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adamico/pack.c

Created November 28, 2015 14:39
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C source of .pack in ruby
Raw
pack.c
static VALUE
pack_pack(VALUE ary, VALUE fmt)
{
static const char nul10[] = "\0\0\0\0\0\0\0\0\0\0";
static const char spc10[] = " ";
const char *p, *pend;
VALUE res, from, associates = 0;
char type;
long items, len, idx, plen;
const char *ptr;
int enc_info = 1; /* 0 - BINARY, 1 - US-ASCII, 2 - UTF-8 */
#ifdef NATINT_PACK
int natint; /* native integer */
#endif
int integer_size, bigendian_p;
StringValue(fmt);
p = RSTRING_PTR(fmt);
pend = p + RSTRING_LEN(fmt);
res = rb_str_buf_new(0);
items = RARRAY_LEN(ary);
idx = 0;
#define TOO_FEW (rb_raise(rb_eArgError, toofew), 0)
#define THISFROM (items > 0 ? RARRAY_AREF(ary, idx) : TOO_FEW)
#define NEXTFROM (items-- > 0 ? RARRAY_AREF(ary, idx++) : TOO_FEW)
while (p < pend) {
int explicit_endian = 0;
if (RSTRING_PTR(fmt) + RSTRING_LEN(fmt) != pend) {
rb_raise(rb_eRuntimeError, "format string modified");
}
type = *p++; /* get data type */
#ifdef NATINT_PACK
natint = 0;
#endif
if (ISSPACE(type)) continue;
if (type == '#') {
while ((p < pend) && (*p != '\n')) {
p++;
}
continue;
}
{
modifiers:
switch (*p) {
case '_':
case '!':
if (strchr(natstr, type)) {
#ifdef NATINT_PACK
natint = 1;
#endif
p++;
}
else {
rb_raise(rb_eArgError, "'%c' allowed only after types %s", *p, natstr);
}
goto modifiers;
case '<':
case '>':
if (!strchr(endstr, type)) {
rb_raise(rb_eArgError, "'%c' allowed only after types %s", *p, endstr);
}
if (explicit_endian) {
rb_raise(rb_eRangeError, "Can't use both '<' and '>'");
}
explicit_endian = *p++;
goto modifiers;
}
}
if (*p == '*') { /* set data length */
len = strchr("@Xxu", type) ? 0
: strchr("PMm", type) ? 1
: items;
p++;
}
else if (ISDIGIT(*p)) {
errno = 0;
len = STRTOUL(p, (char**)&p, 10);
if (errno) {
rb_raise(rb_eRangeError, "pack length too big");
}
}
else {
len = 1;
}
switch (type) {
case 'U':
/* if encoding is US-ASCII, upgrade to UTF-8 */
if (enc_info == 1) enc_info = 2;
break;
case 'm': case 'M': case 'u':
/* keep US-ASCII (do nothing) */
break;
default:
/* fall back to BINARY */
enc_info = 0;
break;
}
switch (type) {
case 'A': case 'a': case 'Z':
case 'B': case 'b':
case 'H': case 'h':
from = NEXTFROM;
if (NIL_P(from)) {
ptr = "";
plen = 0;
}
else {
StringValue(from);
ptr = RSTRING_PTR(from);
plen = RSTRING_LEN(from);
OBJ_INFECT(res, from);
}
if (p[-1] == '*')
len = plen;
switch (type) {
case 'a': /* arbitrary binary string (null padded) */
case 'A': /* arbitrary binary string (ASCII space padded) */
case 'Z': /* null terminated string */
if (plen >= len) {
rb_str_buf_cat(res, ptr, len);
if (p[-1] == '*' && type == 'Z')
rb_str_buf_cat(res, nul10, 1);
}
else {
rb_str_buf_cat(res, ptr, plen);
len -= plen;
while (len >= 10) {
rb_str_buf_cat(res, (type == 'A')?spc10:nul10, 10);
len -= 10;
}
rb_str_buf_cat(res, (type == 'A')?spc10:nul10, len);
}
break;
#define castchar(from) (char)((from) & 0xff)
case 'b': /* bit string (ascending) */
{
int byte = 0;
long i, j = 0;
if (len > plen) {
j = (len - plen + 1)/2;
len = plen;
}
for (i=0; i++ < len; ptr++) {
if (*ptr & 1)
byte |= 128;
if (i & 7)
byte >>= 1;
else {
char c = castchar(byte);
rb_str_buf_cat(res, &c, 1);
byte = 0;
}
}
if (len & 7) {
char c;
byte >>= 7 - (len & 7);
c = castchar(byte);
rb_str_buf_cat(res, &c, 1);
}
len = j;
goto grow;
}
break;
case 'B': /* bit string (descending) */
{
int byte = 0;
long i, j = 0;
if (len > plen) {
j = (len - plen + 1)/2;
len = plen;
}
for (i=0; i++ < len; ptr++) {
byte |= *ptr & 1;
if (i & 7)
byte <<= 1;
else {
char c = castchar(byte);
rb_str_buf_cat(res, &c, 1);
byte = 0;
}
}
if (len & 7) {
char c;
byte <<= 7 - (len & 7);
c = castchar(byte);
rb_str_buf_cat(res, &c, 1);
}
len = j;
goto grow;
}
break;
case 'h': /* hex string (low nibble first) */
{
int byte = 0;
long i, j = 0;
if (len > plen) {
j = (len + 1) / 2 - (plen + 1) / 2;
len = plen;
}
for (i=0; i++ < len; ptr++) {
if (ISALPHA(*ptr))
byte |= (((*ptr & 15) + 9) & 15) << 4;
else
byte |= (*ptr & 15) << 4;
if (i & 1)
byte >>= 4;
else {
char c = castchar(byte);
rb_str_buf_cat(res, &c, 1);
byte = 0;
}
}
if (len & 1) {
char c = castchar(byte);
rb_str_buf_cat(res, &c, 1);
}
len = j;
goto grow;
}
break;
case 'H': /* hex string (high nibble first) */
{
int byte = 0;
long i, j = 0;
if (len > plen) {
j = (len + 1) / 2 - (plen + 1) / 2;
len = plen;
}
for (i=0; i++ < len; ptr++) {
if (ISALPHA(*ptr))
byte |= ((*ptr & 15) + 9) & 15;
else
byte |= *ptr & 15;
if (i & 1)
byte <<= 4;
else {
char c = castchar(byte);
rb_str_buf_cat(res, &c, 1);
byte = 0;
}
}
if (len & 1) {
char c = castchar(byte);
rb_str_buf_cat(res, &c, 1);
}
len = j;
goto grow;
}
break;
}
break;
case 'c': /* signed char */
case 'C': /* unsigned char */
integer_size = 1;
bigendian_p = BIGENDIAN_P(); /* not effective */
goto pack_integer;
case 's': /* s for int16_t, s! for signed short */
integer_size = NATINT_LEN(short, 2);
bigendian_p = BIGENDIAN_P();
goto pack_integer;
case 'S': /* S for uint16_t, S! for unsigned short */
integer_size = NATINT_LEN(short, 2);
bigendian_p = BIGENDIAN_P();
goto pack_integer;
case 'i': /* i and i! for signed int */
integer_size = (int)sizeof(int);
bigendian_p = BIGENDIAN_P();
goto pack_integer;
case 'I': /* I and I! for unsigned int */
integer_size = (int)sizeof(int);
bigendian_p = BIGENDIAN_P();
goto pack_integer;
case 'l': /* l for int32_t, l! for signed long */
integer_size = NATINT_LEN(long, 4);
bigendian_p = BIGENDIAN_P();
goto pack_integer;
case 'L': /* L for uint32_t, L! for unsigned long */
integer_size = NATINT_LEN(long, 4);
bigendian_p = BIGENDIAN_P();
goto pack_integer;
case 'q': /* q for int64_t, q! for signed long long */
integer_size = NATINT_LEN_Q;
bigendian_p = BIGENDIAN_P();
goto pack_integer;
case 'Q': /* Q for uint64_t, Q! for unsigned long long */
integer_size = NATINT_LEN_Q;
bigendian_p = BIGENDIAN_P();
goto pack_integer;
case 'n': /* 16 bit (2 bytes) integer (network byte-order) */
integer_size = 2;
bigendian_p = 1;
goto pack_integer;
case 'N': /* 32 bit (4 bytes) integer (network byte-order) */
integer_size = 4;
bigendian_p = 1;
goto pack_integer;
case 'v': /* 16 bit (2 bytes) integer (VAX byte-order) */
integer_size = 2;
bigendian_p = 0;
goto pack_integer;
case 'V': /* 32 bit (4 bytes) integer (VAX byte-order) */
integer_size = 4;
bigendian_p = 0;
goto pack_integer;
pack_integer:
if (explicit_endian) {
bigendian_p = explicit_endian == '>';
}
if (integer_size > MAX_INTEGER_PACK_SIZE)
rb_bug("unexpected intger size for pack: %d", integer_size);
while (len-- > 0) {
char intbuf[MAX_INTEGER_PACK_SIZE];
from = NEXTFROM;
rb_integer_pack(from, intbuf, integer_size, 1, 0,
INTEGER_PACK_2COMP |
(bigendian_p ? INTEGER_PACK_BIG_ENDIAN : INTEGER_PACK_LITTLE_ENDIAN));
rb_str_buf_cat(res, intbuf, integer_size);
}
break;
case 'f': /* single precision float in native format */
case 'F': /* ditto */
while (len-- > 0) {
float f;
from = NEXTFROM;
f = (float)RFLOAT_VALUE(rb_to_float(from));
rb_str_buf_cat(res, (char*)&f, sizeof(float));
}
break;
case 'e': /* single precision float in VAX byte-order */
while (len-- > 0) {
float f;
FLOAT_CONVWITH(ftmp);
from = NEXTFROM;
f = (float)RFLOAT_VALUE(rb_to_float(from));
f = HTOVF(f,ftmp);
rb_str_buf_cat(res, (char*)&f, sizeof(float));
}
break;
case 'E': /* double precision float in VAX byte-order */
while (len-- > 0) {
double d;
DOUBLE_CONVWITH(dtmp);
from = NEXTFROM;
d = RFLOAT_VALUE(rb_to_float(from));
d = HTOVD(d,dtmp);
rb_str_buf_cat(res, (char*)&d, sizeof(double));
}
break;
case 'd': /* double precision float in native format */
case 'D': /* ditto */
while (len-- > 0) {
double d;
from = NEXTFROM;
d = RFLOAT_VALUE(rb_to_float(from));
rb_str_buf_cat(res, (char*)&d, sizeof(double));
}
break;
case 'g': /* single precision float in network byte-order */
while (len-- > 0) {
float f;
FLOAT_CONVWITH(ftmp);
from = NEXTFROM;
f = (float)RFLOAT_VALUE(rb_to_float(from));
f = HTONF(f,ftmp);
rb_str_buf_cat(res, (char*)&f, sizeof(float));
}
break;
case 'G': /* double precision float in network byte-order */
while (len-- > 0) {
double d;
DOUBLE_CONVWITH(dtmp);
from = NEXTFROM;
d = RFLOAT_VALUE(rb_to_float(from));
d = HTOND(d,dtmp);
rb_str_buf_cat(res, (char*)&d, sizeof(double));
}
break;
case 'x': /* null byte */
grow:
while (len >= 10) {
rb_str_buf_cat(res, nul10, 10);
len -= 10;
}
rb_str_buf_cat(res, nul10, len);
break;
case 'X': /* back up byte */
shrink:
plen = RSTRING_LEN(res);
if (plen < len)
rb_raise(rb_eArgError, "X outside of string");
rb_str_set_len(res, plen - len);
break;
case '@': /* null fill to absolute position */
len -= RSTRING_LEN(res);
if (len > 0) goto grow;
len = -len;
if (len > 0) goto shrink;
break;
case '%':
rb_raise(rb_eArgError, "%% is not supported");
break;
case 'U': /* Unicode character */
while (len-- > 0) {
SIGNED_VALUE l;
char buf[8];
int le;
from = NEXTFROM;
from = rb_to_int(from);
l = NUM2LONG(from);
if (l < 0) {
rb_raise(rb_eRangeError, "pack(U): value out of range");
}
le = rb_uv_to_utf8(buf, l);
rb_str_buf_cat(res, (char*)buf, le);
}
break;
case 'u': /* uuencoded string */
case 'm': /* base64 encoded string */
from = NEXTFROM;
StringValue(from);
ptr = RSTRING_PTR(from);
plen = RSTRING_LEN(from);
if (len == 0 && type == 'm') {
encodes(res, ptr, plen, type, 0);
ptr += plen;
break;
}
if (len <= 2)
len = 45;
else if (len > 63 && type == 'u')
len = 63;
else
len = len / 3 * 3;
while (plen > 0) {
long todo;
if (plen > len)
todo = len;
else
todo = plen;
encodes(res, ptr, todo, type, 1);
plen -= todo;
ptr += todo;
}
break;
case 'M': /* quoted-printable encoded string */
from = rb_obj_as_string(NEXTFROM);
if (len <= 1)
len = 72;
qpencode(res, from, len);
break;
case 'P': /* pointer to packed byte string */
from = THISFROM;
if (!NIL_P(from)) {
StringValue(from);
if (RSTRING_LEN(from) < len) {
rb_raise(rb_eArgError, "too short buffer for P(%ld for %ld)",
RSTRING_LEN(from), len);
}
}
len = 1;
/* FALL THROUGH */
case 'p': /* pointer to string */
while (len-- > 0) {
char *t;
from = NEXTFROM;
if (NIL_P(from)) {
t = 0;
}
else {
t = StringValuePtr(from);
rb_obj_taint(from);
}
if (!associates) {
associates = rb_ary_new();
}
rb_ary_push(associates, from);
rb_str_buf_cat(res, (char*)&t, sizeof(char*));
}
break;
case 'w': /* BER compressed integer */
while (len-- > 0) {
VALUE buf = rb_str_new(0, 0);
size_t numbytes;
int sign;
char *cp;
from = NEXTFROM;
from = rb_to_int(from);
numbytes = rb_absint_numwords(from, 7, NULL);
if (numbytes == 0)
numbytes = 1;
buf = rb_str_new(NULL, numbytes);
sign = rb_integer_pack(from, RSTRING_PTR(buf), RSTRING_LEN(buf), 1, 1, INTEGER_PACK_BIG_ENDIAN);
if (sign < 0)
rb_raise(rb_eArgError, "can't compress negative numbers");
if (sign == 2)
rb_bug("buffer size problem?");
cp = RSTRING_PTR(buf);
while (1 < numbytes) {
*cp |= 0x80;
cp++;
numbytes--;
}
rb_str_buf_cat(res, RSTRING_PTR(buf), RSTRING_LEN(buf));
}
break;
default: {
char unknown[5];
if (ISPRINT(type)) {
unknown[0] = type;
unknown[1] = '\0';
}
else {
snprintf(unknown, sizeof(unknown), "\\x%.2x", type & 0xff);
}
rb_warning("unknown pack directive '%s' in '% "PRIsVALUE"'",
unknown, fmt);
break;
}
}
}
if (associates) {
str_associate(res, associates);
}
OBJ_INFECT(res, fmt);
switch (enc_info) {
case 1:
ENCODING_CODERANGE_SET(res, rb_usascii_encindex(), ENC_CODERANGE_7BIT);
break;
case 2:
rb_enc_set_index(res, rb_utf8_encindex());
break;
default:
/* do nothing, keep ASCII-8BIT */
break;
}
return res;
}
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