size_t pos;

  size_t size;

};

cbuf* cbuf_clear(cbuf* b)

{

  cbuf_setpos(b, 0);

  return b;

}

cbuf* cbuf_new(const void* ctx)

{

  cbuf* s = talloc(ctx, cbuf);

  if (s == NULL)

    return NULL;

  s->size = 32;

  s->buf  = (char *)talloc_size(s, s->size);

  if (s->size && (s->buf == NULL)) {

    talloc_free(s);

    return NULL;

  }

  return cbuf_clear(s);

}

cbuf* cbuf_copy(const cbuf* b)

{

  cbuf* s = talloc(talloc_parent(b), cbuf);

  if (s == NULL) {

    return NULL;

  }

  s->buf = (char *)talloc_memdup(s, b->buf, b->size); /* only up to pos? */

  /* XXX shallow did not work, because realloc */

  /* fails with multiple references */

  /* s->buf = talloc_reference(s, b->buf); */

  if (s->buf == NULL) {

    cbuf_delete(s);

    return NULL;

  }

  s->size = b->size;

  s->pos  = b->pos;

  return s;

}

void cbuf_delete(cbuf* b)

{

  talloc_free(b);

}

#define SWAP(A,B,T) do {     \

    T tmp = A; A = B; B = tmp;  \

  } while(0)

void cbuf_swap(cbuf* b1, cbuf* b2)

{

  if (b1 == b2) {

    return;

  }

  talloc_reparent(b1, b2, b1->buf);

  talloc_reparent(b2, b1, b2->buf);

  SWAP(b1->buf,  b2->buf, char*);

  SWAP(b1->pos,  b2->pos, size_t);

  SWAP(b1->size, b2->size, size_t);

}

cbuf* cbuf_takeover(cbuf* b1, cbuf* b2)

{

  talloc_reparent(b2, b1, b2->buf);

  b1->buf = b2->buf;

  b1->pos = b2->pos;

  b1->size = b2->size;

  cbuf_delete(b2);

  return b1;

}

cbuf* cbuf_swapptr(cbuf* b, char** ptr, size_t len)

{

  void* p = talloc_parent(*ptr);

  SWAP(b->buf, *ptr, char*);

  talloc_steal(b, b->buf);

  talloc_steal(p, *ptr);

  b->size = talloc_get_size(b->buf);

  b->pos  = (len == -1) ? strlen(b->buf) : len;

  assert(b->pos <= b->size);

  return b;

}

cbuf* cbuf_resize(cbuf* b, size_t size)

{

  char* save_buf = b->buf;

  b->buf = talloc_realloc(b, b->buf, char, size);

  if (b->buf == NULL) {

    talloc_free(save_buf);

    b->size = 0;

  } else {

    b->size = size;

  }

  b->pos  = MIN(b->pos, b->size);

  return b->buf ? b : NULL;

}

char* cbuf_reserve(cbuf* b, size_t len)

{

  if(b->size < b->pos + len)

    cbuf_resize(b, MAX(2*b->size, b->pos + len));

  return b->buf ? b->buf + b->pos : NULL;

}

int cbuf_puts(cbuf* b, const char* str, size_t len)

{

  char* dst;

  if (b == NULL)

    return 0;

  if (len == -1) {

    len=strlen(str);

  }

  dst = cbuf_reserve(b, len+1);

  if (dst == NULL)

    return -1;

  memcpy(dst, str, len);

  dst[len] = '\0'; /* just to ease debugging */

  b->pos += len;

  assert(b->pos < b->size);

  return len;

}

int cbuf_putc(cbuf* b, char c) {

  char* dst;

  if (b == NULL)

    return 0;

  dst = cbuf_reserve(b, 2);

  if (dst == NULL) {

    return -1;

  }

  dst[0] = c;

  dst[1] = '\0'; /* just to ease debugging */

  b->pos++;

  assert(b->pos < b->size);

  return 1;

}

int cbuf_putdw(cbuf* b, uint32_t u) {

  char* dst;

  static const size_t LEN = sizeof(uint32_t);

  if (b == NULL)

    return 0;

  dst = cbuf_reserve(b, LEN);

  if (dst == NULL) {

    return -1;

  }

  SIVAL(dst, 0, u);

  b->pos += LEN;

  assert(b->pos <= b->size); /* no NULL termination*/

  return LEN;

}

size_t cbuf_getpos(const cbuf* b) {

  assert(b->pos <= b->size);

  return b->pos;

}

void cbuf_setpos(cbuf* b, size_t pos) {

  assert(pos <= b->size);

  b->pos = pos;

  if (pos < b->size)

    b->buf[pos] = '\0'; /* just to ease debugging */

}

char* cbuf_gets(cbuf* b, size_t idx) {

  assert(idx <= b->pos);

  if (cbuf_reserve(b, 1) == NULL)

    return NULL;

  b->buf[b->pos] = '\0';

  return b->buf + idx;

}

int cbuf_printf(cbuf* b, const char* fmt, ...)

{

  va_list args, args2;

  int len;

  char* dst = b->buf + b->pos;

  const int avail = b->size - b->pos;

  assert(avail >= 0);

  va_start(args, fmt);

  va_copy(args2, args);

  len = vsnprintf(dst, avail, fmt, args);

  if (len >= avail) {

    dst = cbuf_reserve(b, len+1);

    len = (dst != NULL) ? vsnprintf(dst, len+1, fmt, args2) : -1;

  }

  if (len > 0) {

    b->pos += len;

  }

  va_end(args);

  va_end(args2);

  assert(b->pos <= b->size);

  return len;

}

int cbuf_print_quoted_string(cbuf* ost, const char* s)

{

  int n = 1;

  cbuf_putc(ost,'"');

  while(true) {

    switch (*s) {

    case '\0':

      cbuf_putc(ost, '"');

      return n+1;

    case '"':

    case '\\':

      cbuf_putc(ost, '\\');

            n++;

      FALL_THROUGH;

    default:

      cbuf_putc(ost, *s);

      n++;

    }

    s++;

  }

}

int cbuf_print_quoted(cbuf* ost, const char* s, size_t len)

{

  int n = 1;

  int ret;

  cbuf_reserve(ost, len+2);

  cbuf_putc(ost,'"');

  while(len--) {

    switch (*s) {

    case '"':

    case '\\':

      ret = cbuf_printf(ost, "\\%c", *s);

      break;

    default:

      if (isprint(*s) && ((*s == ' ') || !isspace(*s))) {

        ret = cbuf_putc(ost, *s);

      } else {

        ret = cbuf_printf(ost,

              "\\%02x",

              (unsigned char)*s);

      }

    }

    s++;

    if (ret == -1) {

      return -1;

    }

    n += ret;

  }

  ret = cbuf_putc(ost,'"');

  return (ret == -1) ? -1 : (n + ret);

}