1 files changed, 75 insertions, 13 deletions

diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index 5b9f79049..ab21b0bd5 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -222,20 +222,73 @@ StorePath Store::computeStorePathForText(const string & name, const string & s,
 }
 
 
+/*
+The aim of this function is to compute in one pass the correct ValidPathInfo for
+the files that we are trying to add to the store. To accomplish that in one
+pass, given the different kind of inputs that we can take (normal nar archives,
+nar archives with non SHA-256 hashes, and flat files), we set up a net of sinks
+and aliases. Also, since the dataflow is obfuscated by this, we include here a
+graphviz diagram:
+
+digraph graphname {
+    node [shape=box]
+    fileSource -> narSink
+    narSink [style=dashed]
+    narSink -> unsualHashTee [style = dashed, label = "Recursive && !SHA-256"]
+    narSink -> narHashSink [style = dashed, label = "else"]
+    unsualHashTee -> narHashSink
+    unsualHashTee -> caHashSink
+    fileSource -> parseSink
+    parseSink [style=dashed]
+    parseSink-> fileSink [style = dashed, label = "Flat"]
+    parseSink -> blank [style = dashed, label = "Recursive"]
+    fileSink -> caHashSink
+}
+*/
 ValidPathInfo Store::addToStoreSlow(std::string_view name, const Path & srcPath,
     FileIngestionMethod method, HashType hashAlgo,
     std::optional<Hash> expectedCAHash)
 {
-    /* FIXME: inefficient: we're reading/hashing 'tmpFile' three
-       times. */
+    HashSink narHashSink { htSHA256 };
+    HashSink caHashSink { hashAlgo };
+
+    /* Note that fileSink and unusualHashTee must be mutually exclusive, since
+       they both write to caHashSink. Note that that requisite is currently true
+       because the former is only used in the flat case. */
+    RetrieveRegularNARSink fileSink { caHashSink };
+    TeeSink unusualHashTee { narHashSink, caHashSink };
+
+    auto & narSink = method == FileIngestionMethod::Recursive && hashAlgo != htSHA256
+        ? static_cast<Sink &>(unusualHashTee)
+        : narHashSink;
+
+    /* Functionally, this means that fileSource will yield the content of
+       srcPath. The fact that we use scratchpadSink as a temporary buffer here
+       is an implementation detail. */
+    auto fileSource = sinkToSource([&](Sink & scratchpadSink) {
+        dumpPath(srcPath, scratchpadSink);
+    });
 
-    auto [narHash, narSize] = hashPath(htSHA256, srcPath);
+    /* tapped provides the same data as fileSource, but we also write all the
+       information to narSink. */
+    TeeSource tapped { *fileSource, narSink };
 
-    auto hash = method == FileIngestionMethod::Recursive
-        ? hashAlgo == htSHA256
-          ? narHash
-          : hashPath(hashAlgo, srcPath).first
-        : hashFile(hashAlgo, srcPath);
+    ParseSink blank;
+    auto & parseSink = method == FileIngestionMethod::Flat
+        ? fileSink
+        : blank;
+
+    /* The information that flows from tapped (besides being replicated in
+       narSink), is now put in parseSink. */
+    parseDump(parseSink, tapped);
+
+    /* We extract the result of the computation from the sink by calling
+       finish. */
+    auto [narHash, narSize] = narHashSink.finish();
+
+    auto hash = method == FileIngestionMethod::Recursive && hashAlgo == htSHA256
+        ? narHash
+        : caHashSink.finish().first;
 
     if (expectedCAHash && expectedCAHash != hash)
         throw Error("hash mismatch for '%s'", srcPath);
@@ -246,8 +299,8 @@ ValidPathInfo Store::addToStoreSlow(std::string_view name, const Path & srcPath,
     info.ca = FixedOutputHash { .method = method, .hash = hash };
 
     if (!isValidPath(info.path)) {
-        auto source = sinkToSource([&](Sink & sink) {
-            dumpPath(srcPath, sink);
+        auto source = sinkToSource([&](Sink & scratchpadSink) {
+            dumpPath(srcPath, scratchpadSink);
         });
         addToStore(info, *source);
     }
@@ -914,12 +967,20 @@ ref<Store> openStore(const std::string & uri_,
     throw Error("don't know how to open Nix store '%s'", uri);
 }
 
+static bool isNonUriPath(const std::string & spec) {
+    return
+        // is not a URL
+        spec.find("://") == std::string::npos
+        // Has at least one path separator, and so isn't a single word that
+        // might be special like "auto"
+        && spec.find("/") != std::string::npos;
+}
 
 StoreType getStoreType(const std::string & uri, const std::string & stateDir)
 {
     if (uri == "daemon") {
         return tDaemon;
-    } else if (uri == "local" || hasPrefix(uri, "/")) {
+    } else if (uri == "local" || isNonUriPath(uri)) {
         return tLocal;
     } else if (uri == "" || uri == "auto") {
         if (access(stateDir.c_str(), R_OK | W_OK) == 0)
@@ -943,8 +1004,9 @@ static RegisterStoreImplementation regStore([](
             return std::shared_ptr<Store>(std::make_shared<UDSRemoteStore>(params));
         case tLocal: {
             Store::Params params2 = params;
-            if (hasPrefix(uri, "/"))
-                params2["root"] = uri;
+            if (isNonUriPath(uri)) {
+                params2["root"] = absPath(uri);
+            }
             return std::shared_ptr<Store>(std::make_shared<LocalStore>(params2));
         }
         default: