lix/src/libutil/archive.hh
2020-07-13 17:30:42 +02:00

88 lines
2 KiB
C++

#pragma once
#include "types.hh"
#include "serialise.hh"
namespace nix {
/* dumpPath creates a Nix archive of the specified path. The format
is as follows:
IF path points to a REGULAR FILE:
dump(path) = attrs(
[ ("type", "regular")
, ("contents", contents(path))
])
IF path points to a DIRECTORY:
dump(path) = attrs(
[ ("type", "directory")
, ("entries", concat(map(f, sort(entries(path)))))
])
where f(fn) = attrs(
[ ("name", fn)
, ("file", dump(path + "/" + fn))
])
where:
attrs(as) = concat(map(attr, as)) + encN(0)
attrs((a, b)) = encS(a) + encS(b)
encS(s) = encN(len(s)) + s + (padding until next 64-bit boundary)
encN(n) = 64-bit little-endian encoding of n.
contents(path) = the contents of a regular file.
sort(strings) = lexicographic sort by 8-bit value (strcmp).
entries(path) = the entries of a directory, without `.' and
`..'.
`+' denotes string concatenation. */
void dumpPath(const Path & path, Sink & sink,
PathFilter & filter = defaultPathFilter);
void dumpString(const std::string & s, Sink & sink);
/* FIXME: fix this API, it sucks. */
struct ParseSink
{
virtual void createDirectory(const Path & path) { };
virtual void createRegularFile(const Path & path) { };
virtual void isExecutable() { };
virtual void preallocateContents(unsigned long long size) { };
virtual void receiveContents(unsigned char * data, unsigned int len) { };
virtual void createSymlink(const Path & path, const string & target) { };
};
struct TeeParseSink : ParseSink
{
StringSink saved;
TeeSource source;
TeeParseSink(Source & source) : source(source, saved) { }
};
void parseDump(ParseSink & sink, Source & source);
void restorePath(const Path & path, Source & source);
/* Read a NAR from 'source' and write it to 'sink'. */
void copyNAR(Source & source, Sink & sink);
void copyPath(const Path & from, const Path & to);
extern const std::string narVersionMagic1;
}