Use unsafe String operations when writing parameter files.

When a LATIN-1 parameter file is requested, we can take advantage of the fact that JDK9 strings are (usually) stored as LATIN-1.

For UTF-8, we can still optimize for the common case where a LATIN-1 string contains only ASCII characters, as these are bit-identical between UTF-8 and LATIN-1. This would still be expected to be the vast majority of parameter file contents.

RELNOTES: None
PiperOrigin-RevId: 199816430

4 files changed, 118 insertions, 0 deletions

diff --git a/src/test/java/com/google/devtools/build/lib/BUILD b/src/test/java/com/google/devtools/build/lib/BUILD
index 15b05fa809..c20948ac1b 100644
--- a/src/test/java/com/google/devtools/build/lib/BUILD
+++ b/src/test/java/com/google/devtools/build/lib/BUILD
@@ -60,6 +60,7 @@ filegroup(
         "//src/test/java/com/google/devtools/build/lib/skylark:srcs",
         "//src/test/java/com/google/devtools/build/lib/skylarkdebug/server:srcs",
         "//src/test/java/com/google/devtools/build/lib/skylarkinterface/processor:srcs",
+        "//src/test/java/com/google/devtools/build/lib/unsafe:srcs",
     ],
     visibility = ["//src:__pkg__"],
 )
diff --git a/src/test/java/com/google/devtools/build/lib/exec/ParameterFileTest.java b/src/test/java/com/google/devtools/build/lib/exec/ParameterFileTest.java
index 92ea767ca1..4f49092cdf 100644
--- a/src/test/java/com/google/devtools/build/lib/exec/ParameterFileTest.java
+++ b/src/test/java/com/google/devtools/build/lib/exec/ParameterFileTest.java
@@ -16,11 +16,16 @@ package com.google.devtools.build.lib.exec;
 
 import static com.google.common.truth.Truth.assertThat;
 
+import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.actions.ParameterFile;
+import com.google.devtools.build.lib.actions.ParameterFile.ParameterFileType;
 import com.google.devtools.build.lib.testutil.FoundationTestCase;
 import com.google.devtools.build.lib.testutil.Suite;
 import com.google.devtools.build.lib.testutil.TestSpec;
 import com.google.devtools.build.lib.vfs.PathFragment;
+import java.io.ByteArrayOutputStream;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -39,4 +44,37 @@ public class ParameterFileTest extends FoundationTestCase {
     assertThat(ParameterFile.derivePath(PathFragment.create("b")))
         .isEqualTo(PathFragment.create("b-2.params"));
   }
+
+  @Test
+  public void testWriteAscii() throws Exception {
+    assertThat(writeContent(StandardCharsets.ISO_8859_1, ImmutableList.of("--foo", "--bar")))
+        .containsExactly("--foo", "--bar");
+    assertThat(writeContent(StandardCharsets.UTF_8, ImmutableList.of("--foo", "--bar")))
+        .containsExactly("--foo", "--bar");
+  }
+
+  @Test
+  public void testWriteLatin1() throws Exception {
+    assertThat(writeContent(StandardCharsets.ISO_8859_1, ImmutableList.of("--füü")))
+        .containsExactly("--füü");
+    assertThat(writeContent(StandardCharsets.UTF_8, ImmutableList.of("--füü")))
+        .containsExactly("--füü");
+  }
+
+  @Test
+  public void testWriteUtf8() throws Exception {
+    assertThat(writeContent(StandardCharsets.ISO_8859_1, ImmutableList.of("--lambda=λ")))
+        .containsExactly("--lambda=?");
+    assertThat(writeContent(StandardCharsets.UTF_8, ImmutableList.of("--lambda=λ")))
+        .containsExactly("--lambda=λ");
+  }
+
+  private static ImmutableList<String> writeContent(Charset charset, Iterable<String> content)
+      throws Exception {
+    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+    ParameterFile.writeParameterFile(outputStream, content, ParameterFileType.UNQUOTED, charset);
+    return ImmutableList.<String>builder()
+        .add(new String(outputStream.toByteArray(), charset).split("\n"))
+        .build();
+  }
 }
diff --git a/src/test/java/com/google/devtools/build/lib/unsafe/BUILD b/src/test/java/com/google/devtools/build/lib/unsafe/BUILD
new file mode 100644
index 0000000000..3220a80b2c
--- /dev/null
+++ b/src/test/java/com/google/devtools/build/lib/unsafe/BUILD
@@ -0,0 +1,18 @@
+package(
+    default_visibility = ["//src:__subpackages__"],
+)
+
+filegroup(
+    name = "srcs",
+    srcs = glob(["**"]),
+)
+
+java_test(
+    name = "StringUnsafeTest",
+    srcs = ["StringUnsafeTest.java"],
+    deps = [
+        "//src/main/java/com/google/devtools/build/lib/unsafe:string",
+        "//third_party:junit4",
+        "//third_party:truth",
+    ],
+)
diff --git a/src/test/java/com/google/devtools/build/lib/unsafe/StringUnsafeTest.java b/src/test/java/com/google/devtools/build/lib/unsafe/StringUnsafeTest.java
new file mode 100644
index 0000000000..2801d521c3
--- /dev/null
+++ b/src/test/java/com/google/devtools/build/lib/unsafe/StringUnsafeTest.java
@@ -0,0 +1,61 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package com.google.devtools.build.lib.unsafe;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Tests for {@link StringUnsafe}. */
+@RunWith(JUnit4.class)
+public class StringUnsafeTest {
+
+  @Test
+  public void testGetCoder() {
+    if (!StringUnsafe.canUse()) {
+      return;
+    }
+    StringUnsafe stringUnsafe = StringUnsafe.getInstance();
+    assertThat(stringUnsafe.getCoder("")).isEqualTo(StringUnsafe.LATIN1);
+    assertThat(stringUnsafe.getCoder("hello")).isEqualTo(StringUnsafe.LATIN1);
+    assertThat(stringUnsafe.getCoder("lambda λ")).isEqualTo(StringUnsafe.UTF16);
+  }
+
+  @Test
+  public void testGetBytes() {
+    if (!StringUnsafe.canUse()) {
+      return;
+    }
+    StringUnsafe stringUnsafe = StringUnsafe.getInstance();
+    assertThat(ByteBuffer.wrap(stringUnsafe.getByteArray("hello")))
+        .isEqualTo(StandardCharsets.ISO_8859_1.encode("hello"));
+    assertThat(ByteBuffer.wrap(stringUnsafe.getByteArray("lambda λ")))
+        .isEqualTo(StandardCharsets.UTF_16LE.encode("lambda λ"));
+  }
+
+  @Test
+  public void testNewInstance() throws Exception {
+    if (!StringUnsafe.canUse()) {
+      return;
+    }
+    StringUnsafe stringUnsafe = StringUnsafe.getInstance();
+    String s = "hello";
+    assertThat(stringUnsafe.newInstance(stringUnsafe.getByteArray(s), stringUnsafe.getCoder(s)))
+        .isEqualTo("hello");
+  }
+}