Add Git object hashing to the store layer

Part of RFC 133

Extracted from our old IPFS branches.

Co-Authored-By: Matthew Bauer <mjbauer95@gmail.com>
Co-Authored-By: Carlo Nucera <carlo.nucera@protonmail.com>
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Florian Klink <flokli@flokli.de>

tests/functional/git-hashing/common.sh

@@ -0,0 +1,11 @@
+source ../common.sh
+
+clearStore
+clearCache
+
+# Need backend to support git-hashing too
+requireDaemonNewerThan "2.18.0pre20230908"
+
+enableFeatures "git-hashing"
+
+restartDaemon

tests/functional/git-hashing/local.mk

@@ -0,0 +1,7 @@
+git-hashing-tests := \
+  $(d)/simple.sh
+
+install-tests-groups += git-hashing
+
+clean-files += \
+  $(d)/config.nix

tests/functional/git-hashing/simple.sh

@@ -0,0 +1,58 @@
+source common.sh
+
+repo="$TEST_ROOT/scratch"
+git init "$repo"
+
+git -C "$repo" config user.email "you@example.com"
+git -C "$repo" config user.name "Your Name"
+
+try () {
+    hash=$(nix hash path --mode git --format base16 --algo sha1 $TEST_ROOT/hash-path)
+    [[ "$hash" == "$1" ]]
+
+    git -C "$repo" rm -rf hash-path || true
+    cp -r "$TEST_ROOT/hash-path" "$TEST_ROOT/scratch/hash-path"
+    git -C "$repo" add hash-path
+    git -C "$repo" commit -m "x"
+    git -C "$repo" status
+    hash2=$(git -C "$TEST_ROOT/scratch" rev-parse HEAD:hash-path)
+    [[ "$hash2" = "$1" ]]
+}
+
+# blob
+rm -rf $TEST_ROOT/hash-path
+echo "Hello World" > $TEST_ROOT/hash-path
+try "557db03de997c86a4a028e1ebd3a1ceb225be238"
+
+# tree with children
+rm -rf $TEST_ROOT/hash-path
+mkdir $TEST_ROOT/hash-path
+echo "Hello World" > $TEST_ROOT/hash-path/hello
+echo "Run Hello World" > $TEST_ROOT/hash-path/executable
+chmod +x $TEST_ROOT/hash-path/executable
+try "e5c0a11a556801a5c9dcf330ca9d7e2c572697f4"
+
+rm -rf $TEST_ROOT/dummy1
+echo Hello World! > $TEST_ROOT/dummy1
+path1=$(nix store add --mode git --hash-algo sha1 $TEST_ROOT/dummy1)
+hash1=$(nix-store -q --hash $path1)
+test "$hash1" = "sha256:1brffhvj2c0z6x8qismd43m0iy8dsgfmy10bgg9w11szway2wp9v"
+
+rm -rf $TEST_ROOT/dummy2
+mkdir -p $TEST_ROOT/dummy2
+echo Hello World! > $TEST_ROOT/dummy2/hello
+path2=$(nix store add --mode git --hash-algo sha1 $TEST_ROOT/dummy2)
+hash2=$(nix-store -q --hash $path2)
+test "$hash2" = "sha256:1vhv7zxam7x277q0y0jcypm7hwhccbzss81vkdgf0ww5sm2am4y0"
+
+rm -rf $TEST_ROOT/dummy3
+mkdir -p $TEST_ROOT/dummy3
+mkdir -p $TEST_ROOT/dummy3/dir
+touch $TEST_ROOT/dummy3/dir/file
+echo Hello World! > $TEST_ROOT/dummy3/dir/file
+touch $TEST_ROOT/dummy3/dir/executable
+chmod +x $TEST_ROOT/dummy3/dir/executable
+echo Run Hello World! > $TEST_ROOT/dummy3/dir/executable
+path3=$(nix store add --mode git --hash-algo sha1 $TEST_ROOT/dummy3)
+hash3=$(nix-store -q --hash $path3)
+test "$hash3" = "sha256:08y3nm3mvn9qvskqnf13lfgax5lh73krxz4fcjd5cp202ggpw9nv"

tests/unit/libstore/content-address.cc

@@ -13,6 +13,7 @@ TEST(ContentAddressMethod, testRoundTripPrintParse_1) {
         ContentAddressMethod { TextIngestionMethod {} },
         ContentAddressMethod { FileIngestionMethod::Flat },
         ContentAddressMethod { FileIngestionMethod::Recursive },
+        ContentAddressMethod { FileIngestionMethod::Git },
     }) {
         EXPECT_EQ(ContentAddressMethod::parse(cam.render()), cam);
     }
@@ -23,6 +24,7 @@ TEST(ContentAddressMethod, testRoundTripPrintParse_2) {
         "text",
         "flat",
         "nar",
+        "git",
     }) {
         EXPECT_EQ(ContentAddressMethod::parse(camS).render(), camS);
     }

tests/unit/libutil/file-content-address.cc

@@ -4,6 +4,32 @@
 
 namespace nix {
 
+/* ----------------------------------------------------------------------------
+ * parseFileSerialisationMethod, renderFileSerialisationMethod
+ * --------------------------------------------------------------------------*/
+
+TEST(FileSerialisationMethod, testRoundTripPrintParse_1) {
+    for (const FileSerialisationMethod fim : {
+        FileSerialisationMethod::Flat,
+        FileSerialisationMethod::Recursive,
+    }) {
+        EXPECT_EQ(parseFileSerialisationMethod(renderFileSerialisationMethod(fim)), fim);
+    }
+}
+
+TEST(FileSerialisationMethod, testRoundTripPrintParse_2) {
+    for (const std::string_view fimS : {
+        "flat",
+        "nar",
+    }) {
+        EXPECT_EQ(renderFileSerialisationMethod(parseFileSerialisationMethod(fimS)), fimS);
+    }
+}
+
+TEST(FileSerialisationMethod, testParseFileSerialisationMethodOptException) {
+    EXPECT_THROW(parseFileSerialisationMethod("narwhal"), UsageError);
+}
+
 /* ----------------------------------------------------------------------------
  * parseFileIngestionMethod, renderFileIngestionMethod
  * --------------------------------------------------------------------------*/
@@ -12,6 +38,7 @@ TEST(FileIngestionMethod, testRoundTripPrintParse_1) {
     for (const FileIngestionMethod fim : {
         FileIngestionMethod::Flat,
         FileIngestionMethod::Recursive,
+        FileIngestionMethod::Git,
     }) {
         EXPECT_EQ(parseFileIngestionMethod(renderFileIngestionMethod(fim)), fim);
     }
@@ -21,6 +48,7 @@ TEST(FileIngestionMethod, testRoundTripPrintParse_2) {
     for (const std::string_view fimS : {
         "flat",
         "nar",
+        "git",
     }) {
         EXPECT_EQ(renderFileIngestionMethod(parseFileIngestionMethod(fimS)), fimS);
     }