Commit df94b717 authored by Paul Sokolovsky's avatar Paul Sokolovsky
Browse files

modstruct: Implement count specifier for strings (e.g. "100s").

Infra for counts of other types is there, need last mile to be implemented.
parent 147c80bf
......@@ -34,6 +34,7 @@
#include "objtuple.h"
#include "objstr.h"
#include "binary.h"
#include "parsenum.h"
#if MICROPY_ENABLE_MOD_STRUCT
......@@ -56,9 +57,26 @@ STATIC char get_fmt_type(const char **fmt) {
return t;
}
STATIC machine_uint_t get_fmt_num(const char **p) {
const char *num = *p;
uint len = 1;
while (unichar_isdigit(*++num)) {
len++;
}
machine_uint_t val = (machine_uint_t)MP_OBJ_SMALL_INT_VALUE(mp_parse_num_integer(*p, len, 10));
*p = num;
return val;
}
STATIC uint calcsize_items(const char *fmt) {
// TODO
return strlen(fmt);
uint cnt = 0;
while (*fmt) {
// TODO supports size spec only for "s"
if (!unichar_isdigit(*fmt++)) {
cnt++;
}
}
return cnt;
}
STATIC mp_obj_t struct_calcsize(mp_obj_t fmt_in) {
......@@ -67,9 +85,23 @@ STATIC mp_obj_t struct_calcsize(mp_obj_t fmt_in) {
machine_uint_t size;
for (size = 0; *fmt; fmt++) {
uint align;
int sz = mp_binary_get_size(fmt_type, *fmt, &align);
machine_uint_t cnt = 1;
if (unichar_isdigit(*fmt)) {
cnt = get_fmt_num(&fmt);
}
if (cnt > 1) {
// TODO: count spec support only for string len
assert(*fmt == 's');
}
machine_uint_t sz;
if (*fmt == 's') {
sz = cnt;
} else {
sz = (machine_uint_t)mp_binary_get_size(fmt_type, *fmt, &align);
}
// TODO
assert(sz != -1);
assert(sz != (machine_uint_t)-1);
// Apply alignment
size = (size + align - 1) & ~(align - 1);
size += sz;
......@@ -89,7 +121,22 @@ 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(fmt_type, *fmt++, &p);
machine_uint_t sz = 1;
if (unichar_isdigit(*fmt)) {
sz = get_fmt_num(&fmt);
}
if (sz > 1) {
// TODO: size spec support only for string len
assert(*fmt == 's');
}
mp_obj_t item;
if (*fmt == 's') {
item = mp_obj_new_bytes(p, sz);
p += sz;
fmt++;
} else {
item = mp_binary_get_val(fmt_type, *fmt++, &p);
}
res->items[i] = item;
}
return res;
......@@ -106,7 +153,29 @@ STATIC mp_obj_t struct_pack(uint n_args, mp_obj_t *args) {
memset(p, 0, size);
for (uint i = 1; i < n_args; i++) {
mp_binary_set_val(fmt_type, *fmt++, args[i], &p);
machine_uint_t sz = 1;
if (unichar_isdigit(*fmt)) {
sz = get_fmt_num(&fmt);
}
if (sz > 1) {
// TODO: size spec support only for string len
assert(*fmt == 's');
}
if (*fmt == 's') {
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[i], &bufinfo, MP_BUFFER_READ);
machine_uint_t to_copy = sz;
if (bufinfo.len < to_copy) {
to_copy = bufinfo.len;
}
memcpy(p, bufinfo.buf, to_copy);
memset(p + to_copy, 0, sz - to_copy);
p += sz;
fmt++;
} else {
mp_binary_set_val(fmt_type, *fmt++, args[i], &p);
}
}
return res;
}
......
......@@ -16,3 +16,8 @@ print(struct.pack(">b", 1))
print(struct.pack("<bI", -128, 256))
print(struct.pack(">bI", -128, 256))
print(struct.calcsize("100sI"))
print(struct.calcsize("97sI"))
print(struct.unpack("<6sH", b"foo\0\0\0\x12\x34"))
print(struct.pack("<6sH", b"foo", 10000))
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