#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "common.h"

struct blob blob_new(void) {
	return (struct blob) {.data = NULL, .size = 0};
}

void blob_append(struct blob *const blob, void const *const data, size_t const size) {
	char *new = realloc(blob->data, blob->size + size);
	if (new == NULL) {
		abort();
	}
	memcpy(new + blob->size, data, size);
	blob->data = new;
	blob->size += size;
}

void blob_free(struct blob *const blob) {
	free(blob->data);
	blob->data = NULL;
	blob->size = 0;
}

struct blob load_file(char const *const name) {
	const size_t START_SIZE = 8192;
	FILE *file = fopen(name, "rb");
	if (file == NULL) {
		return (struct blob) {.data = NULL};
	}
	char *data = malloc(START_SIZE);
	size_t allocated = START_SIZE;
	size_t used = 0;
	while (1) {
		size_t read = fread(data + used, 1, allocated - used, file);
		if (read != allocated - used) {
			used += read;
			break;
		}
		used += read;
		allocated *= 2;
		void *const newdata = realloc(data, allocated);
		if (newdata == NULL) {
			goto realloc_error;
		}
		data = newdata;
	}
	if (used == 0) {
		free(data);
		fclose(file);
		return (struct blob) {.data = NULL, .size = 0};
	}
	void *const newdata = realloc(data, used);
	if (newdata == NULL) {
		goto realloc_error;
	}
	fclose(file);
	return (struct blob) {.data = newdata, .size = used};
	
	realloc_error:
	free(data);
	fclose(file);
	return (struct blob) {.data = NULL};
}