Basic object manipulation

src/fs.c

@@ -0,0 +1,128 @@
+#include <assert.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <openssl/comp.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <zlib.h>
+
+#include "includes.h"
+#include "fs.h"
+#include "objects.h"
+
+int local_repo_exist()
+{
+    struct stat buffer;
+    return stat(LOCAL_REPO, &buffer) == 0;
+}
+
+int write_object(struct object *obj)
+{
+    if(!local_repo_exist())
+    {
+        return -2;
+    }
+    int result = 0;
+
+    struct stat buffer;
+    if (stat(LOCAL_REPO"/objects", &buffer) != 0)
+    {
+        mkdir(LOCAL_REPO"/objects", DEFAULT_DIR_MODE);
+    }
+    
+    DIR *objects_dir = opendir(LOCAL_REPO"/objects");
+    int objects_dir_fd = dirfd(objects_dir);
+
+    char checksum[DIGEST_LENGTH * 2];
+    hash_object(obj, checksum);
+
+    int save_file_fd = openat(objects_dir_fd, checksum, O_CREAT | O_WRONLY | O_TRUNC, 0774);
+    if(save_file_fd == -1) {
+        error_print("Object %s already exists", checksum);
+        defer(-1);
+    }
+    FILE* save_file = fdopen(save_file_fd, "w");
+
+    size_t data_size = object_size(obj);
+    uLong comp_size = compressBound(data_size);
+    char *compressed = malloc(comp_size);   
+    
+    int res = compress_object(obj, compressed, &comp_size);
+    if (res != Z_OK)
+    {
+        defer(res);
+    }
+    fwrite(compressed, comp_size, 1, save_file);
+    free(compressed);
+    fclose(save_file);
+
+defer:   
+    closedir(objects_dir);
+    return result;
+}
+
+int read_object(char *checksum, struct object *obj)
+{
+    if(!local_repo_exist())
+    {
+        return -2;
+    }
+    int result = 0;
+
+    struct stat buffer;
+    if (stat(LOCAL_REPO"/objects", &buffer) != 0)
+    {
+        error_print("Object dir does not exist");
+        return -1;
+    }
+
+    DIR *objects_dir = opendir(LOCAL_REPO"/objects");
+    int objects_dir_fd = dirfd(objects_dir);
+
+    int save_file_fd = openat(objects_dir_fd, checksum, O_RDONLY, DEFAULT_FILE_MODE);    
+    if (save_file_fd == -1)
+    {
+        error_print("Object %s does not exist", checksum);
+        defer(-1);
+    }
+    fstatat(objects_dir_fd, checksum, &buffer, 0);
+    char* file_content = malloc(buffer.st_size);
+
+    FILE *save_file = fdopen(save_file_fd, "r");
+    fread(file_content, 1, buffer.st_size, save_file);
+    fclose(save_file);
+
+    int res = uncompress_object(obj, file_content, buffer.st_size);
+    if(res != 0)
+    {
+        defer(res);
+    }
+    
+    free(file_content);
+
+defer:
+    closedir(objects_dir);
+    return result;
+}
+
+int main(void)
+{
+    struct object obj = {0};
+    obj.content = "Hello, world!\n";
+    obj.size = strlen(obj.content);
+    obj.object_type = "blob";
+
+    return write_object(&obj);
+
+    // read_object("af5626b4a114abcb82d63db7c8082c3c4756e51b", &obj);
+
+    // debug_print("Object type is \"%s\"", obj.object_type);
+    // debug_print("Content size is %li", obj.size);
+    // debug_print("Content is %.*s", (int)obj.size, obj.content);
+
+    // free_object(&obj);
+    // return 0;
+}