objarray: Implement array slice assignment.
This is rarely used feature which takes enough code to implement, so is
controlled by MICROPY_PY_ARRAY_SLICE_ASSIGN config setting, default off.
But otherwise it may be useful, as allows to update arbitrary-sized data
buffers in-place.
Slice is yet to implement, and actually, slice assignment implemented in
such a way that RHS of assignment should be array of the exact same item
typecode as LHS. CPython has it more relaxed, where RHS can be any sequence
of compatible types (e.g. it's possible to assign list of int's to a
bytearray slice).
Overall, when all "slice write" features are implemented, it may cost ~1KB
of code.
diff --git a/py/mpconfig.h b/py/mpconfig.h
index ed42fbc..acc5f66 100644
--- a/py/mpconfig.h
+++ b/py/mpconfig.h
@@ -409,6 +409,12 @@
#define MICROPY_PY_ARRAY (1)
#endif
+// Whether to support slice assignments for array (and bytearray).
+// This is rarely used, but adds ~0.5K of code.
+#ifndef MICROPY_PY_ARRAY_SLICE_ASSIGN
+#define MICROPY_PY_ARRAY_SLICE_ASSIGN (0)
+#endif
+
// Whether to provide "collections" module
#ifndef MICROPY_PY_COLLECTIONS
#define MICROPY_PY_COLLECTIONS (1)
diff --git a/py/obj.h b/py/obj.h
index db42e79..bfe28e1 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -616,15 +616,15 @@
mp_obj_t mp_seq_extract_slice(mp_uint_t len, const mp_obj_t *seq, mp_bound_slice_t *indexes);
// Helper to clear stale pointers from allocated, but unused memory, to preclude GC problems
#define mp_seq_clear(start, len, alloc_len, item_sz) memset((byte*)(start) + (len) * (item_sz), 0, ((alloc_len) - (len)) * (item_sz))
-#define mp_seq_replace_slice_no_grow(dest, dest_len, beg, end, slice, slice_len, item_t) \
- /*printf("memcpy(%p, %p, %d)\n", dest + beg, slice, slice_len * sizeof(item_t));*/ \
- memcpy(dest + beg, slice, slice_len * sizeof(item_t)); \
- /*printf("memmove(%p, %p, %d)\n", dest + (beg + slice_len), dest + end, (dest_len - end) * sizeof(item_t));*/ \
- memmove(dest + (beg + slice_len), dest + end, (dest_len - end) * sizeof(item_t));
+#define mp_seq_replace_slice_no_grow(dest, dest_len, beg, end, slice, slice_len, item_sz) \
+ /*printf("memcpy(%p, %p, %d)\n", dest + beg, slice, slice_len * (item_sz));*/ \
+ memcpy(((char*)dest) + (beg) * (item_sz), slice, slice_len * (item_sz)); \
+ /*printf("memmove(%p, %p, %d)\n", dest + (beg + slice_len), dest + end, (dest_len - end) * (item_sz));*/ \
+ memmove(((char*)dest) + (beg + slice_len) * (item_sz), ((char*)dest) + (end) * (item_sz), (dest_len - end) * (item_sz));
-#define mp_seq_replace_slice_grow_inplace(dest, dest_len, beg, end, slice, slice_len, len_adj, item_t) \
- /*printf("memmove(%p, %p, %d)\n", dest + beg + len_adj, dest + beg, (dest_len - beg) * sizeof(item_t));*/ \
- memmove(dest + beg + len_adj, dest + beg, (dest_len - beg) * sizeof(item_t)); \
- memcpy(dest + beg, slice, slice_len * sizeof(item_t));
+#define mp_seq_replace_slice_grow_inplace(dest, dest_len, beg, end, slice, slice_len, len_adj, item_sz) \
+ /*printf("memmove(%p, %p, %d)\n", dest + beg + len_adj, dest + beg, (dest_len - beg) * (item_sz));*/ \
+ memmove(((char*)dest) + (beg + len_adj) * (item_sz), ((char*)dest) + (beg) * (item_sz), (dest_len - beg) * (item_sz)); \
+ memcpy(((char*)dest) + (beg) * (item_sz), slice, slice_len * (item_sz));
#endif // __MICROPY_INCLUDED_PY_OBJ_H__
diff --git a/py/objarray.c b/py/objarray.c
index e2fee1f..e030548 100644
--- a/py/objarray.c
+++ b/py/objarray.c
@@ -351,17 +351,48 @@
if (0) {
#if MICROPY_PY_BUILTINS_SLICE
} else if (MP_OBJ_IS_TYPE(index_in, &mp_type_slice)) {
- if (value != MP_OBJ_SENTINEL) {
- // Only getting a slice is suported so far, not assignment
- // TODO: confirmed that both bytearray and array.array support
- // slice assignment (incl. of different size)
- return MP_OBJ_NULL; // op not supported
- }
mp_bound_slice_t slice;
if (!mp_seq_get_fast_slice_indexes(o->len, index_in, &slice)) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_NotImplementedError,
"only slices with step=1 (aka None) are supported"));
}
+ if (value != MP_OBJ_SENTINEL) {
+ #if MICROPY_PY_ARRAY_SLICE_ASSIGN
+ // Assign
+ if (!MP_OBJ_IS_TYPE(value, &mp_type_array) && !MP_OBJ_IS_TYPE(value, &mp_type_bytearray)) {
+ mp_not_implemented("array required on right side");
+ }
+ mp_obj_array_t *src_slice = value;
+ int item_sz = mp_binary_get_size('@', o->typecode, NULL);
+ if (item_sz != mp_binary_get_size('@', src_slice->typecode, NULL)) {
+ mp_not_implemented("arrays should be compatible");
+ }
+
+ // TODO: check src/dst compat
+ mp_int_t len_adj = src_slice->len - (slice.stop - slice.start);
+ if (len_adj > 0) {
+ if (len_adj > o->free) {
+ // TODO: alloc policy; at the moment we go conservative
+ o->items = m_realloc(o->items, (o->len + o->free) * item_sz, (o->len + len_adj) * item_sz);
+ o->free = 0;
+ }
+ mp_seq_replace_slice_grow_inplace(o->items, o->len,
+ slice.start, slice.stop, src_slice->items, src_slice->len, len_adj, item_sz);
+ } else {
+ mp_seq_replace_slice_no_grow(o->items, o->len,
+ slice.start, slice.stop, src_slice->items, src_slice->len, item_sz);
+ // Clear "freed" elements at the end of list
+ // TODO: This is actually only needed for typecode=='O'
+ mp_seq_clear(o->items, o->len + len_adj, o->len, item_sz);
+ // TODO: alloc policy after shrinking
+ }
+ o->len += len_adj;
+ return mp_const_none;
+ #else
+ return MP_OBJ_NULL; // op not supported
+ #endif
+ }
+
mp_obj_array_t *res;
int sz = mp_binary_get_size('@', o->typecode & TYPECODE_MASK, NULL);
assert(sz > 0);
diff --git a/py/objlist.c b/py/objlist.c
index e0c8953..03e3dda 100644
--- a/py/objlist.c
+++ b/py/objlist.c
@@ -165,7 +165,7 @@
mp_int_t len_adj = slice.start - slice.stop;
//printf("Len adj: %d\n", len_adj);
assert(len_adj <= 0);
- mp_seq_replace_slice_no_grow(self->items, self->len, slice.start, slice.stop, self->items/*NULL*/, 0, mp_obj_t);
+ mp_seq_replace_slice_no_grow(self->items, self->len, slice.start, slice.stop, self->items/*NULL*/, 0, sizeof(*self->items));
// Clear "freed" elements at the end of list
mp_seq_clear(self->items, self->len + len_adj, self->len, sizeof(*self->items));
self->len += len_adj;
@@ -211,10 +211,10 @@
self->alloc = self->len + len_adj;
}
mp_seq_replace_slice_grow_inplace(self->items, self->len,
- slice_out.start, slice_out.stop, slice->items, slice->len, len_adj, mp_obj_t);
+ slice_out.start, slice_out.stop, slice->items, slice->len, len_adj, sizeof(*self->items));
} else {
mp_seq_replace_slice_no_grow(self->items, self->len,
- slice_out.start, slice_out.stop, slice->items, slice->len, mp_obj_t);
+ slice_out.start, slice_out.stop, slice->items, slice->len, sizeof(*self->items));
// Clear "freed" elements at the end of list
mp_seq_clear(self->items, self->len + len_adj, self->len, sizeof(*self->items));
// TODO: apply allocation policy re: alloc_size
diff --git a/unix/mpconfigport.h b/unix/mpconfigport.h
index bbfae7b..8c28915 100644
--- a/unix/mpconfigport.h
+++ b/unix/mpconfigport.h
@@ -60,6 +60,7 @@
#define MICROPY_PY_BUILTINS_COMPILE (1)
#define MICROPY_PY_MICROPYTHON_MEM_INFO (1)
#define MICROPY_PY_ALL_SPECIAL_METHODS (1)
+#define MICROPY_PY_ARRAY_SLICE_ASSIGN (1)
#define MICROPY_PY_SYS_EXIT (1)
#define MICROPY_PY_SYS_PLATFORM "linux"
#define MICROPY_PY_SYS_MAXSIZE (1)