add circuitpython code

1 files changed, 583 insertions, 0 deletions

diff --git a/circuitpython/py/stream.c b/circuitpython/py/stream.c
new file mode 100644
index 0000000..b12d693
--- /dev/null
+++ b/circuitpython/py/stream.c
@@ -0,0 +1,583 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * SPDX-FileCopyrightText: Copyright (c) 2014 Damien P. George
+ * SPDX-FileCopyrightText: Copyright (c) 2014-2016 Paul Sokolovsky
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <unistd.h>
+
+#include "py/objstr.h"
+#include "py/stream.h"
+#include "py/runtime.h"
+#include "supervisor/shared/translate.h"
+
+// This file defines generic Python stream read/write methods which
+// dispatch to the underlying stream interface of an object.
+
+// TODO: should be in mpconfig.h
+#define DEFAULT_BUFFER_SIZE 256
+
+STATIC mp_obj_t stream_readall(mp_obj_t self_in);
+
+#define STREAM_CONTENT_TYPE(stream) (((stream)->is_text) ? &mp_type_str : &mp_type_bytes)
+
+// Returns error condition in *errcode, if non-zero, return value is number of bytes written
+// before error condition occurred. If *errcode == 0, returns total bytes written (which will
+// be equal to input size).
+mp_uint_t mp_stream_rw(mp_obj_t stream, void *buf_, mp_uint_t size, int *errcode, byte flags) {
+    byte *buf = buf_;
+    typedef mp_uint_t (*io_func_t)(mp_obj_t obj, void *buf, mp_uint_t size, int *errcode);
+    io_func_t io_func;
+    const mp_stream_p_t *stream_p = mp_get_stream(stream);
+    if (flags & MP_STREAM_RW_WRITE) {
+        io_func = (io_func_t)stream_p->write;
+    } else {
+        io_func = stream_p->read;
+    }
+
+    *errcode = 0;
+    mp_uint_t done = 0;
+    while (size > 0) {
+        mp_uint_t out_sz = io_func(stream, buf, size, errcode);
+        // For read, out_sz == 0 means EOF. For write, it's unspecified
+        // what it means, but we don't make any progress, so returning
+        // is still the best option.
+        if (out_sz == 0) {
+            return done;
+        }
+        if (out_sz == MP_STREAM_ERROR) {
+            // If we read something before getting EAGAIN, don't leak it
+            if (mp_is_nonblocking_error(*errcode) && done != 0) {
+                *errcode = 0;
+            }
+            return done;
+        }
+        if (flags & MP_STREAM_RW_ONCE) {
+            return out_sz;
+        }
+
+        buf += out_sz;
+        size -= out_sz;
+        done += out_sz;
+    }
+    return done;
+}
+
+const mp_stream_p_t *mp_get_stream(mp_const_obj_t self) {
+    return mp_proto_get(MP_QSTR_protocol_stream, self);
+}
+
+const mp_stream_p_t *mp_get_stream_raise(mp_obj_t self_in, int flags) {
+    const mp_stream_p_t *stream_p = mp_proto_get(MP_QSTR_protocol_stream, self_in);
+    if (stream_p == NULL
+        || ((flags & MP_STREAM_OP_READ) && stream_p->read == NULL)
+        || ((flags & MP_STREAM_OP_WRITE) && stream_p->write == NULL)
+        || ((flags & MP_STREAM_OP_IOCTL) && stream_p->ioctl == NULL)) {
+        // CPython: io.UnsupportedOperation, OSError subclass
+        mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("stream operation not supported"));
+    }
+    return stream_p;
+}
+
+STATIC mp_obj_t stream_read_generic(size_t n_args, const mp_obj_t *args, byte flags) {
+    // What to do if sz < -1?  Python docs don't specify this case.
+    // CPython does a readall, let's do the same.
+    mp_int_t sz;
+    const mp_stream_p_t *stream_p = mp_get_stream(args[0]);
+    if (stream_p->pyserial_read_compatibility) {
+        // Pyserial defaults to sz=1 if not specified.
+        if (n_args == 1) {
+            sz = 1;
+        } else {
+            // Pyserial treats negative size as 0.
+            sz = MAX(0, mp_obj_get_int(args[1]));
+        }
+    } else {
+        if (n_args == 1 || args[1] == mp_const_none || (sz = mp_obj_get_int(args[1])) <= -1) {
+            return stream_readall(args[0]);
+        }
+    }
+
+    #if MICROPY_PY_BUILTINS_STR_UNICODE
+    if (stream_p->is_text) {
+        // 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);
+            int error;
+            mp_uint_t out_sz = mp_stream_read_exactly(args[0], p, more_bytes, &error);
+            if (error != 0) {
+                vstr_cut_tail_bytes(&vstr, more_bytes);
+                if (mp_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;
+                }
+                mp_raise_OSError(error);
+            }
+
+            if (out_sz < more_bytes) {
+                // Finish reading.
+                // TODO what if we have read only half a non-ASCII char?
+                vstr_cut_tail_bytes(&vstr, more_bytes - out_sz);
+                if (out_sz == 0) {
+                    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;
+                }
+            }
+        }
+
+        return mp_obj_new_str_from_vstr(&mp_type_str, &vstr);
+    }
+    #endif
+
+    vstr_t vstr;
+    vstr_init_len(&vstr, sz);
+    int error;
+    mp_uint_t out_sz = mp_stream_rw(args[0], vstr.buf, sz, &error, flags);
+    if (error != 0) {
+        vstr_clear(&vstr);
+        if (mp_is_nonblocking_error(error)) {
+            // https://docs.python.org/3.4/library/io.html#io.RawIOBase.read
+            // "If the object is in non-blocking mode and no bytes are available,
+            // None is returned."
+            // This is actually very weird, as naive truth check will treat
+            // this as EOF.
+            return mp_const_none;
+        }
+        mp_raise_OSError(error);
+    } else {
+        vstr.len = out_sz;
+        return mp_obj_new_str_from_vstr(STREAM_CONTENT_TYPE(stream_p), &vstr);
+    }
+}
+
+STATIC mp_obj_t stream_read(size_t n_args, const mp_obj_t *args) {
+    return stream_read_generic(n_args, args, MP_STREAM_RW_READ);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_read_obj, 1, 2, stream_read);
+
+STATIC mp_obj_t stream_read1(size_t n_args, const mp_obj_t *args) {
+    return stream_read_generic(n_args, args, MP_STREAM_RW_READ | MP_STREAM_RW_ONCE);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_read1_obj, 1, 2, stream_read1);
+
+mp_obj_t mp_stream_write(mp_obj_t self_in, const void *buf, size_t len, byte flags) {
+    int error;
+    mp_uint_t out_sz = mp_stream_rw(self_in, (void *)buf, len, &error, flags);
+    if (error != 0) {
+        if (mp_is_nonblocking_error(error)) {
+            // 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."
+            return mp_const_none;
+        }
+        mp_raise_OSError(error);
+    } else {
+        return MP_OBJ_NEW_SMALL_INT(out_sz);
+    }
+}
+
+// This is used to adapt a stream object to an mp_print_t interface
+void mp_stream_write_adaptor(void *self, const char *buf, size_t len) {
+    mp_stream_write(MP_OBJ_FROM_PTR(self), buf, len, MP_STREAM_RW_WRITE);
+}
+
+STATIC mp_obj_t stream_write_method(size_t n_args, const mp_obj_t *args) {
+    mp_buffer_info_t bufinfo;
+    mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_READ);
+    if (!mp_get_stream(args[0])->is_text && mp_obj_is_str(args[1])) {
+        mp_raise_ValueError(MP_ERROR_TEXT("string not supported; use bytes or bytearray"));
+    }
+    size_t max_len = (size_t)-1;
+    size_t off = 0;
+    if (n_args == 3) {
+        max_len = mp_obj_get_int_truncated(args[2]);
+    } else if (n_args == 4) {
+        off = mp_obj_get_int_truncated(args[2]);
+        max_len = mp_obj_get_int_truncated(args[3]);
+        if (off > bufinfo.len) {
+            off = bufinfo.len;
+        }
+    }
+    bufinfo.len -= off;
+    return mp_stream_write(args[0], (byte *)bufinfo.buf + off, MIN(bufinfo.len, max_len), MP_STREAM_RW_WRITE);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_write_obj, 2, 4, stream_write_method);
+
+STATIC mp_obj_t stream_write1_method(mp_obj_t self_in, mp_obj_t arg) {
+    mp_buffer_info_t bufinfo;
+    mp_get_buffer_raise(arg, &bufinfo, MP_BUFFER_READ);
+    return mp_stream_write(self_in, bufinfo.buf, bufinfo.len, MP_STREAM_RW_WRITE | MP_STREAM_RW_ONCE);
+}
+MP_DEFINE_CONST_FUN_OBJ_2(mp_stream_write1_obj, stream_write1_method);
+
+STATIC mp_obj_t stream_readinto(size_t n_args, const mp_obj_t *args) {
+    mp_buffer_info_t bufinfo;
+    mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_WRITE);
+
+    // CPython extension: if 2nd arg is provided, that's max len to read,
+    // instead of full buffer. Similar to
+    // https://docs.python.org/3/library/socket.html#socket.socket.recv_into
+    mp_uint_t len = bufinfo.len;
+    if (n_args > 2) {
+        if (mp_get_stream(args[0])->pyserial_readinto_compatibility) {
+            mp_raise_ValueError(MP_ERROR_TEXT("length argument not allowed for this type"));
+        }
+        len = mp_obj_get_int(args[2]);
+        if (len > bufinfo.len) {
+            len = bufinfo.len;
+        }
+    }
+
+    int error;
+    mp_uint_t out_sz = mp_stream_read_exactly(args[0], bufinfo.buf, len, &error);
+    if (error != 0) {
+        if (mp_is_nonblocking_error(error)) {
+            // pyserial readinto never returns None, just 0.
+            return mp_get_stream(args[0])->pyserial_dont_return_none_compatibility
+                ? MP_OBJ_NEW_SMALL_INT(0)
+                : mp_const_none;
+        }
+        mp_raise_OSError(error);
+    } else {
+        return MP_OBJ_NEW_SMALL_INT(out_sz);
+    }
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_readinto_obj, 2, 3, stream_readinto);
+
+STATIC mp_obj_t stream_readall(mp_obj_t self_in) {
+    const mp_stream_p_t *stream_p = mp_get_stream(self_in);
+
+    mp_uint_t total_size = 0;
+    vstr_t vstr;
+    vstr_init(&vstr, DEFAULT_BUFFER_SIZE);
+    char *p = vstr.buf;
+    mp_uint_t current_read = DEFAULT_BUFFER_SIZE;
+    while (true) {
+        int error;
+        mp_uint_t out_sz = stream_p->read(self_in, p, current_read, &error);
+        if (out_sz == MP_STREAM_ERROR) {
+            if (mp_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.
+                if (total_size == 0) {
+                    // pyserial read() never returns None, just b''.
+                    return stream_p->pyserial_dont_return_none_compatibility
+                        ? mp_const_empty_bytes
+                        : mp_const_none;
+                }
+                break;
+            }
+            mp_raise_OSError(error);
+        }
+        if (out_sz == 0) {
+            break;
+        }
+        total_size += out_sz;
+        if (out_sz < current_read) {
+            current_read -= out_sz;
+            p += out_sz;
+        } else {
+            p = vstr_extend(&vstr, DEFAULT_BUFFER_SIZE);
+            current_read = DEFAULT_BUFFER_SIZE;
+        }
+        #ifdef RUN_BACKGROUND_TASKS
+        RUN_BACKGROUND_TASKS;
+        #endif
+    }
+
+    vstr.len = total_size;
+    return mp_obj_new_str_from_vstr(STREAM_CONTENT_TYPE(stream_p), &vstr);
+}
+
+// Unbuffered, inefficient implementation of readline() for raw I/O files.
+STATIC mp_obj_t stream_unbuffered_readline(size_t n_args, const mp_obj_t *args) {
+    const mp_stream_p_t *stream_p = mp_get_stream(args[0]);
+
+    mp_int_t max_size = -1;
+    if (n_args > 1) {
+        max_size = MP_OBJ_SMALL_INT_VALUE(args[1]);
+    }
+
+    vstr_t vstr;
+    if (max_size != -1) {
+        vstr_init(&vstr, max_size);
+    } else {
+        vstr_init(&vstr, 16);
+    }
+
+    while (max_size == -1 || max_size-- != 0) {
+        char *p = vstr_add_len(&vstr, 1);
+        int error;
+        mp_uint_t out_sz = stream_p->read(args[0], p, 1, &error);
+        if (out_sz == MP_STREAM_ERROR) {
+            if (mp_is_nonblocking_error(error)) {
+                if (vstr.len == 1) {
+                    // We just incremented it, but otherwise we read nothing
+                    // and immediately got EAGAIN. This case is not well
+                    // specified in
+                    // https://docs.python.org/3/library/io.html#io.IOBase.readline
+                    // unlike similar case for read(). But we follow the latter's
+                    // behavior - return None.
+                    vstr_clear(&vstr);
+                    return mp_const_none;
+                } else {
+                    goto done;
+                }
+            }
+            mp_raise_OSError(error);
+        }
+        if (out_sz == 0) {
+        done:
+            // Back out previously added byte
+            // Consider, what's better - read a char and get OutOfMemory (so read
+            // char is lost), or allocate first as we do.
+            vstr_cut_tail_bytes(&vstr, 1);
+            break;
+        }
+        if (*p == '\n') {
+            break;
+        }
+    }
+
+    return mp_obj_new_str_from_vstr(STREAM_CONTENT_TYPE(stream_p), &vstr);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_unbuffered_readline_obj, 1, 2, stream_unbuffered_readline);
+
+// TODO take an optional extra argument (what does it do exactly?)
+STATIC mp_obj_t stream_unbuffered_readlines(mp_obj_t self) {
+    mp_obj_t lines = mp_obj_new_list(0, NULL);
+    for (;;) {
+        mp_obj_t line = stream_unbuffered_readline(1, &self);
+        if (!mp_obj_is_true(line)) {
+            break;
+        }
+        mp_obj_list_append(lines, line);
+    }
+    return lines;
+}
+MP_DEFINE_CONST_FUN_OBJ_1(mp_stream_unbuffered_readlines_obj, stream_unbuffered_readlines);
+
+mp_obj_t mp_stream_unbuffered_iter(mp_obj_t self) {
+    mp_obj_t l_in = stream_unbuffered_readline(1, &self);
+    if (mp_obj_is_true(l_in)) {
+        return l_in;
+    }
+    return MP_OBJ_STOP_ITERATION;
+}
+
+mp_obj_t mp_stream_close(mp_obj_t stream) {
+    const mp_stream_p_t *stream_p = mp_get_stream(stream);
+    int error;
+    mp_uint_t res = stream_p->ioctl(stream, MP_STREAM_CLOSE, 0, &error);
+    if (res == MP_STREAM_ERROR) {
+        mp_raise_OSError(error);
+    }
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_1(mp_stream_close_obj, mp_stream_close);
+
+STATIC mp_obj_t stream_seek(size_t n_args, const mp_obj_t *args) {
+    struct mp_stream_seek_t seek_s;
+    // TODO: Could be uint64
+    seek_s.offset = mp_obj_get_int(args[1]);
+    seek_s.whence = SEEK_SET;
+    if (n_args == 3) {
+        seek_s.whence = mp_obj_get_int(args[2]);
+    }
+
+    // In POSIX, it's error to seek before end of stream, we enforce it here.
+    if (seek_s.whence == SEEK_SET && seek_s.offset < 0) {
+        mp_raise_OSError(MP_EINVAL);
+    }
+
+    const mp_stream_p_t *stream_p = mp_get_stream(args[0]);
+    int error;
+    mp_uint_t res = stream_p->ioctl(args[0], MP_STREAM_SEEK, (mp_uint_t)(uintptr_t)&seek_s, &error);
+    if (res == MP_STREAM_ERROR) {
+        mp_raise_OSError(error);
+    }
+
+    // TODO: Could be uint64
+    return mp_obj_new_int_from_uint(seek_s.offset);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_seek_obj, 2, 3, stream_seek);
+
+STATIC mp_obj_t stream_tell(mp_obj_t self) {
+    mp_obj_t offset = MP_OBJ_NEW_SMALL_INT(0);
+    mp_obj_t whence = MP_OBJ_NEW_SMALL_INT(SEEK_CUR);
+    const mp_obj_t args[3] = {self, offset, whence};
+    return stream_seek(3, args);
+}
+MP_DEFINE_CONST_FUN_OBJ_1(mp_stream_tell_obj, stream_tell);
+
+mp_obj_t mp_stream_flush(mp_obj_t self) {
+    const mp_stream_p_t *stream_p = mp_get_stream(self);
+    int error;
+    if (stream_p->ioctl == NULL) {
+        mp_raise_OSError(MP_EINVAL);
+    }
+    mp_uint_t res = stream_p->ioctl(self, MP_STREAM_FLUSH, 0, &error);
+    if (res == MP_STREAM_ERROR) {
+        mp_raise_OSError(error);
+    }
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_1(mp_stream_flush_obj, mp_stream_flush);
+
+STATIC mp_obj_t stream_ioctl(size_t n_args, const mp_obj_t *args) {
+    mp_buffer_info_t bufinfo;
+    uintptr_t val = 0;
+    if (n_args > 2) {
+        if (mp_get_buffer(args[2], &bufinfo, MP_BUFFER_WRITE)) {
+            val = (uintptr_t)bufinfo.buf;
+        } else {
+            val = mp_obj_get_int_truncated(args[2]);
+        }
+    }
+
+    const mp_stream_p_t *stream_p = mp_get_stream(args[0]);
+    int error;
+    mp_uint_t res = stream_p->ioctl(args[0], mp_obj_get_int(args[1]), val, &error);
+    if (res == MP_STREAM_ERROR) {
+        mp_raise_OSError(error);
+    }
+
+    return mp_obj_new_int(res);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_ioctl_obj, 2, 3, stream_ioctl);
+
+#if MICROPY_STREAMS_POSIX_API
+/*
+ * POSIX-like functions
+ *
+ * These functions have POSIX-compatible signature (except for "void *stream"
+ * first argument instead of "int fd"). They are useful to port existing
+ * POSIX-compatible software to work with MicroPython streams.
+ */
+
+#include <errno.h>
+
+ssize_t mp_stream_posix_write(mp_obj_t stream, const void *buf, size_t len) {
+    mp_obj_base_t *o = (mp_obj_base_t *)MP_OBJ_TO_PTR(stream);
+    const mp_stream_p_t *stream_p = mp_get_stream(o);
+    mp_uint_t out_sz = stream_p->write(stream, buf, len, &errno);
+    if (out_sz == MP_STREAM_ERROR) {
+        return -1;
+    } else {
+        return out_sz;
+    }
+}
+
+ssize_t mp_stream_posix_read(mp_obj_t stream, void *buf, size_t len) {
+    mp_obj_base_t *o = (mp_obj_base_t *)MP_OBJ_TO_PTR(stream);
+    const mp_stream_p_t *stream_p = mp_get_stream(o);
+    mp_uint_t out_sz = stream_p->read(stream, buf, len, &errno);
+    if (out_sz == MP_STREAM_ERROR) {
+        return -1;
+    } else {
+        return out_sz;
+    }
+}
+
+off_t mp_stream_posix_lseek(mp_obj_t stream, off_t offset, int whence) {
+    const mp_obj_base_t *o = (mp_obj_base_t *)MP_OBJ_TO_PTR(stream);
+    const mp_stream_p_t *stream_p = mp_get_stream(o);
+    struct mp_stream_seek_t seek_s;
+    seek_s.offset = offset;
+    seek_s.whence = whence;
+    mp_uint_t res = stream_p->ioctl(MP_OBJ_FROM_PTR(stream), MP_STREAM_SEEK, (mp_uint_t)(uintptr_t)&seek_s, &errno);
+    if (res == MP_STREAM_ERROR) {
+        return -1;
+    }
+    return seek_s.offset;
+}
+
+int mp_stream_posix_fsync(mp_obj_t stream) {
+    mp_obj_base_t *o = (mp_obj_base_t *)MP_OBJ_TO_PTR(stream);
+    const mp_stream_p_t *stream_p = mp_get_stream(o);
+    mp_uint_t res = stream_p->ioctl(stream, MP_STREAM_FLUSH, 0, &errno);
+    if (res == MP_STREAM_ERROR) {
+        return -1;
+    }
+    return res;
+}
+
+#endif