142 lines
3.7 KiB
C++
142 lines
3.7 KiB
C++
#include "nar-accessor.hh"
|
||
#include "archive.hh"
|
||
|
||
#include <map>
|
||
|
||
namespace nix {
|
||
|
||
struct NarMember
|
||
{
|
||
FSAccessor::Type type;
|
||
|
||
bool isExecutable;
|
||
|
||
/* If this is a regular file, position of the contents of this
|
||
file in the NAR. */
|
||
size_t start, size;
|
||
|
||
std::string target;
|
||
};
|
||
|
||
struct NarIndexer : ParseSink, StringSource
|
||
{
|
||
// FIXME: should store this as a tree. Now we're vulnerable to
|
||
// O(nm) memory consumption (e.g. for x_0/.../x_n/{y_0..y_m}).
|
||
typedef std::map<Path, NarMember> Members;
|
||
Members members;
|
||
|
||
Path currentPath;
|
||
std::string currentStart;
|
||
bool isExec = false;
|
||
|
||
NarIndexer(const std::string & nar) : StringSource(nar)
|
||
{
|
||
}
|
||
|
||
void createDirectory(const Path & path) override
|
||
{
|
||
members.emplace(path,
|
||
NarMember{FSAccessor::Type::tDirectory, false, 0, 0});
|
||
}
|
||
|
||
void createRegularFile(const Path & path) override
|
||
{
|
||
currentPath = path;
|
||
}
|
||
|
||
void isExecutable() override
|
||
{
|
||
isExec = true;
|
||
}
|
||
|
||
void preallocateContents(unsigned long long size) override
|
||
{
|
||
currentStart = string(s, pos, 16);
|
||
members.emplace(currentPath,
|
||
NarMember{FSAccessor::Type::tRegular, isExec, pos, size});
|
||
}
|
||
|
||
void receiveContents(unsigned char * data, unsigned int len) override
|
||
{
|
||
// Sanity check
|
||
if (!currentStart.empty()) {
|
||
assert(len < 16 || currentStart == string((char *) data, 16));
|
||
currentStart.clear();
|
||
}
|
||
}
|
||
|
||
void createSymlink(const Path & path, const string & target) override
|
||
{
|
||
members.emplace(path,
|
||
NarMember{FSAccessor::Type::tSymlink, false, 0, 0, target});
|
||
}
|
||
|
||
Members::iterator find(const Path & path)
|
||
{
|
||
auto i = members.find(path);
|
||
if (i == members.end())
|
||
throw Error(format("NAR file does not contain path ‘%1%’") % path);
|
||
return i;
|
||
}
|
||
};
|
||
|
||
struct NarAccessor : public FSAccessor
|
||
{
|
||
ref<const std::string> nar;
|
||
NarIndexer indexer;
|
||
|
||
NarAccessor(ref<const std::string> nar) : nar(nar), indexer(*nar)
|
||
{
|
||
parseDump(indexer, indexer);
|
||
}
|
||
|
||
Stat stat(const Path & path) override
|
||
{
|
||
auto i = indexer.members.find(path);
|
||
if (i == indexer.members.end())
|
||
return {FSAccessor::Type::tMissing, 0, false};
|
||
return {i->second.type, i->second.size, i->second.isExecutable};
|
||
}
|
||
|
||
StringSet readDirectory(const Path & path) override
|
||
{
|
||
auto i = indexer.find(path);
|
||
|
||
if (i->second.type != FSAccessor::Type::tDirectory)
|
||
throw Error(format("path ‘%1%’ inside NAR file is not a directory") % path);
|
||
|
||
++i;
|
||
StringSet res;
|
||
while (i != indexer.members.end() && isInDir(i->first, path)) {
|
||
// FIXME: really bad performance.
|
||
if (i->first.find('/', path.size() + 1) == std::string::npos)
|
||
res.insert(std::string(i->first, path.size() + 1));
|
||
++i;
|
||
}
|
||
return res;
|
||
}
|
||
|
||
std::string readFile(const Path & path) override
|
||
{
|
||
auto i = indexer.find(path);
|
||
if (i->second.type != FSAccessor::Type::tRegular)
|
||
throw Error(format("path ‘%1%’ inside NAR file is not a regular file") % path);
|
||
return std::string(*nar, i->second.start, i->second.size);
|
||
}
|
||
|
||
std::string readLink(const Path & path) override
|
||
{
|
||
auto i = indexer.find(path);
|
||
if (i->second.type != FSAccessor::Type::tSymlink)
|
||
throw Error(format("path ‘%1%’ inside NAR file is not a symlink") % path);
|
||
return i->second.target;
|
||
}
|
||
};
|
||
|
||
ref<FSAccessor> makeNarAccessor(ref<const std::string> nar)
|
||
{
|
||
return make_ref<NarAccessor>(nar);
|
||
}
|
||
|
||
}
|