User configuration

This section explains how to customize the library for your project: enable or disable type-specific APIs, replace memory/copy primitives, and pass options via your build system.

Overview

Type support is controlled by macros in include/statistics_config.h.
A simple port layer allows you to plug in your own allocator and memcpy.
The processing window (sample size and count) is chosen at runtime in Statistics_Init.

Type support toggles

Use these compile-time switches to enable/disable the generated typed functions for basic statistics. If a macro is not defined, it defaults to 1 (enabled).

Defined in include/statistics_config.h:

#ifndef STATISTICS_U8_ENABLED   /* uint8_t */
#define STATISTICS_U8_ENABLED   1
#endif

#ifndef STATISTICS_I8_ENABLED   /* int8_t */
#define STATISTICS_I8_ENABLED   1
#endif

#ifndef STATISTICS_U16_ENABLED  /* uint16_t */
#define STATISTICS_U16_ENABLED  1
#endif

#ifndef STATISTICS_I16_ENABLED  /* int16_t */
#define STATISTICS_I16_ENABLED  1
#endif

#ifndef STATISTICS_U32_ENABLED  /* uint32_t */
#define STATISTICS_U32_ENABLED  1
#endif

#ifndef STATISTICS_I32_ENABLED  /* int32_t */
#define STATISTICS_I32_ENABLED  1
#endif

#ifndef STATISTICS_FLOAT_ENABLED /* float */
#define STATISTICS_FLOAT_ENABLED 1
#endif

How to change values:

Compiler flags (recommended):

GCC/Clang

cc -DSTATISTICS_FLOAT_ENABLED=0 -DSTATISTICS_U8_ENABLED=0 ...

CMake

target_compile_definitions(my_target PRIVATE
  STATISTICS_FLOAT_ENABLED=0
  STATISTICS_U8_ENABLED=0)

PlatformIO (platformio.ini)

build_flags =
  -DSTATISTICS_FLOAT_ENABLED=0
  -DSTATISTICS_U8_ENABLED=0

Or define prior to including statistics_config.h in a translation unit:
```
#define STATISTICS_FLOAT_ENABLED 0
#include <statistics.h>
```

Port layer (custom allocators/memcpy)

By default the library uses the C runtime: malloc, calloc, free and memcpy. To override this, define STATISTICS_PORT_USER in your build and provide compatible macros before including statistics_config.h:

Required macros when using a custom port:

statPortMalloc(size)
statPortCalloc(num, size)
statPortFree(ptr)
statPortMemcpy(dest, src, count)
statPortMemset(ptr, val, count)

Example (wrapping a custom allocator):

#define STATISTICS_PORT_USER 1
#include <my_allocator.h>

#define statPortMalloc(sz)               my_malloc(sz)
#define statPortCalloc(n, sz)            my_calloc(n, sz)
#define statPortFree(p)                  my_free(p)
#define statPortMemcpy(d, s, n)          my_memcpy(d, s, n)
#define statPortMemset(ptr, val, count)  memset(ptr, val, count)

#include <statistics.h>

Runtime window configuration

The size (in bytes) of one sample and the window length (number of samples) are passed to Statistics_Init at runtime:

Statistics s;
Statistics_Init(&s, sizeof(uint16_t), 32); // 32-sample window of uint16_t

Guidelines:

For typed statistics functions (e.g., Statistics_Mean_U16), make sure the itemSize you pass matches the type.
Memory footprint is approximately itemSize * samplesCount bytes per instance, plus small overhead for the structure itself.

Build system quick reference

GCC/Clang CLI

cc -Iinclude -DSTATISTICS_U8_ENABLED=0 -c src/statistics.c