lix/src/nix/diff-closures.cc
Eelco Dolstra 85c8be6286 Remove static variable name clashes
This was useful for an experiment with building Nix as a single
compilation unit. It's not very useful otherwise but also doesn't
hurt...
2020-10-06 13:49:20 +02:00

147 lines
4.6 KiB
C++

#include "command.hh"
#include "shared.hh"
#include "store-api.hh"
#include "common-args.hh"
#include "names.hh"
#include <regex>
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);
}
void printClosureDiff(
ref<Store> store,
const StorePath & beforePath,
const StorePath & afterPath,
std::string_view indent)
{
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 = std::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: %s\n", indent, name, concatStringsSep(", ", items));
}
}
}
}
using namespace nix;
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(store, _before);
auto beforePath = toStorePath(store, Realise::Outputs, operateOn, before);
auto after = parseInstallable(store, _after);
auto afterPath = toStorePath(store, Realise::Outputs, operateOn, after);
printClosureDiff(store, beforePath, afterPath, "");
}
};
static auto rCmdDiffClosures = registerCommand<CmdDiffClosures>("diff-closures");