Commit 6582d64d authored by Paul Sokolovsky's avatar Paul Sokolovsky
Browse files

modstruct: Refactor to support both LE and BE packed structs.

parent 2b9419b5
......@@ -77,50 +77,48 @@ mp_obj_t mp_binary_get_val(char typecode, void *p, int index) {
return MP_OBJ_NEW_SMALL_INT(val);
}
mp_obj_t mp_binary_get_val_unaligned_le(char typecode, byte **ptr) {
machine_int_t val = 0;
#define is_signed(typecode) (typecode > 'Z')
mp_obj_t mp_binary_get_val_unaligned(char typecode, byte **ptr) {
char type = '<';
byte *p = *ptr;
switch (typecode) {
case 'b':
val = (int8_t)*p++;
break;
case BYTEARRAY_TYPECODE:
case 'B':
val = *p++;
break;
case 'h':
val = (int16_t)((p[1] << 8) | p[0]);
break;
case 'H':
val = (p[1] << 8) | p[0];
uint size = 0, align = 0;
switch (type) {
case '<': case '>':
switch (typecode) {
case 'b': case 'B':
size = 1; break;
case 'h': case 'H':
size = 2; break;
case 'i': case 'I':
size = 4; break;
}
break;
case 'i':
case 'l':
val = (p[3] << 24) | (p[2] << 16) | (p[1] << 8) | p[0];
*ptr = p + 4;
return mp_obj_new_int(val);
case 'I':
case 'L':
val = (p[3] << 24) | (p[2] << 16) | (p[1] << 8) | p[0];
*ptr = p + 4;
return mp_obj_new_int_from_uint(val);
#if 0 //TODO
#if MICROPY_LONGINT_IMPL != MICROPY_LONGINT_IMPL_NONE
case 'q':
case 'Q':
// TODO: Explode API more to cover signedness
return mp_obj_new_int_from_ll(((long long*)p)[index]);
#endif
#if MICROPY_ENABLE_FLOAT
case 'f':
return mp_obj_new_float(((float*)p)[index]);
case 'd':
return mp_obj_new_float(((double*)p)[index]);
#endif
#endif
}
*ptr = p;
return MP_OBJ_NEW_SMALL_INT(val);
int delta;
if (type == '<') {
delta = -1;
p += size - 1;
} else {
delta = 1;
}
machine_int_t val = 0;
if (is_signed(typecode) && *p & 0x80) {
val = -1;
}
for (uint i = 0; i < size; i++) {
val <<= 8;
val |= *p;
p += delta;
}
*ptr += size + align;
if (is_signed(typecode)) {
return mp_obj_new_int(val);
} else {
return mp_obj_new_int_from_uint(val);
}
}
void mp_binary_set_val(char typecode, void *p, int index, mp_obj_t val_in) {
......
......@@ -4,5 +4,5 @@
int mp_binary_get_size(char typecode);
mp_obj_t mp_binary_get_val(char typecode, void *p, int index);
mp_obj_t mp_binary_get_val_unaligned_le(char typecode, byte **ptr);
mp_obj_t mp_binary_get_val_unaligned(char typecode, byte **ptr);
void mp_binary_set_val(char typecode, void *p, int index, mp_obj_t val_in);
......@@ -37,7 +37,7 @@ STATIC uint calcsize_items(const char *fmt) {
STATIC mp_obj_t struct_calcsize(mp_obj_t fmt_in) {
const char *fmt = mp_obj_str_get_str(fmt_in);
char fmt_type = get_fmt_type(&fmt);
assert(fmt_type == '<'); (void)fmt_type;
assert(fmt_type == '<' || fmt_type == '>'); (void)fmt_type;
machine_uint_t size;
for (size = 0; *fmt; fmt++) {
int sz = mp_binary_get_size(*fmt);
......@@ -53,7 +53,7 @@ STATIC mp_obj_t struct_unpack(mp_obj_t fmt_in, mp_obj_t data_in) {
// TODO: "The buffer must contain exactly the amount of data required by the format (len(bytes) must equal calcsize(fmt))."
const char *fmt = mp_obj_str_get_str(fmt_in);
char fmt_type = get_fmt_type(&fmt);
assert(fmt_type == '<'); (void)fmt_type;
assert(fmt_type == '<' || fmt_type == '>'); (void)fmt_type;
uint size = calcsize_items(fmt);
mp_obj_tuple_t *res = mp_obj_new_tuple(size, NULL);
buffer_info_t bufinfo;
......@@ -61,7 +61,7 @@ STATIC mp_obj_t struct_unpack(mp_obj_t fmt_in, mp_obj_t data_in) {
byte *p = bufinfo.buf;
for (uint i = 0; i < size; i++) {
mp_obj_t item = mp_binary_get_val_unaligned_le(*fmt++, &p);
mp_obj_t item = mp_binary_get_val_unaligned(*fmt++, &p);
res->items[i] = item;
}
return res;
......
import struct
print(struct.calcsize("<bI"))
print(struct.unpack("<bI", b"\x80\0\0\x01\0"))
print(struct.calcsize(">bI"))
print(struct.unpack(">bI", b"\x80\0\0\x01\0"))
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