#ifndef HEATSHRINK_ENCODER_H #define HEATSHRINK_ENCODER_H #include <stdint.h> #include <stddef.h> #include "heatshrink_common.h" #include "heatshrink_config.h" typedef enum { HSER_SINK_OK, /* data sunk into input buffer */ HSER_SINK_ERROR_NULL=-1, /* NULL argument */ HSER_SINK_ERROR_MISUSE=-2, /* API misuse */ } HSE_sink_res; typedef enum { HSER_POLL_EMPTY, /* input exhausted */ HSER_POLL_MORE, /* poll again for more output */ HSER_POLL_ERROR_NULL=-1, /* NULL argument */ HSER_POLL_ERROR_MISUSE=-2, /* API misuse */ } HSE_poll_res; typedef enum { HSER_FINISH_DONE, /* encoding is complete */ HSER_FINISH_MORE, /* more output remaining; use poll */ HSER_FINISH_ERROR_NULL=-1, /* NULL argument */ } HSE_finish_res; #if HEATSHRINK_DYNAMIC_ALLOC #define HEATSHRINK_ENCODER_WINDOW_BITS(HSE) \ ((HSE)->window_sz2) #define HEATSHRINK_ENCODER_LOOKAHEAD_BITS(HSE) \ ((HSE)->lookahead_sz2) #define HEATSHRINK_ENCODER_INDEX(HSE) \ ((HSE)->search_index) struct hs_index { uint16_t size; int16_t index[]; }; #else #define HEATSHRINK_ENCODER_WINDOW_BITS(_) \ (HEATSHRINK_STATIC_WINDOW_BITS) #define HEATSHRINK_ENCODER_LOOKAHEAD_BITS(_) \ (HEATSHRINK_STATIC_LOOKAHEAD_BITS) #define HEATSHRINK_ENCODER_INDEX(HSE) \ (&(HSE)->search_index) struct hs_index { uint16_t size; int16_t index[2 << HEATSHRINK_STATIC_WINDOW_BITS]; }; #endif typedef struct { uint16_t input_size; /* bytes in input buffer */ uint16_t match_scan_index; uint16_t match_length; uint16_t match_pos; uint16_t outgoing_bits; /* enqueued outgoing bits */ uint8_t outgoing_bits_count; uint8_t flags; uint8_t state; /* current state machine node */ uint8_t current_byte; /* current byte of output */ uint8_t bit_index; /* current bit index */ #if HEATSHRINK_DYNAMIC_ALLOC uint8_t window_sz2; /* 2^n size of window */ uint8_t lookahead_sz2; /* 2^n size of lookahead */ #if HEATSHRINK_USE_INDEX struct hs_index *search_index; #endif /* input buffer and / sliding window for expansion */ uint8_t* buffer; #else #if HEATSHRINK_USE_INDEX struct hs_index search_index; #endif /* input buffer and / sliding window for expansion */ uint8_t buffer[2 << HEATSHRINK_ENCODER_WINDOW_BITS(_)]; #endif } heatshrink_encoder; #if HEATSHRINK_DYNAMIC_ALLOC /* Allocate a new encoder struct and its buffers. * Returns NULL on error. */ heatshrink_encoder *heatshrink_encoder_alloc(uint8_t* buffer, uint8_t window_sz2, uint8_t lookahead_sz2); /* Free an encoder. */ void heatshrink_encoder_free(heatshrink_encoder *hse); #endif /* Reset an encoder. */ void heatshrink_encoder_reset(heatshrink_encoder *hse); /* Sink up to SIZE bytes from IN_BUF into the encoder. * INPUT_SIZE is set to the number of bytes actually sunk (in case a * buffer was filled.). */ HSE_sink_res heatshrink_encoder_sink(heatshrink_encoder *hse, uint8_t *in_buf, size_t size, size_t *input_size); /* Poll for output from the encoder, copying at most OUT_BUF_SIZE bytes into * OUT_BUF (setting *OUTPUT_SIZE to the actual amount copied). */ HSE_poll_res heatshrink_encoder_poll(heatshrink_encoder *hse, uint8_t *out_buf, size_t out_buf_size, size_t *output_size); /* Notify the encoder that the input stream is finished. * If the return value is HSER_FINISH_MORE, there is still more output, so * call heatshrink_encoder_poll and repeat. */ HSE_finish_res heatshrink_encoder_finish(heatshrink_encoder *hse); #endif