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91fb1c9b13
micropython/py/objstr.c
Paul Sokolovsky 91fb1c9b13 Add basic implementation of bytes type, piggybacking on str. 
This reuses as much str implementation as possible, from this we
can make them more separate as needed.
2014-01-24 22:56:26 +02:00

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#include <stdlib.h>
#include <stdint.h>
#include <stdarg.h>
#include <string.h>
#include <assert.h>
#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "runtime0.h"
#include "runtime.h"
typedef struct _mp_obj_str_t {
mp_obj_base_t base;
machine_uint_t hash : 16; // XXX here we assume the hash size is 16 bits (it is at the moment; see qstr.c)
machine_uint_t len : 16; // len == number of bytes used in data, alloc = len + 1 because (at the moment) we also append a null byte
byte data[];
} mp_obj_str_t;
// use this macro to extract the string hash
#define GET_STR_HASH(str_obj_in, str_hash) uint str_hash; if (MP_OBJ_IS_QSTR(str_obj_in)) { str_hash = qstr_hash(MP_OBJ_QSTR_VALUE(str_obj_in)); } else { str_hash = ((mp_obj_str_t*)str_obj_in)->hash; }
// use this macro to extract the string length
#define GET_STR_LEN(str_obj_in, str_len) uint str_len; if (MP_OBJ_IS_QSTR(str_obj_in)) { str_len = qstr_len(MP_OBJ_QSTR_VALUE(str_obj_in)); } else { str_len = ((mp_obj_str_t*)str_obj_in)->len; }
// use this macro to extract the string data and length
#define GET_STR_DATA_LEN(str_obj_in, str_data, str_len) const byte *str_data; uint str_len; if (MP_OBJ_IS_QSTR(str_obj_in)) { str_data = qstr_data(MP_OBJ_QSTR_VALUE(str_obj_in), &str_len); } else { str_len = ((mp_obj_str_t*)str_obj_in)->len; str_data = ((mp_obj_str_t*)str_obj_in)->data; }
static mp_obj_t mp_obj_new_str_iterator(mp_obj_t str);
static mp_obj_t mp_obj_new_bytes_iterator(mp_obj_t str);
/******************************************************************************/
/* str */
void str_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
GET_STR_DATA_LEN(self_in, str_data, str_len);
bool is_bytes = MP_OBJ_IS_TYPE(self_in, &bytes_type);
if (kind == PRINT_STR && !is_bytes) {
print(env, "%.*s", str_len, str_data);
} else {
if (is_bytes) {
print(env, "b");
}
// TODO need to escape chars etc
print(env, "'%.*s'", str_len, str_data);
}
}
// like strstr but with specified length and allows \0 bytes
// TODO replace with something more efficient/standard
static const byte *find_subbytes(const byte *haystack, uint hlen, const byte *needle, uint nlen) {
if (hlen >= nlen) {
for (uint i = 0; i <= hlen - nlen; i++) {
bool found = true;
for (uint j = 0; j < nlen; j++) {
if (haystack[i + j] != needle[j]) {
found = false;
break;
}
}
if (found) {
return haystack + i;
}
}
}
return NULL;
}
mp_obj_t str_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
GET_STR_DATA_LEN(lhs_in, lhs_data, lhs_len);
switch (op) {
case RT_BINARY_OP_SUBSCR:
// TODO: need predicate to check for int-like type (bools are such for example)
// ["no", "yes"][1 == 2] is common idiom
if (MP_OBJ_IS_SMALL_INT(rhs_in)) {
uint index = mp_get_index(mp_obj_get_type(lhs_in), lhs_len, rhs_in);
if (MP_OBJ_IS_TYPE(lhs_in, &bytes_type)) {
return MP_OBJ_NEW_SMALL_INT(lhs_data[index]);
} else {
return mp_obj_new_str(lhs_data + index, 1, true);
}
#if MICROPY_ENABLE_SLICE
} else if (MP_OBJ_IS_TYPE(rhs_in, &slice_type)) {
machine_int_t start, stop, step;
mp_obj_slice_get(rhs_in, &start, &stop, &step);
assert(step == 1);
if (start < 0) {
start = lhs_len + start;
if (start < 0) {
start = 0;
}
} else if (start > lhs_len) {
start = lhs_len;
}
if (stop <= 0) {
stop = lhs_len + stop;
// CPython returns empty string in such case
if (stop < 0) {
stop = start;
}
} else if (stop > lhs_len) {
stop = lhs_len;
}
return mp_obj_new_str(lhs_data + start, stop - start, false);
#endif
} else {
// Message doesn't match CPython, but we don't have so much bytes as they
// to spend them on verbose wording
nlr_jump(mp_obj_new_exception_msg(MP_QSTR_TypeError, "index must be int"));
}
case RT_BINARY_OP_ADD:
case RT_BINARY_OP_INPLACE_ADD:
if (MP_OBJ_IS_STR(rhs_in)) {
// add 2 strings
GET_STR_DATA_LEN(rhs_in, rhs_data, rhs_len);
int alloc_len = lhs_len + rhs_len;
/* code for making qstr
byte *q_ptr;
byte *val = qstr_build_start(alloc_len, &q_ptr);
memcpy(val, lhs_data, lhs_len);
memcpy(val + lhs_len, rhs_data, rhs_len);
return MP_OBJ_NEW_QSTR(qstr_build_end(q_ptr));
*/
// code for non-qstr
byte *data;
mp_obj_t s = mp_obj_str_builder_start(mp_obj_get_type(lhs_in), alloc_len, &data);
memcpy(data, lhs_data, lhs_len);
memcpy(data + lhs_len, rhs_data, rhs_len);
return mp_obj_str_builder_end(s);
}
break;
case RT_COMPARE_OP_IN:
case RT_COMPARE_OP_NOT_IN:
/* NOTE `a in b` is `b.__contains__(a)` */
if (MP_OBJ_IS_STR(rhs_in)) {
GET_STR_DATA_LEN(rhs_in, rhs_data, rhs_len);
return MP_BOOL((op == RT_COMPARE_OP_IN) ^ (find_subbytes(lhs_data, lhs_len, rhs_data, rhs_len) == NULL));
}
break;
case RT_BINARY_OP_MULTIPLY:
{
if (!MP_OBJ_IS_SMALL_INT(rhs_in)) {
return NULL;
}
int n = MP_OBJ_SMALL_INT_VALUE(rhs_in);
byte *data;
mp_obj_t s = mp_obj_str_builder_start(mp_obj_get_type(lhs_in), lhs_len * n, &data);
mp_seq_multiply(lhs_data, sizeof(*lhs_data), lhs_len, n, data);
return mp_obj_str_builder_end(s);
}
}
return MP_OBJ_NULL; // op not supported
}
mp_obj_t str_join(mp_obj_t self_in, mp_obj_t arg) {
assert(MP_OBJ_IS_STR(self_in));
// get separation string
GET_STR_DATA_LEN(self_in, sep_str, sep_len);
// process args
uint seq_len;
mp_obj_t *seq_items;
if (MP_OBJ_IS_TYPE(arg, &tuple_type)) {
mp_obj_tuple_get(arg, &seq_len, &seq_items);
} else if (MP_OBJ_IS_TYPE(arg, &list_type)) {
mp_obj_list_get(arg, &seq_len, &seq_items);
} else {
goto bad_arg;
}
// count required length
int required_len = 0;
for (int i = 0; i < seq_len; i++) {
if (!MP_OBJ_IS_STR(seq_items[i])) {
goto bad_arg;
}
if (i > 0) {
required_len += sep_len;
}
GET_STR_LEN(seq_items[i], l);
required_len += l;
}
// make joined string
byte *data;
mp_obj_t joined_str = mp_obj_str_builder_start(mp_obj_get_type(self_in), required_len, &data);
for (int i = 0; i < seq_len; i++) {
if (i > 0) {
memcpy(data, sep_str, sep_len);
data += sep_len;
}
GET_STR_DATA_LEN(seq_items[i], s, l);
memcpy(data, s, l);
data += l;
}
// return joined string
return mp_obj_str_builder_end(joined_str);
bad_arg:
nlr_jump(mp_obj_new_exception_msg(MP_QSTR_TypeError, "?str.join expecting a list of str's"));
}
#define is_ws(c) ((c) == ' ' || (c) == '\t')
static mp_obj_t str_split(uint n_args, const mp_obj_t *args) {
int splits = -1;
mp_obj_t sep = mp_const_none;
if (n_args > 1) {
sep = args[1];
if (n_args > 2) {
splits = MP_OBJ_SMALL_INT_VALUE(args[2]);
}
}
assert(sep == mp_const_none);
(void)sep; // unused; to hush compiler warning
mp_obj_t res = mp_obj_new_list(0, NULL);
GET_STR_DATA_LEN(args[0], s, len);
const byte *top = s + len;
const byte *start;
// Initial whitespace is not counted as split, so we pre-do it
while (s < top && is_ws(*s)) s++;
while (s < top && splits != 0) {
start = s;
while (s < top && !is_ws(*s)) s++;
rt_list_append(res, mp_obj_new_str(start, s - start, false));
if (s >= top) {
break;
}
while (s < top && is_ws(*s)) s++;
if (splits > 0) {
splits--;
}
}
if (s < top) {
rt_list_append(res, mp_obj_new_str(s, top - s, false));
}
return res;
}
static mp_obj_t str_find(uint n_args, const mp_obj_t *args) {
assert(2 <= n_args && n_args <= 4);
assert(MP_OBJ_IS_STR(args[0]));
assert(MP_OBJ_IS_STR(args[1]));
GET_STR_DATA_LEN(args[0], haystack, haystack_len);
GET_STR_DATA_LEN(args[1], needle, needle_len);
size_t start = 0;
size_t end = haystack_len;
/* TODO use a non-exception-throwing mp_get_index */
if (n_args >= 3 && args[2] != mp_const_none) {
start = mp_get_index(&str_type, haystack_len, args[2]);
}
if (n_args >= 4 && args[3] != mp_const_none) {
end = mp_get_index(&str_type, haystack_len, args[3]);
}
const byte *p = find_subbytes(haystack + start, haystack_len - start, needle, needle_len);
if (p == NULL) {
// not found
return MP_OBJ_NEW_SMALL_INT(-1);
} else {
// found
machine_int_t pos = p - haystack;
if (pos + needle_len > end) {
pos = -1;
}
return MP_OBJ_NEW_SMALL_INT(pos);
}
}
// TODO: (Much) more variety in args
static mp_obj_t str_startswith(mp_obj_t self_in, mp_obj_t arg) {
GET_STR_DATA_LEN(self_in, str, str_len);
GET_STR_DATA_LEN(arg, prefix, prefix_len);
if (prefix_len > str_len) {
return mp_const_false;
}
return MP_BOOL(memcmp(str, prefix, prefix_len) == 0);
}
static bool chr_in_str(const byte* const str, const size_t str_len, int c) {
for (size_t i = 0; i < str_len; i++) {
if (str[i] == c) {
return true;
}
}
return false;
}
mp_obj_t str_strip(uint n_args, const mp_obj_t *args) {
assert(1 <= n_args && n_args <= 2);
assert(MP_OBJ_IS_STR(args[0]));
const byte *chars_to_del;
uint chars_to_del_len;
static const byte whitespace[] = " \t\n\r\v\f";
if (n_args == 1) {
chars_to_del = whitespace;
chars_to_del_len = sizeof(whitespace);
} else {
assert(MP_OBJ_IS_STR(args[1]));
GET_STR_DATA_LEN(args[1], s, l);
chars_to_del = s;
chars_to_del_len = l;
}
GET_STR_DATA_LEN(args[0], orig_str, orig_str_len);
size_t first_good_char_pos = 0;
bool first_good_char_pos_set = false;
size_t last_good_char_pos = 0;
for (size_t i = 0; i < orig_str_len; i++) {
if (!chr_in_str(chars_to_del, chars_to_del_len, orig_str[i])) {
last_good_char_pos = i;
if (!first_good_char_pos_set) {
first_good_char_pos = i;
first_good_char_pos_set = true;
}
}
}
if (first_good_char_pos == 0 && last_good_char_pos == 0) {
// string is all whitespace, return ''
return MP_OBJ_NEW_QSTR(MP_QSTR_);
}
assert(last_good_char_pos >= first_good_char_pos);
//+1 to accomodate the last character
size_t stripped_len = last_good_char_pos - first_good_char_pos + 1;
return mp_obj_new_str(orig_str + first_good_char_pos, stripped_len, false);
}
mp_obj_t str_format(uint n_args, const mp_obj_t *args) {
assert(MP_OBJ_IS_STR(args[0]));
GET_STR_DATA_LEN(args[0], str, len);
int arg_i = 1;
vstr_t *vstr = vstr_new();
for (const byte *top = str + len; str < top; str++) {
if (*str == '{') {
str++;
if (str < top && *str == '{') {
vstr_add_char(vstr, '{');
} else {
while (str < top && *str != '}') str++;
if (arg_i >= n_args) {
nlr_jump(mp_obj_new_exception_msg(MP_QSTR_IndexError, "tuple index out of range"));
}
// TODO: may be PRINT_REPR depending on formatting code
mp_obj_print_helper((void (*)(void*, const char*, ...))vstr_printf, vstr, args[arg_i], PRINT_STR);
arg_i++;
}
} else {
vstr_add_char(vstr, *str);
}
}
mp_obj_t s = mp_obj_new_str((byte*)vstr->buf, vstr->len, false);
vstr_free(vstr);
return s;
}
static MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_find_obj, 2, 4, str_find);
static MP_DEFINE_CONST_FUN_OBJ_2(str_join_obj, str_join);
static MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_split_obj, 1, 3, str_split);
static MP_DEFINE_CONST_FUN_OBJ_2(str_startswith_obj, str_startswith);
static MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_strip_obj, 1, 2, str_strip);
static MP_DEFINE_CONST_FUN_OBJ_VAR(str_format_obj, 1, str_format);
static const mp_method_t str_type_methods[] = {
{ "find", &str_find_obj },
{ "join", &str_join_obj },
{ "split", &str_split_obj },
{ "startswith", &str_startswith_obj },
{ "strip", &str_strip_obj },
{ "format", &str_format_obj },
{ NULL, NULL }, // end-of-list sentinel
};
const mp_obj_type_t str_type = {
{ &mp_const_type },
"str",
.print = str_print,
.binary_op = str_binary_op,
.getiter = mp_obj_new_str_iterator,
.methods = str_type_methods,
};
// Reuses most of methods from str
const mp_obj_type_t bytes_type = {
{ &mp_const_type },
"bytes",
.print = str_print,
.binary_op = str_binary_op,
.getiter = mp_obj_new_bytes_iterator,
.methods = str_type_methods,
};
mp_obj_t mp_obj_str_builder_start(const mp_obj_type_t *type, uint len, byte **data) {
mp_obj_str_t *o = m_new_obj_var(mp_obj_str_t, byte, len + 1);
o->base.type = type;
o->len = len;
*data = o->data;
return o;
}
mp_obj_t mp_obj_str_builder_end(mp_obj_t o_in) {
assert(MP_OBJ_IS_STR(o_in));
mp_obj_str_t *o = o_in;
o->hash = qstr_compute_hash(o->data, o->len);
o->data[o->len] = '\0'; // for now we add null for compatibility with C ASCIIZ strings
return o;
}
static mp_obj_t str_new(const mp_obj_type_t *type, const byte* data, uint len) {
mp_obj_str_t *o = m_new_obj_var(mp_obj_str_t, byte, len + 1);
o->base.type = type;
o->hash = qstr_compute_hash(data, len);
o->len = len;
memcpy(o->data, data, len * sizeof(byte));
o->data[len] = '\0'; // for now we add null for compatibility with C ASCIIZ strings
return o;
}
mp_obj_t mp_obj_new_str(const byte* data, uint len, bool make_qstr_if_not_already) {
qstr q = qstr_find_strn(data, len);
if (q != MP_QSTR_NULL) {
// qstr with this data already exists
return MP_OBJ_NEW_QSTR(q);
} else if (make_qstr_if_not_already) {
// no existing qstr, make a new one
return MP_OBJ_NEW_QSTR(qstr_from_strn((const char*)data, len));
} else {
// no existing qstr, don't make one
return str_new(&str_type, data, len);
}
}
mp_obj_t mp_obj_new_bytes(const byte* data, uint len) {
return str_new(&bytes_type, data, len);
}
bool mp_obj_str_equal(mp_obj_t s1, mp_obj_t s2) {
if (MP_OBJ_IS_QSTR(s1) && MP_OBJ_IS_QSTR(s2)) {
return s1 == s2;
} else {
GET_STR_HASH(s1, h1);
GET_STR_HASH(s2, h2);
if (h1 != h2) {
return false;
}
GET_STR_DATA_LEN(s1, d1, l1);
GET_STR_DATA_LEN(s2, d2, l2);
if (l1 != l2) {
return false;
}
return memcmp(d1, d2, l1) == 0;
}
}
uint mp_obj_str_get_hash(mp_obj_t self_in) {
if (MP_OBJ_IS_STR(self_in)) {
GET_STR_HASH(self_in, h);
return h;
} else {
nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_TypeError, "Can't convert '%s' object to str implicitly",
mp_obj_get_type_str(self_in)));
}
}
uint mp_obj_str_get_len(mp_obj_t self_in) {
if (MP_OBJ_IS_STR(self_in)) {
GET_STR_LEN(self_in, l);
return l;
} else {
nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_TypeError, "Can't convert '%s' object to str implicitly",
mp_obj_get_type_str(self_in)));
}
}
// only use this function if you need the str data to be zero terminated
// at the moment all strings are zero terminated to help with C ASCIIZ compatibility
const char *mp_obj_str_get_str(mp_obj_t self_in) {
if (MP_OBJ_IS_STR(self_in)) {
GET_STR_DATA_LEN(self_in, s, l);
(void)l; // len unused
return (const char*)s;
} else {
nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_TypeError, "Can't convert '%s' object to str implicitly",
mp_obj_get_type_str(self_in)));
}
}
const byte *mp_obj_str_get_data(mp_obj_t self_in, uint *len) {
if (MP_OBJ_IS_STR(self_in)) {
GET_STR_DATA_LEN(self_in, s, l);
*len = l;
return s;
} else {
nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_TypeError, "Can't convert '%s' object to str implicitly",
mp_obj_get_type_str(self_in)));
}
}
/******************************************************************************/
/* str iterator */
typedef struct _mp_obj_str_it_t {
mp_obj_base_t base;
mp_obj_t str;
machine_uint_t cur;
} mp_obj_str_it_t;
mp_obj_t str_it_iternext(mp_obj_t self_in) {
mp_obj_str_it_t *self = self_in;
GET_STR_DATA_LEN(self->str, str, len);
if (self->cur < len) {
mp_obj_t o_out = mp_obj_new_str(str + self->cur, 1, true);
self->cur += 1;
return o_out;
} else {
return mp_const_stop_iteration;
}
}
static const mp_obj_type_t str_it_type = {
{ &mp_const_type },
"str_iterator",
.iternext = str_it_iternext,
};
mp_obj_t bytes_it_iternext(mp_obj_t self_in) {
mp_obj_str_it_t *self = self_in;
GET_STR_DATA_LEN(self->str, str, len);
if (self->cur < len) {
mp_obj_t o_out = MP_OBJ_NEW_SMALL_INT(str[self->cur]);
self->cur += 1;
return o_out;
} else {
return mp_const_stop_iteration;
}
}
static const mp_obj_type_t bytes_it_type = {
{ &mp_const_type },
"bytes_iterator",
.iternext = bytes_it_iternext,
};
mp_obj_t mp_obj_new_str_iterator(mp_obj_t str) {
mp_obj_str_it_t *o = m_new_obj(mp_obj_str_it_t);
o->base.type = &str_it_type;
o->str = str;
o->cur = 0;
return o;
}
mp_obj_t mp_obj_new_bytes_iterator(mp_obj_t str) {
mp_obj_str_it_t *o = m_new_obj(mp_obj_str_it_t);
o->base.type = &bytes_it_type;
o->str = str;
o->cur = 0;
return o;
}
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