* Merged the `fast-eval' branch.

1 files changed, 257 insertions, 0 deletions

diff --git a/src/nix-env/user-env.cc b/src/nix-env/user-env.cc
new file mode 100644
index 000000000000..72e13fceb191
--- /dev/null
+++ b/src/nix-env/user-env.cc
@@ -0,0 +1,257 @@
+#include "util.hh"
+#include "get-drvs.hh"
+#include "derivations.hh"
+#include "store-api.hh"
+#include "globals.hh"
+#include "shared.hh"
+#include "eval.hh"
+#include "parser.hh"
+#include "profiles.hh"
+
+
+namespace nix {
+
+
+static void readLegacyManifest(const Path & path, DrvInfos & elems);
+
+
+DrvInfos queryInstalled(EvalState & state, const Path & userEnv)
+{
+    DrvInfos elems;
+
+    Path manifestFile = userEnv + "/manifest.nix";
+    Path oldManifestFile = userEnv + "/manifest";
+
+    if (pathExists(manifestFile)) {
+        Value v;
+        state.eval(parseExprFromFile(state, manifestFile), v);
+        getDerivations(state, v, "", Bindings(), elems);
+    } else if (pathExists(oldManifestFile))
+        readLegacyManifest(oldManifestFile, elems);
+
+    return elems;
+}
+
+
+bool createUserEnv(EvalState & state, DrvInfos & elems,
+    const Path & profile, bool keepDerivations,
+    const string & lockToken)
+{
+    /* Build the components in the user environment, if they don't
+       exist already. */
+    PathSet drvsToBuild;
+    foreach (DrvInfos::const_iterator, i, elems)
+        if (i->queryDrvPath(state) != "")
+            drvsToBuild.insert(i->queryDrvPath(state));
+
+    debug(format("building user environment dependencies"));
+    store->buildDerivations(drvsToBuild);
+
+    /* Construct the whole top level derivation. */
+    PathSet references;
+    Value manifest;
+    state.mkList(manifest, elems.size());
+    unsigned int n = 0;
+    foreach (DrvInfos::iterator, i, elems) {
+        /* Create a pseudo-derivation containing the name, system,
+           output path, and optionally the derivation path, as well as
+           the meta attributes. */
+        Path drvPath = keepDerivations ? i->queryDrvPath(state) : "";
+
+        Value & v(*state.allocValues(1));
+        manifest.list.elems[n++] = &v;
+        state.mkAttrs(v);
+
+        mkString((*v.attrs)[state.sType].value, "derivation");
+        mkString((*v.attrs)[state.sName].value, i->name);
+        mkString((*v.attrs)[state.sSystem].value, i->system);
+        mkString((*v.attrs)[state.sOutPath].value, i->queryOutPath(state));
+        if (drvPath != "")
+            mkString((*v.attrs)[state.sDrvPath].value, i->queryDrvPath(state));
+        
+        state.mkAttrs((*v.attrs)[state.sMeta].value);
+        
+        MetaInfo meta = i->queryMetaInfo(state);
+
+        foreach (MetaInfo::const_iterator, j, meta) {
+            Value & v2((*(*v.attrs)[state.sMeta].value.attrs)[state.symbols.create(j->first)].value);
+            switch (j->second.type) {
+                case MetaValue::tpInt: mkInt(v2, j->second.intValue); break;
+                case MetaValue::tpString: mkString(v2, j->second.stringValue); break;
+                case MetaValue::tpStrings: {
+                    state.mkList(v2, j->second.stringValues.size());
+                    unsigned int m = 0;
+                    foreach (Strings::const_iterator, k, j->second.stringValues) {
+                        v2.list.elems[m] = state.allocValues(1);
+                        mkString(*v2.list.elems[m++], *k);
+                    }
+                    break;
+                }
+                default: abort();
+            }
+        }
+    
+        /* This is only necessary when installing store paths, e.g.,
+           `nix-env -i /nix/store/abcd...-foo'. */
+        store->addTempRoot(i->queryOutPath(state));
+        store->ensurePath(i->queryOutPath(state));
+        
+        references.insert(i->queryOutPath(state));
+        if (drvPath != "") references.insert(drvPath);
+    }
+
+    /* Also write a copy of the list of user environment elements to
+       the store; we need it for future modifications of the
+       environment. */
+    Path manifestFile = store->addTextToStore("env-manifest.nix",
+        (format("%1%") % manifest).str(), references);
+
+    printMsg(lvlError, manifestFile);
+
+    /* Get the environment builder expression. */
+    Value envBuilder;
+    state.eval(parseExprFromFile(state, nixDataDir + "/nix/corepkgs/buildenv"), envBuilder);
+
+    /* Construct a Nix expression that calls the user environment
+       builder with the manifest as argument. */
+    Value args, topLevel;
+    state.mkAttrs(args);
+    mkString((*args.attrs)[state.sSystem].value, thisSystem);
+    mkString((*args.attrs)[state.symbols.create("manifest")].value,
+        manifestFile, singleton<PathSet>(manifestFile));
+    (*args.attrs)[state.symbols.create("derivations")].value = manifest;
+    mkApp(topLevel, envBuilder, args);
+        
+    /* Evaluate it. */
+    debug("evaluating user environment builder");
+    DrvInfo topLevelDrv;
+    if (!getDerivation(state, topLevel, topLevelDrv))
+        abort();
+    
+    /* Realise the resulting store expression. */
+    debug("building user environment");
+    store->buildDerivations(singleton<PathSet>(topLevelDrv.queryDrvPath(state)));
+
+    /* Switch the current user environment to the output path. */
+    PathLocks lock;
+    lockProfile(lock, profile);
+
+    Path lockTokenCur = optimisticLockProfile(profile);
+    if (lockToken != lockTokenCur) {
+        printMsg(lvlError, format("profile `%1%' changed while we were busy; restarting") % profile);
+        return false;
+    }
+    
+    debug(format("switching to new user environment"));
+    Path generation = createGeneration(profile, topLevelDrv.queryOutPath(state));
+    switchLink(profile, generation);
+
+    return true;
+}
+
+
+/* Code for parsing manifests in the old textual ATerm format. */
+
+static string parseStr(std::istream & str)
+{
+    expect(str, "Str(");
+    string s = parseString(str);
+    expect(str, ",[])");
+    return s;
+}
+
+
+static string parseWord(std::istream & str)
+{
+    string res;
+    while (isalpha(str.peek()))
+        res += str.get();
+    return res;
+}
+
+
+static MetaInfo parseMeta(std::istream & str)
+{
+    MetaInfo meta;
+
+    expect(str, "Attrs([");
+    while (!endOfList(str)) {
+        expect(str, "Bind(");
+
+        MetaValue value;
+        
+        string name = parseString(str);
+        expect(str, ",");
+
+        string type = parseWord(str);
+
+        if (type == "Str") {
+            expect(str, "(");
+            value.type = MetaValue::tpString;
+            value.stringValue = parseString(str);
+            expect(str, ",[])");
+        }
+
+        else if (type == "List") {
+            expect(str, "([");
+            value.type = MetaValue::tpStrings;
+            while (!endOfList(str))
+                value.stringValues.push_back(parseStr(str));
+            expect(str, ")");
+        }
+
+        else throw Error(format("unexpected token `%1%'") % type);
+
+        expect(str, ",NoPos)");
+        meta[name] = value;
+    }
+    
+    expect(str, ")");
+
+    return meta;
+}
+
+
+static void readLegacyManifest(const Path & path, DrvInfos & elems)
+{
+    string manifest = readFile(path);
+    std::istringstream str(manifest);
+    expect(str, "List([");
+
+    unsigned int n = 0;
+    
+    while (!endOfList(str)) {
+        DrvInfo elem;
+        expect(str, "Attrs([");
+
+        while (!endOfList(str)) {
+            expect(str, "Bind(");
+            string name = parseString(str);
+            expect(str, ",");
+            
+            if (name == "meta") elem.setMetaInfo(parseMeta(str));
+            else {
+                string value = parseStr(str);
+                if (name == "name") elem.name = value;
+                else if (name == "outPath") elem.setOutPath(value);
+                else if (name == "drvPath") elem.setDrvPath(value);
+                else if (name == "system") elem.system = value;
+            }
+
+            expect(str, ",NoPos)");
+        }
+
+        expect(str, ")");
+
+        if (elem.name != "") {
+            elem.attrPath = int2String(n++);
+            elems.push_back(elem);
+        }
+    }
+
+    expect(str, ")");
+}
+
+
+}
+