src/odb.h

   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_vector backends;
  44         git_cache own_cache;
  45         unsigned int do_fsync :1;
  46 };
  47
  48 typedef enum {
  49         GIT_ODB_CAP_FROM_OWNER = -1,
  50 } git_odb_cap_t;
  51
  52 /*
  53  * Set the capabilities for the object database.
  54  */
  55 int git_odb__set_caps(git_odb *odb, int caps);
  56
  57 /*
  58  * Add the default loose and packed backends for a database.
  59  */
  60 int git_odb__add_default_backends(
  61         git_odb *db, const char *objects_dir,
  62         bool as_alternates, int alternate_depth);
  63
  64 /*
  65  * Hash a git_rawobj internally.
  66  * The `git_rawobj` is supposed to be previously initialized
  67  */
  68 int git_odb__hashobj(git_oid *id, git_rawobj *obj);
  69
  70 /*
  71  * Format the object header such as it would appear in the on-disk object
  72  */
  73 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);
  74
  75 /*
  76  * Hash an open file descriptor.
  77  * This is a performance call when the contents of a fd need to be hashed,
  78  * but the fd is already open and we have the size of the contents.
  79  *
  80  * Saves us some `stat` calls.
  81  *
  82  * The fd is never closed, not even on error. It must be opened and closed
  83  * by the caller
  84  */
  85 int git_odb__hashfd(git_oid *out, git_file fd, size_t size, git_object_t type);
  86
  87 /*
  88  * Hash an open file descriptor applying an array of filters
  89  * Acts just like git_odb__hashfd with the addition of filters...
  90  */
  91 int git_odb__hashfd_filtered(
  92         git_oid *out, git_file fd, size_t len, git_object_t type, git_filter_list *fl);
  93
  94 /*
  95  * Hash a `path`, assuming it could be a POSIX symlink: if the path is a
  96  * symlink, then the raw contents of the symlink will be hashed. Otherwise,
  97  * this will fallback to `git_odb__hashfd`.
  98  *
  99  * The hash type for this call is always `GIT_OBJECT_BLOB` because
 100  * symlinks may only point to blobs.
 101  */
 102 int git_odb__hashlink(git_oid *out, const char *path);
 103
 104 /**
 105  * Generate a GIT_EMISMATCH error for the ODB.
 106  */
 107 int git_odb__error_mismatch(
 108         const git_oid *expected, const git_oid *actual);
 109
 110 /*
 111  * Generate a GIT_ENOTFOUND error for the ODB.
 112  */
 113 int git_odb__error_notfound(
 114         const char *message, const git_oid *oid, size_t oid_len);
 115
 116 /*
 117  * Generate a GIT_EAMBIGUOUS error for the ODB.
 118  */
 119 int git_odb__error_ambiguous(const char *message);
 120
 121 /*
 122  * Attempt to read object header or just return whole object if it could
 123  * not be read.
 124  */
 125 int git_odb__read_header_or_object(
 126         git_odb_object **out, size_t *len_p, git_object_t *type_p,
 127         git_odb *db, const git_oid *id);
 128
 129 /* freshen an entry in the object database */
 130 int git_odb__freshen(git_odb *db, const git_oid *id);
 131
 132 /* fully free the object; internal method, DO NOT EXPORT */
 133 void git_odb_object__free(void *object);
 134
 135 #endif