CircuitPython now has struct instead of ustruct (#302)

Added struct module to shared-bindings and shared-module.  removed ustruct

1 files changed, 190 insertions, 0 deletions

diff --git a/shared-module/struct/__init__.c b/shared-module/struct/__init__.c
new file mode 100644
index 000000000..e944f7738
--- /dev/null
+++ b/shared-module/struct/__init__.c
@@ -0,0 +1,190 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Paul Sokolovsky
+ * Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
+ * Copyright (c) 2017 Michael McWethy
+ *
+ * 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 <assert.h>
+#include <string.h>
+
+#include "py/runtime.h"
+#include "py/binary.h"
+#include "py/parsenum.h"
+
+void struct_validate_format(char fmt) {
+    if( fmt == 'S' || fmt == 'O') {
+        mp_raise_RuntimeError("'S' and 'O' are not supported format types");
+    }
+}
+
+char get_fmt_type(const char **fmt) {
+    char t = **fmt;
+    switch (t) {
+        case '!':
+            t = '>';
+            break;
+        case '@':
+        case '=':
+        case '<':
+        case '>':
+            break;
+        default:
+            return '@';
+    }
+    // Skip type char
+    (*fmt)++;
+    return t;
+}
+
+mp_uint_t get_fmt_num(const char **p) {
+    const char *num = *p;
+    uint len = 1;
+    while (unichar_isdigit(*++num)) {
+        len++;
+    }
+    mp_uint_t val = (mp_uint_t)MP_OBJ_SMALL_INT_VALUE(mp_parse_num_integer(*p, len, 10, NULL));
+    *p = num;
+    return val;
+}
+
+
+void shared_modules_struct_pack_into(mp_obj_t fmt_in, byte *p, byte* end_p, size_t n_args, const mp_obj_t *args) {
+    const char *fmt = mp_obj_str_get_str(fmt_in);
+    char fmt_type = get_fmt_type(&fmt);
+
+    size_t i;
+    for (i = 0; i < n_args;) {
+        mp_uint_t sz = 1;
+        if (*fmt == '\0') {
+            // more arguments given than used by format string; CPython raises struct.error here
+            mp_raise_RuntimeError("too many arguments provided with the given format");
+        }
+        struct_validate_format(*fmt);
+
+        if (unichar_isdigit(*fmt)) {
+            sz = get_fmt_num(&fmt);
+        }
+        if (p + sz > end_p) {
+            mp_raise_RuntimeError("buffer too small");
+        }
+
+        if (*fmt == 's') {
+            mp_buffer_info_t bufinfo;
+            mp_get_buffer_raise(args[i++], &bufinfo, MP_BUFFER_READ);
+            mp_uint_t to_copy = sz;
+            if (bufinfo.len < to_copy) {
+                to_copy = bufinfo.len;
+            }
+            memcpy(p, bufinfo.buf, to_copy);
+            memset(p + to_copy, 0, sz - to_copy);
+            p += sz;
+        } else {
+            while (sz--) {
+                mp_binary_set_val(fmt_type, *fmt, args[i++], &p);
+            }
+        }
+        fmt++;
+    }
+}
+
+mp_uint_t calcsize_items(const char *fmt) {
+    mp_uint_t cnt = 0;
+    while (*fmt) {
+        int num = 1;
+        if (unichar_isdigit(*fmt)) {
+            num = get_fmt_num(&fmt);
+            if (*fmt == 's') {
+                num = 1;
+            }
+        }
+        cnt += num;
+        fmt++;
+    }
+    return cnt;
+}
+
+mp_uint_t shared_modules_struct_calcsize(mp_obj_t fmt_in) {
+    const char *fmt = mp_obj_str_get_str(fmt_in);
+    char fmt_type = get_fmt_type(&fmt);
+
+    mp_uint_t size;
+    for (size = 0; *fmt; fmt++) {
+
+        struct_validate_format(*fmt);
+
+        mp_uint_t cnt = 1;
+        if (unichar_isdigit(*fmt)) {
+            cnt = get_fmt_num(&fmt);
+        }
+
+        if (*fmt == 's') {
+            size += cnt;
+        } else {
+            mp_uint_t align;
+            size_t sz = mp_binary_get_size(fmt_type, *fmt, &align);
+            while (cnt--) {
+                // Apply alignment
+                size = (size + align - 1) & ~(align - 1);
+                size += sz;
+            }
+        }
+    }
+    return size;
+}
+
+
+mp_obj_tuple_t * shared_modules_struct_unpack_from(mp_obj_t fmt_in, byte *p, byte *end_p) {
+
+  const char *fmt = mp_obj_str_get_str(fmt_in);
+  char fmt_type = get_fmt_type(&fmt);
+  mp_uint_t num_items = calcsize_items(fmt);
+  mp_obj_tuple_t *res = MP_OBJ_TO_PTR(mp_obj_new_tuple(num_items, NULL));
+
+  for (uint i = 0; i < num_items;) {
+      mp_uint_t sz = 1;
+
+      struct_validate_format(*fmt);
+
+      if (unichar_isdigit(*fmt)) {
+          sz = get_fmt_num(&fmt);
+      }
+      if (p + sz > end_p) {
+          mp_raise_RuntimeError("buffer too small");
+      }
+      mp_obj_t item;
+      if (*fmt == 's') {
+          item = mp_obj_new_bytes(p, sz);
+          p += sz;
+          res->items[i++] = item;
+      } else {
+          while (sz--) {
+              item = mp_binary_get_val(fmt_type, *fmt, &p);
+              res->items[i++] = item;
+          }
+      }
+      fmt++;
+  }
+  return res;
+
+}