ngx_http_websocket_stat_frame_counter.h

#include <ngx_core.h>

static const unsigned int MASK_SIZE = 4;

typedef enum {
    HEADER,
    PAYLOAD_LEN,
    PAYLOAD_LEN_LARGE,
    PAYLOAD_LEN_HUGE,
    MASK,
    PAYLOAD
} packet_reading_stage;

typedef enum { CONTINUATION, TEXT, BINARY, CLOSE = 8, PING, PONG } frame_type;

// Structure representing frame statistic and parsing stage
typedef struct {
    ngx_int_t total_payload_size;

    // private fields representing current parcing stage
    ngx_int_t bytes_consumed;
    packet_reading_stage stage;
    char payload_masked : 1;
    frame_type current_frame_type;
    ngx_int_t current_payload_size;
} ngx_frame_counter_t;

const char *frame_type_to_str(frame_type frame);
char frame_counter_process_message(u_char **buffer, ssize_t *size,
                                   ngx_frame_counter_t *frame_counter);
const char *frame_type_to_str(frame_type frame);