wroclaw-git-backups/nix
1
0
Fork 0
mirror of https://github.com/NixOS/nix synced 2025-07-06 00:51:47 +02:00
Code Activity

Improve the FileSystemObjectSink interface

Browse source 
More invariants are enforced in the type, and less state needs to be
stored in the main sink itself. The method here is roughly that known as
"session types".

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
This commit is contained in:
John Ericson 2023-12-20 14:47:05 -05:00
parent 966d6fcd01
commit 6365bbfa81
9 changed files with 357 additions and 219 deletions
Download patch file Download diff file Expand all files Collapse all files

60
src/libstore/nar-accessor.cc
View file

@ -19,6 +19,35 @@ struct NarMember
std::map<std::string, NarMember> children;
};
struct NarMemberConstructor : CreateRegularFileSink
{
private:
NarMember & narMember;
uint64_t & pos;
public:
NarMemberConstructor(NarMember & nm, uint64_t & pos)
: narMember(nm), pos(pos)
{ }
void isExecutable() override
{
narMember.stat.isExecutable = true;
}
void preallocateContents(uint64_t size) override
{
narMember.stat.fileSize = size;
narMember.stat.narOffset = pos;
}
void operator () (std::string_view data) override
{ }
};
struct NarAccessor : public SourceAccessor
{
std::optional<const std::string> nar;
@ -42,7 +71,7 @@ struct NarAccessor : public SourceAccessor
: acc(acc), source(source)
{ }
void createMember(const Path & path, NarMember member)
NarMember & createMember(const Path & path, NarMember member)
{
size_t level = std::count(path.begin(), path.end(), '/');
while (parents.size() > level) parents.pop();
@ -50,11 +79,14 @@ struct NarAccessor : public SourceAccessor
if (parents.empty()) {
acc.root = std::move(member);
parents.push(&acc.root);
return acc.root;
} else {
if (parents.top()->stat.type != Type::tDirectory)
throw Error("NAR file missing parent directory of path '%s'", path);
auto result = parents.top()->children.emplace(baseNameOf(path), std::move(member));
parents.push(&result.first->second);
auto & ref = result.first->second;
parents.push(&ref);
return ref;
}
}
@ -68,34 +100,18 @@ struct NarAccessor : public SourceAccessor
} });
}
void createRegularFile(const Path & path) override
void createRegularFile(const Path & path, std::function<void(CreateRegularFileSink &)> func) override
{
createMember(path, NarMember{ .stat = {
auto & nm = createMember(path, NarMember{ .stat = {
.type = Type::tRegular,
.fileSize = 0,
.isExecutable = false,
.narOffset = 0
} });
NarMemberConstructor nmc { nm, pos };
func(nmc);
}
void closeRegularFile() override
{ }
void isExecutable() override
{
parents.top()->stat.isExecutable = true;
}
void preallocateContents(uint64_t size) override
{
auto & st = parents.top()->stat;
st.fileSize = size;
st.narOffset = pos;
}
void receiveContents(std::string_view data) override
{ }
void createSymlink(const Path & path, const std::string & target) override
{
createMember(path,