Bazel server: ensure OutputStreams are closed

Use try-with-resources to ensure OutputStreams
that we open via FileSystem.OutputStream(path)
are closed.

Eagerly closing OutputStreams avoids hanging on to
file handles until the garbage collector finalizes
the OutputStream, meaning Bazel on Windows (and
other processes) can delete or mutate these files.

Hopefully this avoids intermittent file deletion
errors that sometimes occur on Windows.

See https://github.com/bazelbuild/bazel/issues/5512

RELNOTES: none
PiperOrigin-RevId: 203342889

2 files changed, 34 insertions, 8 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/util/DependencySet.java b/src/main/java/com/google/devtools/build/lib/util/DependencySet.java
index e2ce5fb6ce..66f1bd0f25 100644
--- a/src/main/java/com/google/devtools/build/lib/util/DependencySet.java
+++ b/src/main/java/com/google/devtools/build/lib/util/DependencySet.java
@@ -228,15 +228,12 @@ public final class DependencySet {
     Path dotdFile =
         outFile.getRelative(FileSystemUtils.replaceExtension(outFile.asFragment(), suffix));
 
-    PrintStream out = new PrintStream(dotdFile.getOutputStream());
-    try {
+    try (PrintStream out = new PrintStream(dotdFile.getOutputStream())) {
       out.print(outFile.relativeTo(root) + ": ");
       for (Path d : dependencies) {
         out.print(" \\\n  " + d.getPathString());  // should already be root relative
       }
       out.println();
-    } finally {
-      out.close();
     }
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/vfs/FileSystemUtils.java b/src/main/java/com/google/devtools/build/lib/vfs/FileSystemUtils.java
index e2ab1d8002..9883030cb6 100644
--- a/src/main/java/com/google/devtools/build/lib/vfs/FileSystemUtils.java
+++ b/src/main/java/com/google/devtools/build/lib/vfs/FileSystemUtils.java
@@ -698,7 +698,14 @@ public class FileSystemUtils {
    */
   public static void writeContent(Path outputFile, Charset charset, String content)
       throws IOException {
-    asByteSink(outputFile).asCharSink(charset).write(content);
+    try (OutputStream out = outputFile.getOutputStream()) {
+      new ByteSink() {
+        @Override
+        public OutputStream openStream() throws IOException {
+          return out;
+        }
+      }.asCharSink(charset).write(content);
+    }
   }
 
   /**
@@ -729,7 +736,14 @@ public class FileSystemUtils {
   public static void writeLinesAs(Path file, Charset charset, Iterable<String> lines)
       throws IOException {
     createDirectoryAndParents(file.getParentDirectory());
-    asByteSink(file).asCharSink(charset).writeLines(lines);
+    try (OutputStream out = file.getOutputStream()) {
+      new ByteSink() {
+        @Override
+        public OutputStream openStream() throws IOException {
+          return out;
+        }
+      }.asCharSink(charset).writeLines(lines);
+    }
   }
 
   /**
@@ -740,7 +754,14 @@ public class FileSystemUtils {
   public static void appendLinesAs(Path file, Charset charset, Iterable<String> lines)
       throws IOException {
     createDirectoryAndParents(file.getParentDirectory());
-    asByteSink(file, true).asCharSink(charset).writeLines(lines);
+    try (OutputStream out = file.getOutputStream(true)) {
+      new ByteSink() {
+        @Override
+        public OutputStream openStream() throws IOException {
+          return out;
+        }
+      }.asCharSink(charset).writeLines(lines);
+    }
   }
 
   /**
@@ -749,7 +770,15 @@ public class FileSystemUtils {
    * @throws IOException if there was an error
    */
   public static void writeContent(Path outputFile, byte[] content) throws IOException {
-    asByteSink(outputFile).write(content);
+    try (OutputStream out = outputFile.getOutputStream()) {
+      new ByteSink() {
+        @Override
+        public OutputStream openStream() throws IOException {
+          return out;
+        }
+      }.write(content);
+      ;
+    }
   }
 
   /**