tree.c

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include "tree.h"
#include "index.h"
#include "object.h"
#include "path.h"

char *write_tree() {
    char *indexpath = get_repo_troll_dir();
    indexpath = (char *) realloc(indexpath, strlen(indexpath) + 5);
    strcat(indexpath, "index");

    int fd = open(indexpath, O_RDWR);
    free(indexpath);

    struct stat buf;
    fstat(fd, &buf);

    char *data = (char *) malloc((size_t) buf.st_size + 15);
    sprintf(data, "tree %lu", (unsigned long) buf.st_size);
    int left_part_len = strlen(data) + 1;
    read(fd, data + left_part_len, buf.st_size);
    int full_len = left_part_len + buf.st_size;

    char *hash = hash_object(data, full_len);

    char *path = get_repo_troll_dir();
    path = (char *) realloc(path, strlen(path) + 49); // Path + "objects/" + 40 digit hash + null terminator
    strcat(path, "objects/");
    strncat(path, hash, 40);

    /* Create object file */
    int objectfd = open(path, O_CREAT | O_TRUNC | O_WRONLY, 0644);
    write(objectfd, data, full_len);

    return hash;
}