fit 是一种文件协议,体积小巧,多用于可穿戴设备记录、传输运动与健康数据。官方提供了 C、C++、Java 语言的 SDK 和非常详细的使用文档。因此在 iOS 端接入 fit 就需要在 C 或 C++ 的 SDK 基础上进行一点面向对象的封装。

认识 Fit

我使用的 C 语言的 SDK,官方有示例 demo,在 fit_mgr 文件中提供了一些示例,这些代码未必全部都要用到。创建一个最简单的 .fit 文件的流程是:

写 fileid

void fit_transaction_file(FIT_FILE type, FIT_MANUFACTURER manufacturer, FIT_UINT16 product, FIT_UINT32Z serial_number){
// Write file id message.
FIT_UINT8 local_mesg_number = 0;
FIT_FILE_ID_MESG file_id;
Fit_InitMesg(fit_mesg_defs[FIT_MESG_FILE_ID], &file_id);

// @xaoxuu: type FIT_FILE_ACTIVITY = 4 活动数据
file_id.type = type;
// @xaoxuu: 厂商
file_id.manufacturer = manufacturer;
// @xaoxuu: 产品
// file_id.product_name
file_id.product = product;
// @xaoxuu: 序列号
file_id.serial_number = serial_number;
// @xaoxuu: 生产日期
// time_t now;
// time(&now);
// file_id.time_created = now;

WriteMessageDefinition(local_mesg_number, fit_mesg_defs[FIT_MESG_FILE_ID], FIT_FILE_ID_MESG_DEF_SIZE, static_fp);
WriteMessage(local_mesg_number, &file_id, FIT_FILE_ID_MESG_SIZE, static_fp);
}

void fit_transaction_field_desc() {
// Write a Field Description
FIT_UINT8 local_mesg_number = 1;
FIT_FIELD_DESCRIPTION_MESG field_description_mesg;

Fit_InitMesg(fit_mesg_defs[FIT_MESG_FIELD_DESCRIPTION], &field_description_mesg);
field_description_mesg.developer_data_index = 0;
field_description_mesg.field_definition_number = 0;
field_description_mesg.fit_base_type_id = FIT_BASE_TYPE_UINT16;
WriteMessageDefinition(local_mesg_number, fit_mesg_defs[FIT_MESG_FIELD_DESCRIPTION], FIT_FIELD_DESCRIPTION_MESG_DEF_SIZE, static_fp);
WriteMessage(local_mesg_number, &field_description_mesg, FIT_FIELD_DESCRIPTION_MESG_SIZE, static_fp);
}

写 record

// 写入Record Defenition
void fit_transaction_record_def(){
FIT_UINT8 local_mesg_number = 2;
WriteMessageDefinition(local_mesg_number, fit_mesg_defs[FIT_MESG_RECORD], FIT_RECORD_MESG_DEF_SIZE, static_fp);
}
// 循环写入record数据
void fit_transaction_record_msg(unsigned int timestamp, int position_lat, int position_long, unsigned int distance, unsigned short altitude, unsigned short speed, unsigned char heart_rate){
//Record message
FIT_UINT8 local_mesg_number = 2;
FIT_RECORD_MESG record;

Fit_InitMesg(fit_mesg_defs[FIT_MESG_RECORD], &record);
record.timestamp = timestamp;
record.position_lat = position_lat;
record.position_long = position_long;
record.distance = distance;
record.altitude = altitude;
record.speed = speed;
record.heart_rate = heart_rate;
WriteMessage(local_mesg_number,&record,FIT_RECORD_MESG_SIZE,static_fp);
}

开始封装

设计模型

FitActivity.h

//
// FitAcitvity.h
// FitSDK
//
// Created by xaoxuu on 04/07/2017.
// Copyright © 2017 xaoxuu. All rights reserved.
//

#import <Foundation/Foundation.h>

@class FitActivityRecord;
typedef NS_ENUM(NSUInteger, FitActivityType) {
FitActivityTypeWalk = 11, // 枚举值等于FIT_SPORT值
FitActivityTypeRun = 1,
FitActivityTypeRide = 2,
FitActivityTypeSwim = 5,
FitActivityTypeHike = 17,
};

@interface FitActivity : NSObject

// @xaoxuu: fit 文件路径
@property (copy, readonly, nonatomic) NSString *path;

// @xaoxuu: 活动名
@property (copy, nonatomic) NSString *name;

// @xaoxuu: 活动类型
@property (assign, nonatomic) FitActivityType type;

// @xaoxuu: 活动类型
@property (copy, readonly, nonatomic) NSString *typeString;

// @xaoxuu: records
@property (strong, nonatomic) NSMutableArray<FitActivityRecord *> *records;

/**
添加一条record

@param record record
*/
- (void)addRecord:(void (^)(FitActivityRecord *aRecord))record;

@end

@interface FitActivityRecord : NSObject

// @xaoxuu: timestamp
@property (assign, nonatomic) unsigned int timestamp;

// @xaoxuu: position_lat
@property (assign, nonatomic) int position_lat;

// @xaoxuu: position_long
@property (assign, nonatomic) int position_long;

// @xaoxuu: distance
@property (assign, nonatomic) unsigned int distance;

// @xaoxuu: altitude
@property (assign, nonatomic) unsigned short altitude;

// @xaoxuu: speed
@property (assign, nonatomic) unsigned short speed;

// @xaoxuu: heart_rate
@property (assign, nonatomic) unsigned char heart_rate;

@end

FitActivity.m

//
// FitAcitvity.m
// FitSDK
//
// Created by xaoxuu on 04/07/2017.
// Copyright © 2017 xaoxuu. All rights reserved.
//

#import "FitAcitvity.h"

@implementation FitActivity

- (instancetype)init {
if (self = [super init]) {
_records = [NSMutableArray array];
self.type = FitActivityTypeWalk;
}
return self;
}


- (void)setType:(FitActivityType)type{
_type = type;

switch (type) {
case FitActivityTypeWalk:
_typeString = @"walk";
break;
case FitActivityTypeRun:
_typeString = @"run";
break;
case FitActivityTypeRide:
_typeString = @"ride";
break;
case FitActivityTypeSwim:
_typeString = @"swim";
break;
case FitActivityTypeHike:
_typeString = @"hike";
break;

}
}


- (void)setName:(NSString *)name{
_name = name;
_path = [self pathWithName:name];
}

- (void)addRecord:(void (^)(FitActivityRecord *aRecord))record{
if (record) {
FitActivityRecord *rec = [FitActivityRecord new];
record(rec);
[self.records addObject:rec];
}
}

- (NSString *)pathWithName:(NSString *)name{
NSString *path = [[NSTemporaryDirectory() stringByAppendingPathComponent:@"com.xaoxuu.fitsdk"] stringByAppendingPathComponent:name];
path = [path stringByAppendingPathExtension:@"fit"];
// create dir if not exist
NSFileManager *fm = [NSFileManager defaultManager];
NSString *dir = path.stringByDeletingLastPathComponent;
BOOL result = [fm createDirectoryAtPath:dir withIntermediateDirectories:YES attributes:nil error:nil];
if (!result) {
NSLog(@"can not create the directory at path %@",dir);
}
return path;
}

@end

@implementation FitActivityRecord

- (instancetype)init{
if (self = [super init]) {
_timestamp = 702940946;
_position_lat = 0;
_position_long = 0;
_distance = 0;
_altitude = 0;
_speed = 0;
_heart_rate = 0;
}
return self;
}

@end

封装接口

FitSDK.h

//
// FitSDK.h
// FitSDK
//
// Created by xaoxuu on 04/07/2017.
// Copyright © 2017 xaoxuu. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "FitAcitvity.h"

@interface FitSDK : NSObject

/**
创建一个活动数据fit文件

@param activity 活动数据
@return 活动数据模型
*/
+ (FitActivity *)createActivity:(void (^)(FitActivity *activity))activity;

@end

FitSDK.m

//
// FitSDK.m
// FitSDK
//
// Created by xaoxuu on 04/07/2017.
// Copyright © 2017 xaoxuu. All rights reserved.
//

#import "FitSDK.h"
#import "fit_mgr.h"

@implementation FitSDK

+ (FitActivity *)createActivity:(void (^)(FitActivity *activity))activity{
FitActivity *act = [FitActivity new];
if (activity) {
activity(act);
}
[self createActivityWithModel:act];
return act;
}


+ (void)createActivityWithModel:(FitActivity *)activity{
// @xaoxuu: fit file
const char *fp = [activity.path cStringUsingEncoding:NSUTF8StringEncoding];
fit_transaction(fp, activity.type, ^{
[activity.records enumerateObjectsUsingBlock:^(FitActivityRecord * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
fit_transaction_record_msg(obj.timestamp, obj.position_lat, obj.position_long, obj.distance, obj.altitude, obj.speed, obj.heart_rate);
}];
});
}

@end

使用

FitActivity *activity = [FitSDK createActivity:^(FitActivity *activity) {
activity.name = @"test";
activity.type = FitActivityTypeRun;
for (int i = 0; i<100; i++) {
[activity addRecord:^(FitActivityRecord *aRecord) {
aRecord.timestamp = [[NSDate date] timeIntervalSince1970] - 631065600;
aRecord.position_lat = 495280430+i*1000;
aRecord.position_long = -872696681-i*1500;
aRecord.distance = 2+i/100;
aRecord.altitude = 287.2+i;
aRecord.speed = 0.29+i/50;
aRecord.heart_rate = 68+i/4;
}];
}
}];
// activity.path就是生成的fit文件路径
NSLog(@"%@", activity.path);