nix-super/src/nix/path-info.cc

#include "command.hh"
#include "shared.hh"
#include "store-api.hh"
#include "json.hh"

#include <iomanip>
#include <algorithm>

using namespace nix;

struct CmdPathInfo : StorePathsCommand
{
    bool showSize = false;
    bool showClosureSize = false;
    bool showSigs = false;
    bool json = false;

    CmdPathInfo()
    {
        mkFlag('s', "size", "print size of the NAR dump of each path", &showSize);
        mkFlag('S', "closure-size", "print sum size of the NAR dumps of the closure of each path", &showClosureSize);
        mkFlag(0, "sigs", "show signatures", &showSigs);
        mkFlag(0, "json", "produce JSON output", &json);
    }

    std::string name() override
    {
        return "path-info";
    }

    std::string description() override
    {
        return "query information about store paths";
    }

    Examples examples() override
    {
        return {
            Example{
                "To show the closure sizes of every path in the current NixOS system closure, sorted by size:",
                "nix path-info -rS /run/current-system | sort -nk2"
            },
            Example{
                "To check the existence of a path in a binary cache:",
                "nix path-info -r /nix/store/7qvk5c91...-geeqie-1.1 --store https://cache.nixos.org/"
            },
            Example{
                "To print the 10 most recently added paths (using --json and the jq(1) command):",
                "nix path-info --json --all | jq -r 'sort_by(.registrationTime)[-11:-1][].path'"
            },
            Example{
                "To show the size of the entire Nix store:",
                "nix path-info --json --all | jq 'map(.narSize) | add'"
            },
            Example{
                "To show every path whose closure is bigger than 1 GB, sorted by closure size:",
                "nix path-info --json --all -S | jq 'map(select(.closureSize > 1e9)) | sort_by(.closureSize) | map([.path, .closureSize])'"
            },
        };
    }

    void run(ref<Store> store, Paths storePaths) override
    {
        size_t pathLen = 0;
        for (auto & storePath : storePaths)
            pathLen = std::max(pathLen, storePath.size());

        auto getClosureSize = [&](const Path & storePath) -> unsigned long long {
            unsigned long long totalSize = 0;
            PathSet closure;
            store->computeFSClosure(storePath, closure, false, false);
            for (auto & p : closure)
                totalSize += store->queryPathInfo(p)->narSize;
            return totalSize;
        };

        if (json) {
            JSONList jsonRoot(std::cout, true);

            for (auto storePath : storePaths) {
                auto info = store->queryPathInfo(storePath);
                storePath = info->path;

                auto jsonPath = jsonRoot.object();
                jsonPath
                    .attr("path", storePath)
                    .attr("narHash", info->narHash.to_string())
                    .attr("narSize", info->narSize);

                if (showClosureSize)
                    jsonPath.attr("closureSize", getClosureSize(storePath));

                if (info->deriver != "")
                    jsonPath.attr("deriver", info->deriver);

                {
                    auto jsonRefs = jsonPath.list("references");
                    for (auto & ref : info->references)
                        jsonRefs.elem(ref);
                }

                if (info->registrationTime)
                    jsonPath.attr("registrationTime", info->registrationTime);

                if (info->ultimate)
                    jsonPath.attr("ultimate", info->ultimate);

                if (info->ca != "")
                    jsonPath.attr("ca", info->ca);

                if (!info->sigs.empty()) {
                    auto jsonSigs = jsonPath.list("signatures");
                    for (auto & sig : info->sigs)
                        jsonSigs.elem(sig);
                }
            }
        }

        else {

            for (auto storePath : storePaths) {
                auto info = store->queryPathInfo(storePath);
                storePath = info->path; // FIXME: screws up padding

                std::cout << storePath << std::string(std::max(0, (int) pathLen - (int) storePath.size()), ' ');

                if (showSize)
                    std::cout << '\t' << std::setw(11) << info->narSize;

                if (showClosureSize)
                    std::cout << '\t' << std::setw(11) << getClosureSize(storePath);

                if (showSigs) {
                    std::cout << '\t';
                    Strings ss;
                    if (info->ultimate) ss.push_back("ultimate");
                    if (info->ca != "") ss.push_back("ca:" + info->ca);
                    for (auto & sig : info->sigs) ss.push_back(sig);
                    std::cout << concatStringsSep(" ", ss);
                }

                std::cout << std::endl;
            }

        }

    }
};

static RegisterCommand r1(make_ref<CmdPathInfo>());