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| -rw-r--r-- | src/nix/diff-closures.cc | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/src/nix/diff-closures.cc b/src/nix/diff-closures.cc new file mode 100644 index 000000000..df0b26ab1 --- /dev/null +++ b/src/nix/diff-closures.cc @@ -0,0 +1,134 @@ +#include "command.hh" +#include "shared.hh" +#include "store-api.hh" +#include "common-args.hh" +#include "names.hh" + +#include <regex> + +using namespace nix; + +struct Info +{ + std::string outputName; +}; + +// name -> version -> store paths +typedef std::map<std::string, std::map<std::string, std::map<StorePath, Info>>> GroupedPaths; + +GroupedPaths getClosureInfo(ref<Store> store, const StorePath & toplevel) +{ + StorePathSet closure; + store->computeFSClosure({toplevel}, closure); + + GroupedPaths groupedPaths; + + for (auto & path : closure) { + /* Strip the output name. Unfortunately this is ambiguous (we + can't distinguish between output names like "bin" and + version suffixes like "unstable"). */ + static std::regex regex("(.*)-([a-z]+|lib32|lib64)"); + std::smatch match; + std::string name(path.name()); + std::string outputName; + if (std::regex_match(name, match, regex)) { + name = match[1]; + outputName = match[2]; + } + + DrvName drvName(name); + groupedPaths[drvName.name][drvName.version].emplace(path, Info { .outputName = outputName }); + } + + return groupedPaths; +} + +std::string showVersions(const std::set<std::string> & versions) +{ + if (versions.empty()) return "∅"; + std::set<std::string> versions2; + for (auto & version : versions) + versions2.insert(version.empty() ? "ε" : version); + return concatStringsSep(", ", versions2); +} + +struct CmdDiffClosures : SourceExprCommand +{ + std::string _before, _after; + + CmdDiffClosures() + { + expectArg("before", &_before); + expectArg("after", &_after); + } + + std::string description() override + { + return "show what packages and versions were added and removed between two closures"; + } + + Category category() override { return catSecondary; } + + Examples examples() override + { + return { + { + "To show what got added and removed between two versions of the NixOS system profile:", + "nix diff-closures /nix/var/nix/profiles/system-655-link /nix/var/nix/profiles/system-658-link", + }, + }; + } + + void run(ref<Store> store) override + { + auto before = parseInstallable(*this, store, _before, false); + auto beforePath = toStorePath(store, Build, before); + auto after = parseInstallable(*this, store, _after, false); + auto afterPath = toStorePath(store, NoBuild, after); + + auto beforeClosure = getClosureInfo(store, beforePath); + auto afterClosure = getClosureInfo(store, afterPath); + + std::set<std::string> allNames; + for (auto & [name, _] : beforeClosure) allNames.insert(name); + for (auto & [name, _] : afterClosure) allNames.insert(name); + + for (auto & name : allNames) { + auto & beforeVersions = beforeClosure[name]; + auto & afterVersions = afterClosure[name]; + + auto totalSize = [&](const std::map<std::string, std::map<StorePath, Info>> & versions) + { + uint64_t sum = 0; + for (auto & [_, paths] : versions) + for (auto & [path, _] : paths) + sum += store->queryPathInfo(path)->narSize; + return sum; + }; + + auto beforeSize = totalSize(beforeVersions); + auto afterSize = totalSize(afterVersions); + auto sizeDelta = (int64_t) afterSize - (int64_t) beforeSize; + auto showDelta = abs(sizeDelta) >= 8 * 1024; + + std::set<std::string> removed, unchanged; + for (auto & [version, _] : beforeVersions) + if (!afterVersions.count(version)) removed.insert(version); else unchanged.insert(version); + + std::set<std::string> added; + for (auto & [version, _] : afterVersions) + if (!beforeVersions.count(version)) added.insert(version); + + if (showDelta || !removed.empty() || !added.empty()) { + std::vector<std::string> items; + if (!removed.empty() || !added.empty()) + items.push_back(fmt("%s → %s", showVersions(removed), showVersions(added))); + if (showDelta) + items.push_back(fmt("%s%+.1f KiB" ANSI_NORMAL, sizeDelta > 0 ? ANSI_RED : ANSI_GREEN, sizeDelta / 1024.0)); + std::cout << fmt("%s: %s\n", name, concatStringsSep(", ", items)); + } + } + } +}; + +static auto r1 = registerCommand<CmdDiffClosures>("diff-closures"); |