ref: fb2a95afedc6d559614675b9e0763301cbd56072
dir: /tools/lz/util.c/
#include "proto.h" noreturn error_exit (int error_code, const char * error, ...) { va_list ap; va_start(ap, error); fputs("error: ", stderr); vfprintf(stderr, error, ap); va_end(ap); fputc('\n', stderr); exit(error_code); } unsigned char * read_file_into_buffer (const char * file, unsigned short * size) { FILE * fp = file ? fopen(file, "rb") : stdin; if (!fp) error_exit(1, "could not open file %s for reading", file); unsigned char * buf = malloc(MAX_FILE_SIZE + 1); int rv = fread(buf, 1, MAX_FILE_SIZE + 1, fp); if (file) fclose(fp); if (rv < 0) error_exit(1, "could not read from file %s", file); if (rv > MAX_FILE_SIZE) error_exit(1, "file %s is too big", file ? file : "<standard input>"); *size = rv; return buf; } struct command pick_best_command (unsigned count, struct command command, ...) { struct command result = command; va_list ap; va_start(ap, command); while (-- count) { command = va_arg(ap, struct command); if (is_better(command, result)) result = command; } va_end(ap); return result; } int is_better (struct command new, struct command old) { if (new.command == 7) return 0; if (old.command == 7) return 1; short new_savings = new.count - command_size(new), old_savings = old.count - command_size(old); return new_savings > old_savings; } short command_size (struct command command) { short header_size = 1 + (command.count > SHORT_COMMAND_COUNT); if (command.command & 4) return header_size + 1 + (command.value >= 0); return header_size + command.command[(short []) {command.count, 1, 2, 0}]; } unsigned short compressed_length (const struct command * commands, unsigned short count) { unsigned short current, total = 0; for (current = 0; current < count; current ++) if (commands[current].command != 7) total += command_size(commands[current]); return total; }