py/stream: Factor stream implementations.

So there's only one location that does the ioctl(MP_STREAM_SEEK) call.

Signed-off-by: Damien George <damien@micropython.org>

2 files changed, 13 insertions, 20 deletions

diff --git a/py/stream.c b/py/stream.c
index e008fb999..d7a8881e1 100644
--- a/py/stream.c
+++ b/py/stream.c
@@ -82,14 +82,14 @@ mp_uint_t mp_stream_rw(mp_obj_t stream, void *buf_, mp_uint_t size, int *errcode
     return done;
 }
 
-mp_uint_t mp_stream_seek(mp_obj_t stream, mp_off_t offset, int whence, int *errcode) {
+mp_off_t mp_stream_seek(mp_obj_t stream, mp_off_t offset, int whence, int *errcode) {
     struct mp_stream_seek_t seek_s;
     seek_s.offset = offset;
     seek_s.whence = whence;
     const mp_stream_p_t *stream_p = mp_get_stream(stream);
     mp_uint_t res = stream_p->ioctl(MP_OBJ_FROM_PTR(stream), MP_STREAM_SEEK, (mp_uint_t)(uintptr_t)&seek_s, errcode);
     if (res == MP_STREAM_ERROR) {
-        return -1;
+        return (mp_off_t)-1;
     }
     return seek_s.offset;
 }
@@ -457,28 +457,26 @@ static mp_obj_t mp_stream___exit__(size_t n_args, const mp_obj_t *args) {
 MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream___exit___obj, 4, 4, mp_stream___exit__);
 
 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;
+    mp_off_t offset = mp_obj_get_int(args[1]);
+    int whence = SEEK_SET;
     if (n_args == 3) {
-        seek_s.whence = mp_obj_get_int(args[2]);
+        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) {
+    if (whence == SEEK_SET && 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_off_t res = mp_stream_seek(args[0], offset, whence, &error);
+    if (res == (mp_off_t)-1) {
         mp_raise_OSError(error);
     }
 
     // TODO: Could be uint64
-    return mp_obj_new_int_from_uint(seek_s.offset);
+    return mp_obj_new_int_from_uint(res);
 }
 MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_seek_obj, 2, 3, stream_seek);
 
@@ -557,16 +555,11 @@ ssize_t mp_stream_posix_read(void *stream, void *buf, size_t len) {
 }
 
 off_t mp_stream_posix_lseek(void *stream, off_t offset, int whence) {
-    const mp_obj_base_t *o = stream;
-    const mp_stream_p_t *stream_p = MP_OBJ_TYPE_GET_SLOT(o->type, protocol);
-    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) {
+    mp_off_t res = mp_stream_seek(MP_OBJ_FROM_PTR(stream), offset, whence, &errno);
+    if (res == (mp_off_t)-1) {
         return -1;
     }
-    return seek_s.offset;
+    return res;
 }
 
 int mp_stream_posix_fsync(void *stream) {
diff --git a/py/stream.h b/py/stream.h
index 7c2e87a87..7c4d38afa 100644
--- a/py/stream.h
+++ b/py/stream.h
@@ -115,7 +115,7 @@ mp_obj_t mp_stream_write(mp_obj_t self_in, const void *buf, size_t len, byte fla
 mp_uint_t mp_stream_rw(mp_obj_t stream, void *buf, mp_uint_t size, int *errcode, byte flags);
 #define mp_stream_write_exactly(stream, buf, size, err) mp_stream_rw(stream, (byte *)buf, size, err, MP_STREAM_RW_WRITE)
 #define mp_stream_read_exactly(stream, buf, size, err) mp_stream_rw(stream, buf, size, err, MP_STREAM_RW_READ)
-mp_uint_t mp_stream_seek(mp_obj_t stream, mp_off_t offset, int whence, int *errcode);
+mp_off_t mp_stream_seek(mp_obj_t stream, mp_off_t offset, int whence, int *errcode);
 
 void mp_stream_write_adaptor(void *self, const char *buf, size_t len);