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/*
*
*/
#include "cdf.h"
/*
* Global configuration variables. These are set based on command-line
* arguments, and read-only beyond that point.
*/
static bool ARG_REVERSE_CDF = false;
static bool ARG_FP_INPUT = false;
static bool ARG_UINT_INPUT = false;
static bool ARG_HELP = false;
static int parse_options(int argc, char *const *argv) {
int arg_index = 0;
int arg;
bool error = false;
while ((arg = getopt(argc, argv, "frhu")) != -1 && !error) {
switch (arg) {
case 'f':
ARG_FP_INPUT = true;
break;
case 'r':
ARG_REVERSE_CDF = true;
break;
case 'u':
ARG_UINT_INPUT = true;
break;
case 'h':
ARG_HELP = true;
break;
case '?':
if (isprint(optopt)) {
fprintf(stderr, "Error: unknown option `-%c`.\n", optopt);
} else {
fprintf(stderr, "Error: unknown option character `\\x%x`.\n", optopt);
}
error = true;
break;
default:
error = true;
break;
}
}
if (ARG_UINT_INPUT && ARG_FP_INPUT) {
fprintf(stderr, "Error: the -u and -f flags are mutually exclusive.\n");
error = true;
}
if (!error) {
arg_index = optind;
}
return arg_index;
}
static void help() { fprintf(stderr, "Usage:\ncdf [-f|-u] [-r] [filename]\n"); }
static DistRecord *expand_array(DistRecord *records, size_t *capacity) {
(*capacity) *= 2;
DistRecord *new = realloc(records, (*capacity * sizeof(DistRecord)));
if (!new) {
fprintf(stderr, "ERROR: Memory allocation failed\n");
return nullptr;
}
return new;
}
static int parse_line(DistRecord *record, char *line) {
if (ARG_FP_INPUT) {
return sscanf(line, "%lld %lf", &record->count, &record->data.d);
} else if (ARG_UINT_INPUT) {
return sscanf(line, "%lld %llu", &record->count, &record->data.u);
} else {
return sscanf(line, "%lld %lld", &record->count, &record->data.i);
}
}
static ssize_t read_data(DistRecord **records, size_t capacity, FILE *file) {
size_t reccnt = 0;
char *line = nullptr;
size_t line_len = 0;
while (getline(&line, &line_len, file) != -1) {
if (parse_line(*records + reccnt, line) != 2) {
fprintf(stderr, "[W] Skipping invalid input line: %s\n", line);
continue;
}
reccnt++;
if (reccnt == capacity) {
if (!(*records = expand_array(*records, &capacity))) {
return -1;
}
}
}
return reccnt;
}
static void print_record(long double freq, DistRecord *record) {
if (ARG_FP_INPUT) {
fprintf(stdout, "%.15Lf\t%lf\n", freq, record->data.d);
} else if (ARG_UINT_INPUT) {
fprintf(stdout, "%.15Lf\t%llu\n", freq, record->data.u);
} else {
fprintf(stdout, "%.15Lf\t%lld\n", freq, record->data.i);
}
}
static int print_data(DistRecord *records, long double *freqs, size_t cnt) {
if (ARG_REVERSE_CDF) {
long double total_freq = 1.0;
for (size_t i = 0; i < cnt; i++) {
print_record(total_freq, records + i);
total_freq -= freqs[i];
}
} else {
for (size_t i = 0; i < cnt; i++) {
print_record(freqs[i], records + i);
}
}
return 1;
}
static int process_data(FILE *file) {
int rc = 1;
size_t reccap = 100;
DistRecord *records = malloc(reccap * sizeof(DistRecord));
if (!records) {
rc = 0;
goto process_data_end;
}
ssize_t cnt = read_data(&records, reccap, file);
/* propogate the error */
if (cnt == -1) {
rc = 0;
goto free_records;
}
/* calculate total sum of counts */
uint64_t total_count = 0;
for (size_t i = 0; i < cnt; i++) {
total_count += records[i].count;
}
/* calculate relative frequency for each item */
long double *freqs = malloc(sizeof(long double) * cnt);
if (!freqs) {
fprintf(stderr, "ERROR: memory allocation failure.\n");
goto free_freqs;
}
for (size_t i = 0; i < cnt; i++) {
freqs[i] = (long double)(records[i].count) / (long double)(total_count);
}
rc = print_data(records, freqs, cnt);
free_freqs:
free(freqs);
free_records:
free(records);
process_data_end:
return rc;
}
int main(int argc, char **argv) {
int rc = EXIT_SUCCESS;
int file_index = 0;
if (!(file_index = parse_options(argc, argv))) {
help();
rc = EXIT_FAILURE;
goto program_exit;
}
/* if the -h argument is supplied, print usage and exit successfully */
if (ARG_HELP) {
help();
goto program_exit;
}
/* open the input file, if one is specified, otherwise default to stdin */
FILE *input_file;
if (file_index < argc && strcmp(argv[file_index], "-") != 0) {
if (!(input_file = fopen(argv[file_index], "r"))) {
fprintf(stderr, "Error: Unable to open input file %s\n",
argv[file_index]);
rc = EXIT_FAILURE;
goto program_exit;
}
} else {
input_file = stdin;
}
if (!process_data(input_file)) {
rc = EXIT_FAILURE;
}
close_file:
if (input_file != stdin) {
fclose(input_file);
}
program_exit:
exit(rc);
}
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