C语言 泛型编程
奔驰的战猪 人气:0心理历程
写了一段时间C++后，真心感觉STL里的容器是个好东西。一个容器可以容纳任意类型，容器对外的接口可以操作任意类型的数据，甚至包括自定义类型的数据。这种泛型编程的思想，对于大型项目而言是非常有好处的。
对于C而言，想实现泛型编程并非易事，甚至可以说非常繁琐，一大堆坑。最主要也没有现成的轮子可用。当然也有一些通过宏实现了泛型的基础功能，但是可读性，可调试性太差了。
于是就想自己造一个轮子，实现基于C对窗口（顺序表）的泛化，目标就是实现不同类型下，规范接口的一致性。抛砖引玉。
轮子用法
int main( void )
{
// 1、创建一个窗口，并初始化它，大小为10，类型为double
ValueWindowSquential tmp;
InitValueWindow( &tmp, kValueTypeList[ DOUBLE ], 10 );
double insert_data = 0;
for ( int i = 0; i < tmp.max_size; i++ )
{
// 2、填充这个窗口，直到窗口填满
insert_data = i * 10;
if ( kWindowAlreadyFull == ValueWindowFixedInsert( &tmp, &insert_data ) )
{
// 3、打印整个窗口
printf( "start sort \r\n" );
ShowTheWindow( &tmp );
// 4、整个窗口排序
ValueWindowSelectSort( &tmp );
// 5、打印排序后的窗口
printf( "end sort \r\n" );
ShowTheWindow( &tmp );
break;
}
}
printf( "test generics \r\n" );
return 0;
}
打印log如下：
这时想换成创建一个uint8_t类型的串口，只需要改两个地方，这两个地方在C++里也避免不了。
int main( void )
{
ValueWindowSquential tmp;
InitValueWindow( &tmp, kValueTypeList[ UINT8 ], 10 );
uint8_t insert_data = 0;
for ( int i = 0; i < tmp.max_size; i++ )
{
insert_data = ( tmp.max_size - i ) * 1;
if ( kWindowAlreadyFull == ValueWindowFixedInsert( &tmp, &insert_data ) )
{
printf( "start sort \r\n" );
ShowTheWindow( &tmp );
ValueWindowSelectSort( &tmp );
printf( "end sort \r\n" );
ShowTheWindow( &tmp );
break;
}
}
printf( "test generics \r\n" );
return 0;
}
大体流程
1.首先初始化一个空窗口对象，然后调用 InitValueWindow 传入窗口类型，大小，然后初始化它。
2.调用 ValueWindowFixedInsert 往窗口中插入值，直到窗口满后反馈状态。
3.打印整个窗口
4.对窗口排序
5.打印整个窗口
这里的泛型主要通过查表实现了，将希望包含的类型加入表中，然后初始化时传入其类型和大小。
插入数据的时候，需要保证数据类型和窗口类型统一，这算是个局限性了。
窗口被填充完毕后，会有反馈窗口状态，这时可以调用 ShowTheWindow 将原始窗口打印。
在调用 ValueWindowSelectSort 将窗口排序。排序完后再次打印。
可以看到除了初始化的时候，需要设定窗口的类型，这和 std::vector< double > 没什么两样，插入数据时需要调用者确保数据类型与窗口统一。
部分源码
#ifndef __TEST_GENERICS_h
#define __TEST_GENERICS_h
#include <stdio.h>
#include <string.h>
#include <malloc.h>
#include <stdlib.h>
#include <assert.h>
typedef signed char int8_t;
typedef unsigned char uint8_t;
typedef signed short int16_t;
typedef unsigned short uint16_t;
typedef signed int int32_t;
typedef unsigned int uint32_t;
typedef enum
{
UINT8 = 0,
INT,
FLOAT,
DOUBLE,
ERROR
} TypeName;
const char* kValueTypeList[ ERROR + 1 ] = {
"uint8_t",
"int",
"float",
"double",
"error",
};
TypeName ChangeStringToEnum( const char* tmp );
/**
* @brief 该结构体用于构建基础窗口顺序表
* this structure is used to build the basic window sequence table
*/
typedef struct ValueWindowSquential
{
char* type;
void* data;
uint32_t max_size;
uint32_t sequence;
} ValueWindowSquential;
/**
* @brief 初始化窗口，根据窗口类型，大小，动态分配内存给到内部缓冲区
* initialize the window, and dynamically allocate memory to the internal buffer according to the window type and size
*
* @param tmp base structure for Window
* @param type Window type
* @param max_size Window size
*
* @throw assert
*/
void InitValueWindow( ValueWindowSquential* tmp, const char* type, uint32_t max_size );
/**
* @brief 重置或销毁窗口
* reset or destroy window
*
* @param tmp base structure for Window
*/
void ResetValueWindow( ValueWindowSquential* tmp );
typedef enum
{
kWindowIsNotFull = ( 0 ),
kWindowIsSliding,
kWindowCanNotInsert,
kWindowInputFail,
} SlideWindowState;
/**
* @brief 滑动插入数据进入窗口，先入先出（FIFO模型）
* slide insert data into the window, first in first out (FIFO model)
*
* @param tmp base structure for Window
* @param data insert data
*
* @return SlideWindowState
* kWindowIsNotFull 窗口未填充满
* kWindowIsSliding 窗口已填充满并开始滑动
*
* kWindowCanNotInsert 窗口不允许插入
* kWindowInputFail 窗口插入数据失败
*/
SlideWindowState ValueWindowSlideInsert( ValueWindowSquential* tmp, void* data );
typedef enum
{
kWindowNotFull = ( 0 ),
kWindowAlreadyFull,
kFixWindowCanNotInsert,
kFixWindowInputFail,
} FixedWindowState;
/**
* @brief 固定窗，往窗口里插入数据，直到窗口满了反馈 kWindowAlreadyFull ，否在反馈 kWindowNotFull
* 与滑动窗区别是，固定窗会采集多组数据，采集完成才能使用窗口，使用完后从头重新采集
* 也就是降频处理数据，窗口大小20,10ms插入一次，那么降频到200ms处理一次窗口（数据）
*
* @param tmp base structure for Window
* @param data insert data
*
* @return FixedWindowState
* kWindowNotFull 窗口未满
* kWindowAlreadyFull 窗口已满，可以开始操作
*
* kFixWindowCanNotInsert 窗口不允许插入
* kFixWindowInputFail 窗口插入数据失败
*/
FixedWindowState ValueWindowFixedInsert( ValueWindowSquential* tmp, void* data );
/**
* @brief 遍历并打印窗口
*
* @param tmp base structure for Window
*/
void ShowTheWindow( ValueWindowSquential* tmp );
#endif // __TEST_GENERICS_h
/**
* @file test_generics.cpp
* @author benzs_war_pig (benzwarpig@outlook.com)
* @brief 构建一种基于C的泛型顺序表,针对不同类型的顺序表，实现接口一致化。
* 同时针对顺序表实现一些常用操作（排序，滤波，统计等）
*
* build a generic sequence table based on C, and realize interface consistency
* for different types of sequence tables. At the same time, some common operations (sorting, filtering, statistics, etc.)
* are implemented for the sequence table
*
* @version 1.0
* @date 2022-06-30
*
* @copyright Copyright (c) 2022
*
*/
#include "test_generics.h"
#include "generics_impl.h"
/**
* @brief 将字符串转换成TypeName
* private interface
*
* @param tmp
* @return TypeName
*/
TypeName ChangeStringToEnum( const char* tmp )
{
assert( tmp != NULL );
TypeName return_tmp = ERROR;
if ( strcmp( tmp, kValueTypeList[ UINT8 ] ) == 0 )
{
return_tmp = UINT8;
}
else if ( strcmp( tmp, kValueTypeList[ FLOAT ] ) == 0 )
{
return_tmp = FLOAT;
}
else if ( strcmp( tmp, kValueTypeList[ DOUBLE ] ) == 0 )
{
return_tmp = DOUBLE;
}
else if ( strcmp( tmp, kValueTypeList[ INT ] ) == 0 )
{
return_tmp = INT;
}
else
{
printf( "error char* input !!!" );
assert( 0 );
}
return return_tmp;
}
// 初始化窗口
// Initialize window
void InitValueWindow( ValueWindowSquential* tmp, const char* type, uint32_t max_size )
{
assert( tmp != NULL );
tmp->type = ( char* ) malloc( strlen( type ) * sizeof( char ) );
strncpy( tmp->type, type, strlen( type ) );
tmp->max_size = max_size;
tmp->sequence = 0;
switch ( ChangeStringToEnum( tmp->type ) )
{
case UINT8: {
tmp->data = ( uint8_t* ) malloc( max_size * sizeof( uint8_t ) );
memset( tmp->data, 0, tmp->max_size );
}
break;
case INT: {
tmp->data = ( int* ) malloc( max_size * sizeof( int ) );
memset( tmp->data, 0, tmp->max_size );
}
break;
case FLOAT: {
tmp->data = ( float* ) malloc( max_size * sizeof( float ) );
memset( tmp->data, 0, tmp->max_size );
}
break;
case DOUBLE: {
tmp->data = ( double* ) malloc( max_size * sizeof( double ) );
memset( tmp->data, 0, tmp->max_size );
}
break;
default: {
printf( "error tmp->type input !!!" );
assert( 0 );
}
break;
}
printf( "type is : %s , number is : %d \r\n", tmp->type, max_size );
}
// 重置/销毁窗口
void ResetValueWindow( ValueWindowSquential* tmp )
{
tmp->sequence = 0;
tmp->max_size = 0;
if ( tmp->data != NULL )
{
free( tmp->data );
tmp->data = NULL;
}
if ( tmp->type != NULL )
{
free( tmp->type );
tmp->type = NULL;
}
}
// 滑动往窗口插入数据
SlideWindowState ValueWindowSlideInsert( ValueWindowSquential* tmp, void* data )
{
SlideWindowState return_tmp = kWindowIsNotFull;
switch ( ChangeStringToEnum( tmp->type ) )
{
case UINT8: {
uint8_t* tmp_buffer = ( uint8_t* ) tmp->data;
for ( int i = 1; i < tmp->max_size; i++ )
{
tmp_buffer[ i - 1 ] = tmp_buffer[ i ];
}
uint8_t* res = ( uint8_t* ) data;
tmp_buffer[ tmp->max_size - 1 ] = *res;
}
break;
case INT: {
int* tmp_buffer = ( int* ) tmp->data;
for ( int i = 1; i < tmp->max_size; i++ )
{
tmp_buffer[ i - 1 ] = tmp_buffer[ i ];
}
int* res = ( int* ) data;
tmp_buffer[ tmp->max_size - 1 ] = *res;
}
break;
case FLOAT: {
float* tmp_buffer = ( float* ) tmp->data;
for ( int i = 1; i < tmp->max_size; i++ )
{
tmp_buffer[ i - 1 ] = tmp_buffer[ i ];
}
float* res = ( float* ) data;
tmp_buffer[ tmp->max_size - 1 ] = *res;
}
break;
case DOUBLE: {
double* tmp_buffer = ( double* ) tmp->data;
for ( int i = 1; i < tmp->max_size; i++ )
{
tmp_buffer[ i - 1 ] = tmp_buffer[ i ];
}
double* res = ( double* ) data;
tmp_buffer[ tmp->max_size - 1 ] = *res;
}
break;
default: {
printf( "error tmp->type input !!!" );
assert( 0 );
}
break;
}
if ( ++tmp->sequence > tmp->max_size )
{
return_tmp = kWindowIsSliding;
tmp->sequence = tmp->max_size;
}
return return_tmp;
}
// 插入数据直到填满整个窗口
FixedWindowState ValueWindowFixedInsert( ValueWindowSquential* tmp, void* data )
{
FixedWindowState return_tmp = kWindowNotFull;
switch ( ChangeStringToEnum( tmp->type ) )
{
case UINT8: {
uint8_t* tmp_buffer = ( uint8_t* ) tmp->data;
uint8_t* res = ( uint8_t* ) data;
tmp_buffer[ tmp->sequence ] = *res;
}
break;
case INT: {
int* tmp_buffer = ( int* ) tmp->data;
int* res = ( int* ) data;
tmp_buffer[ tmp->sequence ] = *res;
}
break;
case FLOAT: {
float* tmp_buffer = ( float* ) tmp->data;
float* res = ( float* ) data;
tmp_buffer[ tmp->sequence ] = *res;
}
break;
case DOUBLE: {
double* tmp_buffer = ( double* ) tmp->data;
double* res = ( double* ) data;
tmp_buffer[ tmp->sequence ] = *res;
}
break;
default: {
printf( "error tmp->type input !!!" );
assert( 0 );
}
break;
}
if ( ++tmp->sequence >= tmp->max_size )
{
tmp->sequence = 0;
return_tmp = kWindowAlreadyFull;
}
return return_tmp;
}
// 打印窗口内全部值
void ShowTheWindow( ValueWindowSquential* tmp )
{
// printf("current_type:{%d}", ChangeStringToEnum(tmp->type));
switch ( ChangeStringToEnum( tmp->type ) )
{
case UINT8: {
uint8_t* msg = ( uint8_t* ) tmp->data;
for ( int i = 0; i < tmp->max_size; ++i )
{
printf( "i : {%d} , %d \r\n", i, msg[ i ] );
}
}
break;
case INT: {
int* msg = ( int* ) tmp->data;
for ( int i = 0; i < tmp->max_size; ++i )
{
printf( "i : {%d} , %d \r\n", i, msg[ i ] );
}
}
break;
case FLOAT: {
float* msg = ( float* ) tmp->data;
for ( int i = 0; i < tmp->max_size; ++i )
{
printf( "i : {%d} , %f \r\n", i, msg[ i ] );
}
}
break;
case DOUBLE: {
double* msg = ( double* ) tmp->data;
for ( int i = 0; i < tmp->max_size; ++i )
{
printf( "i : {%d} , %f \r\n", i, msg[ i ] );
}
}
break;
default: {
printf( "error tmp->type input !!!" );
assert( 0 );
}
break;
}
}
int main( void )
{
ValueWindowSquential tmp;
InitValueWindow( &tmp, kValueTypeList[ DOUBLE ], 10 );
double insert_data = 0;
for ( int i = 0; i < tmp.max_size; i++ )
{
insert_data = ( tmp.max_size - i ) * 10;
if ( kWindowAlreadyFull == ValueWindowFixedInsert( &tmp, &insert_data ) )
{
printf( "start sort \r\n" );
ShowTheWindow( &tmp );
ValueWindowSelectSort( &tmp );
printf( "end sort \r\n" );
ShowTheWindow( &tmp );
break;
}
}
ResetValueWindow(&tmp);
printf( "test generics \r\n" );
return 0;
}
这是最开始的一版源码，基本的思路是基于 void* 实现对窗口的泛化，把窗口的地址，大小，类型 在初始化时设定好，以后所有的结构便基于这些信息，实现接口一致性。
目前实现了两种窗口类型, ValueWindowSlideInsert (滑动窗) 和 ValueWindowFixedInsert(固定窗) 。 两者不同之处只是插入数据时的处理不同。滑动窗遵循FIFO模型，即先入先出，窗口状态有未满和开始滑动，一般开始滑动后再对窗口进行操作。
固定窗有未满和已满两种状态，已满后会清空窗口，重新开始填充，这也是两种常见的窗口模型。
在STL里，当有一些底层数据结构去存储数据时，要有一些容器的方法（算法），比如排序等，这里先实现了一些基础的泛型算法接口：
#ifndef GENERICS_IMPL_H
#define GENERICS_IMPL_H
#include <stdbool.h>
#include "test_generics.h"
/**
* @file generics_impl.h
* @author benzs_war_pig (benzwarpig@outlook.com)
* @brief 该文件实现了一些操作泛型顺序表的算法，如排序，查找，遍历，判断变化率等等
*
* this file implements some algorithms for operating generic sequential tables, such as sorting, searching, traversing,
* judging the rate of change, and so on
*
* @version 1.0
* @date 2022-06-30
*
* @copyright Copyright (c) 2022
*
*/
/**
* @brief 交换顺序表中两个成员的值
*
* @param tmp base structure for Window
* @param i
* @param j
*/
static void swap( ValueWindowSquential* tmp, uint32_t i, uint32_t j )
{
assert( tmp != NULL );
// assert( i > tmp->max_size || j > tmp->max_size );
// assert( i >= tmp->max_size || j >= tmp->max_size );
switch ( ChangeStringToEnum( tmp->type ) )
{
case UINT8: {
uint8_t* tmp_buffer = ( uint8_t* ) tmp->data;
uint8_t res = tmp_buffer[ i ];
tmp_buffer[ i ] = tmp_buffer[ j ];
tmp_buffer[ j ] = res;
}
break;
case INT: {
int* tmp_buffer = ( int* ) tmp->data;
int res = tmp_buffer[ i ];
tmp_buffer[ i ] = tmp_buffer[ j ];
tmp_buffer[ j ] = res;
}
break;
case FLOAT: {
float* tmp_buffer = ( float* ) tmp->data;
float res = tmp_buffer[ i ];
tmp_buffer[ i ] = tmp_buffer[ j ];
tmp_buffer[ j ] = res;
}
break;
case DOUBLE: {
double* tmp_buffer = ( double* ) tmp->data;
double res = tmp_buffer[ i ];
tmp_buffer[ i ] = tmp_buffer[ j ];
tmp_buffer[ j ] = res;
}
break;
default: {
printf( "error tmp->type input !!!" );
assert( 0 );
}
break;
}
}
static inline void ValueWindowBubbleSort( ValueWindowSquential* tmp )
{
switch ( ChangeStringToEnum( tmp->type ) )
{
case UINT8: {
uint8_t* tmp_buffer = ( uint8_t* ) tmp->data;
bool is_end_loop = true;
for ( int i = 0; i < tmp->max_size && is_end_loop; i++ )
{
is_end_loop = false;
for ( int j = tmp->max_size - 1; j >= i; j-- )
{
if ( tmp_buffer[ j - 1 ] > tmp_buffer[ j ] )
{
swap( tmp, j - 1, j );
is_end_loop = true;
}
}
}
}
break;
case INT: {
int* tmp_buffer = ( int* ) tmp->data;
bool is_end_loop = true;
for ( int i = 0; i < tmp->max_size && is_end_loop; i++ )
{
is_end_loop = false;
for ( int j = tmp->max_size - 1; j >= i; j-- )
{
if ( tmp_buffer[ j - 1 ] > tmp_buffer[ j ] )
{
swap( tmp, j - 1, j );
is_end_loop = true;
}
}
}
}
break;
case FLOAT: {
float* tmp_buffer = ( float* ) tmp->data;
bool is_end_loop = true;
for ( int i = 0; i < tmp->max_size && is_end_loop; i++ )
{
is_end_loop = false;
for ( int j = tmp->max_size - 1; j >= i; j-- )
{
if ( tmp_buffer[ j - 1 ] > tmp_buffer[ j ] )
{
swap( tmp, j - 1, j );
is_end_loop = true;
}
}
}
}
break;
case DOUBLE: {
double* tmp_buffer = ( double* ) tmp->data;
bool is_end_loop = true;
for ( int i = 0; i < tmp->max_size && is_end_loop; i++ )
{
is_end_loop = false;
for ( int j = tmp->max_size - 1; j >= i; j-- )
{
if ( tmp_buffer[ j - 1 ] > tmp_buffer[ j ] )
{
swap( tmp, j - 1, j );
is_end_loop = true;
}
}
}
}
break;
default: {
printf( "error tmp->type input !!!" );
assert( 0 );
}
break;
}
}
static inline void ValueWindowSelectSort( ValueWindowSquential* tmp )
{
switch ( ChangeStringToEnum( tmp->type ) )
{
case UINT8: {
uint8_t* tmp_buffer = ( uint8_t* ) tmp->data;
int tmp_data = 0;
for ( int i = 0; i < tmp->max_size; i++ )
{
tmp_data = i;
for ( int j = i; j < tmp->max_size; j++ )
{
if ( tmp_buffer[ tmp_data ] > tmp_buffer[ j ] )
{
tmp_data = j;
}
}
if ( tmp_data != i )
{
swap( tmp, i, tmp_data );
}
}
}
break;
case INT: {
int* tmp_buffer = ( int* ) tmp->data;
int tmp_data = 0;
for ( int i = 0; i < tmp->max_size; i++ )
{
tmp_data = i;
for ( int j = i; j < tmp->max_size; j++ )
{
if ( tmp_buffer[ tmp_data ] > tmp_buffer[ j ] )
{
tmp_data = j;
}
}
if ( tmp_data != i )
{
swap( tmp, i, tmp_data );
}
}
}
break;
case FLOAT: {
float* tmp_buffer = ( float* ) tmp->data;
int tmp_data = 0;
for ( int i = 0; i < tmp->max_size; i++ )
{
tmp_data = i;
for ( int j = i; j < tmp->max_size; j++ )
{
if ( tmp_buffer[ tmp_data ] > tmp_buffer[ j ] )
{
tmp_data = j;
}
}
if ( tmp_data != i )
{
swap( tmp, i, tmp_data );
}
}
}
break;
case DOUBLE: {
double* tmp_buffer = ( double* ) tmp->data;
int tmp_data = 0;
for ( int i = 0; i < tmp->max_size; i++ )
{
tmp_data = i;
for ( int j = i; j < tmp->max_size; j++ )
{
if ( tmp_buffer[ tmp_data ] > tmp_buffer[ j ] )
{
tmp_data = j;
}
}
if ( tmp_data != i )
{
swap( tmp, i, tmp_data );
}
}
}
break;
default: {
printf( "error tmp->type input !!!" );
assert( 0 );
}
break;
}
}
static inline void ValueWindowInsertSort( ValueWindowSquential* tmp )
{
switch ( ChangeStringToEnum( tmp->type ) )
{
case UINT8: {
uint8_t* tmp_buffer = ( uint8_t* ) tmp->data;
uint8_t tmp_data = 0;
int j = 0;
for ( int i = 1; i < tmp->max_size; i++ )
{
if ( tmp_buffer[ i ] < tmp_buffer[ i - 1 ] )
{
tmp_data = tmp_buffer[ i ];
// TAG : 数据整体向后迁移,寻找数值更大的成员
for ( j = i - 1; tmp_buffer[ j ] > tmp_data && j >= 0; j-- )
{
tmp_buffer[ j + 1 ] = tmp_buffer[ j ];
}
tmp_buffer[ j + 1 ] = tmp_data;
}
}
}
break;
case INT: {
int* tmp_buffer = ( int* ) tmp->data;
int tmp_data = 0;
int j = 0;
for ( int i = 1; i < tmp->max_size; i++ )
{
if ( tmp_buffer[ i ] < tmp_buffer[ i - 1 ] )
{
tmp_data = tmp_buffer[ i ];
// TAG : 数据整体向后迁移,寻找数值更大的成员
for ( j = i - 1; tmp_buffer[ j ] > tmp_data && j >= 0; j-- )
{
tmp_buffer[ j + 1 ] = tmp_buffer[ j ];
}
tmp_buffer[ j + 1 ] = tmp_data;
}
}
}
break;
case FLOAT: {
float* tmp_buffer = ( float* ) tmp->data;
float tmp_data = 0;
int j = 0;
for ( int i = 1; i < tmp->max_size; i++ )
{
if ( tmp_buffer[ i ] < tmp_buffer[ i - 1 ] )
{
tmp_data = tmp_buffer[ i ];
// TAG : 数据整体向后迁移,寻找数值更大的成员
for ( j = i - 1; tmp_buffer[ j ] > tmp_data && j >= 0; j-- )
{
tmp_buffer[ j + 1 ] = tmp_buffer[ j ];
}
tmp_buffer[ j + 1 ] = tmp_data;
}
}
}
break;
case DOUBLE: {
double* tmp_buffer = ( double* ) tmp->data;
double tmp_data = 0;
int j = 0;
for ( int i = 1; i < tmp->max_size; i++ )
{
if ( tmp_buffer[ i ] < tmp_buffer[ i - 1 ] )
{
tmp_data = tmp_buffer[ i ];
// TAG : 数据整体向后迁移,寻找数值更大的成员
for ( j = i - 1; tmp_buffer[ j ] > tmp_data && j >= 0; j-- )
{
tmp_buffer[ j + 1 ] = tmp_buffer[ j ];
}
tmp_buffer[ j + 1 ] = tmp_data;
}
}
}
break;
default: {
printf( "error tmp->type input !!!" );
assert( 0 );
}
break;
}
}
#endif // GENERICS_IMPL_H
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