1 files changed, 103 insertions, 0 deletions
diff --git a/c_implementation/src/ak_fs.c b/c_implementation/src/ak_fs.c
index 6594f2d..8ede3f6 100644
--- a/c_implementation/src/ak_fs.c
+++ b/c_implementation/src/ak_fs.c
@@ -278,3 +278,106 @@ int ak_fs_ls()
     ak_fs_maps_v3_print_bif(&maps_ptr, len);
     return 0;
 }
+
+int ak_fs_cat_file_from_root_hash(const sha512sum* rh)
+{
+    const char* chunks_dir = getenv("AK_CHUNKSDIR");
+    if ( chunks_dir == NULL )
+    {
+        ak_log_error(__func__, "No directory for chunks found");
+        return -2;
+    }
+    const char* leafs_dir = getenv("AK_LEAFSDIR");
+    if ( leafs_dir == NULL )
+    {
+        ak_log_error(__func__, "No directory for leafs found");
+        return -3;
+    }
+    FILE *fd;
+    char *fullpath;
+    bool is_chunk = false;
+    char root_hash_str[129] = {0};
+    ak_fs_sha512sum_struct_to_string(rh, root_hash_str);
+    if ( asprintf(&fullpath, "%s/%s", leafs_dir, root_hash_str) == -1 ) return -1;
+    fd = fopen(fullpath, "r");
+    if ( fd == NULL )
+    {
+        free(fullpath);
+        if ( asprintf(&fullpath, "%s/%s", chunks_dir, ak_fs_sha512sum_struct_read_as_string(rh)) == -1 ) return -1;
+        fd = fopen(fullpath, "r");
+        if ( fd == NULL )
+        {
+            ak_log_error(__func__, "Could not be found");
+            free(fullpath);
+            return 1;
+        }
+        is_chunk = true;
+    }
+    if ( !is_chunk )
+    {
+        char buffer[258] = {0};
+        size_t bytes_read = fread(&buffer, 1, sizeof(buffer), fd);
+        if ( bytes_read < sizeof(buffer) )
+        {
+            ak_log_error(__func__, "File is smaller than expected. Wrong format?");
+            fclose(fd);
+            free(fullpath);
+            return 2;
+        }
+        if ( buffer[128] != '\n' || buffer[257] != '\n' )
+        {
+            ak_log_error(__func__, "Unknown format");
+            fclose(fd);
+            free(fullpath);
+            return 2;
+        }
+        char h_str[129] = {0};
+        char t_str[129] = {0};
+        mt_branch h0;
+        ak_fs_sha512sum_init(&h0.root);
+        ak_fs_sha512sum_init(&h0.head);
+        ak_fs_sha512sum_init(&h0.tail);
+        h0.root = *rh;
+        memcpy(h_str, buffer, 128);
+        h_str[128] = '\0';
+        memcpy(t_str, buffer + 129, 128);
+        t_str[128] = '\0';
+        fclose(fd);
+        // free(fullpath);
+        ak_fs_sha512sum_string_to_struct(h_str, &h0.head);
+        ak_fs_sha512sum_string_to_struct(t_str, &h0.tail);
+        ak_fs_cat_file_from_root_hash(&h0.head);
+        if ( !ak_fs_sha512sum_compare(&h0.head, &h0.tail) ) ak_fs_cat_file_from_root_hash(&h0.tail);
+    }
+    else
+    {
+        struct stat sb;
+        if (stat(fullpath, &sb) == -1) {
+            perror("stat");
+            fclose(fd);
+            free(fullpath);
+            return 2;
+        }
+        char buffer[(long long) sb.st_size+1];
+        fread(&buffer, sizeof(buffer), 1, fd);
+        fclose(fd);
+        buffer[sizeof(buffer)-1] = '\0';
+        printf("%s", buffer);
+    }
+    free(fullpath);
+    return 0;
+}
+
+int ak_fs_cfm(akfs_map_v3* map)
+{
+    sha512sum x;
+    ak_fs_sha512sum_init(&x);
+    const sha512sum *rh_ptr = ak_fs_map_v3_get_root_hash(map);
+    if ( rh_ptr == NULL )
+    {
+        ak_log_debug(__func__, "No root hash found on the map");
+        return -1;
+    }
+    x = *rh_ptr;
+    return ak_fs_cat_file_from_root_hash(&x);
+}