aboutsummaryrefslogtreecommitdiff
path: root/src/libstore/store.hh
blob: 7b18871e4f27dce19f51ca0aa462ff88efd2b4de (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
#ifndef __STORE_H
#define __STORE_H

#include <string>

#include "hash.hh"


namespace nix {


class Transaction;


/* Nix store and database schema version.  Version 1 (or 0) was Nix <=
   0.7.  Version 2 was Nix 0.8 and 0.8.  Version 3 is Nix 0.10 and
   up. */
const int nixSchemaVersion = 3;


/* A substitute is a program invocation that constructs some store
   path (typically by fetching it from somewhere, e.g., from the
   network). */
struct Substitute
{       
    /* The derivation that built this store path (empty if none). */
    Path deriver;
    
    /* Program to be executed to create the store path.  Must be in
       the output path of `storeExpr'. */
    Path program;

    /* Extra arguments to be passed to the program (the first argument
       is the store path to be substituted). */
    Strings args;

    bool operator == (const Substitute & sub) const;
};

typedef list<Substitute> Substitutes;


/* Open the database environment.  If `reserveSpace' is true, make
   sure that a big empty file exists in /nix/var/nix/db/reserved.  If
   `reserveSpace' is false, delete this file if it exists.  The idea
   is that on normal operation, the file exists; but when we run the
   garbage collector, it is deleted.  This is to ensure that the
   garbage collector has a small amount of disk space available, which
   is required to open the Berkeley DB environment. */
void openDB(bool reserveSpace = true);

/* Create the required database tables. */
void initDB();

/* Close the database. */
void closeDB();

/* Get a transaction object. */
void createStoreTransaction(Transaction & txn);

/* Copy a path recursively. */
void copyPath(const Path & src, const Path & dst);

/* Register a substitute. */
void registerSubstitute(const Transaction & txn,
    const Path & srcPath, const Substitute & sub);

/* Return the substitutes for the given path. */
Substitutes querySubstitutes(const Transaction & txn, const Path & srcPath);

/* Deregister all substitutes. */
void clearSubstitutes();

/* Register the validity of a path, i.e., that `path' exists, that the
   paths referenced by it exists, and in the case of an output path of
   a derivation, that it has been produced by a succesful execution of
   the derivation (or something equivalent).  Also register the hash
   of the file system contents of the path.  The hash must be a
   SHA-256 hash. */
void registerValidPath(const Transaction & txn,
    const Path & path, const Hash & hash, const PathSet & references,
    const Path & deriver);

struct ValidPathInfo 
{
    Path path;
    Path deriver;
    Hash hash;
    PathSet references;
};

typedef list<ValidPathInfo> ValidPathInfos;

void registerValidPaths(const Transaction & txn,
    const ValidPathInfos & infos);

/* Throw an exception if `path' is not directly in the Nix store. */
void assertStorePath(const Path & path);

bool isInStore(const Path & path);
bool isStorePath(const Path & path);

void checkStoreName(const string & name);

/* Chop off the parts after the top-level store name, e.g.,
   /nix/store/abcd-foo/bar => /nix/store/abcd-foo. */
Path toStorePath(const Path & path);

/* "Fix", or canonicalise, the meta-data of the files in a store path
   after it has been built.  In particular:
   - the last modification date on each file is set to 0 (i.e.,
     00:00:00 1/1/1970 UTC)
   - the permissions are set of 444 or 555 (i.e., read-only with or
     without execute permission; setuid bits etc. are cleared)
   - the owner and group are set to the Nix user and group, if we're
     in a setuid Nix installation. */
void canonicalisePathMetaData(const Path & path);

/* Checks whether a path is valid. */ 
bool isValidPathTxn(const Transaction & txn, const Path & path);
bool isValidPath(const Path & path);

/* Queries the hash of a valid path. */ 
Hash queryPathHash(const Path & path);

/* Sets the set of outgoing FS references for a store path.  Use with
   care! */
void setReferences(const Transaction & txn, const Path & storePath,
    const PathSet & references);

/* Queries the set of outgoing FS references for a store path.  The
   result is not cleared. */
void queryReferences(const Transaction & txn,
    const Path & storePath, PathSet & references);

/* Queries the set of incoming FS references for a store path.  The
   result is not cleared. */
void queryReferrers(const Transaction & txn,
    const Path & storePath, PathSet & referrers);

/* Sets the deriver of a store path.  Use with care! */
void setDeriver(const Transaction & txn, const Path & storePath,
    const Path & deriver);

/* Query the deriver of a store path.  Return the empty string if no
   deriver has been set. */
Path queryDeriver(const Transaction & txn, const Path & storePath);

/* Constructs a unique store path name. */
Path makeStorePath(const string & type,
    const Hash & hash, const string & suffix);
    
/* Copy the contents of a path to the store and register the validity
   the resulting path.  The resulting path is returned. */
Path addToStore(const Path & srcPath);

/* Like addToStore(), but for pre-adding the outputs of fixed-output
   derivations. */
Path addToStoreFixed(bool recursive, string hashAlgo, const Path & srcPath);

Path makeFixedOutputPath(bool recursive,
    string hashAlgo, Hash hash, string name);

/* Like addToStore, but the contents written to the output path is a
   regular file containing the given string. */
Path addTextToStore(const string & suffix, const string & s,
    const PathSet & references);

/* Delete a value from the nixStore directory. */
void deleteFromStore(const Path & path, unsigned long long & bytesFreed);

void verifyStore(bool checkContents);

 
}


#endif /* !__STORE_H */