Split BlazeDirectories into two classes.

This is done in preparation for allowing multiple workspaces / commands in a
single server. That requires changes to the module API, which currently
hard-codes a 1:1 correspondence between workspaces and servers. Note how
BlazeDirectories exists even when it runs outside a workspace.

It's not ideal that the output base is in ServerDirectories, and the
BlazeRuntime creation also still requires a BlazeDirectories instance.

--
MOS_MIGRATED_REVID=129736613

5 files changed, 159 insertions, 48 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/BlazeDirectories.java b/src/main/java/com/google/devtools/build/lib/analysis/BlazeDirectories.java
index 374c9e684c..c7474f2854 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/BlazeDirectories.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/BlazeDirectories.java
@@ -15,9 +15,7 @@
 package com.google.devtools.build.lib.analysis;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Strings;
 import com.google.common.hash.HashCode;
-import com.google.common.hash.Hashing;
 import com.google.devtools.build.lib.actions.Root;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.util.Preconditions;
@@ -26,21 +24,20 @@ import com.google.devtools.build.lib.vfs.FileSystem;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
 
-import javax.annotation.Nullable;
-
 /**
- * Encapsulation of all of the interesting top-level directories in any Blaze application.
+ * Encapsulates the directories related to a workspace.
+ *
+ * <p>The <code>workspace</code> is the top-level directory in the user's client (possibly
+ * read-only). The <code>execRoot</code> is the working directory for all spawned tools, which is
+ * generally below the <code>outputBase</code>.
  *
- * <p>The <code>installBase</code> is the directory where the Blaze binary has been installed.The
- * <code>workspace</code> is the top-level directory in the user's client (possibly read-only).The
- * <code>outputBase</code> is the directory below which Blaze puts all its state. The
- * <code>execRoot</code> is the working directory for all spawned tools, which is generally below
- * <code>outputBase</code>.
+ * <p>Care must be taken to avoid multiple Bazel instances trying to write to the same output
+ * directory. At this time, this is enforced by requiring a 1:1 correspondence between a running
+ * Bazel instance and an output base directory, though this requirement may be softened in the
+ * future.
  *
- * <p>There is a 1:1 correspondence between a running Blaze instance and an output base directory;
- * however, multiple Blaze instances may compile code that's in the same workspace, even on the same
- * machine. If the user does not qualify an output base directory, the startup code will derive it
- * deterministically from the workspace. Note also that while the Blaze server process runs with the
+ * <p>If the user does not qualify an output base directory, the startup code will derive it
+ * deterministically from the workspace. Note also that while the Bazel server process runs with the
  * workspace directory as its working directory, the client process may have a different working
  * directory, typically a subdirectory.
  *
@@ -54,27 +51,27 @@ public final class BlazeDirectories {
   @VisibleForTesting
   static final String DEFAULT_EXEC_ROOT = "default-exec-root";
 
-  private final Path installBase;     // Where Blaze gets unpacked
-  private final HashCode installMD5;  // The content hash of everything in installBase
-  private final Path workspace;       // Workspace root and server CWD
-  private final Path outputBase;      // The root of the temp and output trees
-  private final Path execRoot;        // the root of all build actions
+  private final ServerDirectories serverDirectories;
+  /** Workspace root and server CWD. */
+  private final Path workspace;
+  /** The root of all build actions. */
+  private final Path execRoot;
 
   // These two are kept to avoid creating new objects every time they are accessed. This showed up
   // in a profiler.
   private final Path outputPath;
   private final Path localOutputPath;
 
-  public BlazeDirectories(Path installBase, Path outputBase, Path workspace,
-      boolean deepExecRoot, @Nullable String installMD5, String productName) {
-    this.installBase = installBase;
+  public BlazeDirectories(
+      ServerDirectories serverDirectories,
+      Path workspace,
+      boolean deepExecRoot,
+      String productName) {
+    this.serverDirectories = serverDirectories;
     this.workspace = workspace;
-    this.outputBase = outputBase;
-    this.installMD5 =
-        Strings.isNullOrEmpty(installMD5) ? null : checkMD5(HashCode.fromString(installMD5));
     boolean useDefaultExecRootName = this.workspace == null || this.workspace.isRootDirectory();
-    Path execRootBase = deepExecRoot
-        ? outputBase.getChild("execroot") : outputBase;
+    Path outputBase = serverDirectories.getOutputBase();
+    Path execRootBase = deepExecRoot ? outputBase.getChild("execroot") : outputBase;
     if (useDefaultExecRootName) {
       // TODO(bazel-team): if workspace is null execRoot should be null, but at the moment there is
       // a lot of code that depends on it being non-null.
@@ -91,15 +88,14 @@ public final class BlazeDirectories {
     this.localOutputPath = outputBase.getRelative(relativeOutputPath);
   }
 
-  private static HashCode checkMD5(HashCode hash) {
-    Preconditions.checkArgument(hash.bits() == Hashing.md5().bits(),
-                                "Hash '%s' has %s bits", hash, hash.bits());
-    return hash;
+  @VisibleForTesting
+  public BlazeDirectories(ServerDirectories serverDirectories, Path workspace, String productName) {
+    this(serverDirectories, workspace, false, productName);
   }
 
   @VisibleForTesting
   public BlazeDirectories(Path installBase, Path outputBase, Path workspace, String productName) {
-    this(installBase, outputBase, workspace, false, null, productName);
+    this(new ServerDirectories(installBase, outputBase), workspace, false, productName);
   }
 
   /**
@@ -107,14 +103,19 @@ public final class BlazeDirectories {
    * resolving absolute paths.
    */
   public FileSystem getFileSystem() {
-    return installBase.getFileSystem();
+    return serverDirectories.getFileSystem();
+  }
+
+  public ServerDirectories getServerDirectories() {
+    return serverDirectories;
   }
 
   /**
-   * Returns the installation base directory. Currently used by info command only.
+   * Returns the base of the output tree, which hosts all build and scratch
+   * output for a user and workspace.
    */
   public Path getInstallBase() {
-    return installBase;
+    return serverDirectories.getInstallBase();
   }
 
   /**
@@ -136,7 +137,7 @@ public final class BlazeDirectories {
    * output for a user and workspace.
    */
   public Path getOutputBase() {
-    return outputBase;
+    return serverDirectories.getOutputBase();
   }
 
   /**
@@ -191,7 +192,7 @@ public final class BlazeDirectories {
    * installBase location.
    */
   public Path getEmbeddedBinariesRoot() {
-    return installBase.getChild("_embedded_binaries");
+    return serverDirectories.getEmbeddedBinariesRoot();
   }
 
   /**
@@ -207,7 +208,7 @@ public final class BlazeDirectories {
   * anything else that ends up in the install_base).
   */
   public HashCode getInstallMD5() {
-    return installMD5;
+    return serverDirectories.getInstallMD5();
   }
 
   /**
@@ -217,5 +218,4 @@ public final class BlazeDirectories {
   public static String getRelativeOutputPath(String productName) {
     return StringCanonicalizer.intern(productName + "-out");
   }
-
 }
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/ServerDirectories.java b/src/main/java/com/google/devtools/build/lib/analysis/ServerDirectories.java
new file mode 100644
index 0000000000..4c57ae6496
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/analysis/ServerDirectories.java
@@ -0,0 +1,98 @@
+// Copyright 2016 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.analysis;
+
+import com.google.common.base.Strings;
+import com.google.common.hash.HashCode;
+import com.google.common.hash.Hashing;
+import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
+import com.google.devtools.build.lib.util.Preconditions;
+import com.google.devtools.build.lib.vfs.FileSystem;
+import com.google.devtools.build.lib.vfs.Path;
+
+import javax.annotation.Nullable;
+
+/**
+ * Represents the server install directory, which contains the Bazel installation and embedded
+ * binaries.
+ *
+ * <p>The <code>installBase</code> is the directory where the Blaze binary has been installed. The
+ * <code>outputBase</code> is the directory below which Blaze puts all its state.
+ */
+@Immutable
+public final class ServerDirectories {
+  /** Where Blaze gets unpacked. */
+  private final Path installBase;
+  /** The content hash of everything in installBase. */
+  private final HashCode installMD5;
+  /** The root of the temp and output trees. */
+  private final Path outputBase;
+
+  public ServerDirectories(Path installBase, Path outputBase, @Nullable String installMD5) {
+    this.installBase = installBase;
+    this.outputBase = outputBase;
+    this.installMD5 =
+        Strings.isNullOrEmpty(installMD5) ? null : checkMD5(HashCode.fromString(installMD5));
+  }
+
+  public ServerDirectories(Path installBase, Path outputBase) {
+    this(installBase, outputBase, null);
+  }
+
+  private static HashCode checkMD5(HashCode hash) {
+    Preconditions.checkArgument(hash.bits() == Hashing.md5().bits(),
+                                "Hash '%s' has %s bits", hash, hash.bits());
+    return hash;
+  }
+
+  /**
+   * Returns the Filesystem that all of our directories belong to. Handy for
+   * resolving absolute paths.
+   */
+  public FileSystem getFileSystem() {
+    return installBase.getFileSystem();
+  }
+
+  /**
+   * Returns the installation base directory. Currently used by info command only.
+   */
+  public Path getInstallBase() {
+    return installBase;
+  }
+
+  /**
+   * Returns the base of the output tree, which hosts all build and scratch
+   * output for a user and workspace.
+   */
+  public Path getOutputBase() {
+    return outputBase;
+  }
+
+  /**
+   * Returns the installed embedded binaries directory, under the shared
+   * installBase location.
+   */
+  public Path getEmbeddedBinariesRoot() {
+    return installBase.getChild("_embedded_binaries");
+  }
+
+ /**
+  * Returns the MD5 content hash of the blaze binary (includes deploy JAR, embedded binaries, and
+  * anything else that ends up in the install_base).
+  */
+  public HashCode getInstallMD5() {
+    return installMD5;
+  }
+}
\ No newline at end of file
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeModule.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeModule.java
index 9879ab05cf..077cf5c55c 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeModule.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeModule.java
@@ -21,6 +21,7 @@ import com.google.devtools.build.lib.actions.ActionInputFileCache;
 import com.google.devtools.build.lib.analysis.BlazeDirectories;
 import com.google.devtools.build.lib.analysis.BlazeVersionInfo;
 import com.google.devtools.build.lib.analysis.ConfiguredRuleClassProvider;
+import com.google.devtools.build.lib.analysis.ServerDirectories;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.exec.OutputService;
 import com.google.devtools.build.lib.packages.NoSuchThingException;
@@ -91,7 +92,7 @@ public abstract class BlazeModule {
    */
   @SuppressWarnings("unused")
   public void blazeStartup(OptionsProvider startupOptions,
-      BlazeVersionInfo versionInfo, UUID instanceId, BlazeDirectories directories,
+      BlazeVersionInfo versionInfo, UUID instanceId, ServerDirectories directories,
       Clock clock) throws AbruptExitException {
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
index f896545fd2..bdc8652973 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
@@ -28,6 +28,7 @@ import com.google.common.util.concurrent.Uninterruptibles;
 import com.google.devtools.build.lib.analysis.BlazeDirectories;
 import com.google.devtools.build.lib.analysis.BlazeVersionInfo;
 import com.google.devtools.build.lib.analysis.ConfiguredRuleClassProvider;
+import com.google.devtools.build.lib.analysis.ServerDirectories;
 import com.google.devtools.build.lib.analysis.config.BinTools;
 import com.google.devtools.build.lib.analysis.config.BuildOptions;
 import com.google.devtools.build.lib.analysis.config.ConfigurationFactory;
@@ -916,10 +917,11 @@ public final class BlazeRuntime {
               Predicates.notNull()));
     }
 
+    ServerDirectories serverDirectories =
+        new ServerDirectories(installBasePath, outputBasePath, startupOptions.installMD5);
     BlazeDirectories directories =
-        new BlazeDirectories(installBasePath, outputBasePath, workspaceDirectoryPath,
-                             startupOptions.deepExecRoot, startupOptions.installMD5,
-                             productName);
+        new BlazeDirectories(
+            serverDirectories, workspaceDirectoryPath, startupOptions.deepExecRoot, productName);
 
     Clock clock = BlazeClock.instance();
 
@@ -934,6 +936,7 @@ public final class BlazeRuntime {
 
     BlazeRuntime.Builder runtimeBuilder = new BlazeRuntime.Builder()
         .setProductName(productName)
+        .setServerDirectories(serverDirectories)
         .setDirectories(directories)
         .setStartupOptionsProvider(options)
         .setBinTools(binTools)
@@ -1027,6 +1030,7 @@ public final class BlazeRuntime {
    * an exception. Please plan appropriately.
    */
   public static class Builder {
+    private ServerDirectories serverDirectories;
     private BlazeDirectories directories;
     private Clock clock;
     private OptionsProvider startupOptionsProvider;
@@ -1038,6 +1042,7 @@ public final class BlazeRuntime {
 
     public BlazeRuntime build() throws AbruptExitException {
       Preconditions.checkNotNull(productName);
+      Preconditions.checkNotNull(serverDirectories);
       Preconditions.checkNotNull(directories);
       Preconditions.checkNotNull(startupOptionsProvider);
       Clock clock = (this.clock == null) ? BlazeClock.instance() : this.clock;
@@ -1047,7 +1052,7 @@ public final class BlazeRuntime {
 
       for (BlazeModule module : blazeModules) {
         module.blazeStartup(startupOptionsProvider,
-            BlazeVersionInfo.instance(), instanceId, directories, clock);
+            BlazeVersionInfo.instance(), instanceId, serverDirectories, clock);
       }
       ServerBuilder serverBuilder = new ServerBuilder();
       for (BlazeModule module : blazeModules) {
@@ -1070,7 +1075,7 @@ public final class BlazeRuntime {
       Package.Builder.Helper packageBuilderHelper = null;
       for (BlazeModule module : blazeModules) {
         Package.Builder.Helper candidateHelper =
-            module.getPackageBuilderHelper(ruleClassProvider, directories.getFileSystem());
+            module.getPackageBuilderHelper(ruleClassProvider, serverDirectories.getFileSystem());
         if (candidateHelper != null) {
           Preconditions.checkState(packageBuilderHelper == null,
               "more than one module defines a package builder helper");
@@ -1133,6 +1138,11 @@ public final class BlazeRuntime {
       return this;
     }
 
+    public Builder setServerDirectories(ServerDirectories serverDirectories) {
+      this.serverDirectories = serverDirectories;
+      return this;
+    }
+
     public Builder setDirectories(BlazeDirectories directories) {
       this.directories = directories;
       return this;
diff --git a/src/test/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcherRcoptionsTest.java b/src/test/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcherRcoptionsTest.java
index dad3d2de0e..eff79d93bf 100644
--- a/src/test/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcherRcoptionsTest.java
+++ b/src/test/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcherRcoptionsTest.java
@@ -24,6 +24,7 @@ import com.google.common.collect.Lists;
 import com.google.devtools.build.lib.analysis.BlazeDirectories;
 import com.google.devtools.build.lib.analysis.ConfigurationCollectionFactory;
 import com.google.devtools.build.lib.analysis.ConfiguredRuleClassProvider;
+import com.google.devtools.build.lib.analysis.ServerDirectories;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.analysis.config.FragmentOptions;
 import com.google.devtools.build.lib.cmdline.Label;
@@ -128,13 +129,14 @@ public class BlazeCommandDispatcherRcoptionsTest {
   @Before
   public final void initializeRuntime() throws Exception {
     String productName = TestConstants.PRODUCT_NAME;
+    ServerDirectories serverDirectories =
+        new ServerDirectories(scratch.dir("install_base"), scratch.dir("output_base"));
     BlazeDirectories directories =
-        new BlazeDirectories(
-            scratch.dir("install_base"), scratch.dir("output_base"), scratch.dir("pkg"),
-            productName);
+        new BlazeDirectories(serverDirectories, scratch.dir("pkg"), productName);
     this.runtime =
         new BlazeRuntime.Builder()
             .setProductName(productName)
+            .setServerDirectories(serverDirectories)
             .setDirectories(directories)
             .setStartupOptionsProvider(
                 OptionsParser.newOptionsParser(BlazeServerStartupOptions.class))