text: /*
   * %CopyrightBegin%
   * 
   * Copyright Ericsson AB 2002-2016. All Rights Reserved.
   * 
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   * 
   * %CopyrightEnd%
   */
  #include "eidef.h"
  #include "eiext.h"
  #include "putget.h"
  
  #ifdef EI_64BIT
  int ei_decode_ulong(const char *buf, int *index, unsigned long *p)
  {
      return ei_decode_ulonglong(buf, index, (EI_ULONGLONG *)p);
  }
  #endif
  
  int ei_decode_ulonglong(const char *buf, int *index, EI_ULONGLONG *p)
  {
    const char *s = buf + *index;
    const char *s0 = s;
    EI_ULONGLONG n;
    int arity;
    int sn;
  
    switch (get8(s)) {
    case ERL_SMALL_INTEGER_EXT:
      n = get8(s);
      break;
      
    case ERL_INTEGER_EXT:
      sn = get32be(s);
      if (sn < 0) return -1;
      n = (EI_ULONGLONG)sn;
      break;
      
    case ERL_SMALL_BIG_EXT:
      arity = get8(s);
      goto decode_big;
  
    case ERL_LARGE_BIG_EXT:
      arity = get32be(s);
  
    decode_big:
      {
        int sign = get8(s);
        int i;
        n = 0;
  
        if (sign) return -1;
  
        /* Little Endian, up to four bytes always fit into unsigned long */
        for (i = 0; i < arity; i++) {
  	if (i < 8) {
  	  n |= ((EI_ULONGLONG)get8(s)) << (i * 8);
  	} else if (get8(s) != 0) {
  	  return -1; /* All but first byte have to be 0 */
  	}
        }
      }
      break;
  
    default:
      return -1;
    }
  
    if (p) *p = n;
    *index += s-s0;
    
    return 0; 
  }
  