Record.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2018 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #ifndef NFC_NDEF_RECORD_H_
00018 #define NFC_NDEF_RECORD_H_
00019 
00020 #include <stdint.h>
00021 
00022 #include "platform/Span.h"
00023 
00024 namespace mbed {
00025 namespace nfc {
00026 namespace ndef {
00027 
00028 /**
00029  * @addtogroup nfc
00030  * @{
00031  */
00032 
00033 
00034 /**
00035  * Set of constants of a record header
00036  */
00037 struct Header {
00038     static const uint8_t message_begin_bit = (1 << 7);
00039     static const uint8_t message_end_bit = (1 << 6);
00040     static const uint8_t chunk_flag_bit = (1 << 5);
00041     static const uint8_t short_record_bit = (1 << 4);
00042     static const uint8_t id_length_bit = (1 << 3);
00043     static const uint8_t tnf_bits = (1 << 0) | (1 << 1) | (1 << 2);
00044 };
00045 
00046 /**
00047  * Encode a record type.
00048  *
00049  * A RecordType is composed of a type name format flag and an optional type
00050  * value.
00051  */
00052 struct RecordType {
00053     /**
00054      * Type name format of a record.
00055      */
00056     enum tnf_t {
00057         /**
00058          * empty type; value must be empty.
00059          */
00060         empty = 0x00,          //!< empty
00061 
00062         /**
00063          * Type defined by the NFC forum; value must be defined.
00064          */
00065         well_known_type = 0x01,//!< well_known_type
00066 
00067         /**
00068          * Mime type; value must be defined.
00069          */
00070         media_type = 0x02,     //!< media_type
00071 
00072         /**
00073          * Absolute URI; value must be defined.
00074          */
00075         absolute_uri = 0x03,   //!< absolute_uri
00076 
00077         /**
00078          * Type defined by vendors; value must be defined.
00079          */
00080         external_type = 0x04,  //!< external_type
00081 
00082         /**
00083          * Unknown type; value must be empty.
00084          */
00085         unknown = 0x05,        //!< unknown
00086 
00087         /**
00088          * Use for middle and terminating chunk record.
00089          * value must be empty.
00090          */
00091         unchanged = 0x06       //!< unchanged
00092     };
00093 
00094     /**
00095      * Construct an unknown type.
00096      */
00097     RecordType() : tnf(unknown), value() { }
00098 
00099     /**
00100      * Construct a type with no value.
00101      *
00102      * @note Valid tnf are: empty, unknown and unchanged.
00103      *
00104      * @param tnf The type name format of the type.
00105      */
00106     RecordType(tnf_t tnf) :
00107         tnf(tnf), value()
00108     { }
00109 
00110     /**
00111      * Construct a RecordType from a type name format and its associated value.
00112      *
00113      * @param tnf The type name format of the record type.
00114      * @param value The value associated with the tnf.
00115      */
00116     RecordType(tnf_t tnf, const Span<const uint8_t>  &value) :
00117         tnf(tnf), value(value)
00118     { }
00119 
00120     /**
00121      * Type name format of the record type.
00122      */
00123     tnf_t tnf;
00124 
00125     /**
00126      * Value associated with the record type. It can be empty.
00127      */
00128     Span<const uint8_t>  value;
00129 };
00130 
00131 /**
00132  * Definition of a Record payload.
00133  *
00134  * @note A payload can be empty.
00135  */
00136 typedef Span<const uint8_t>  RecordPayload;
00137 
00138 /**
00139  * Definition of a Record IR.
00140  *
00141  * @note ID's are optional and therefore it can be empty.
00142  */
00143 typedef Span<const uint8_t>  RecordID;
00144 
00145 /**
00146  * Represent a record.
00147  */
00148 struct Record {
00149     /**
00150      * Construct an empty record.
00151      */
00152     Record() : type(), payload(), id(), chunk(false), last_record(false) { }
00153 
00154     /**
00155      * Construct a record from its type, payload and id.
00156      *
00157      * The flags chunk and last_record can be added to indicate if the record
00158      * is aprt of a chunk or the last one in a message.
00159      *
00160      * @param type The type of the record.
00161      * @param payload The payload of the record.
00162      * @param id The id associated with the record.
00163      * @param chunk If true then this record is a chunk of a bigger record.
00164      * @param last_record If true then this record is the last of the message
00165      * containing it.
00166      */
00167     Record(
00168         RecordType type,
00169         const RecordPayload  &payload,
00170         const RecordID  &id,
00171         bool chunk,
00172         bool last_record
00173     ) :
00174         type(type),
00175         payload(payload),
00176         id(id),
00177         chunk(chunk),
00178         last_record(last_record)
00179     { }
00180 
00181     /**
00182      * Type of the record.
00183      */
00184     RecordType type;
00185 
00186     /**
00187      * Value of the payload.
00188      */
00189     RecordPayload  payload;
00190 
00191     /**
00192      * ID of the record.
00193      */
00194     RecordID  id;
00195 
00196     /**
00197      * If true, this record is a chunked record.
00198      */
00199     bool chunk: 1;
00200 
00201     /**
00202      * If true, this record is the last one of the payload containing it.
00203      */
00204     bool last_record: 1;
00205 };
00206 
00207 
00208 /**
00209  * @}
00210  */
00211 
00212 } // namespace ndef
00213 } // namespace nfc
00214 } // namespace mbed
00215 
00216 #endif /* NFC_NDEF_RECORD_H_ */