Add skeleton implementation of array.array and bytearray.

So far, only storage, initialization, repr() and buffer protocol is
implemented - alredy suitable for passing binary data around.

py/mpqstrraw.h

@@ -37,7 +37,9 @@ Q(OverflowError)
 Q(abs)
 Q(all)
 Q(any)
+Q(array)
 Q(bool)
+Q(bytearray)
 Q(callable)
 Q(chr)
 Q(complex)

py/obj.h

@@ -328,6 +328,8 @@ void mp_obj_slice_get(mp_obj_t self_in, machine_int_t *start, machine_int_t *sto
 // zip
 extern const mp_obj_type_t zip_type;
 
+// array
+extern const mp_obj_type_t array_type;
 
 // functions
 typedef struct _mp_obj_fun_native_t { // need this so we can define const objects (to go in ROM)

py/objarray.c

+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdarg.h>
+#include <assert.h>
+
+#include "nlr.h"
+#include "misc.h"
+#include "mpconfig.h"
+#include "mpqstr.h"
+#include "obj.h"
+#include "map.h"
+#include "runtime0.h"
+#include "runtime.h"
+
+// Use special typecode to differentiate repr() of bytearray vs array.array('B')
+// (underlyingly they're same).
+#define BYTEARRAY_TYPECODE 0
+
+typedef struct _mp_obj_array_t {
+    mp_obj_base_t base;
+    struct {
+        machine_uint_t typecode : 8;
+        // free is number of unused elements after len used elements
+        // alloc size = len + free
+        machine_uint_t free : (8 * sizeof(machine_uint_t) - 8);
+    };
+    machine_uint_t len; // in elements
+    void *items;
+} mp_obj_array_t;
+
+static mp_obj_array_t *array_new(char typecode, uint n);
+static mp_obj_t array_append(mp_obj_t self_in, mp_obj_t arg);
+
+/******************************************************************************/
+/* array                                                                       */
+
+static machine_int_t array_get_el_size(char typecode) {
+    // This assumes that unsigned and signed types are of the same type,
+    // which is invariant for [u]intN_t.
+    switch (typecode) {
+        case BYTEARRAY_TYPECODE:
+        case 'b':
+        case 'B':
+            return sizeof(int8_t);
+        case 'h':
+        case 'H':
+            return sizeof(int16_t);
+        case 'i':
+        case 'I':
+            return sizeof(int32_t);
+        case 'l':
+        case 'L':
+            return sizeof(int32_t);
+    }
+    return -1;
+}
+
+static machine_int_t array_get_el(mp_obj_array_t *o, int index) {
+    machine_int_t val = 0;
+    switch (o->typecode) {
+        case 'b':
+            val = ((int8_t*)o->items)[index];
+            break;
+        case BYTEARRAY_TYPECODE:
+        case 'B':
+            val = ((uint8_t*)o->items)[index];
+            break;
+        case 'h':
+            val = ((int16_t*)o->items)[index];
+            break;
+        case 'H':
+            val = ((uint16_t*)o->items)[index];
+            break;
+        case 'i':
+            val = ((int32_t*)o->items)[index];
+            break;
+        case 'I':
+            val = ((uint32_t*)o->items)[index];
+            break;
+        case 'l':
+            val = ((int32_t*)o->items)[index];
+            break;
+        case 'L':
+            val = ((uint32_t*)o->items)[index];
+            break;
+    }
+    return val;
+}
+
+static void array_set_el(mp_obj_array_t *o, int index, mp_obj_t val_in) {
+    machine_int_t val = mp_obj_int_get(val_in);
+    switch (o->typecode) {
+        case 'b':
+            ((int8_t*)o->items)[index] = val;
+            break;
+        case BYTEARRAY_TYPECODE:
+        case 'B':
+            ((uint8_t*)o->items)[index] = val;
+            break;
+        case 'h':
+            ((int16_t*)o->items)[index] = val;
+            break;
+        case 'H':
+            ((uint16_t*)o->items)[index] = val;
+            break;
+        case 'i':
+            ((int32_t*)o->items)[index] = val;
+            break;
+        case 'I':
+            ((uint32_t*)o->items)[index] = val;
+            break;
+        case 'l':
+            ((int32_t*)o->items)[index] = val;
+            break;
+        case 'L':
+            ((uint32_t*)o->items)[index] = val;
+            break;
+    }
+}
+
+
+static void array_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
+    mp_obj_array_t *o = o_in;
+    if (o->typecode == BYTEARRAY_TYPECODE) {
+        print(env, "bytearray([", o->typecode);
+    } else {
+        print(env, "array('%c', [", o->typecode);
+    }
+    for (int i = 0; i < o->len; i++) {
+        if (i > 0) {
+            print(env, ", ");
+        }
+        print(env, "%d", array_get_el(o, i));
+    }
+    print(env, "])");
+}
+
+static mp_obj_t array_construct(char typecode, mp_obj_t initializer) {
+    uint len;
+    // Try to create array of exact len if initializer len is known
+    mp_obj_t len_in = mp_obj_len_maybe(initializer);
+    if (len_in == MP_OBJ_NULL) {
+        len = 0;
+    } else {
+        len = MP_OBJ_SMALL_INT_VALUE(len_in);
+    }
+
+    mp_obj_array_t *array = array_new(typecode, len);
+
+    mp_obj_t iterable = rt_getiter(initializer);
+    mp_obj_t item;
+    int i = 0;
+    while ((item = rt_iternext(iterable)) != mp_const_stop_iteration) {
+        if (len == 0) {
+            array_append(array, item);
+        } else {
+            array_set_el(array, i++, item);
+        }
+    }
+
+    return array;
+}
+
+static mp_obj_t array_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
+    switch (n_args) {
+        case 2:
+        {
+            const char *code = qstr_str(mp_obj_str_get(args[0]));
+            mp_obj_t initializer = args[1];
+            return array_construct(*code, initializer);
+        }
+
+        default:
+            nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_TypeError, "unexpected # of arguments, %d given", n_args));
+    }
+    return NULL;
+}
+
+// This is top-level factory function, not virtual method
+// TODO: "bytearray" really should be type, not function
+static mp_obj_t mp_builtin_bytearray(mp_obj_t arg) {
+    return array_construct(BYTEARRAY_TYPECODE, arg);
+}
+MP_DEFINE_CONST_FUN_OBJ_1(mp_builtin_bytearray_obj, mp_builtin_bytearray);
+
+static mp_obj_t array_binary_op(int op, mp_obj_t lhs, mp_obj_t rhs) {
+    mp_obj_array_t *o = lhs;
+    switch (op) {
+        case RT_BINARY_OP_SUBSCR:
+        {
+            uint index = mp_get_index(o->base.type, o->len, rhs);
+            machine_int_t val = array_get_el(o, index);
+            return mp_obj_new_int(val);
+        }
+
+        default:
+            // op not supported
+            return MP_OBJ_NULL;
+    }
+}
+
+static mp_obj_t array_append(mp_obj_t self_in, mp_obj_t arg) {
+    assert(MP_OBJ_IS_TYPE(self_in, &array_type));
+    mp_obj_array_t *self = self_in;
+    if (self->free == 0) {
+        int item_sz = array_get_el_size(self->typecode);
+        // TODO: alloc policy
+        self->free = 8;
+        self->items = m_realloc(self->items,  item_sz * self->len, item_sz * (self->len + self->free));
+    }
+    array_set_el(self, self->len++, arg);
+    self->free--;
+    return mp_const_none; // return None, as per CPython
+}
+static MP_DEFINE_CONST_FUN_OBJ_2(array_append_obj, array_append);
+
+static bool array_store_item(mp_obj_t self_in, mp_obj_t index_in, mp_obj_t value) {
+    mp_obj_array_t *o = self_in;
+    uint index = mp_get_index(o->base.type, o->len, index_in);
+    array_set_el(o, index, value);
+    return true;
+}
+
+static machine_int_t array_get_buffer(mp_obj_t o_in, buffer_info_t *bufinfo, int flags) {
+    mp_obj_array_t *o = o_in;
+    bufinfo->buf = o->items;
+    bufinfo->len = o->len * array_get_el_size(o->typecode);
+    return 0;
+}
+
+static const mp_method_t array_type_methods[] = {
+    { "append", &array_append_obj },
+    { NULL, NULL },
+};
+
+const mp_obj_type_t array_type = {
+    { &mp_const_type },
+    "array",
+    .print = array_print,
+    .make_new = array_make_new,
+    .binary_op = array_binary_op,
+    .store_item = array_store_item,
+    .methods = array_type_methods,
+    .buffer_p = { .get_buffer = array_get_buffer },
+};
+
+static mp_obj_array_t *array_new(char typecode, uint n) {
+    mp_obj_array_t *o = m_new_obj(mp_obj_array_t);
+    o->base.type = &array_type;
+    o->typecode = typecode;
+    o->free = 0;
+    o->len = n;
+    o->items = m_malloc(array_get_el_size(typecode) * o->len);
+    return o;
+}
+
+mp_obj_t mp_obj_new_bytearray(uint n, void *items) {
+    mp_obj_array_t *o = array_new(BYTEARRAY_TYPECODE, n);
+    memcpy(o->items, items, n);
+    return o;
+}

py/py.mk

@@ -72,6 +72,7 @@ PY_O_BASENAME = \
 	map.o \
 	strtonum.o \
 	obj.o \
+	objarray.o \
 	objbool.o \
 	objboundmeth.o \
 	objcell.o \

py/runtime.c

@@ -17,6 +17,7 @@
 #include "runtime.h"
 #include "map.h"
 #include "builtin.h"
+#include "objarray.h"
 
 #if 0 // print debugging info
 #define DEBUG_PRINT (1)
@@ -121,6 +122,10 @@ void rt_init(void) {
     mp_map_add_qstr(&map_builtins, MP_QSTR_type, (mp_obj_t)&mp_const_type);
     mp_map_add_qstr(&map_builtins, MP_QSTR_zip, (mp_obj_t)&zip_type);
 
+    mp_obj_t m_array = mp_obj_new_module(MP_QSTR_array);
+    rt_store_attr(m_array, MP_QSTR_array, (mp_obj_t)&array_type);
+    rt_store_name(MP_QSTR_array, m_array);
+
     // built-in user functions
     mp_map_add_qstr(&map_builtins, MP_QSTR_abs, (mp_obj_t)&mp_builtin_abs_obj);
     mp_map_add_qstr(&map_builtins, MP_QSTR_all, (mp_obj_t)&mp_builtin_all_obj);
@@ -145,6 +150,7 @@ void rt_init(void) {
     mp_map_add_qstr(&map_builtins, MP_QSTR_sorted, (mp_obj_t)&mp_builtin_sorted_obj);
     mp_map_add_qstr(&map_builtins, MP_QSTR_sum, (mp_obj_t)&mp_builtin_sum_obj);
     mp_map_add_qstr(&map_builtins, MP_QSTR_str, (mp_obj_t)&mp_builtin_str_obj);
+    mp_map_add_qstr(&map_builtins, MP_QSTR_bytearray, (mp_obj_t)&mp_builtin_bytearray_obj);
 
 #if MICROPY_CPYTHON_COMPAT
     // Add (empty) micropython module, so it was possible to "import micropython",