Import of the watch repository from Pebble

src/fw/util/pstring.h

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+
+// PascalStrings with string length of 0 are considered empty.
+typedef struct {
+  uint16_t str_length;
+  char str_value[];
+} PascalString16;
+
+typedef struct {
+  uint16_t data_size;
+  uint8_t data[];
+} SerializedArray;
+
+// Used to encapsulate multiple PascalStrings.
+// Empty PascalStrings only have their length serialized (no byte for value).
+typedef struct {
+  uint16_t count;
+  SerializedArray *pstrings;
+} PascalString16List;
+
+// Create a PascalString16 with the passed max pstring size.
+PascalString16 *pstring_create_pstring16(uint16_t size);
+
+// Create a PascalString16 from the passed string.
+PascalString16 *pstring_create_pstring16_from_string(char string[]);
+
+void pstring_destroy_pstring16(PascalString16 *pstring);
+
+//! @param string_out Array of chars to hold the converted pstring.
+//!                   Must be at least size (pstring->length + 1).
+void pstring_pstring16_to_string(const PascalString16 *pstring, char *string_out);
+
+//! @param pstring_out Array of chars to hold the converted string.
+//!                    Must be at least size (string + 1).
+void pstring_string_to_pstring16(char string[], PascalString16 *pstring_out);
+
+//! Checks if 2 pstrings are euqual and returns true if so.
+//! @note returns false if either / both pstrings are NULL
+bool pstring_equal(const PascalString16 *ps1, const PascalString16 *ps2);
+
+//! Compares a pstring to a cstring and returns true if they match
+//! @note returns false if either / both params are NULL
+bool pstring_equal_cstring(const PascalString16 *pstr, const char *cstr);
+
+//------
+
+SerializedArray *pstring_create_serialized_array(uint16_t data_size);
+
+void pstring_destroy_serialized_array(SerializedArray* serialized_array);
+
+// Projects a list on a serialized array so that pstring operations may be performed on it.
+void pstring_project_list_on_serialized_array(PascalString16List *pstring16_list,
+                                              SerializedArray *serialized_array);
+
+// Adds a PascalString16 to the end of the list.
+// Returns true if the PascalString16 was successfully added, false if there was no room.
+bool pstring_add_pstring16_to_list(PascalString16List *pstring16_list, PascalString16* pstring);
+
+// Retrieves the number of PascalString16s in the list.
+uint16_t pstring_get_number_of_pstring16s_in_list(PascalString16List *pstring16_list);
+
+// Returns a pointer to a PascalString16 of the passed index within the list.
+// If the given index is not valid or the list is empty, returns NULL.
+PascalString16* pstring_get_pstring16_from_list(PascalString16List *pstring16_list, uint16_t index);
+
+void pstring_print_pstring(PascalString16 *pstring);
+
+void pstring_print_pstring16list(PascalString16List *list);