advent-of-c-ode/libs/buffered_reader.c

#include "buffered_reader.h"

#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>

filelines* flines(const char* filename) {
  // Define input file
  FILE *file;
  file = fopen(filename, "r");

  //Define loop things
  bool loop = true;
  char *buffer;
  size_t bufsize = 8;
  size_t characters;

  filelines *lines;
  initFileLines(&lines);

  int c;
  //loop over file
  if (file) {
    while (loop) {
		int size = bufsize;
		buffer = (char *)malloc(size * sizeof(char));

		int i = 0;
		while((c = getc(file)) != EOF) {
			if (c == '\n') {
				break;
			}

			if (i == size) {
				size <<= 1;
				buffer = (char*)realloc(buffer, size * sizeof(char));
			}

			//TODO: resize string if input is too big
			buffer[i] = c;
			i += 1;
		}
		if (i > 0){
			if (i == size) {
				buffer = (char*)realloc(buffer, size * sizeof(char) + 1);
			}
			buffer[i] = '\0';
			insert(lines, buffer);
		}
		if (c == EOF) {
			break;
		}
    }
  }

 return lines;
}

void initFileLines(filelines **flines_ptr) {
	filelines *flines;
	flines = (filelines*)malloc(sizeof(filelines));
	if (!flines) {
		printf("Failed to allocate memory for filelines\n");
		exit(1);
	}

	flines->size = 0;
	flines->capacity = STARTING_SIZE;
	flines->lines = (char**)malloc(STARTING_SIZE * sizeof(char*));
	if (!flines->lines) {
		printf("Failed to allocate memory for lines in filelines\n");
		exit(1);
	}

	*flines_ptr = flines;
}

//inserts copy of string into array
void insert(filelines *flines_ptr, char *str){
	if (flines_ptr->size == flines_ptr->capacity) {
		char **temp = flines_ptr->lines;
		flines_ptr->capacity <<= 1;
		flines_ptr->lines = realloc(flines_ptr->lines, flines_ptr->capacity * sizeof(char*));
		if (!flines_ptr->lines) {
			printf("Out of mem\n");
			return;
		}
	}
	flines_ptr->lines[flines_ptr->size] = str;
	flines_ptr->size += 1;
}

char* get(filelines *flines_ptr, int index) {
	if(index >=flines_ptr->size) {
		printf("index out of bounds");
		return NULL;
	}
	return flines_ptr->lines[index];
}

void freeLines(filelines* flines_ptr){
	free(flines_ptr->lines);
	free(flines_ptr);
}