diff options
Diffstat (limited to 'third_party/nix/src/nix/why-depends.cc')
| -rw-r--r-- | third_party/nix/src/nix/why-depends.cc | 433 |
1 files changed, 206 insertions, 227 deletions
diff --git a/third_party/nix/src/nix/why-depends.cc b/third_party/nix/src/nix/why-depends.cc index 325a2be0a7..7b8650a4e8 100644 --- a/third_party/nix/src/nix/why-depends.cc +++ b/third_party/nix/src/nix/why-depends.cc @@ -1,267 +1,246 @@ +#include <queue> #include "command.hh" -#include "store-api.hh" -#include "progress-bar.hh" #include "fs-accessor.hh" +#include "progress-bar.hh" #include "shared.hh" - -#include <queue> +#include "store-api.hh" using namespace nix; -static std::string hilite(const std::string & s, size_t pos, size_t len, - const std::string & colour = ANSI_RED) -{ - return - std::string(s, 0, pos) - + colour - + std::string(s, pos, len) - + ANSI_NORMAL - + std::string(s, pos + len); +static std::string hilite(const std::string& s, size_t pos, size_t len, + const std::string& colour = ANSI_RED) { + return std::string(s, 0, pos) + colour + std::string(s, pos, len) + + ANSI_NORMAL + std::string(s, pos + len); } -static std::string filterPrintable(const std::string & s) -{ - std::string res; - for (char c : s) - res += isprint(c) ? c : '.'; - return res; +static std::string filterPrintable(const std::string& s) { + std::string res; + for (char c : s) res += isprint(c) ? c : '.'; + return res; } -struct CmdWhyDepends : SourceExprCommand -{ - std::string _package, _dependency; - bool all = false; - - CmdWhyDepends() - { - expectArg("package", &_package); - expectArg("dependency", &_dependency); - - mkFlag() - .longName("all") - .shortName('a') - .description("show all edges in the dependency graph leading from 'package' to 'dependency', rather than just a shortest path") - .set(&all, true); +struct CmdWhyDepends : SourceExprCommand { + std::string _package, _dependency; + bool all = false; + + CmdWhyDepends() { + expectArg("package", &_package); + expectArg("dependency", &_dependency); + + mkFlag() + .longName("all") + .shortName('a') + .description( + "show all edges in the dependency graph leading from 'package' to " + "'dependency', rather than just a shortest path") + .set(&all, true); + } + + std::string name() override { return "why-depends"; } + + std::string description() override { + return "show why a package has another package in its closure"; + } + + Examples examples() override { + return { + Example{"To show one path through the dependency graph leading from " + "Hello to Glibc:", + "nix why-depends nixpkgs.hello nixpkgs.glibc"}, + Example{ + "To show all files and paths in the dependency graph leading from " + "Thunderbird to libX11:", + "nix why-depends --all nixpkgs.thunderbird nixpkgs.xorg.libX11"}, + Example{"To show why Glibc depends on itself:", + "nix why-depends nixpkgs.glibc nixpkgs.glibc"}, + }; + } + + void run(ref<Store> store) override { + auto package = parseInstallable(*this, store, _package, false); + auto packagePath = toStorePath(store, Build, package); + auto dependency = parseInstallable(*this, store, _dependency, false); + auto dependencyPath = toStorePath(store, NoBuild, dependency); + auto dependencyPathHash = storePathToHash(dependencyPath); + + PathSet closure; + store->computeFSClosure({packagePath}, closure, false, false); + + if (!closure.count(dependencyPath)) { + printError("'%s' does not depend on '%s'", package->what(), + dependency->what()); + return; } - std::string name() override - { - return "why-depends"; - } + stopProgressBar(); // FIXME - std::string description() override - { - return "show why a package has another package in its closure"; - } + auto accessor = store->getFSAccessor(); - Examples examples() override - { - return { - Example{ - "To show one path through the dependency graph leading from Hello to Glibc:", - "nix why-depends nixpkgs.hello nixpkgs.glibc" - }, - Example{ - "To show all files and paths in the dependency graph leading from Thunderbird to libX11:", - "nix why-depends --all nixpkgs.thunderbird nixpkgs.xorg.libX11" - }, - Example{ - "To show why Glibc depends on itself:", - "nix why-depends nixpkgs.glibc nixpkgs.glibc" - }, - }; - } + auto const inf = std::numeric_limits<size_t>::max(); + + struct Node { + Path path; + PathSet refs; + PathSet rrefs; + size_t dist = inf; + Node* prev = nullptr; + bool queued = false; + bool visited = false; + }; + + std::map<Path, Node> graph; + + for (auto& path : closure) + graph.emplace(path, Node{path, store->queryPathInfo(path)->references}); + + // Transpose the graph. + for (auto& node : graph) + for (auto& ref : node.second.refs) graph[ref].rrefs.insert(node.first); + + /* Run Dijkstra's shortest path algorithm to get the distance + of every path in the closure to 'dependency'. */ + graph[dependencyPath].dist = 0; + + std::priority_queue<Node*> queue; - void run(ref<Store> store) override - { - auto package = parseInstallable(*this, store, _package, false); - auto packagePath = toStorePath(store, Build, package); - auto dependency = parseInstallable(*this, store, _dependency, false); - auto dependencyPath = toStorePath(store, NoBuild, dependency); - auto dependencyPathHash = storePathToHash(dependencyPath); + queue.push(&graph.at(dependencyPath)); - PathSet closure; - store->computeFSClosure({packagePath}, closure, false, false); + while (!queue.empty()) { + auto& node = *queue.top(); + queue.pop(); - if (!closure.count(dependencyPath)) { - printError("'%s' does not depend on '%s'", package->what(), dependency->what()); - return; + for (auto& rref : node.rrefs) { + auto& node2 = graph.at(rref); + auto dist = node.dist + 1; + if (dist < node2.dist) { + node2.dist = dist; + node2.prev = &node; + if (!node2.queued) { + node2.queued = true; + queue.push(&node2); + } } + } + } - stopProgressBar(); // FIXME + /* Print the subgraph of nodes that have 'dependency' in their + closure (i.e., that have a non-infinite distance to + 'dependency'). Print every edge on a path between `package` + and `dependency`. */ + std::function<void(Node&, const string&, const string&)> printNode; - auto accessor = store->getFSAccessor(); + const string treeConn = "╠═══"; + const string treeLast = "╚═══"; + const string treeLine = "║ "; + const string treeNull = " "; - auto const inf = std::numeric_limits<size_t>::max(); + struct BailOut {}; - struct Node - { - Path path; - PathSet refs; - PathSet rrefs; - size_t dist = inf; - Node * prev = nullptr; - bool queued = false; - bool visited = false; - }; + printNode = [&](Node& node, const string& firstPad, const string& tailPad) { + assert(node.dist != inf); + std::cout << fmt("%s%s%s%s" ANSI_NORMAL "\n", firstPad, + node.visited ? "\e[38;5;244m" : "", + firstPad != "" ? "=> " : "", node.path); - std::map<Path, Node> graph; + if (node.path == dependencyPath && !all && packagePath != dependencyPath) + throw BailOut(); - for (auto & path : closure) - graph.emplace(path, Node{path, store->queryPathInfo(path)->references}); + if (node.visited) return; + node.visited = true; - // Transpose the graph. - for (auto & node : graph) - for (auto & ref : node.second.refs) - graph[ref].rrefs.insert(node.first); + /* Sort the references by distance to `dependency` to + ensure that the shortest path is printed first. */ + std::multimap<size_t, Node*> refs; + std::set<std::string> hashes; - /* Run Dijkstra's shortest path algorithm to get the distance - of every path in the closure to 'dependency'. */ - graph[dependencyPath].dist = 0; + for (auto& ref : node.refs) { + if (ref == node.path && packagePath != dependencyPath) continue; + auto& node2 = graph.at(ref); + if (node2.dist == inf) continue; + refs.emplace(node2.dist, &node2); + hashes.insert(storePathToHash(node2.path)); + } - std::priority_queue<Node *> queue; + /* For each reference, find the files and symlinks that + contain the reference. */ + std::map<std::string, Strings> hits; - queue.push(&graph.at(dependencyPath)); + std::function<void(const Path&)> visitPath; - while (!queue.empty()) { - auto & node = *queue.top(); - queue.pop(); + visitPath = [&](const Path& p) { + auto st = accessor->stat(p); - for (auto & rref : node.rrefs) { - auto & node2 = graph.at(rref); - auto dist = node.dist + 1; - if (dist < node2.dist) { - node2.dist = dist; - node2.prev = &node; - if (!node2.queued) { - node2.queued = true; - queue.push(&node2); - } - } + auto p2 = p == node.path ? "/" : std::string(p, node.path.size() + 1); - } + auto getColour = [&](const std::string& hash) { + return hash == dependencyPathHash ? ANSI_GREEN : ANSI_BLUE; + }; + + if (st.type == FSAccessor::Type::tDirectory) { + auto names = accessor->readDirectory(p); + for (auto& name : names) visitPath(p + "/" + name); } - /* Print the subgraph of nodes that have 'dependency' in their - closure (i.e., that have a non-infinite distance to - 'dependency'). Print every edge on a path between `package` - and `dependency`. */ - std::function<void(Node &, const string &, const string &)> printNode; - - const string treeConn = "╠═══"; - const string treeLast = "╚═══"; - const string treeLine = "║ "; - const string treeNull = " "; - - struct BailOut { }; - - printNode = [&](Node & node, const string & firstPad, const string & tailPad) { - assert(node.dist != inf); - std::cout << fmt("%s%s%s%s" ANSI_NORMAL "\n", - firstPad, - node.visited ? "\e[38;5;244m" : "", - firstPad != "" ? "=> " : "", - node.path); - - if (node.path == dependencyPath && !all - && packagePath != dependencyPath) - throw BailOut(); - - if (node.visited) return; - node.visited = true; - - /* Sort the references by distance to `dependency` to - ensure that the shortest path is printed first. */ - std::multimap<size_t, Node *> refs; - std::set<std::string> hashes; - - for (auto & ref : node.refs) { - if (ref == node.path && packagePath != dependencyPath) continue; - auto & node2 = graph.at(ref); - if (node2.dist == inf) continue; - refs.emplace(node2.dist, &node2); - hashes.insert(storePathToHash(node2.path)); + else if (st.type == FSAccessor::Type::tRegular) { + auto contents = accessor->readFile(p); + + for (auto& hash : hashes) { + auto pos = contents.find(hash); + if (pos != std::string::npos) { + size_t margin = 32; + auto pos2 = pos >= margin ? pos - margin : 0; + hits[hash].emplace_back(fmt( + "%s: …%s…\n", p2, + hilite( + filterPrintable(std::string( + contents, pos2, pos - pos2 + hash.size() + margin)), + pos - pos2, storePathHashLen, getColour(hash)))); } + } + } - /* For each reference, find the files and symlinks that - contain the reference. */ - std::map<std::string, Strings> hits; - - std::function<void(const Path &)> visitPath; - - visitPath = [&](const Path & p) { - auto st = accessor->stat(p); - - auto p2 = p == node.path ? "/" : std::string(p, node.path.size() + 1); - - auto getColour = [&](const std::string & hash) { - return hash == dependencyPathHash ? ANSI_GREEN : ANSI_BLUE; - }; - - if (st.type == FSAccessor::Type::tDirectory) { - auto names = accessor->readDirectory(p); - for (auto & name : names) - visitPath(p + "/" + name); - } - - else if (st.type == FSAccessor::Type::tRegular) { - auto contents = accessor->readFile(p); - - for (auto & hash : hashes) { - auto pos = contents.find(hash); - if (pos != std::string::npos) { - size_t margin = 32; - auto pos2 = pos >= margin ? pos - margin : 0; - hits[hash].emplace_back(fmt("%s: …%s…\n", - p2, - hilite(filterPrintable( - std::string(contents, pos2, pos - pos2 + hash.size() + margin)), - pos - pos2, storePathHashLen, - getColour(hash)))); - } - } - } - - else if (st.type == FSAccessor::Type::tSymlink) { - auto target = accessor->readLink(p); - - for (auto & hash : hashes) { - auto pos = target.find(hash); - if (pos != std::string::npos) - hits[hash].emplace_back(fmt("%s -> %s\n", p2, - hilite(target, pos, storePathHashLen, getColour(hash)))); - } - } - }; - - // FIXME: should use scanForReferences(). - - visitPath(node.path); - - RunPager pager; - for (auto & ref : refs) { - auto hash = storePathToHash(ref.second->path); - - bool last = all ? ref == *refs.rbegin() : true; - - for (auto & hit : hits[hash]) { - bool first = hit == *hits[hash].begin(); - std::cout << tailPad - << (first ? (last ? treeLast : treeConn) : (last ? treeNull : treeLine)) - << hit; - if (!all) break; - } - - printNode(*ref.second, - tailPad + (last ? treeNull : treeLine), - tailPad + (last ? treeNull : treeLine)); - } - }; + else if (st.type == FSAccessor::Type::tSymlink) { + auto target = accessor->readLink(p); + + for (auto& hash : hashes) { + auto pos = target.find(hash); + if (pos != std::string::npos) + hits[hash].emplace_back( + fmt("%s -> %s\n", p2, + hilite(target, pos, storePathHashLen, getColour(hash)))); + } + } + }; + + // FIXME: should use scanForReferences(). + + visitPath(node.path); + + RunPager pager; + for (auto& ref : refs) { + auto hash = storePathToHash(ref.second->path); + + bool last = all ? ref == *refs.rbegin() : true; + + for (auto& hit : hits[hash]) { + bool first = hit == *hits[hash].begin(); + std::cout << tailPad + << (first ? (last ? treeLast : treeConn) + : (last ? treeNull : treeLine)) + << hit; + if (!all) break; + } + + printNode(*ref.second, tailPad + (last ? treeNull : treeLine), + tailPad + (last ? treeNull : treeLine)); + } + }; - try { - printNode(graph.at(packagePath), "", ""); - } catch (BailOut & ) { } + try { + printNode(graph.at(packagePath), "", ""); + } catch (BailOut&) { } + } }; static RegisterCommand r1(make_ref<CmdWhyDepends>()); |