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py: Implement memoryview slice assignment.

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Adds ability to do "memcpy" with memoryview objects, such as:
m1[0:3] = m2[2:5].
This commit is contained in:
Delio Brignoli 2015-06-03 07:07:35 +02:00 committed by Damien George
parent f576057274
commit 32aba40830
2 changed files with 69 additions and 9 deletions
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36
py/objarray.c
View File

@ -373,12 +373,12 @@ STATIC mp_obj_t array_subscr(mp_obj_t self_in, mp_obj_t index_in, mp_obj_t value
// Assign
mp_uint_t src_len;
void *src_items;
size_t item_sz = mp_binary_get_size('@', o->typecode, NULL);
size_t item_sz = mp_binary_get_size('@', o->typecode & TYPECODE_MASK, NULL);
if (MP_OBJ_IS_TYPE(value, &mp_type_array) || MP_OBJ_IS_TYPE(value, &mp_type_bytearray)) {
mp_obj_array_t *src_slice = value;
if (item_sz != mp_binary_get_size('@', src_slice->typecode, NULL)) {
if (item_sz != mp_binary_get_size('@', src_slice->typecode & TYPECODE_MASK, NULL)) {
compat_error:
mp_not_implemented("lhs and rhs should be compatible");
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "lhs and rhs should be compatible"));
}
src_len = src_slice->len;
src_items = src_slice->items;
@ -390,6 +390,13 @@ STATIC mp_obj_t array_subscr(mp_obj_t self_in, mp_obj_t index_in, mp_obj_t value
mp_get_buffer_raise(value, &bufinfo, MP_BUFFER_READ);
src_len = bufinfo.len;
src_items = bufinfo.buf;
} else if (MP_OBJ_IS_TYPE(value, &mp_type_memoryview)) {
mp_obj_array_t *src_slice = value;
if (item_sz != mp_binary_get_size('@', src_slice->typecode & TYPECODE_MASK, NULL)) {
goto compat_error;
}
src_len = src_slice->len;
src_items = (uint8_t*)src_slice->items + (src_slice->free * item_sz);
} else {
mp_not_implemented("array/bytes required on right side");
}
@ -397,6 +404,9 @@ STATIC mp_obj_t array_subscr(mp_obj_t self_in, mp_obj_t index_in, mp_obj_t value
// TODO: check src/dst compat
mp_int_t len_adj = src_len - (slice.stop - slice.start);
if (len_adj > 0) {
if (o->base.type == &mp_type_memoryview) {
goto compat_error;
}
if (len_adj > o->free) {
// TODO: alloc policy; at the moment we go conservative
o->items = m_renew(byte, o->items, (o->len + o->free) * item_sz, (o->len + len_adj) * item_sz);
@ -405,12 +415,20 @@ STATIC mp_obj_t array_subscr(mp_obj_t self_in, mp_obj_t index_in, mp_obj_t value
mp_seq_replace_slice_grow_inplace(o->items, o->len,
slice.start, slice.stop, src_items, src_len, len_adj, item_sz);
} else {
mp_seq_replace_slice_no_grow(o->items, o->len,
slice.start, slice.stop, src_items, src_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
if (o->base.type == &mp_type_memoryview) {
if (len_adj != 0) {
goto compat_error;
}
mp_seq_replace_slice_no_grow((uint8_t*)o->items + (o->free * item_sz), o->len,
slice.start, slice.stop, src_items, src_len, item_sz);
} else {
mp_seq_replace_slice_no_grow(o->items, o->len,
slice.start, slice.stop, src_items, src_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;

42
tests/basics/memoryview1.py
View File

@ -36,3 +36,45 @@ print(list(m))
print(list(m[1:-1]))
m[2] = 6
print(a)
# test slice assignment between memoryviews
b1 = bytearray(b'1234')
b2 = bytearray(b'5678')
b3 = bytearray(b'5678')
m1 = memoryview(b1)
m2 = memoryview(b2)
m3 = memoryview(b3)
m2[1:3] = m1[0:2]
print(b2)
b3[1:3] = m1[0:2]
print(b3)
m1[2:4] = b3[1:3]
print(b1)
try:
m2[1:3] = b1[0:4]
except ValueError:
print("ValueError")
try:
m2[1:3] = m1[0:4]
except ValueError:
print("ValueError")
try:
m2[0:4] = m1[1:3]
except ValueError:
print("ValueError")
# test memoryview of arrays with items sized larger than 1
a1 = array.array('i', [0]*5)
m4 = memoryview(a1)
a2 = array.array('i', [3]*5)
m5 = memoryview(a2)
m4[1:3] = m5[1:3]
print(a1)
try:
m4[1:3] = m2[1:3]
except ValueError:
print("ValueError")