utils.c

OTP是开放电信平台的简称

		}
	    case (_TAG_HEADER_EXTERNAL_PID >> _TAG_PRIMARY_SIZE):
		if (is_internal_pid(b)) {
		    bnode = erts_this_node;
		    bdata = internal_pid_data(b);
		} else if (is_external_pid(b)) {
		    bnode = external_pid_node(b);
		    bdata = external_pid_data(b);
		} else {
		    a_tag = EXTERNAL_PID_DEF;
		    goto mixed_types;
		}
		anode = external_pid_node(a);
		adata = external_pid_data(a);
		goto pid_common;
	    case (_TAG_HEADER_EXTERNAL_PORT >> _TAG_PRIMARY_SIZE):
		if (is_internal_port(b)) {
		    bnode = erts_this_node;
		    bdata = internal_port_data(b);
		} else if (is_external_port(b)) {
		    bnode = external_port_node(b);
		    bdata = external_port_data(b);
		} else {
		    a_tag = EXTERNAL_PORT_DEF;
		    goto mixed_types;
		}
		anode = external_port_node(a);
		adata = external_port_data(a);
		goto port_common;
	    case (_TAG_HEADER_REF >> _TAG_PRIMARY_SIZE):
		/*
		 * Note! When comparing refs we need to compare ref numbers
		 * (32-bit words), *not* ref data words.
		 */
		
		if (is_internal_ref(b)) {
		    bnode = erts_this_node;
		    bnum = internal_ref_numbers(b);
		    blen = internal_ref_no_of_numbers(b);
		} else if(is_external_ref(b)) {
		    bnode = external_ref_node(b);
		    bnum = external_ref_numbers(b);
		    blen = external_ref_no_of_numbers(b);
		} else {
		    a_tag = REF_DEF;
		    goto mixed_types;
		}
		anode = erts_this_node;
		anum = internal_ref_numbers(a);
		alen = internal_ref_no_of_numbers(a);
		
	    ref_common:
		CMP_NODES(anode, bnode);
		
		ASSERT(alen > 0 && blen > 0);
		if (alen != blen) {
		    if (alen > blen) {
			do {
			    if (anum[alen - 1] != 0)
				return 1;
			    alen--;
			} while (alen > blen);
		    }
		    else {
			do {
			    if (bnum[blen - 1] != 0)
				return -1;
			    blen--;
			} while (alen < blen);
		    }
		}
		
		ASSERT(alen == blen);
		for (i = (Sint) alen - 1; i >= 0; i--)
		    if (anum[i] != bnum[i])
			return anum[i] < bnum[i] ? -1 : 1;
		return 0;
	    case (_TAG_HEADER_EXTERNAL_REF >> _TAG_PRIMARY_SIZE):
		if (is_internal_ref(b)) {
		    bnode = erts_this_node;
		    bnum = internal_ref_numbers(b);
		    blen = internal_ref_no_of_numbers(b);
		} else if (is_external_ref(b)) {
		    bnode = external_ref_node(b);
		    bnum = external_ref_numbers(b);
		    blen = external_ref_no_of_numbers(b);
		} else {
		    a_tag = EXTERNAL_REF_DEF;
		    goto mixed_types;
		}
		anode = external_ref_node(a);
		anum = external_ref_numbers(a);
		alen = external_ref_no_of_numbers(a);
		goto ref_common;
	    default:
		/* Must be a binary */
		ASSERT(is_binary(a));
		if (is_not_binary(b)) {
		    a_tag = BINARY_DEF;
		    goto mixed_types;
		} else {
		    Uint a_size = binary_size(a);
		    Uint b_size = binary_size(b);
		    Uint a_bitsize;
		    Uint b_bitsize;
		    Uint a_bitoffs;
		    Uint b_bitoffs;
		    Uint min_size;
		    int cmp;
		    byte* a_ptr;
		    byte* b_ptr;
		    ERTS_GET_BINARY_BYTES(a, a_ptr, a_bitoffs, a_bitsize);
		    ERTS_GET_BINARY_BYTES(b, b_ptr, b_bitoffs, b_bitsize);
		    if ((a_bitsize | b_bitsize | a_bitoffs | b_bitoffs) == 0) {
			min_size = (a_size < b_size) ? a_size : b_size;
			if ((cmp = sys_memcmp(a_ptr, b_ptr, min_size)) != 0) {
			    return cmp;
			} else {
			    return a_size - b_size;
			}
		    }
		    else {
			a_size = (a_size << 3) + a_bitsize;
			b_size = (b_size << 3) + b_bitsize;
			min_size = (a_size < b_size) ? a_size : b_size;
			if ((cmp = erts_cmp_bits(a_ptr,a_bitoffs,
						 b_ptr,b_bitoffs,min_size)) != 0) {
			    return cmp;
			}
			else {
			    return a_size - b_size;
			}
		    }
		}
	    }
	}
    }

    /*
     * Take care of the case that the tags are different.
     */

 mixed_types:
    b_tag = tag_val_def(b);

    {
	FloatDef f1, f2;
	Eterm big;

	switch(_NUMBER_CODE(a_tag, b_tag)) {
	case SMALL_BIG:
	    big = small_to_big(signed_val(a), big_buf);
	    return big_comp(big, b);
	case SMALL_FLOAT:
	    f1.fd = signed_val(a);
	    GET_DOUBLE(b, f2);
	    return float_comp(f1.fd, f2.fd);
	case BIG_SMALL:
	    big = small_to_big(signed_val(b), big_buf);
	    return big_comp(a, big);
	case BIG_FLOAT:
	    if (big_to_double(a, &f1.fd) < 0) {
		return big_sign(a) ? -1 : 1;
	    }
	    GET_DOUBLE(b, f2);
	    return float_comp(f1.fd, f2.fd);
	case FLOAT_SMALL:
	    GET_DOUBLE(a, f1);
	    f2.fd = signed_val(b);
	    return float_comp(f1.fd, f2.fd);
	case FLOAT_BIG:
	    if (big_to_double(b, &f2.fd) < 0) {
		return big_sign(b) ? 1 : -1;
	    }
	    GET_DOUBLE(a, f1);
	    return float_comp(f1.fd, f2.fd);
	default:
	    return b_tag - a_tag;
	}
    }

#undef CMP_NODES

}

void
erts_cleanup_externals(ExternalThing *etp)
{
    ExternalThing *tetp;

    tetp = etp;

    while(tetp) {
	erts_deref_node_entry(tetp->node);
	tetp = tetp->next;
    }
}

Eterm
store_external_or_ref_(Uint **hpp, ExternalThing **etpp, Eterm ns)
{
    Uint i;
    Uint size;
    Uint *from_hp;
    Uint *to_hp = *hpp;

    ASSERT(is_external(ns) || is_internal_ref(ns));

    if(is_external(ns)) {
	from_hp = external_val(ns);
	size = thing_arityval(*from_hp) + 1;
	*hpp += size;

	for(i = 0; i < size; i++)
	    to_hp[i] = from_hp[i];

	erts_refc_inc(&((ExternalThing *) to_hp)->node->refc, 2);

	((ExternalThing *) to_hp)->next = *etpp;
	*etpp = (ExternalThing *) to_hp;

	return make_external(to_hp);
    }

    /* Internal ref */
    from_hp = internal_ref_val(ns);

    size = thing_arityval(*from_hp) + 1;

    *hpp += size;

    for(i = 0; i < size; i++)
	to_hp[i] = from_hp[i];

    return make_internal_ref(to_hp);
}

Eterm
store_external_or_ref_in_proc_(Process *proc, Eterm ns)
{
    Uint sz;
    Uint *hp;

    ASSERT(is_external(ns) || is_internal_ref(ns));

    sz = NC_HEAP_SIZE(ns);
    ASSERT(sz > 0);
    hp = HAlloc(proc, sz);
    return store_external_or_ref_(&hp, &MSO(proc).externals, ns);
}

/* 
 *  member(X,Y)
 *  returns 0 if X is a member of list Y
 *  returns 1 if X is not a member of list Y
 *  returns 2 if Y is not a list or is a badly formed list
 */

int
member(Eterm x, Eterm y)
{
    Eterm* z;
    if (is_nil(y)) return(1); /* empty list */
    if (is_not_list(y)) return(2); /* bad argument */
    z = list_val(y);
    for (;;) {
	if (eq(*z, x)) return(0);
	if (is_nil(*(z + 1))) return(1); /* end of list */
	if (is_not_list(*(z + 1))) return(2); /* badly formed list */
	z = list_val(*(z + 1));
    }
}

void bin_write(int to, void *to_arg, byte* buf, int sz)
{
    int i;

    for (i=0;i<sz;i++) {
	if (IS_DIGIT(buf[i]))
	    erts_print(to, to_arg, "%d,", buf[i]);
	else if (IS_PRINT(buf[i])) {
	    erts_print(to, to_arg, "%c,", buf[i]);
	}
	else
	    erts_print(to, to_arg, "%d,", buf[i]);
    }
    erts_putc(to, to_arg, '\n');
}

/* Fill buf with the contents of bytelist list 
   return number of chars in list or -1 for error */

int
intlist_to_buf(Eterm list, char *buf, int len)
{
    Eterm* listptr;
    int sz = 0;

    if (is_nil(list)) 
	return 0;
    if (is_not_list(list))
	return -1;
    listptr = list_val(list);

    while (sz < len) {
	if (!is_byte(*listptr)) 
	    return -1;
	buf[sz++] = unsigned_val(*listptr);
	if (is_nil(*(listptr + 1)))
	    return(sz);
	if (is_not_list(*(listptr + 1))) 
	    return -1;
	listptr = list_val(*(listptr + 1));
    }
    return -1;			/* not enough space */
}

/*
** Convert an integer to a byte list
** return pointer to converted stuff (need not to be at start of buf!)
*/
char* Sint_to_buf(Sint n, struct Sint_buf *buf)
{
    char* p = &buf->s[sizeof(buf->s)-1];
    int sign = 0;

    *p-- = '\0'; /* null terminate */
    if (n == 0)
	*p-- = '0';
    else if (n < 0) {
	sign = 1;
	n = -n;
    }

    while (n != 0) {
	*p-- = (n % 10) + '0';
	n /= 10;
    }
    if (sign)
	*p-- = '-';
    return p+1;
}

/* Build a list of integers in some safe memory area
** Memory must be pre allocated prio call 2*len in size
** hp is a pointer to the "heap" pointer on return
** this pointer is updated to point after the list
*/

Eterm
buf_to_intlist(Eterm** hpp, char *buf, int len, Eterm tail)
{
    Eterm* hp = *hpp;

    buf += (len-1);
    while(len > 0) {
	tail = CONS(hp, make_small((byte)*buf), tail);
	hp += 2;
	buf--;
	len--;
    }
    *hpp = hp;
    return tail;
}

/*
** Write io list in to a buffer.
**
** An iolist is defined as:
**
** iohead ::= Binary
**        |   Byte (i.e integer in range [0..255]
**        |   iolist
**        ;
**
** iotail ::= []
**        |   Binary  (added by tony)
**        |   iolist
**        ;
**
** iolist ::= []
**        |   Binary
**        |   [ iohead | iotail]
**        ;
** 
** Return remaining bytes in buffer on success
**        -1 on overflow
**        -2 on type error (including that result would not be a whole number of bytes)
*/

int io_list_to_buf(Eterm obj, char* buf, int len)
{
    Eterm* objp;
    DECLARE_ESTACK(s);
    goto L_again;
    
    while (!ESTACK_ISEMPTY(s)) {
	obj = ESTACK_POP(s);
    L_again:
	if (is_list(obj)) {
	L_iter_list:
	    objp = list_val(obj);
	    obj = CAR(objp);
	    if (is_byte(obj)) {
		if (len == 0) {
		    goto L_overflow;
		}
		*buf++ = unsigned_val(obj);
		len--;
	    } else if (is_binary(obj)) {
		byte* bptr;
		size_t size = binary_size(obj);
		Uint bitsize;
		Uint bitoffs;
		Uint num_bits;
		
		if (len < size) {
		    goto L_overflow;
		}
		ERTS_GET_BINARY_BYTES(obj, bptr, bitoffs, bitsize);
		if (bitsize != 0) {
		    goto L_type_error;
		}
		num_bits = 8*size;
		copy_binary_to_buffer(buf, 0, bptr, bitoffs, num_bits);
		buf += size;
		len -= size;
	    } else if (is_list(obj)) {
		ESTACK_PUSH(s, CDR(objp));
		goto L_iter_list; /* on head */
	    } else if (is_not_nil(obj)) {
		goto L_type_error;
	    }

	    obj = CDR(objp);
	    if (is_list(obj)) {
		goto L_iter_list; /* on tail */
	    } else if (is_binary(obj)) {
		byte* bptr;
		size_t size = binary_size(obj);
		Uint bitsize;
		Uint bitoffs;
		Uint num_bits;
		if (len < size) {
		    goto L_overflow;
		}
		ERTS_GET_BINARY_BYTES(obj, bptr, bitoffs, bitsize);
		if (bitsize != 0) {
		    goto L_type_error;
		}
		num_bits = 8*size;
		copy_binary_to_buffer(buf, 0, bptr, bitoffs, num_bits);
		buf += size;
		len -= size;
	    } else if (is_not_nil(obj)) {
		goto L_type_error;
	    }
	} else if (is_binary(obj)) {
	    byte* bptr;
	    size_t size = binary_size(obj);
	    Uint bitsize;
	    Uint bitoffs;
	    Uint num_bits;
	    if (len < size) {
		goto L_overflow;
	    }
	    ERTS_GET_BINARY_BYTES(obj, bptr, bitoffs, bitsize);
	    if (bitsize != 0) {
		goto L_type_error;
	    }
	    num_bits = 8*size;
	    copy_binary_to_buffer(buf, 0, bptr, bitoffs, num_bits);
	    buf += size;
	    len -= size;
	} else if (is_not_nil(obj)) {
	    goto L_type_error;
	}
    }
      
    DESTROY_ESTACK(s);
    return len;

 L_type_error:
    DESTROY_ESTACK(s);
    return -2;

 L_overflow:
    DESTROY_ESTACK(s);
    return -1;
}

int io_list_len(Eterm obj)
{
    Eterm* objp;
    Sint len = 0;
    DECLARE_ESTACK(s);
    goto L_again;

    while (!ESTACK_ISEMPTY(s)) {
	obj = ESTACK_POP(s);
    L_again:
	if (is_list(obj)) {
	L_iter_list:
	    objp = list_val(obj);
	    /* Head */
	    obj = CAR(objp);
	    if (is_byte(obj)) {
		len++;
	    } else if (is_binary(obj) && binary_bitsize(obj) == 0) {
		len += binary_size(obj);
	    } else if (is_list(obj)) {
		ESTACK_PUSH(s, CDR(objp));
		goto L_iter_list; /* on head */
	    } else if (is_not_nil(obj)) {
		goto L_type_error;
	    }
	    /* Tail */
	    obj = CDR(objp);
	    if (is_list(obj))
		goto L_iter_list; /* on tail */
	    else if (is_binary(obj) && binary_bitsize(obj) == 0) {
		len += binary_size(obj);
	    } else if (is_not_nil(obj)) {
		goto L_type_error;
	    }
	} else if (is_binary(obj) && binary_bitsize(obj) == 0) { /* Tail was binary */
	    len += binary_size(obj);
	} else if (is_not_nil(obj)) {
	    goto L_type_error;
	}
    }

    DESTROY_ESTACK(s);
    return len;

 L_type_error:
    DESTROY_ESTACK(s);
    return -1;
}

/* return 0 if item is not a non-empty flat list of bytes */
int
is_string(Eterm list)
{
    int len = 0;

    while(is_list(list)) {
	Eterm* consp = list_val(list);
	Eterm hd = CAR(consp);

	if (!is_byte(hd))
	    return 0;
	len++;
	list = CDR(con