1 files changed, 220 insertions, 0 deletions
diff --git a/nix/libstore/misc.cc b/nix/libstore/misc.cc
new file mode 100644
index 0000000000..1bf3f93782
--- /dev/null
+++ b/nix/libstore/misc.cc
@@ -0,0 +1,220 @@
+#include "misc.hh"
+#include "store-api.hh"
+#include "local-store.hh"
+#include "globals.hh"
+
+
+namespace nix {
+
+
+Derivation derivationFromPath(StoreAPI & store, const Path & drvPath)
+{
+    assertStorePath(drvPath);
+    store.ensurePath(drvPath);
+    return parseDerivation(readFile(drvPath));
+}
+
+
+void computeFSClosure(StoreAPI & store, const Path & path,
+    PathSet & paths, bool flipDirection, bool includeOutputs, bool includeDerivers)
+{
+    if (paths.find(path) != paths.end()) return;
+    paths.insert(path);
+
+    PathSet edges;
+
+    if (flipDirection) {
+        store.queryReferrers(path, edges);
+
+        if (includeOutputs) {
+            PathSet derivers = store.queryValidDerivers(path);
+            foreach (PathSet::iterator, i, derivers)
+                edges.insert(*i);
+        }
+
+        if (includeDerivers && isDerivation(path)) {
+            PathSet outputs = store.queryDerivationOutputs(path);
+            foreach (PathSet::iterator, i, outputs)
+                if (store.isValidPath(*i) && store.queryDeriver(*i) == path)
+                    edges.insert(*i);
+        }
+
+    } else {
+        store.queryReferences(path, edges);
+
+        if (includeOutputs && isDerivation(path)) {
+            PathSet outputs = store.queryDerivationOutputs(path);
+            foreach (PathSet::iterator, i, outputs)
+                if (store.isValidPath(*i)) edges.insert(*i);
+        }
+
+        if (includeDerivers) {
+            Path deriver = store.queryDeriver(path);
+            if (store.isValidPath(deriver)) edges.insert(deriver);
+        }
+    }
+
+    foreach (PathSet::iterator, i, edges)
+        computeFSClosure(store, *i, paths, flipDirection, includeOutputs, includeDerivers);
+}
+
+
+Path findOutput(const Derivation & drv, string id)
+{
+    foreach (DerivationOutputs::const_iterator, i, drv.outputs)
+        if (i->first == id) return i->second.path;
+    throw Error(format("derivation has no output `%1%'") % id);
+}
+
+
+void queryMissing(StoreAPI & store, const PathSet & targets,
+    PathSet & willBuild, PathSet & willSubstitute, PathSet & unknown,
+    unsigned long long & downloadSize, unsigned long long & narSize)
+{
+    downloadSize = narSize = 0;
+
+    PathSet todo(targets.begin(), targets.end()), done;
+
+    /* Getting substitute info has high latency when using the binary
+       cache substituter.  Thus it's essential to do substitute
+       queries in parallel as much as possible.  To accomplish this
+       we do the following:
+
+       - For all paths still to be processed (‘todo’), we add all
+         paths for which we need info to the set ‘query’.  For an
+         unbuilt derivation this is the output paths; otherwise, it's
+         the path itself.
+
+       - We get info about all paths in ‘query’ in parallel.
+
+       - We process the results and add new items to ‘todo’ if
+         necessary.  E.g. if a path is substitutable, then we need to
+         get info on its references.
+
+       - Repeat until ‘todo’ is empty.
+    */
+
+    while (!todo.empty()) {
+
+        PathSet query, todoDrv, todoNonDrv;
+
+        foreach (PathSet::iterator, i, todo) {
+            if (done.find(*i) != done.end()) continue;
+            done.insert(*i);
+
+            DrvPathWithOutputs i2 = parseDrvPathWithOutputs(*i);
+
+            if (isDerivation(i2.first)) {
+                if (!store.isValidPath(i2.first)) {
+                    // FIXME: we could try to substitute p.
+                    unknown.insert(*i);
+                    continue;
+                }
+                Derivation drv = derivationFromPath(store, i2.first);
+
+                PathSet invalid;
+                foreach (DerivationOutputs::iterator, j, drv.outputs)
+                    if (wantOutput(j->first, i2.second)
+                        && !store.isValidPath(j->second.path))
+                        invalid.insert(j->second.path);
+                if (invalid.empty()) continue;
+
+                todoDrv.insert(*i);
+                if (settings.useSubstitutes && !willBuildLocally(drv))
+                    query.insert(invalid.begin(), invalid.end());
+            }
+
+            else {
+                if (store.isValidPath(*i)) continue;
+                query.insert(*i);
+                todoNonDrv.insert(*i);
+            }
+        }
+
+        todo.clear();
+
+        SubstitutablePathInfos infos;
+        store.querySubstitutablePathInfos(query, infos);
+
+        foreach (PathSet::iterator, i, todoDrv) {
+            DrvPathWithOutputs i2 = parseDrvPathWithOutputs(*i);
+
+            // FIXME: cache this
+            Derivation drv = derivationFromPath(store, i2.first);
+
+            PathSet outputs;
+            bool mustBuild = false;
+            if (settings.useSubstitutes && !willBuildLocally(drv)) {
+                foreach (DerivationOutputs::iterator, j, drv.outputs) {
+                    if (!wantOutput(j->first, i2.second)) continue;
+                    if (!store.isValidPath(j->second.path)) {
+                        if (infos.find(j->second.path) == infos.end())
+                            mustBuild = true;
+                        else
+                            outputs.insert(j->second.path);
+                    }
+                }
+            } else
+                mustBuild = true;
+
+            if (mustBuild) {
+                willBuild.insert(i2.first);
+                todo.insert(drv.inputSrcs.begin(), drv.inputSrcs.end());
+                foreach (DerivationInputs::iterator, j, drv.inputDrvs)
+                    todo.insert(makeDrvPathWithOutputs(j->first, j->second));
+            } else
+                todoNonDrv.insert(outputs.begin(), outputs.end());
+        }
+
+        foreach (PathSet::iterator, i, todoNonDrv) {
+            done.insert(*i);
+            SubstitutablePathInfos::iterator info = infos.find(*i);
+            if (info != infos.end()) {
+                willSubstitute.insert(*i);
+                downloadSize += info->second.downloadSize;
+                narSize += info->second.narSize;
+                todo.insert(info->second.references.begin(), info->second.references.end());
+            } else
+                unknown.insert(*i);
+        }
+    }
+}
+
+
+static void dfsVisit(StoreAPI & store, const PathSet & paths,
+    const Path & path, PathSet & visited, Paths & sorted,
+    PathSet & parents)
+{
+    if (parents.find(path) != parents.end())
+        throw BuildError(format("cycle detected in the references of `%1%'") % path);
+
+    if (visited.find(path) != visited.end()) return;
+    visited.insert(path);
+    parents.insert(path);
+
+    PathSet references;
+    if (store.isValidPath(path))
+        store.queryReferences(path, references);
+
+    foreach (PathSet::iterator, i, references)
+        /* Don't traverse into paths that don't exist.  That can
+           happen due to substitutes for non-existent paths. */
+        if (*i != path && paths.find(*i) != paths.end())
+            dfsVisit(store, paths, *i, visited, sorted, parents);
+
+    sorted.push_front(path);
+    parents.erase(path);
+}
+
+
+Paths topoSortPaths(StoreAPI & store, const PathSet & paths)
+{
+    Paths sorted;
+    PathSet visited, parents;
+    foreach (PathSet::const_iterator, i, paths)
+        dfsVisit(store, paths, *i, visited, sorted, parents);
+    return sorted;
+}
+
+
+}