extmod: Add uheapq module.

extmod/moduheapq.c

+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2014 Damien P. George
+ *
+ * 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 <unistd.h>
+
+#include "mpconfig.h"
+#include "misc.h"
+#include "nlr.h"
+#include "qstr.h"
+#include "obj.h"
+#include "objlist.h"
+#include "runtime0.h"
+#include "runtime.h"
+
+#if MICROPY_PY_UHEAPQ
+
+// the algorithm here is modelled on CPython's heapq.py
+
+STATIC mp_obj_list_t *get_heap(mp_obj_t heap_in) {
+    if (!MP_OBJ_IS_TYPE(heap_in, &mp_type_list)) {
+        nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "heap must be a list"));
+    }
+    return heap_in;
+}
+
+STATIC void heap_siftdown(mp_obj_list_t *heap, mp_uint_t start_pos, mp_uint_t pos) {
+    mp_obj_t item = heap->items[pos];
+    while (pos > start_pos) {
+        mp_uint_t parent_pos = (pos - 1) >> 1;
+        mp_obj_t parent = heap->items[parent_pos];
+        if (mp_binary_op(MP_BINARY_OP_LESS, item, parent) == mp_const_true) {
+            heap->items[pos] = parent;
+            pos = parent_pos;
+        } else {
+            break;
+        }
+    }
+    heap->items[pos] = item;
+}
+
+STATIC void heap_siftup(mp_obj_list_t *heap, mp_uint_t pos) {
+    mp_uint_t start_pos = pos;
+    mp_uint_t end_pos = heap->len;
+    mp_obj_t item = heap->items[pos];
+    for (mp_uint_t child_pos = 2 * pos + 1; child_pos < end_pos; child_pos = 2 * pos + 1) {
+        // choose right child if it's <= left child
+        if (child_pos + 1 < end_pos && mp_binary_op(MP_BINARY_OP_LESS, heap->items[child_pos], heap->items[child_pos + 1]) == mp_const_false) {
+            child_pos += 1;
+        }
+        // bubble up the smaller child
+        heap->items[pos] = heap->items[child_pos];
+        pos = child_pos;
+    }
+    heap->items[pos] = item;
+    heap_siftdown(heap, start_pos, pos);
+}
+
+STATIC mp_obj_t mod_uheapq_heappush(mp_obj_t heap_in, mp_obj_t item) {
+    mp_obj_list_t *heap = get_heap(heap_in);
+    mp_obj_list_append(heap, item);
+    heap_siftdown(heap, 0, heap->len - 1);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_uheapq_heappush_obj, mod_uheapq_heappush);
+
+STATIC mp_obj_t mod_uheapq_heappop(mp_obj_t heap_in) {
+    mp_obj_list_t *heap = get_heap(heap_in);
+    if (heap->len == 0) {
+        nlr_raise(mp_obj_new_exception_msg(&mp_type_IndexError, "empty heap"));
+    }
+    mp_obj_t item = heap->items[0];
+    heap->len -= 1;
+    heap->items[0] = heap->items[heap->len];
+    heap->items[heap->len] = MP_OBJ_NULL; // so we don't retain a pointer
+    if (heap->len) {
+        heap_siftup(heap, 0);
+    }
+    return item;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_uheapq_heappop_obj, mod_uheapq_heappop);
+
+STATIC mp_obj_t mod_uheapq_heapify(mp_obj_t heap_in) {
+    mp_obj_list_t *heap = get_heap(heap_in);
+    for (mp_uint_t i = heap->len / 2; i > 0;) {
+        heap_siftup(heap, --i);
+    }
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_uheapq_heapify_obj, mod_uheapq_heapify);
+
+STATIC const mp_map_elem_t mp_module_uheapq_globals_table[] = {
+    { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_uheapq) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_heappush), (mp_obj_t)&mod_uheapq_heappush_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_heappop), (mp_obj_t)&mod_uheapq_heappop_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_heapify), (mp_obj_t)&mod_uheapq_heapify_obj },
+};
+
+STATIC const mp_obj_dict_t mp_module_uheapq_globals = {
+    .base = {&mp_type_dict},
+    .map = {
+        .all_keys_are_qstrs = 1,
+        .table_is_fixed_array = 1,
+        .used = MP_ARRAY_SIZE(mp_module_uheapq_globals_table),
+        .alloc = MP_ARRAY_SIZE(mp_module_uheapq_globals_table),
+        .table = (mp_map_elem_t*)mp_module_uheapq_globals_table,
+    },
+};
+
+const mp_obj_module_t mp_module_uheapq = {
+    .base = { &mp_type_module },
+    .name = MP_QSTR_uheapq,
+    .globals = (mp_obj_dict_t*)&mp_module_uheapq_globals,
+};
+
+#endif //MICROPY_PY_UHEAPQ

py/builtin.h

@@ -91,3 +91,4 @@ extern const mp_obj_module_t mp_module_uctypes;
 extern const mp_obj_module_t mp_module_uzlib;
 extern const mp_obj_module_t mp_module_ujson;
 extern const mp_obj_module_t mp_module_ure;
+extern const mp_obj_module_t mp_module_uheapq;

py/builtintables.c

@@ -211,6 +211,9 @@ STATIC const mp_map_elem_t mp_builtin_module_table[] = {
 #if MICROPY_PY_URE
     { MP_OBJ_NEW_QSTR(MP_QSTR_ure), (mp_obj_t)&mp_module_ure },
 #endif
+#if MICROPY_PY_UHEAPQ
+    { MP_OBJ_NEW_QSTR(MP_QSTR_uheapq), (mp_obj_t)&mp_module_uheapq },
+#endif
 
     // extra builtin modules as defined by a port
     MICROPY_PORT_BUILTIN_MODULES

py/mpconfig.h

@@ -403,6 +403,10 @@ typedef double mp_float_t;
 #define MICROPY_PY_URE (0)
 #endif
 
+#ifndef MICROPY_PY_UHEAPQ
+#define MICROPY_PY_UHEAPQ (0)
+#endif
+
 /*****************************************************************************/
 /* Hooks for a port to add builtins                                          */
 

py/py.mk

@@ -114,6 +114,7 @@ PY_O_BASENAME = \
 	../extmod/modujson.o \
 	../extmod/modure.o \
 	../extmod/moduzlib.o \
+	../extmod/moduheapq.o \
 
 # prepend the build destination prefix to the py object files
 PY_O = $(addprefix $(PY_BUILD)/, $(PY_O_BASENAME))

py/qstrdefs.h

@@ -485,3 +485,10 @@ Q(search)
 Q(group)
 Q(DEBUG)
 #endif
+
+#if MICROPY_PY_UHEAPQ
+Q(uheapq)
+Q(heappush)
+Q(heappop)
+Q(heapify)
+#endif

stmhal/mpconfigport.h

@@ -60,6 +60,7 @@
 #define MICROPY_PY_UZLIB            (1)
 #define MICROPY_PY_UJSON            (1)
 #define MICROPY_PY_URE              (1)
+#define MICROPY_PY_UHEAPQ           (1)
 
 #define MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF   (1)
 #define MICROPY_EMERGENCY_EXCEPTION_BUF_SIZE  (0)

tests/extmod/uheapq1.py

+try:
+    import uheapq as heapq
+except:
+    import heapq
+
+try:
+    heapq.heappop([])
+except IndexError:
+    print("IndexError")
+
+try:
+    heapq.heappush((), 1)
+except TypeError:
+    print("TypeError")
+
+def pop_and_print(h):
+    l = []
+    while h:
+        l.append(str(heapq.heappop(h)))
+    print(' '.join(l))
+
+h = []
+heapq.heappush(h, 3)
+heapq.heappush(h, 1)
+heapq.heappush(h, 2)
+print(h)
+pop_and_print(h)
+
+h = [4, 3, 8, 9, 10, 2, 7, 11, 5]
+heapq.heapify(h)
+print(h)
+heapq.heappush(h, 1)
+heapq.heappush(h, 6)
+heapq.heappush(h, 12)
+print(h)
+pop_and_print(h)

unix/mpconfigport.h

@@ -58,6 +58,7 @@
 #define MICROPY_PY_UZLIB            (1)
 #define MICROPY_PY_UJSON            (1)
 #define MICROPY_PY_URE              (1)
+#define MICROPY_PY_UHEAPQ           (1)
 
 // Define to MICROPY_ERROR_REPORTING_DETAILED to get function, etc.
 // names in exception messages (may require more RAM).