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#include "canon-path.hh"
#include "util.hh"
namespace nix {
CanonPath CanonPath::root = CanonPath("/");
CanonPath::CanonPath(std::string_view raw)
: path(absPath((Path) raw, "/"))
{ }
CanonPath::CanonPath(std::string_view raw, const CanonPath & root)
: path(absPath((Path) raw, root.abs()))
{ }
std::optional<CanonPath> CanonPath::parent() const
{
if (isRoot()) return std::nullopt;
return CanonPath(unchecked_t(), path.substr(0, std::max((size_t) 1, path.rfind('/'))));
}
void CanonPath::pop()
{
assert(!isRoot());
path.resize(std::max((size_t) 1, path.rfind('/')));
}
bool CanonPath::isWithin(const CanonPath & parent) const
{
return !(
path.size() < parent.path.size()
|| path.substr(0, parent.path.size()) != parent.path
|| (parent.path.size() > 1 && path.size() > parent.path.size()
&& path[parent.path.size()] != '/'));
}
CanonPath CanonPath::removePrefix(const CanonPath & prefix) const
{
assert(isWithin(prefix));
if (prefix.isRoot()) return *this;
if (path.size() == prefix.path.size()) return root;
return CanonPath(unchecked_t(), path.substr(prefix.path.size()));
}
void CanonPath::extend(const CanonPath & x)
{
if (x.isRoot()) return;
if (isRoot())
path += x.rel();
else
path += x.abs();
}
CanonPath CanonPath::operator + (const CanonPath & x) const
{
auto res = *this;
res.extend(x);
return res;
}
void CanonPath::push(std::string_view c)
{
assert(c.find('/') == c.npos);
assert(c != "." && c != "..");
if (!isRoot()) path += '/';
path += c;
}
CanonPath CanonPath::operator + (std::string_view c) const
{
auto res = *this;
res.push(c);
return res;
}
bool CanonPath::isAllowed(const std::set<CanonPath> & allowed) const
{
/* Check if `this` is an exact match or the parent of an
allowed path. */
auto lb = allowed.lower_bound(*this);
if (lb != allowed.end()) {
if (lb->isWithin(*this))
return true;
}
/* Check if a parent of `this` is allowed. */
auto path = *this;
while (!path.isRoot()) {
path.pop();
if (allowed.count(path))
return true;
}
return false;
}
std::ostream & operator << (std::ostream & stream, const CanonPath & path)
{
stream << path.abs();
return stream;
}
std::string CanonPath::makeRelative(const CanonPath & path) const
{
auto p1 = begin();
auto p2 = path.begin();
for (; p1 != end() && p2 != path.end() && *p1 == *p2; ++p1, ++p2) ;
if (p1 == end() && p2 == path.end())
return ".";
else if (p1 == end())
return std::string(p2.remaining);
else {
std::string res;
while (p1 != end()) {
++p1;
if (!res.empty()) res += '/';
res += "..";
}
if (p2 != path.end()) {
if (!res.empty()) res += '/';
res += p2.remaining;
}
return res;
}
}
}
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