exportReferencesGraph: Export more complete info in JSON format

This writes info about every path in the closure in the same format as
‘nix path-info --json’. Thus it also includes NAR hashes and sizes.

Example:

  [
    {
      "path": "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10",
      "narHash": "sha256:0ckdc4z20kkmpqdilx0wl6cricxv90lh85xpv2qljppcmz6vzcxl",
      "narSize": 197648,
      "references": [
        "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10",
        "/nix/store/27binbdy296qvjycdgr1535v8872vz3z-glibc-2.24"
      ],
      "closureSize": 20939776
    },
    {
      "path": "/nix/store/27binbdy296qvjycdgr1535v8872vz3z-glibc-2.24",
      "narHash": "sha256:1nfn3m3p98y1c0kd0brp80dn9n5mycwgrk183j17rajya0h7gax3",
      "narSize": 20742128,
      "references": [
        "/nix/store/27binbdy296qvjycdgr1535v8872vz3z-glibc-2.24"
      ],
      "closureSize": 20742128
    }
  ]

Fixes #1134.

1 files changed, 59 insertions, 0 deletions

diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index 8fdd62771552..a42d11834053 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -4,6 +4,7 @@
 #include "util.hh"
 #include "nar-info-disk-cache.hh"
 #include "thread-pool.hh"
+#include "json.hh"
 
 #include <future>
 
@@ -439,6 +440,64 @@ string Store::makeValidityRegistration(const PathSet & paths,
 }
 
 
+void Store::pathInfoToJSON(JSONPlaceholder & jsonOut, const PathSet & storePaths,
+    bool includeImpureInfo, bool showClosureSize)
+{
+    auto jsonList = jsonOut.list();
+
+    for (auto storePath : storePaths) {
+        auto info = queryPathInfo(storePath);
+        storePath = info->path;
+
+        auto jsonPath = jsonList.object();
+        jsonPath
+            .attr("path", storePath)
+            .attr("narHash", info->narHash.to_string())
+            .attr("narSize", info->narSize);
+
+        {
+            auto jsonRefs = jsonPath.list("references");
+            for (auto & ref : info->references)
+                jsonRefs.elem(ref);
+        }
+
+        if (info->ca != "")
+            jsonPath.attr("ca", info->ca);
+
+        if (showClosureSize)
+            jsonPath.attr("closureSize", getClosureSize(storePath));
+
+        if (!includeImpureInfo) continue;
+
+        if (info->deriver != "")
+            jsonPath.attr("deriver", info->deriver);
+
+        if (info->registrationTime)
+            jsonPath.attr("registrationTime", info->registrationTime);
+
+        if (info->ultimate)
+            jsonPath.attr("ultimate", info->ultimate);
+
+        if (!info->sigs.empty()) {
+            auto jsonSigs = jsonPath.list("signatures");
+            for (auto & sig : info->sigs)
+                jsonSigs.elem(sig);
+        }
+    }
+}
+
+
+unsigned long long Store::getClosureSize(const Path & storePath)
+{
+    unsigned long long totalSize = 0;
+    PathSet closure;
+    computeFSClosure(storePath, closure, false, false);
+    for (auto & p : closure)
+        totalSize += queryPathInfo(p)->narSize;
+    return totalSize;
+}
+
+
 const Store::Stats & Store::getStats()
 {
     {