Diff: features/FEATURE_BLE/ble/UUID.h

Revision:

0:5c4d7b2438d3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/features/FEATURE_BLE/ble/UUID.h	Fri Nov 11 20:59:50 2016 +0000
@@ -0,0 +1,331 @@
+/* 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 __UUID_H__
+#define __UUID_H__
+
+#include <stdint.h>
+#include <string.h>
+#include <algorithm>
+
+#include "blecommon.h"
+
+/**
+ * A trivial converter for single hexadecimal character to an unsigned integer.
+ *
+ * @param  c
+ *          Hexadecimal character.
+ *
+ * @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;
+    }
+}
+
+/**
+ * An instance of this class represents a Universally Unique Identifier (UUID)
+ * in the BLE API.
+ */
+class UUID {
+public:
+    /**
+     * Enumeration of the possible types of UUIDs in BLE with regards to length.
+     */
+    enum UUID_Type_t {
+        UUID_TYPE_SHORT = 0,    /**< Short 16-bit UUID. */
+        UUID_TYPE_LONG  = 1     /**< Full 128-bit UUID. */
+    };
+
+    /**
+     * Enumeration to specify byte ordering of the long version of the UUID.
+     */
+    typedef enum {
+        MSB, /**< Most-significant byte first (at the smallest address) */
+        LSB  /**< least-significant byte first (at the smallest address) */
+    } ByteOrder_t;
+
+    /**
+     * Type for a 16-bit UUID.
+     */
+    typedef uint16_t      ShortUUIDBytes_t;
+
+    /**
+     * Length of a long UUID in bytes.
+     */
+    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 of a string representation of a UUID not including the
+     * null termination ('\0'): two characters per
+     * byte plus four '-' characters.
+     */
+    static const unsigned MAX_UUID_STRING_LENGTH = LENGTH_OF_LONG_UUID * 2 + 4;
+
+public:
+
+    /**
+     * Creates a new 128-bit UUID.
+     *
+     * @note   The UUID is a unique 128-bit (16 byte) ID used to identify
+     *         different service or characteristics on the BLE device.
+     *
+     * @param  stringUUID
+     *          The 128-bit (16-byte) UUID as a human readable const-string.
+     *          Format: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
+     *          Upper and lower case supported. Hyphens are optional, but only
+     *          upto four of them. The UUID is stored internally as a 16 byte
+     *          array, LSB (little endian), which is opposite from the string.
+     */
+    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 upto 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);
+        }
+    }
+
+    /**
+     * Creates a new 128-bit UUID.
+     *
+     * @param[in] longUUID
+     *              The 128-bit (16-byte) UUID value.
+     * @param[in] order
+     *              The bit order of the UUID, MSB by default.
+     *
+     * @note   The UUID is a unique 128-bit (16 byte) ID used to identify
+     *         different service or characteristics on the BLE device.
+     */
+    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.
+     *
+     * For efficiency, and because 16 bytes would take a large chunk of the
+     * 27-byte data payload length of the Link Layer, the BLE specification adds
+     * two additional UUID formats: 16-bit and 32-bit UUIDs. These shortened
+     * formats can be used only with UUIDs that are defined in the Bluetooth
+     * specification (listed by the Bluetooth SIG as standard
+     * Bluetooth UUIDs).
+     *
+     * To reconstruct the full 128-bit UUID from the shortened version, insert
+     * the 16-bit short value (indicated by xxxx, including leading zeros) into
+     * the Bluetooth Base UUID:
+     *
+     *  0000xxxx-0000-1000-8000-00805F9B34FB
+     *
+     * @param[in] _shortUUID
+     *              The short UUID value.
+     *
+     * @note Shortening is not available for UUIDs that are not derived from the
+     *       Bluetooth Base UUID. Such non-standard UUIDs are commonly called
+     *       vendor-specific UUIDs. In these cases, you’ll need to use the full
+     *       128-bit UUID value at all times.
+     *
+     * @note The UUID is a unique 16-bit (2 byte) ID used to identify
+     *       different service or characteristics on the BLE device.
+     *
+     * @note We do not yet support 32-bit shortened UUIDs.
+     */
+    UUID(ShortUUIDBytes_t _shortUUID) : type(UUID_TYPE_SHORT), baseUUID(), shortUUID(_shortUUID) {
+        /* Empty */
+    }
+
+    /**
+     * 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);
+    }
+
+    /**
+     * The empty constructor.
+     *
+     * @note The type of the resulting UUID instance is UUID_TYPE_SHORT and the
+     *       value BLE_UUID_UNKNOWN.
+     */
+    UUID(void) : type(UUID_TYPE_SHORT), shortUUID(BLE_UUID_UNKNOWN) {
+        /* empty */
+    }
+
+    /**
+     * Fill in a 128-bit UUID; this is useful when the UUID is not known at the
+     * time of the object construction.
+     *
+     * @param[in] longUUID
+     *              The UUID value to copy.
+     * @param[in]  order
+     *              The byte ordering of the UUID at @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:
+    /**
+     * Check whether this UUID is short or long.
+     *
+     * @return UUID_TYPE_SHORT if the UUID is short, UUID_TYPE_LONG otherwise.
+     */
+    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 the short UUID if the type is set to
+     *         UUID_TYPE_SHORT. Otherwise, a pointer to the long UUID if the
+     *         type is set to UUID_TYPE_LONG.
+     */
+    const uint8_t *getBaseUUID(void) const {
+        if (type == UUID_TYPE_SHORT) {
+            return (const uint8_t*)&shortUUID;
+        } else {
+            return baseUUID;
+        }
+    }
+
+    /**
+     * Get the short UUID.
+     *
+     * @return The short UUID.
+     */
+    ShortUUIDBytes_t getShortUUID(void) const {
+        return shortUUID;
+    }
+
+    /**
+     * Get the length (in bytes) of the UUID based on its type.
+     *
+     * @retval sizeof(ShortUUIDBytes_t) if the UUID type is UUID_TYPE_SHORT.
+     * @retval 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);
+    }
+
+    /**
+     * Overload == operator to enable UUID comparisons.
+     *
+     * @param[in] other
+     *              The other UUID in the comparison.
+     *
+     * @return true if this == @p other, 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;
+    }
+
+    /**
+     * Overload != operator to enable UUID comparisons.
+     *
+     * @param[in] other
+     *              The other UUID in the comparison.
+     *
+     * @return true if this != @p other, false otherwise.
+     */
+    bool operator!= (const UUID &other) const {
+        return !(*this == other);
+    }
+
+private:
+    /**
+     * The UUID type. Refer to UUID_Type_t.
+     */
+    UUID_Type_t      type;
+    /**
+     * The long UUID value.
+     */
+    LongUUIDBytes_t  baseUUID;
+    /**
+     * The short UUID value.
+     */
+    ShortUUIDBytes_t shortUUID;
+};
+
+#endif // ifndef __UUID_H__