circuitpython/py/stream.c

98 lines
3.5 KiB
C

#include <string.h>
#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "mpqstr.h"
#include "obj.h"
#include "stream.h"
// This file defines generic Python stream read/write methods which
// dispatch to the underlying stream interface of an object.
static mp_obj_t stream_read(mp_obj_t self_in, mp_obj_t arg) {
struct _mp_obj_base_t *o = (struct _mp_obj_base_t *)self_in;
if (o->type->stream_p.read == NULL) {
// CPython: io.UnsupportedOperation, OSError subclass
nlr_jump(mp_obj_new_exception_msg(MP_QSTR_OSError, "Operation not supported"));
}
machine_int_t sz = mp_obj_get_int(arg);
// +1 because so far we mark end of string with \0
char *buf = m_new(char, sz + 1);
int error;
machine_int_t out_sz = o->type->stream_p.read(self_in, buf, sz, &error);
if (out_sz == -1) {
nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_OSError, "[Errno %d]", error));
} else {
buf[out_sz] = 0;
return mp_obj_new_str(qstr_from_str_take(buf, /*out_sz,*/ sz + 1));
}
}
static mp_obj_t stream_write(mp_obj_t self_in, mp_obj_t arg) {
struct _mp_obj_base_t *o = (struct _mp_obj_base_t *)self_in;
if (o->type->stream_p.write == NULL) {
// CPython: io.UnsupportedOperation, OSError subclass
nlr_jump(mp_obj_new_exception_msg(MP_QSTR_OSError, "Operation not supported"));
}
const char *buf = qstr_str(mp_obj_get_qstr(arg));
machine_int_t sz = strlen(buf);
int error;
machine_int_t out_sz = o->type->stream_p.write(self_in, buf, sz, &error);
if (out_sz == -1) {
nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_OSError, "[Errno %d]", error));
} else {
// http://docs.python.org/3/library/io.html#io.RawIOBase.write
// "None is returned if the raw stream is set not to block and no single byte could be readily written to it."
// Do they mean that instead of 0 they return None?
return MP_OBJ_NEW_SMALL_INT(out_sz);
}
}
// TODO: should be in mpconfig.h
#define READ_SIZE 256
static mp_obj_t stream_readall(mp_obj_t self_in) {
struct _mp_obj_base_t *o = (struct _mp_obj_base_t *)self_in;
if (o->type->stream_p.read == NULL) {
// CPython: io.UnsupportedOperation, OSError subclass
nlr_jump(mp_obj_new_exception_msg(MP_QSTR_OSError, "Operation not supported"));
}
int total_size = 0;
vstr_t *vstr = vstr_new_size(READ_SIZE);
char *buf = vstr_str(vstr);
char *p = buf;
int error;
int current_read = READ_SIZE;
while (true) {
machine_int_t out_sz = o->type->stream_p.read(self_in, p, current_read, &error);
if (out_sz == -1) {
nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_OSError, "[Errno %d]", error));
}
if (out_sz == 0) {
break;
}
total_size += out_sz;
if (out_sz < current_read) {
current_read -= out_sz;
p += out_sz;
} else {
current_read = READ_SIZE;
p = vstr_extend(vstr, current_read);
if (p == NULL) {
// TODO
nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_OSError/*MP_QSTR_RuntimeError*/, "Out of memory"));
}
}
}
vstr_set_size(vstr, total_size + 1); // TODO: for \0
buf[total_size] = 0;
return mp_obj_new_str(qstr_from_str_take(buf, total_size + 1));
}
MP_DEFINE_CONST_FUN_OBJ_2(mp_stream_read_obj, stream_read);
MP_DEFINE_CONST_FUN_OBJ_1(mp_stream_readall_obj, stream_readall);
MP_DEFINE_CONST_FUN_OBJ_2(mp_stream_write_obj, stream_write);