1 /*
2  * Copyright (C) the libgit2 contributors. All rights reserved.
3  *
4  * This file is part of libgit2, distributed under the GNU GPL v2 with
5  * a Linking Exception. For full terms see the included COPYING file.
6  */
7 #ifndef INCLUDE_odb_h__
8 #define INCLUDE_odb_h__
9 
10 #include "common.h"
11 
12 #include "git2/odb.h"
13 #include "git2/oid.h"
14 #include "git2/types.h"
15 
16 #include "vector.h"
17 #include "cache.h"
18 #include "posix.h"
19 #include "filter.h"
20 
21 #define GIT_OBJECTS_DIR "objects/"
22 #define GIT_OBJECT_DIR_MODE 0777
23 #define GIT_OBJECT_FILE_MODE 0444
24 
25 extern bool git_odb__strict_hash_verification;
26 
27 /* DO NOT EXPORT */
28 typedef struct {
29 	void *data;			/**< Raw, decompressed object data. */
30 	size_t len;			/**< Total number of bytes in data. */
31 	git_object_t type;		/**< Type of this object. */
32 } git_rawobj;
33 
34 /* EXPORT */
35 struct git_odb_object {
36 	git_cached_obj cached;
37 	void *buffer;
38 };
39 
40 /* EXPORT */
41 struct git_odb {
42 	git_refcount rc;
43 	git_mutex lock;  /* protects backends */
44 	git_vector backends;
45 	git_cache own_cache;
46 	unsigned int do_fsync :1;
47 };
48 
49 typedef enum {
50 	GIT_ODB_CAP_FROM_OWNER = -1,
51 } git_odb_cap_t;
52 
53 /*
54  * Set the capabilities for the object database.
55  */
56 int git_odb__set_caps(git_odb *odb, int caps);
57 
58 /*
59  * Add the default loose and packed backends for a database.
60  */
61 int git_odb__add_default_backends(
62 	git_odb *db, const char *objects_dir,
63 	bool as_alternates, int alternate_depth);
64 
65 /*
66  * Hash a git_rawobj internally.
67  * The `git_rawobj` is supposed to be previously initialized
68  */
69 int git_odb__hashobj(git_oid *id, git_rawobj *obj);
70 
71 /*
72  * Format the object header such as it would appear in the on-disk object
73  */
74 int git_odb__format_object_header(size_t *out_len, char *hdr, size_t hdr_size, git_object_size_t obj_len, git_object_t obj_type);
75 
76 /*
77  * Hash an open file descriptor.
78  * This is a performance call when the contents of a fd need to be hashed,
79  * but the fd is already open and we have the size of the contents.
80  *
81  * Saves us some `stat` calls.
82  *
83  * The fd is never closed, not even on error. It must be opened and closed
84  * by the caller
85  */
86 int git_odb__hashfd(git_oid *out, git_file fd, size_t size, git_object_t type);
87 
88 /*
89  * Hash an open file descriptor applying an array of filters
90  * Acts just like git_odb__hashfd with the addition of filters...
91  */
92 int git_odb__hashfd_filtered(
93 	git_oid *out, git_file fd, size_t len, git_object_t type, git_filter_list *fl);
94 
95 /*
96  * Hash a `path`, assuming it could be a POSIX symlink: if the path is a
97  * symlink, then the raw contents of the symlink will be hashed. Otherwise,
98  * this will fallback to `git_odb__hashfd`.
99  *
100  * The hash type for this call is always `GIT_OBJECT_BLOB` because
101  * symlinks may only point to blobs.
102  */
103 int git_odb__hashlink(git_oid *out, const char *path);
104 
105 /**
106  * Generate a GIT_EMISMATCH error for the ODB.
107  */
108 int git_odb__error_mismatch(
109 	const git_oid *expected, const git_oid *actual);
110 
111 /*
112  * Generate a GIT_ENOTFOUND error for the ODB.
113  */
114 int git_odb__error_notfound(
115 	const char *message, const git_oid *oid, size_t oid_len);
116 
117 /*
118  * Generate a GIT_EAMBIGUOUS error for the ODB.
119  */
120 int git_odb__error_ambiguous(const char *message);
121 
122 /*
123  * Attempt to read object header or just return whole object if it could
124  * not be read.
125  */
126 int git_odb__read_header_or_object(
127 	git_odb_object **out, size_t *len_p, git_object_t *type_p,
128 	git_odb *db, const git_oid *id);
129 
130 /* freshen an entry in the object database */
131 int git_odb__freshen(git_odb *db, const git_oid *id);
132 
133 /* fully free the object; internal method, DO NOT EXPORT */
134 void git_odb_object__free(void *object);
135 
136 #endif
137