about summary refs log tree commit diff
path: root/src/nix.cc
blob: 8fc0fa2c325c4477c815d506aa3042134e216921 (plain) (blame)
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
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
#include <iostream>

#include "globals.hh"
#include "store.hh"
#include "fstate.hh"
#include "archive.hh"
#include "shared.hh"


typedef void (* Operation) (Strings opFlags, Strings opArgs);


typedef enum { atpHash, atpPath, atpUnknown } ArgType;

static ArgType argType = atpUnknown;


/* Nix syntax:

   nix [OPTIONS...] [ARGUMENTS...]

   Operations:

     --install / -i: realise an fstate
     --delete / -d: delete paths from the Nix store
     --add / -A: copy a path to the Nix store
     --query / -q: query information

     --successor: register a successor expression
     --substitute: register a substitute expression

     --dump: dump a path as a Nix archive
     --restore: restore a path from a Nix archive

     --init: initialise the Nix database
     --verify: verify Nix structures

     --version: output version information
     --help: display help

   Source selection for --install, --dump:

     --file / -f: by file name  !!! -> path
     --hash / -h: by hash

   Query flags:

     --path / -p: query the path of an fstate 
     --refs / -r: query paths referenced by an fstate

   Options:

     --verbose / -v: verbose operation
*/


/* Parse the `-f' / `-h' / flags, i.e., the type of arguments.  These
   flags are deleted from the referenced vector. */
static void getArgType(Strings & flags)
{
    for (Strings::iterator it = flags.begin();
         it != flags.end(); )
    {
        string arg = *it;
        ArgType tp;
        if (arg == "--hash" || arg == "-h") tp = atpHash;
        else if (arg == "--file" || arg == "-f") tp = atpPath;
        else { it++; continue; }
        if (argType != atpUnknown)
            throw UsageError("only one argument type specified may be specified");
        argType = tp;
        it = flags.erase(it);
    }
    if (argType == atpUnknown)
        throw UsageError("argument type not specified");
}


static Hash argToHash(const string & arg)
{
    if (argType == atpHash)
        return parseHash(arg);
    else if (argType == atpPath) {
        string path;
        Hash hash;
        addToStore(arg, path, hash);
        return hash;
    }
    else abort();
}


/* Realise (or install) paths from the given Nix fstate
   expressions. */
static void opInstall(Strings opFlags, Strings opArgs)
{
    getArgType(opFlags);
    if (!opFlags.empty()) throw UsageError("unknown flag");

    for (Strings::iterator it = opArgs.begin();
         it != opArgs.end(); it++)
    {
        StringSet paths;
        realiseFState(hash2fstate(argToHash(*it)), paths);
    }
}


/* Delete a path in the Nix store directory. */
static void opDelete(Strings opFlags, Strings opArgs)
{
    if (!opFlags.empty()) throw UsageError("unknown flag");

    for (Strings::iterator it = opArgs.begin();
         it != opArgs.end(); it++)
        deleteFromStore(absPath(*it));
}


/* Add paths to the Nix values directory and print the hashes of those
   paths. */
static void opAdd(Strings opFlags, Strings opArgs)
{
    getArgType(opFlags);
    if (!opFlags.empty()) throw UsageError("unknown flag");

    for (Strings::iterator it = opArgs.begin();
         it != opArgs.end(); it++)
    {
        string path;
        Hash hash;
        addToStore(*it, path, hash);
        cout << format("%1% %2%\n") % (string) hash % path;
    }
}


/* Perform various sorts of queries. */
static void opQuery(Strings opFlags, Strings opArgs)
{
    enum { qPath, qRefs, qUnknown } query = qPath;

    for (Strings::iterator it = opFlags.begin();
         it != opFlags.end(); )
    {
        string arg = *it;
        if (arg == "--path" || arg == "-p") query = qPath;
        else if (arg == "--refs" || arg == "-r") query = qRefs;
        else { it++; continue; }
        it = opFlags.erase(it);
    }

    getArgType(opFlags);
    if (!opFlags.empty()) throw UsageError("unknown flag");

    for (Strings::iterator it = opArgs.begin();
         it != opArgs.end(); it++)
    {
        Hash hash = argToHash(*it);

        switch (query) {

        case qPath: {
            StringSet refs;
            cout << format("%s\n") % 
                (string) fstatePath(realiseFState(termFromHash(hash), refs));
            break;
        }

        case qRefs: {
            StringSet refs;
            FState fs = hash2fstate(hash);
            fstateRefs(realiseFState(fs, refs), refs);
            for (StringSet::iterator j = refs.begin(); 
                 j != refs.end(); j++)
                cout << format("%s\n") % *j;
            break;
        }

        default:
            abort();
        }
    }
}


static void opSuccessor(Strings opFlags, Strings opArgs)
{
    if (!opFlags.empty()) throw UsageError("unknown flag");
    if (opArgs.size() % 2) throw UsageError("expecting even number of arguments");
    
    for (Strings::iterator i = opArgs.begin();
         i != opArgs.end(); )
    {
        Hash fsHash = parseHash(*i++);
        Hash scHash = parseHash(*i++);
        registerSuccessor(fsHash, scHash);
    }
}


static void opSubstitute(Strings opFlags, Strings opArgs)
{
    if (!opFlags.empty()) throw UsageError("unknown flag");
    if (opArgs.size() % 2) throw UsageError("expecting even number of arguments");
    
    for (Strings::iterator i = opArgs.begin();
         i != opArgs.end(); )
    {
        Hash srcHash = parseHash(*i++);
        Hash subHash = parseHash(*i++);
        registerSubstitute(srcHash, subHash);
    }
}


/* A sink that writes dump output to stdout. */
struct StdoutSink : DumpSink
{
    virtual void operator ()
        (const unsigned char * data, unsigned int len)
    {
        if (write(STDOUT_FILENO, (char *) data, len) != (ssize_t) len)
            throw SysError("writing to stdout");
    }
};


/* Dump a path as a Nix archive.  The archive is written to standard
   output. */
static void opDump(Strings opFlags, Strings opArgs)
{
    getArgType(opFlags);
    if (!opFlags.empty()) throw UsageError("unknown flag");
    if (opArgs.size() != 1) throw UsageError("only one argument allowed");

    StdoutSink sink;
    string arg = *opArgs.begin();
    string path;
    
    if (argType == atpHash) path = expandHash(parseHash(arg));
    else if (argType == atpPath) path = arg;

    dumpPath(path, sink);
}


/* A source that read restore intput to stdin. */
struct StdinSource : RestoreSource
{
    virtual void operator () (const unsigned char * data, unsigned int len)
    {
        while (len) {
            ssize_t res = read(STDIN_FILENO, (char *) data, len);
            if (res == -1) throw SysError("reading from stdin");
            if (res == 0) throw SysError("unexpected end-of-file on stdin");
            len -= res;
            data += res;
        }
    }
};


/* Restore a value from a Nix archive.  The archive is written to
   standard input. */
static void opRestore(Strings opFlags, Strings opArgs)
{
    if (!opFlags.empty()) throw UsageError("unknown flag");
    if (opArgs.size() != 1) throw UsageError("only one argument allowed");

    StdinSource source;
    restorePath(*opArgs.begin(), source);
}


/* Initialise the Nix databases. */
static void opInit(Strings opFlags, Strings opArgs)
{
    if (!opFlags.empty()) throw UsageError("unknown flag");
    if (!opArgs.empty())
        throw UsageError("--init does not have arguments");
    initDB();
}


/* Scan the arguments; find the operation, set global flags, put all
   other flags in a list, and put all other arguments in another
   list. */
void run(Strings args)
{
    Strings opFlags, opArgs;
    Operation op = 0;

    for (Strings::iterator it = args.begin();
         it != args.end(); it++)
    {
        string arg = *it;

        Operation oldOp = op;

        if (arg == "--install" || arg == "-i")
            op = opInstall;
        else if (arg == "--delete" || arg == "-d")
            op = opDelete;
        else if (arg == "--add" || arg == "-A")
            op = opAdd;
        else if (arg == "--query" || arg == "-q")
            op = opQuery;
        else if (arg == "--successor")
            op = opSuccessor;
        else if (arg == "--substitute")
            op = opSubstitute;
        else if (arg == "--dump")
            op = opDump;
        else if (arg == "--restore")
            op = opRestore;
        else if (arg == "--init")
            op = opInit;
        else if (arg[0] == '-')
            opFlags.push_back(arg);
        else
            opArgs.push_back(arg);

        if (oldOp && oldOp != op)
            throw UsageError("only one operation may be specified");
    }

    if (!op) throw UsageError("no operation specified");

    op(opFlags, opArgs);
}


string programId = "nix";