Diff: mbed-os/features/FEATURE_BLE/ble/UUID.h

Revision:

1:9c5af431a1f1

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/features/FEATURE_BLE/ble/UUID.h	Tue May 01 15:47:08 2018 +0000
@@ -0,0 +1,378 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * 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.
+ */
+
+#ifndef MBED_UUID_H__
+#define MBED_UUID_H__
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <algorithm>
+
+#include "blecommon.h"
+
+/**
+ * @file
+ * @addtogroup ble
+ * @{
+ * @addtogroup common
+ * @{
+ */
+
+/**
+ * Convert a character containing an hexadecimal digit into an unsigned integer.
+ *
+ * @param[in] c Hexadecimal digit in a character representation.
+ *
+ * @return The corresponding value as unsigned integer.
+ */
+static uint8_t char2int(char c)
+{
+    if ((c >= '0') && (c <= '9')) {
+        return c - '0';
+    } else if ((c >= 'a') && (c <= 'f')) {
+        return c - 'a' + 10;
+    } else if ((c >= 'A') && (c <= 'F')) {
+        return c - 'A' + 10;
+    } else {
+        return 0;
+    }
+}
+
+/**
+ * Representation of a Universally Unique Identifier (UUID).
+ *
+ * UUIDs are 128-bit wide numbers used to identify data type and elements in
+ * many layers of the Bluetooth specification.
+ *
+ * Two representations of UUIDS exist:
+ *   - 16-bit UUIDs: Shortened representation of the 128 bit UUID
+ *     0000xxxx-0000-1000-8000-00805F9B34FB where xxxx is the 16 bit UUID.
+ *     Values of those UUIDs are defined by the Bluetooth body. The short
+ *     representation saves bandwidth during protocol transactions.
+ *   - 128-bit UUIDs: Complete representation of a UUID. They are commonly
+ *     used for user defined UUID.
+ *
+ * This class acts as an adapter over these two kinds of UUIDs to allow
+ * indiscriminate use of both forms in Mbed BLE APIs.
+ *
+ * @note 32-bit UUID representation is not supported currently.
+ */
+class UUID {
+public:
+
+    /**
+     * Enumeration of the types of UUIDs.
+     */
+    enum UUID_Type_t {
+        /**
+         * 16-bit wide UUID representation.
+         */
+        UUID_TYPE_SHORT = 0,
+
+        /**
+         * 128-bit wide UUID representation.
+         */
+        UUID_TYPE_LONG  = 1
+    };
+
+    /**
+     * Enumeration of byte ordering.
+     *
+     * It is used to construct 128-byte UUIDs.
+     */
+    typedef enum {
+        /**
+         * Most significant byte first (at the smallest address).
+         */
+        MSB,
+
+        /**
+         * Least significant byte first (at the smallest address).
+         */
+        LSB
+    } ByteOrder_t;
+
+    /**
+     * Type for a 16-bit UUID.
+     */
+    typedef uint16_t ShortUUIDBytes_t;
+
+    /**
+     * Length in bytes of a long UUID.
+     */
+    static const unsigned LENGTH_OF_LONG_UUID = 16;
+
+    /**
+     * Type for a 128-bit UUID.
+     */
+    typedef uint8_t LongUUIDBytes_t[LENGTH_OF_LONG_UUID];
+
+    /**
+     * Maximum length for the string representation of a UUID excluding the null
+     * terminator.
+     *
+     * The string is composed of two characters per byte plus four '-'
+     * characters.
+     */
+    static const unsigned MAX_UUID_STRING_LENGTH = LENGTH_OF_LONG_UUID * 2 + 4;
+
+public:
+
+    /**
+     * Construct a 128-bit UUID from a string.
+     *
+     * @param[in] stringUUID Human readable representation of the UUID following
+     * the format XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX.
+     *
+     * @note Upper and lower case are supported.
+     * @note Hyphens are optional. The string must include at most four hyphens.
+     *
+     * @note Internally, the UUID is stored in the little endian order as a
+     * 16-byte array.
+     */
+    UUID(const char* stringUUID) :
+        type(UUID_TYPE_LONG),
+        baseUUID(),
+        shortUUID(0)
+    {
+        bool nibble = false;
+        uint8_t byte = 0;
+        size_t baseIndex = 0;
+        uint8_t tempUUID[LENGTH_OF_LONG_UUID];
+
+        /*
+         * Iterate through string; abort if NULL is encountered prematurely.
+         * Ignore up to four hyphens.
+         */
+        for (size_t index = 0; (index < MAX_UUID_STRING_LENGTH) && (baseIndex < LENGTH_OF_LONG_UUID); index++) {
+            if (stringUUID[index] == '\0') {
+                /* Error abort */
+                break;
+            } else if (stringUUID[index] == '-') {
+                /* Ignore hyphen */
+                continue;
+            } else if (nibble) {
+                /* Got second nibble */
+                byte |= char2int(stringUUID[index]);
+                nibble = false;
+
+                /* Store copy */
+                tempUUID[baseIndex++] = byte;
+            } else {
+                /* Got first nibble */
+                byte = char2int(stringUUID[index]) << 4;
+                nibble = true;
+            }
+        }
+
+        /* Populate internal variables if string was successfully parsed */
+        if (baseIndex == LENGTH_OF_LONG_UUID) {
+            setupLong(tempUUID, UUID::MSB);
+        } else {
+            const uint8_t sig[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
+                                    0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB };
+            setupLong(sig, UUID::MSB);
+        }
+    }
+
+    /**
+     * Construct a new UUID from a 128-bit representation.
+     *
+     * @param[in] longUUID The 128-bit (16-byte) of the UUID value.
+     * @param[in] order Bytes order of @p longUUID.
+     */
+    UUID(const LongUUIDBytes_t longUUID, ByteOrder_t order = UUID::MSB) : type(UUID_TYPE_LONG), baseUUID(), shortUUID(0) {
+        setupLong(longUUID, order);
+    }
+
+    /**
+     * Creates a new 16-bit UUID.
+     *
+     * The Bluetooth standard body defines 16-bit wide UUIDs. They are the
+     * shortened version of the UUID 0000xxxx-0000-1000-8000-00805F9B34FB, where
+     * xxxx is the value of the 16-bit UUID.
+     *
+     * @attention 16-bit UUIDs are not used in user defined data type or
+     * user defined element ID.
+     *
+     * @param[in] _shortUUID 16-bit part of the standard UUID.
+     *              The short UUID value.
+     *
+     * @note User defined UUIDs are commonly named vendor-specific UUIDs across
+     * the Bluetooth literature.
+     */
+    UUID(ShortUUIDBytes_t _shortUUID) :
+        type(UUID_TYPE_SHORT),
+        baseUUID(),
+        shortUUID(_shortUUID) {
+    }
+
+    /**
+     * UUID copy constructor.
+     *
+     * @param[in] source The UUID to copy.
+     */
+    UUID(const UUID &source)
+    {
+        type      = source.type;
+        shortUUID = source.shortUUID;
+        memcpy(baseUUID, source.baseUUID, LENGTH_OF_LONG_UUID);
+    }
+
+    /**
+     * Default constructor.
+     *
+     * Construct an invalid UUID.
+     *
+     * @post shortOrLong() returns the value UUID_TYPE_SHORT.
+     * @post getShortUUID() returns the value BLE_UUID_UNKNOWN.
+     */
+    UUID(void) :
+        type(UUID_TYPE_SHORT),
+        shortUUID(BLE_UUID_UNKNOWN) {
+    }
+
+    /**
+     * Replace existing value with a 128-bit UUID.
+     *
+     * @param[in] longUUID New 16-byte wide UUID value.
+     * @param[in] order Byte ordering of @p longUUID.
+     */
+    void setupLong(const LongUUIDBytes_t longUUID, ByteOrder_t order = UUID::MSB)
+    {
+        type = UUID_TYPE_LONG;
+        if (order == UUID::MSB) {
+            /*
+             * Switch endian. Input is big-endian, internal representation
+             * is little endian.
+             */
+            std::reverse_copy(longUUID, longUUID + LENGTH_OF_LONG_UUID, baseUUID);
+        } else {
+            std::copy(longUUID, longUUID + LENGTH_OF_LONG_UUID, baseUUID);
+        }
+        shortUUID = (uint16_t)((baseUUID[13] << 8) | (baseUUID[12]));
+    }
+
+public:
+    /**
+     * Return the internal type of the UUID.
+     *
+     * @return UUID_TYPE_SHORT if the UUID is 16-bit wide.
+     * @return UUID_TYPE_LONG if the UUID is 128-bit wide.
+     */
+    UUID_Type_t shortOrLong(void) const
+    {
+        return type;
+    }
+
+    /**
+     * Get a pointer to the UUID value based on the current UUID type.
+     *
+     * @return A pointer to an uint16_t object if the UUID is 16 bits long.
+     * @return A pointer to an array of 16 bytes if the UUID is 128 bits long.
+     */
+    const uint8_t *getBaseUUID(void) const
+    {
+        if (type == UUID_TYPE_SHORT) {
+            return (const uint8_t*)&shortUUID;
+        } else {
+            return baseUUID;
+        }
+    }
+
+    /**
+     * Get the uint16_t value of the UUID.
+     *
+     * @attention This function is not used on long UUIDs.
+     *
+     * @return The value of the shortened UUID.
+     */
+    ShortUUIDBytes_t getShortUUID(void) const
+    {
+        return shortUUID;
+    }
+
+    /**
+     * Get the length (in bytes) of the internal UUID representation.
+     *
+     * @return sizeof(ShortUUIDBytes_t) if the UUID type is UUID_TYPE_SHORT.
+     * @return LENGTH_OF_LONG_UUID if the UUID type is UUID_TYPE_LONG.
+     */
+    uint8_t getLen(void) const
+    {
+        return ((type == UUID_TYPE_SHORT) ?
+            sizeof(ShortUUIDBytes_t) :
+            LENGTH_OF_LONG_UUID);
+    }
+
+    /**
+     * Equal to operator between UUIDs.
+     *
+     * @param[in] other The UUID to compare to this.
+     *
+     * @return true if both UUIDs are equal and false otherwise.
+     */
+    bool operator== (const UUID &other) const
+    {
+        if ((this->type == UUID_TYPE_SHORT) && (other.type == UUID_TYPE_SHORT) &&
+            (this->shortUUID == other.shortUUID)) {
+            return true;
+        }
+
+        if ((this->type == UUID_TYPE_LONG) && (other.type == UUID_TYPE_LONG) &&
+            (memcmp(this->baseUUID, other.baseUUID, LENGTH_OF_LONG_UUID) == 0)) {
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Not equal to operator.
+     *
+     * @param[in] other The UUID compared to this.
+     *
+     * @return true if both UUIDs are not equal and false otherwise.
+     */
+    bool operator!= (const UUID &other) const
+    {
+        return !(*this == other);
+    }
+
+private:
+    /**
+     * Representation type of the UUID.
+     */
+    UUID_Type_t type;
+
+    /**
+     * Container of UUID value if the UUID type is equal to UUID_TYPE_LONG.
+     */
+    LongUUIDBytes_t  baseUUID;
+
+    /**
+     * Container of UUID value if the UUID type is equal to UUID_TYPE_SHORT.
+     */
+    ShortUUIDBytes_t shortUUID;
+};
+
+/**
+ * @}
+ * @}
+ */
+
+#endif // ifndef MBED_UUID_H__