Change tree encoding to be compatible with git; Add cat-file and show-index command

src/commit.c

@@ -76,27 +76,23 @@ int commit()
     struct tree commit_tree = {0};
     get_last_commit(&last_commit);
     if (last_commit.size != 0) {
-        hash_object(&last_commit, last_commit_checksum);
+        hash_object_str(&last_commit, last_commit_checksum);
         commit_from_object(&commit, &last_commit);
 
         struct object last_commit_tree = {0};
         read_object(commit.tree, &last_commit_tree);
-        get_tree(last_commit_tree.content, &commit_tree);
+        tree_from_object(&commit_tree, &last_commit_tree);
         free_object(&last_commit_tree);
     }
     free_object(&last_commit);
 
     struct entry *current = index.first_entry;
     while(current != NULL)
-    {
-        size_t entry_size = DIGEST_LENGTH * 2 + 2 + strlen(current->filename);
-        char tmp[entry_size + 1];
-        sprintf(tmp, "%s %s\n", current->checksum, current->filename);
-        
+    {   
         struct object object = {0};
         blob_from_file(current->filename, &object);
 
-        add_object_to_tree(&commit_tree, current->filename, &object);
+        add_object_to_tree(&commit_tree, current->filename, current->mode, &object);
 
         free_object(&object);
         current = current->next;
@@ -122,7 +118,7 @@ int commit()
     struct object commit_tree_obj = {0};
     tree_to_object(&commit_tree, &commit_tree_obj);
     char *commit_tree_checksum = malloc(DIGEST_LENGTH * 2 + 1);
-    hash_object(&commit_tree_obj, commit_tree_checksum);
+    hash_object_str(&commit_tree_obj, commit_tree_checksum);
     write_object(&commit_tree_obj);
 
     if(commit.tree != NULL)
@@ -135,7 +131,7 @@ int commit()
     commit_to_object(&commit, &commit_obj);
     write_object(&commit_obj);
     char commit_checksum[DIGEST_LENGTH * 2 + 1];
-    hash_object(&commit_obj, commit_checksum);
+    hash_object_str(&commit_obj, commit_checksum);
 
     update_current_branch_head(commit_checksum);
 
@@ -167,9 +163,9 @@ int diff_commit_with_working_tree(char *checksum, int for_print)
     read_object(commit.tree, &obj);
 
     struct tree commit_tree = {0};
-    get_tree(obj.content, &commit_tree);
+    tree_from_object(&commit_tree, &obj);
 
-    rmdir(TMP"/a");
+    remove_dir(TMP"/a");
     create_dir(TMP"/a");
 
     dump_tree(TMP"/a", &commit_tree);
@@ -218,11 +214,11 @@ int diff_commit(char* checksum_a, char* checksum_b, int for_print)
     read_object(commit_b.tree, &tree_b_obj);
 
     struct tree tree_a, tree_b;
-    get_tree(tree_a_obj.content, &tree_a);
-    get_tree(tree_b_obj.content, &tree_b);
+    tree_from_object(&tree_a, &tree_a_obj);
+    tree_from_object(&tree_b, &tree_b_obj);
 
-    rmdir(TMP"/a");
-    rmdir(TMP"/b");
+    remove_dir(TMP"/a");
+    remove_dir(TMP"/b");
 
     create_dir(TMP"/a");
     create_dir(TMP"/b");

src/fs.c

@@ -59,10 +59,6 @@ int init_repo()
     if (!index_exist())
     {
         int fd = open(INDEX_FILE, O_WRONLY | O_CREAT | O_TRUNC, 0644);
-        FILE *index = fdopen(fd, "w");
-
-        fprintf(index, "0\n");
-        fclose(index);
     }
 
     if (!head_file_exist(NULL))
@@ -120,13 +116,13 @@ int write_object(struct object *obj)
     int objects_dir_fd = dirfd(objects_dir);
 
     char checksum[DIGEST_LENGTH * 2];
-    hash_object(obj, checksum);
+    hash_object_str(obj, checksum);
 
     int save_file_fd = openat(objects_dir_fd, checksum, O_CREAT | O_WRONLY | O_TRUNC, DEFAULT_FILE_MODE);
     if(save_file_fd == -1) {
         if (errno == EACCES)
         {
-            debug_print("Object %s already exists", checksum);
+            // debug_print("Object %s already exists", checksum);
             defer(OBJECT_ALREADY_EXIST);
         }
         defer(FS_ERROR);
@@ -215,7 +211,7 @@ int create_dir(char *dir)
 
     if(stat(dir, &buffer) == 0)
     {
-        if (!S_ISREG(buffer.st_mode))
+        if (S_ISDIR(buffer.st_mode))
         {
             result = remove(dir);
             if (result != 0)
@@ -283,14 +279,16 @@ int dump_tree(char *cwd, struct tree *tree)
         sprintf(filename, "%s/%s", cwd, current->filename);
 
         struct object obj = {0};
-        read_object(current->checksum, &obj);
+        char checksum_str[DIGEST_LENGTH * 2 + 1];
+        hash_to_hexa(current->checksum, checksum_str);
+        read_object(checksum_str, &obj);
 
         if(current->type == BLOB)
         {
             tmp_dump(&obj, filename);
         } else if (current->type == TREE) {
             struct tree subtree = {0};
-            get_tree(obj.content, &subtree);
+            tree_from_object(&subtree, &obj);
 
             create_dir(filename);
             dump_tree(filename, &subtree);
@@ -318,7 +316,7 @@ int load_tree(char* checksum, struct tree *tree)
         return WRONG_OBJECT_TYPE;
     }
 
-    get_tree(object.content, tree);
+    tree_from_object(tree, &object);
     free_object(&object);
 
     return 0;
@@ -339,7 +337,9 @@ int load_index(struct tree *index)
     fread(file_content, buffer.st_size, 1, index_file);
     fclose(index_file);
 
-    get_tree(file_content, index);
+    object_t obj = { content: file_content, size: buffer.st_size, object_type: TREE };
+
+    tree_from_object(index, &obj);
 
     free(file_content);
 
@@ -533,11 +533,14 @@ int is_file_ignored(char *filename)
     fread(content, buffer.st_size, 1, ignore_file);
     fclose(ignore_file);    
 
+    int i = 0;
+    for(; filename[i] != '/'; i ++);
+
     char *current_line = strtok(content, "\n");
     
     while(current_line != NULL)
     {
-        if(strncmp(current_line, filename, strlen(current_line)) == 0)
+        if(strncmp(current_line, filename, i-1) == 0)
         {
             return 1;
         }
@@ -561,7 +564,7 @@ int add_file_to_index(struct tree *index, char *filename)
     {
         return FILE_NOT_FOUND;
     }
-    if (!S_ISREG(st.st_mode))
+    if (S_ISDIR(st.st_mode))
     {
         DIR *dp;
         struct dirent *ep;
@@ -589,7 +592,12 @@ int add_file_to_index(struct tree *index, char *filename)
             return 0;
         }
     } else {
-        if (add_to_index(index, filename) == FILE_NOT_FOUND)
+        enum file_mode mode = REG_NONX_FILE;
+        if(S_ISLNK(st.st_mode))
+            mode = SYM_LINK;
+        if (st.st_mode & S_IXUSR == S_IXUSR)
+            mode = REG_EXE_FILE;
+        if (add_to_index(index, filename, mode) == FILE_NOT_FOUND)
             return FILE_NOT_FOUND;
     }
 }
@@ -602,7 +610,7 @@ int remove_file_from_index(struct tree *index, char *filename)
     struct stat st = {0};
     if (stat(filename, &st) != 0)
         return FILE_NOT_FOUND;
-    if (!S_ISREG(st.st_mode))
+    if (S_ISDIR(st.st_mode))
     {
         DIR *dp;
         struct dirent *ep;
@@ -628,7 +636,7 @@ int remove_file_from_index(struct tree *index, char *filename)
             return 0;
         }
     } else {
-        remove_from_index(index, filename, 1);
+        remove_from_tree(index, filename, 1);
     }
 }
 
@@ -645,7 +653,7 @@ int dump_log()
 
     FILE *log_file = fopen(LOG_FILE, "w");
     char checksum[DIGEST_LENGTH * 2 + 1];
-    hash_object(&current_obj, checksum);
+    hash_object_str(&current_obj, checksum);
     fprintf(log_file, "commit %s HEAD\n", checksum);
     fprintf(log_file, "Author: %s\n", current.author);
     fprintf(log_file, "Tree: %s\n", current.tree);
@@ -659,7 +667,7 @@ int dump_log()
         commit_from_object(&current, &current_obj);
 
         checksum[DIGEST_LENGTH * 2 + 1];
-        hash_object(&current_obj, checksum);
+        hash_object_str(&current_obj, checksum);
         fprintf(log_file, "commit %s\n", checksum);
         fprintf(log_file, "Author: %s\n", current.author);
         fprintf(log_file, "Tree: %s\n", current.tree);

src/fs.h

@@ -60,6 +60,7 @@ int checkout_branch(char *branch);
 int reset_to(char* commit_checksum);
 
 int create_dir(char *dir);
+void remove_dir(char *dir);
 int dump_tree(char *cwd, struct tree *tree);
 int dump_log();
 int dump_branches();

src/includes.h

@@ -19,6 +19,9 @@
 #define error_print(X, ...)
 #endif 
 
+#define look_for(str, delim, index) \
+    for(; str[index] != delim; index ++); 
+
 #define defer(X) \
     result = X; \
     goto defer; \

src/main.c

@@ -9,6 +9,7 @@
 #include "includes.h"
 #include "commit.h"
 #include "fs.h"
+#include "objects.h"
 #include "tree.h"
 
 #define ARGS_MAX_SIZE 256
@@ -225,6 +226,54 @@ int log_cmd(int argc, char **argv)
     pclose(p);
 }
 
+int cat_file(int argc, char **argv)
+{
+    char buf[ARGS_MAX_SIZE];
+
+    if(pop_arg(&argc, &argv, buf) == 1)
+    {
+        printf("usage: cgit cat-file <object>\n");
+        return 129;
+    }
+
+    object_t obj = {0};
+    int res = read_object(buf, &obj);
+    if (res != FS_OK)
+    {
+        if (res == OBJECT_DOES_NOT_EXIST)
+        {
+            printf("fatal: not a valid object name %s\n", buf);
+            return 128;
+        }
+
+        if (res == REPO_NOT_INITIALIZED)
+        {
+            printf("Not a cgit repository\n");
+            return 128;
+        }
+    }
+
+    cat_object(STDIN_FILENO, &obj);
+    free_object(&obj);
+    
+    return 0;
+}
+
+int show_index(int argc, char **argv)
+{
+    tree_t index = {0};
+    load_index(&index);
+
+    object_t obj = {0};
+    tree_to_object(&index, &obj);
+    free_tree(&index);
+
+    cat_object(STDIN_FILENO, &obj);
+    free_object(&obj);
+
+    return 0;
+}
+
 int main(int argc, char **argv)
 {
     char cmd[ARGS_MAX_SIZE];
@@ -266,6 +315,30 @@ int main(int argc, char **argv)
         return log_cmd(argc, argv);
     } else if (strcmp(buf, "-h") == 0) {
         return print_help();
+    } else if (strcmp(buf, "cat-file") == 0) 
+    {  
+        return cat_file(argc, argv);
+    } else if (strcmp(buf, "show-index") == 0) 
+    {  
+        return show_index(argc, argv);
+    } else if (strcmp(buf, "test") == 0) 
+    {  
+        object_t obj = {0};
+        read_object("192f287aebddb0080e6ea7cb567d76d78b54dee2", &obj);
+
+        tree_t tree = {0};
+        tree_from_object(&tree, &obj);
+        free_object(&obj);
+
+        debug_print("entries_size: %li", tree.entries_size);
+        debug_print("first_entry->filename: %s", tree.first_entry->filename);
+        debug_print("last_entry->filename: %s", tree.last_entry->filename);
+
+        tree_to_object(&tree, &obj);
+        write_object(&obj);
+
+        free_tree(&tree);
+        free_object(&obj);
     } else {
         printf("Unknown command %s, try using %s -h\n", buf, cmd);
         return 0;

src/objects.c

@@ -5,29 +5,33 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 #include <zlib.h>
 
 #include "includes.h"
+#include "fs.h"
+#include "tree.h"
 #include "utils.h"
 #include "objects.h"
 
 char *object_type_str[3] = {
-    "blob", 
+    "blob",
     "tree",
     "commit",
 };
 
-char* object_type_to_str(enum object_type type)
+char *object_type_to_str(enum object_type type)
 {
     return object_type_str[type];
 }
 
-enum object_type str_to_object_type(char* str)
+enum object_type str_to_object_type(char *str)
 {
-    if(strncmp("tree", str, 4) == 0)
+    if (strncmp("tree", str, 4) == 0)
     {
         return TREE;
-    } else if (strncmp("commit", str, 5) == 0)
+    }
+    else if (strncmp("commit", str, 5) == 0)
     {
         return COMMIT;
     }
@@ -47,7 +51,7 @@ size_t object_size(struct object *obj)
 
 int full_object(struct object *obj, char *buffer, size_t buffer_size)
 {
-    char* hr_size = malloc(decimal_len(obj->size) + 1);
+    char *hr_size = malloc(decimal_len(obj->size) + 1);
     sprintf(hr_size, "%li", obj->size);
 
     size_t data_size = object_size(obj);
@@ -58,11 +62,11 @@ int full_object(struct object *obj, char *buffer, size_t buffer_size)
     memcpy(writing, type, strlen(type));
     writing += strlen(type);
     memcpy(writing, " ", 1);
-    writing ++;
+    writing++;
     memcpy(writing, hr_size, strlen(hr_size));
     writing += strlen(hr_size);
     memcpy(writing, "\0", 1);
-    writing ++;
+    writing++;
     memcpy(writing, obj->content, obj->size);
 
     free(hr_size);
@@ -70,29 +74,45 @@ int full_object(struct object *obj, char *buffer, size_t buffer_size)
     return 0;
 }
 
-void hash_object(struct object *obj, char *result)
+/// @brief Hash object and copy it in result
+/// @param obj
+/// @param result char array of size DIGEST_LENGTH, it is not a C-string.
+void hash_object(object_t *obj, unsigned char *result)
 {
-    unsigned char md_buffer[DIGEST_LENGTH] = {0};
     size_t data_size = object_size(obj);
-    char* data = malloc(data_size);
+    char data[data_size];
     full_object(obj, data, data_size);
 
-    SHA1(data, data_size, md_buffer);
-
-    for (int i = 0; i < DIGEST_LENGTH; i++)
-    {
-        sprintf((result + (2 * i)), "%.2x", md_buffer[i]);
-    }
-
-    free(data);
+    SHA1(data, data_size, result);
+    return;
 }
 
-int uncompress_object(struct object *obj, char* compressed, uLongf comp_size)
+void hash_to_hexa(unsigned char *hash, char *result)
+{
+    for (int i = 0; i < DIGEST_LENGTH; i ++)
+        sprintf((result + (2 * i)), "%.2x", hash[i]);
+
+    return;
+}
+
+/// @brief Hash object and copy its hexa representation in result
+/// @param obj
+/// @param result A C-string of length equals DIGEST_LENGTH * 2
+void hash_object_str(object_t *obj, char *result)
+{
+    unsigned char md_buffer[DIGEST_LENGTH] = {0};
+    hash_object(obj, md_buffer);
+
+    hash_to_hexa(md_buffer, result);
+    return;
+}
+
+int uncompress_object(struct object *obj, char *compressed, uLongf comp_size)
 {
     uLongf def_size = HEADER_MAX_SIZE;
     uLongf content_size = 0;
-    char* deflated = malloc(def_size);
-    int res = uncompress((Bytef *) deflated, &def_size, (Bytef *)compressed, comp_size);
+    char *deflated = malloc(def_size);
+    int res = uncompress((Bytef *)deflated, &def_size, (Bytef *)compressed, comp_size);
     if (res != Z_OK && res != Z_BUF_ERROR)
     {
         return res;
@@ -104,8 +124,9 @@ int uncompress_object(struct object *obj, char* compressed, uLongf comp_size)
     content_size = strtol(hr_size, NULL, 10);
     def_size += content_size;
     deflated = realloc(deflated, def_size);
-    res = uncompress((Bytef *) deflated, &def_size, (Bytef *)compressed, comp_size);
-    if(res != Z_OK) {
+    res = uncompress((Bytef *)deflated, &def_size, (Bytef *)compressed, comp_size);
+    if (res != Z_OK)
+    {
         return res;
     }
     char *content_type_tmp = strtok(deflated, " ");
@@ -119,10 +140,10 @@ int uncompress_object(struct object *obj, char* compressed, uLongf comp_size)
     return 0;
 }
 
-int compress_object(struct object *obj, char* compressed, uLongf *comp_size)
+int compress_object(struct object *obj, char *compressed, uLongf *comp_size)
 {
     size_t data_size = object_size(obj);
-    char* data = malloc(data_size);
+    char *data = malloc(data_size);
     full_object(obj, data, data_size);
 
     int res = compress((Bytef *)compressed, comp_size, (Bytef *)data, data_size);
@@ -131,6 +152,40 @@ int compress_object(struct object *obj, char* compressed, uLongf *comp_size)
     return res;
 }
 
+int cat_object(int fd, object_t *obj)
+{
+
+    switch (obj->object_type)
+    {
+    case BLOB:
+    case COMMIT:
+        write(fd, obj->content, obj->size);
+        break;
+
+    case TREE:
+        tree_t tree = {0};
+        tree_from_object(&tree, obj);
+
+        entry_t *current = tree.first_entry;
+        while(current != NULL)
+        {
+            char buf[DIGEST_LENGTH * 2 + 1];
+            hash_to_hexa(current->checksum, buf);
+            dprintf(fd, "%.6o %s %s %s\n", current->mode, object_type_to_str(current->type), buf, current->filename);
+            current = current->next;
+        }
+
+        free_tree(&tree);
+        break;
+
+    default:
+        break;
+    }
+
+    free_object;
+    return 0;
+}
+
 void free_object(struct object *obj)
 {
     if (obj->content != NULL)

src/objects.h

@@ -14,7 +14,10 @@ size_t object_size(struct object *obj);
 int full_object(struct object *obj, char* buffer, size_t buffer_size);
 int uncompress_object(struct object *obj, char* compressed, uLongf comp_size);
 int compress_object(struct object *obj, char* compressed, uLongf *comp_size);
-void hash_object(struct object *obj, char* result);
+void hash_object(object_t *obj, unsigned char *result);
+void hash_object_str(struct object *obj, char* result);
+void hash_to_hexa(unsigned char *hash, char *result);
+int cat_object(int fd, object_t *obj);
 void free_object(struct object *obj);
 
 #endif // OBJECTS_H

src/tree.c

@@ -1,11 +1,14 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 
 #include "tree.h"
 #include "includes.h"
 #include "fs.h"
 #include "objects.h"
+#include "types.h"
 #include "utils.h"
 
 void free_entry(struct entry *entry)
@@ -18,7 +21,7 @@ void free_entry(struct entry *entry)
 
 }
 
-void free_tree(struct tree *tree)
+void free_tree(tree_t *tree)
 {
     struct entry *current = tree->first_entry;
     struct entry *next;
@@ -31,7 +34,7 @@ void free_tree(struct tree *tree)
     }
 }
 
-struct entry *find_entry(struct tree *tree, char* filename)
+struct entry *find_entry(tree_t *tree, char* filename)
 {
     struct entry *current = tree->first_entry;
     for (int i = 0; i < tree->entries_size; ++i)
@@ -45,71 +48,24 @@ struct entry *find_entry(struct tree *tree, char* filename)
     return NULL;
 }
 
-void get_tree(char* content, struct tree *tree)
-{
-    char* current_line;
-    current_line = strtok(content, "\n");
-    tree->entries_size = strtol(current_line, NULL, 10);
-    tree->first_entry = NULL;
-    tree->last_entry = NULL;
-
-    for(int i = 0; i < tree->entries_size; i++)
-    {
-        struct entry *entry = calloc(1, sizeof(struct entry));
-        current_line = strtok(NULL, "\n");
-        int j = 0;
-        while(current_line[j] != ' ')
-        {
-            j++;
-        }
-
-        current_line[j] = '\0';
-        entry->type = str_to_object_type(current_line);
-        current_line += j + 1;
-        j = 0;
-        while(current_line[j] != ' ')
-        {
-            j++;
-        }
-
-        char* checksum = calloc(j + 1, sizeof(char));
-        char* filename = calloc(strlen(current_line) - j, sizeof(char));
-        strncat(checksum, current_line, j);
-        strncat(filename, current_line + j + 1, strlen(current_line) - j);
-        entry->checksum = checksum;
-        entry->filename = filename;
-        entry->next = NULL;
-
-        if(i == 0)
-        {
-            tree->first_entry = entry;
-            tree->last_entry = entry;
-        } else 
-        {
-            entry->previous = tree->last_entry;
-            tree->last_entry->next = entry;
-        }
-        tree->last_entry = entry;
-    }
-}
-
-int add_to_tree(struct tree *tree, struct object *object, char *filename)
+int add_to_tree(tree_t *tree, object_t *object, char *filename, enum file_mode mode)
 {
 
     int new = 0;
-    struct entry *entry = find_entry(tree, filename);
+    entry_t *entry = find_entry(tree, filename);
     if (entry == NULL)
     {
         new = 1;
-        entry = calloc(sizeof(struct entry), 1);
+        entry = calloc(sizeof(entry_t), 1);
     } else {
         free_entry(entry);
     }
 
     entry->type = object->object_type;
+    entry->mode = mode;
     entry->filename = calloc(sizeof(char), strlen(filename) + 1);
     strncat(entry->filename, filename, strlen(filename));
-    entry->checksum = calloc(sizeof(char), DIGEST_LENGTH * 2 + 1);
+    entry->checksum = calloc(sizeof(char), DIGEST_LENGTH);
     hash_object(object, entry->checksum);
     // int res = write_object(object);
     // if (res != FS_OK && res != OBJECT_ALREADY_EXIST)
@@ -153,7 +109,7 @@ int add_to_tree(struct tree *tree, struct object *object, char *filename)
     }
 }
 
-int add_to_index(struct tree *index, char *filename)
+int add_to_index(tree_t *index, char *filename, enum file_mode mode)
 {
     int result = FS_OK;
     struct object object = {0};
@@ -164,22 +120,17 @@ int add_to_index(struct tree *index, char *filename)
 
     result = write_object(&object);
     if (result == FS_OK)
-    {
-        add_to_tree(index, &object, filename);
-        defer(FS_OK);
-    }
+        add_to_tree(index, &object, filename, mode);
 
     if (result == OBJECT_ALREADY_EXIST)
-    {
-        defer(FS_OK);
-    }
+        return FS_OK;
 
 defer:
     free_object(&object);
     return result;
 }
 
-int remove_from_index(struct tree *index, char *filename, int delete)
+int remove_from_tree(tree_t *index, char *filename, int delete)
 {
     struct entry *entry = find_entry(index, filename);
     if (entry == NULL)
@@ -211,58 +162,127 @@ int remove_from_index(struct tree *index, char *filename, int delete)
     return FS_OK;
 }
 
-int tree_to_object(struct tree *tree, struct object *object)
+int tree_to_object(tree_t *tree, object_t *object)
 {
     object->object_type = TREE;
-    object->content = calloc(1, decimal_len(tree->entries_size) + 2);
-    object->size = decimal_len(tree->entries_size) + 2;
-    sprintf(object->content, "%li\n", tree->entries_size);
+    object->size = 0;
+    object->content = NULL;
 
     struct entry *current = tree->first_entry;
     for(int i = 0; i < tree->entries_size; i++)
     {
         char *type = object_type_to_str(current->type);
-        size_t entry_size = strlen(type) + DIGEST_LENGTH * 2 + 3 + strlen(current->filename);
-        char tmp[entry_size + 1];
+        // Entry will be <mode>(in ASCII) + ' ' + <filename> + '\0' + <checksum>
+        int mode_length = 6;
+        if (current->mode == DIRECTORY)
+            mode_length = 5;
+        size_t entry_size = mode_length + 1 + strlen(current->filename) + 1 + DIGEST_LENGTH;
+        char tmp[entry_size];
+        sprintf(tmp, "%o %s", current->mode, current->filename);
+        memcpy(tmp + entry_size - DIGEST_LENGTH, current->checksum, DIGEST_LENGTH);
+
         object->size = object->size + entry_size;
         object->content = realloc(object->content, object->size);
-        sprintf(tmp, "%s %s %s\n", type, current->checksum, current->filename);
-        strncat(object->content, tmp, entry_size);
+        memcpy((object->content) + object->size - entry_size, tmp, entry_size);
         current = current->next;
     }
 
-    object->size --;
+    return 0;
 }
 
-int add_object_to_tree(struct tree *tree, char* filename, struct object *source)
+int tree_from_object(tree_t *tree, object_t *object)
+{
+    tree->entries_size = 0;
+    tree->first_entry = NULL;
+    tree->last_entry = NULL;
+    
+    int i = 0, j = 0;
+    while (j < object->size)
+    {
+        i = j;
+        entry_t *entry = malloc(sizeof(entry_t));
+
+        look_for(object->content, ' ', j);
+        int pot_mode = strtol(object->content + i, NULL, 8);
+        switch (pot_mode)
+        {
+            case DIRECTORY:
+                entry->type = TREE;
+                break;
+            case REG_NONX_FILE:
+            case REG_EXE_FILE:
+            case SYM_LINK:
+                entry->type = BLOB;
+            case GIT_LINK:
+                break;
+            
+            default:
+                return INVALID_TREE;
+                break;
+        }
+        entry->mode = (enum file_mode) pot_mode;
+
+        i = j + 1;
+        look_for(object->content, '\0', j);
+        if (j - i == 0)
+            return INVALID_TREE;
+        entry->filename = malloc(j - i + 1);
+        memcpy(entry->filename, object->content + i, j - i + 1);
+
+        i = j + 1;
+        entry->checksum = malloc(DIGEST_LENGTH);
+        memcpy(entry->checksum, object->content + i, DIGEST_LENGTH);
+        j += DIGEST_LENGTH + 1;
+
+        entry->previous = tree->last_entry;
+        entry->next = NULL;
+
+        if(tree->last_entry == NULL)
+        {
+            tree->first_entry = entry;
+        } else
+        {
+            entry->previous->next = entry;
+        }
+        tree->last_entry = entry;
+        tree->entries_size ++;
+
+    }
+
+    return 0;
+}
+
+int add_object_to_tree(tree_t *tree, char* filename, enum file_mode mode, object_t *source)
 {
     char top_folder_name[strlen(filename)];
     char path_left[strlen(filename)];
     int res = get_top_folder(filename, top_folder_name, path_left); 
     if (res > 0)
     {
-        struct tree subtree = {0};
-        struct object result = {0};
+        tree_t subtree = {0};
+        object_t result = {0};
         result.object_type = TREE;
-        struct entry *top_folder = find_entry(tree, top_folder_name);
+        entry_t *top_folder = find_entry(tree, top_folder_name);
         if(top_folder != NULL)
         {
-            load_tree(top_folder->checksum, &subtree);
-            remove_from_index(tree, top_folder->filename, 0);
+            char checksum[DIGEST_LENGTH * 2 + 1];
+            hash_to_hexa(top_folder->checksum, checksum);
+            load_tree(checksum, &subtree);
+            remove_from_tree(tree, top_folder->filename, 0);
         }
 
-        add_to_tree(&subtree, source, path_left);
+        add_to_tree(&subtree, source, path_left, mode);
 
-        add_object_to_tree(&subtree, path_left, source);
+        add_object_to_tree(&subtree, path_left, mode, source);
 
         tree_to_object(&subtree, &result);
         write_object(&result);
-        remove_from_index(tree, filename, 0);
-        add_to_tree(tree, &result, top_folder_name);
+        remove_from_tree(tree, filename, 0);
+        add_to_tree(tree, &result, top_folder_name, DIRECTORY);
         free_object(&result);
         free_tree(&subtree);
     } else {
-        add_to_tree(tree, source, filename);
+        add_to_tree(tree, source, filename, mode);
         write_object(source);
     }
 }

src/tree.h

@@ -4,18 +4,21 @@
 #include <stddef.h>
 #include "types.h"
 
+#define INVALID_TREE (-1)
+
 // Index file should follow the format
 // number of entries\n
 // entry1\n
 // entry2\n
 // ...
 
-void free_tree(struct tree *index);
-struct entry *find_entry(struct tree *index, char* filename);
-void get_tree(char* content, struct tree *tree);
-int add_to_index(struct tree *index, char *filename);
-int remove_from_index(struct tree *index, char *filename, int delete);
-int tree_to_object(struct tree *tree, struct object *object);
-int add_object_to_tree(struct tree *tree, char* filename, struct object *source);
+void free_tree(tree_t *index);
+entry_t *find_entry(tree_t *index, char* filename);
+void index_from_content(char* content, tree_t *tree);
+int add_to_index(tree_t *index, char *filename, enum file_mode mode);
+int remove_from_tree(tree_t *index, char *filename, int delete);
+int tree_to_object(tree_t *tree, object_t *object);
+int tree_from_object(tree_t *tree, object_t *object);
+int add_object_to_tree(tree_t *tree, char* filename, enum file_mode mode, object_t *source);
 
 #endif // INDEX_H

src/types.h

@@ -10,33 +10,46 @@ enum object_type
     COMMIT
 };
 
-struct object
+typedef struct object
 {
     char* content;
     size_t size;
     enum object_type object_type;
+} object_t;
+
+enum file_mode
+{
+    DIRECTORY = 0040000,
+    REG_NONX_FILE = 0100644,
+    REG_EXE_FILE = 0100755,
+    SYM_LINK = 0120000,
+    GIT_LINK = 0160000,
 };
 
-struct entry {
-    char *checksum;
+/// @brief entry of a tree
+/// checksum is an array of size DIGEST_LENGTH
+/// filename is a C-string
+typedef struct entry {
+    enum file_mode mode;
+    unsigned char *checksum;
     char *filename;
     enum object_type type;
     struct entry *previous;
     struct entry *next;
-};
+} entry_t;
 
-struct tree {
+typedef struct tree {
     size_t entries_size;
     struct entry *first_entry;
     struct entry *last_entry;
-};
+} tree_t;
 
-struct commit
+typedef struct commit
 {
     char *tree;
     char *parent;
     char *author;
     char *message;
-};
+} commit_t;
 
 #endif // TYPES_H