Commit 2c070110 authored by Damien George's avatar Damien George
Browse files

Merge pull request #759 from micropython/unicode-read-chars

py: Add stream reading of n unicode chars; unicode support by default.
parents 02bc882c 1694bc73
......@@ -67,6 +67,9 @@ STATIC mp_obj_t stream_read(uint n_args, const mp_obj_t *args) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "Operation not supported"));
}
// What to do if sz < -1? Python docs don't specify this case.
// CPython does a readall, but here we silently let negatives through,
// and they will cause a MemoryError.
mp_int_t sz;
if (n_args == 1 || ((sz = mp_obj_get_int(args[1])) == -1)) {
return stream_readall(args[0]);
......@@ -74,7 +77,90 @@ STATIC mp_obj_t stream_read(uint n_args, const mp_obj_t *args) {
#if MICROPY_PY_BUILTINS_STR_UNICODE
if (!o->type->stream_p->is_bytes) {
mp_not_implemented("Reading from unicode text streams by character count");
// We need to read sz number of unicode characters. Because we don't have any
// buffering, and because the stream API can only read bytes, we must read here
// in units of bytes and must never over read. If we want sz chars, then reading
// sz bytes will never over-read, so we follow this approach, in a loop to keep
// reading until we have exactly enough chars. This will be 1 read for text
// with ASCII-only chars, and about 2 reads for text with a couple of non-ASCII
// chars. For text with lots of non-ASCII chars, it'll be pretty inefficient
// in time and memory.
vstr_t vstr;
vstr_init(&vstr, sz);
mp_uint_t more_bytes = sz;
mp_uint_t last_buf_offset = 0;
while (more_bytes > 0) {
char *p = vstr_add_len(&vstr, more_bytes);
if (p == NULL) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_MemoryError, "out of memory"));
}
int error;
mp_int_t out_sz = o->type->stream_p->read(o, p, more_bytes, &error);
if (out_sz == -1) {
vstr_cut_tail_bytes(&vstr, more_bytes);
if (is_nonblocking_error(error)) {
// With non-blocking streams, we read as much as we can.
// If we read nothing, return None, just like read().
// Otherwise, return data read so far.
// TODO what if we have read only half a non-ASCII char?
if (vstr.len == 0) {
vstr_clear(&vstr);
return mp_const_none;
}
break;
}
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_OSError, "[Errno %d]", error));
}
if (out_sz == 0) {
// Finish reading.
// TODO what if we have read only half a non-ASCII char?
vstr_cut_tail_bytes(&vstr, more_bytes);
break;
}
// count chars from bytes just read
for (mp_uint_t off = last_buf_offset;;) {
byte b = vstr.buf[off];
int n;
if (!UTF8_IS_NONASCII(b)) {
// 1-byte ASCII char
n = 1;
} else if ((b & 0xe0) == 0xc0) {
// 2-byte char
n = 2;
} else if ((b & 0xf0) == 0xe0) {
// 3-byte char
n = 3;
} else if ((b & 0xf8) == 0xf0) {
// 4-byte char
n = 4;
} else {
// TODO
n = 5;
}
if (off + n <= vstr.len) {
// got a whole char in n bytes
off += n;
sz -= 1;
last_buf_offset = off;
if (off >= vstr.len) {
more_bytes = sz;
break;
}
} else {
// didn't get a whole char, so work out how many extra bytes are needed for
// this partial char, plus bytes for additional chars that we want
more_bytes = (off + n - vstr.len) + (sz - 1);
break;
}
}
}
mp_obj_t ret = mp_obj_new_str_of_type(&mp_type_str, (byte*)vstr.buf, vstr.len);
vstr_clear(&vstr);
return ret;
}
#endif
......
......@@ -44,7 +44,7 @@
*/
#define MICROPY_ENABLE_LFN (1)
#define MICROPY_LFN_CODE_PAGE (437) /* 1=SFN/ANSI 437=LFN/U.S.(OEM) */
#define MICROPY_PY_BUILTINS_STR_UNICODE (0)
#define MICROPY_PY_BUILTINS_STR_UNICODE (1)
#define MICROPY_PY_BUILTINS_FROZENSET (1)
#define MICROPY_PY_SYS_EXIT (1)
#define MICROPY_PY_SYS_STDFILES (1)
......
......@@ -134,7 +134,7 @@ def main():
if args.test_dirs is None:
if pyb is None:
# run PC tests
test_dirs = ('basics', 'micropython', 'float', 'import', 'io', 'misc')
test_dirs = ('basics', 'micropython', 'float', 'import', 'io', 'misc', 'unicode')
else:
# run pyboard tests
test_dirs = ('basics', 'micropython', 'float', 'pyb', 'pybnative', 'inlineasm')
......
# test reading a given number of characters
def do(mode):
f = open('unicode/data/utf-8_2.txt', mode)
print(f.read(1))
print(f.read(1))
print(f.read(2))
print(f.read(4))
f.close()
do('rb')
do('rt')
......@@ -43,7 +43,7 @@
#define MICROPY_LONGINT_IMPL (MICROPY_LONGINT_IMPL_MPZ)
#define MICROPY_STREAMS_NON_BLOCK (1)
#define MICROPY_OPT_COMPUTED_GOTO (1)
#define MICROPY_PY_BUILTINS_STR_UNICODE (0)
#define MICROPY_PY_BUILTINS_STR_UNICODE (1)
#define MICROPY_PY_BUILTINS_FROZENSET (1)
#define MICROPY_PY_SYS_EXIT (1)
#define MICROPY_PY_SYS_PLATFORM "linux"
......
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