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 #include "git2/sys/commit_graph.h"
  16
  17 #include "cache.h"
  18 #include "commit_graph.h"
  19 #include "filter.h"
  20 #include "posix.h"
  21 #include "vector.h"
  22
  23 #define GIT_OBJECTS_DIR "objects/"
  24 #define GIT_OBJECT_DIR_MODE 0777
  25 #define GIT_OBJECT_FILE_MODE 0444
  26
  27 #define GIT_ODB_DEFAULT_LOOSE_PRIORITY 1
  28 #define GIT_ODB_DEFAULT_PACKED_PRIORITY 2
  29
  30 extern bool git_odb__strict_hash_verification;
  31
  32 /* DO NOT EXPORT */
  33 typedef struct {
  34         void *data;                     /**< Raw, decompressed object data. */
  35         size_t len;                     /**< Total number of bytes in data. */
  36         git_object_t type;              /**< Type of this object. */
  37 } git_rawobj;
  38
  39 /* EXPORT */
  40 struct git_odb_object {
  41         git_cached_obj cached;
  42         void *buffer;
  43 };
  44
  45 /* EXPORT */
  46 struct git_odb {
  47         git_refcount rc;
  48         git_mutex lock;  /* protects backends */
  49         git_vector backends;
  50         git_cache own_cache;
  51         git_commit_graph *cgraph;
  52         unsigned int do_fsync :1;
  53 };
  54
  55 typedef enum {
  56         GIT_ODB_CAP_FROM_OWNER = -1
  57 } git_odb_cap_t;
  58
  59 /*
  60  * Set the capabilities for the object database.
  61  */
  62 int git_odb__set_caps(git_odb *odb, int caps);
  63
  64 /*
  65  * Add the default loose and packed backends for a database.
  66  */
  67 int git_odb__add_default_backends(
  68         git_odb *db, const char *objects_dir,
  69         bool as_alternates, int alternate_depth);
  70
  71 /*
  72  * Hash a git_rawobj internally.
  73  * The `git_rawobj` is supposed to be previously initialized
  74  */
  75 int git_odb__hashobj(git_oid *id, git_rawobj *obj);
  76
  77 /*
  78  * Format the object header such as it would appear in the on-disk object
  79  */
  80 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);
  81
  82 /*
  83  * Hash an open file descriptor.
  84  * This is a performance call when the contents of a fd need to be hashed,
  85  * but the fd is already open and we have the size of the contents.
  86  *
  87  * Saves us some `stat` calls.
  88  *
  89  * The fd is never closed, not even on error. It must be opened and closed
  90  * by the caller
  91  */
  92 int git_odb__hashfd(git_oid *out, git_file fd, size_t size, git_object_t type);
  93
  94 /*
  95  * Hash an open file descriptor applying an array of filters
  96  * Acts just like git_odb__hashfd with the addition of filters...
  97  */
  98 int git_odb__hashfd_filtered(
  99         git_oid *out, git_file fd, size_t len, git_object_t type, git_filter_list *fl);
 100
 101 /*
 102  * Hash a `path`, assuming it could be a POSIX symlink: if the path is a
 103  * symlink, then the raw contents of the symlink will be hashed. Otherwise,
 104  * this will fallback to `git_odb__hashfd`.
 105  *
 106  * The hash type for this call is always `GIT_OBJECT_BLOB` because
 107  * symlinks may only point to blobs.
 108  */
 109 int git_odb__hashlink(git_oid *out, const char *path);
 110
 111 /**
 112  * Generate a GIT_EMISMATCH error for the ODB.
 113  */
 114 int git_odb__error_mismatch(
 115         const git_oid *expected, const git_oid *actual);
 116
 117 /*
 118  * Generate a GIT_ENOTFOUND error for the ODB.
 119  */
 120 int git_odb__error_notfound(
 121         const char *message, const git_oid *oid, size_t oid_len);
 122
 123 /*
 124  * Generate a GIT_EAMBIGUOUS error for the ODB.
 125  */
 126 int git_odb__error_ambiguous(const char *message);
 127
 128 /*
 129  * Attempt to read object header or just return whole object if it could
 130  * not be read.
 131  */
 132 int git_odb__read_header_or_object(
 133         git_odb_object **out, size_t *len_p, git_object_t *type_p,
 134         git_odb *db, const git_oid *id);
 135
 136 /*
 137  * Attempt to get the ODB's commit-graph file. This object is still owned by
 138  * the ODB. If the repository does not contain a commit-graph, it will return
 139  * GIT_ENOTFOUND.
 140  */
 141 int git_odb__get_commit_graph_file(git_commit_graph_file **out, git_odb *odb);
 142
 143 /* freshen an entry in the object database */
 144 int git_odb__freshen(git_odb *db, const git_oid *id);
 145
 146 /* fully free the object; internal method, DO NOT EXPORT */
 147 void git_odb_object__free(void *object);
 148
 149 #endif