tools/java/runfiles/Runfiles.java - bazel - Git at Google

 // 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.runfiles;

 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.nio.charset.StandardCharsets;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;

 /**
  * Runfiles lookup library for Bazel-built Java binaries and tests.
  *
  * <p>USAGE:
  *
  * <p>1. Depend on this runfiles library from your build rule:
  *
  * <pre>
  *   java_binary(
  *       name = "my_binary",
  *       ...
  *       deps = ["@bazel_tools//tools/java/runfiles"],
  *   )
  * </pre>
  *
  * <p>2. Import the runfiles library.
  *
  * <pre>
  *   import com.google.devtools.build.runfiles.Runfiles;
  * </pre>
  *
  * <p>3. Create a Runfiles object and use rlocation to look up runfile paths:
  *
  * <pre>
  *   public void myFunction() {
  *     Runfiles runfiles = Runfiles.create();
  *     String path = runfiles.rlocation("my_workspace/path/to/my/data.txt");
  *     ...
  * </pre>
  *
  * <p>If you want to start subprocesses that also need runfiles, you need to set the right
  * environment variables for them:
  *
  * <pre>
  *   String path = r.rlocation("path/to/binary");
  *   ProcessBuilder pb = new ProcessBuilder(path);
  *   pb.environment().putAll(r.getEnvVars());
  *   ...
  *   Process p = pb.start();
  * </pre>
  */
 public abstract class Runfiles {

   // Package-private constructor, so only package-private classes may extend it.
   private Runfiles() {}

   /**
    * Returns a new {@link Runfiles} instance.
    *
    * <p>This method passes the JVM's environment variable map to {@link #create(Map)}.
    */
   public static Runfiles create() throws IOException {
     return create(System.getenv());
   }

   /**
    * Returns a new {@link Runfiles} instance.
    *
    * <p>The returned object is either:
    *
    * <ul>
    *   <li>manifest-based, meaning it looks up runfile paths from a manifest file, or
    *   <li>directory-based, meaning it looks up runfile paths under a given directory path
    * </ul>
    *
    * <p>If {@code env} contains "RUNFILES_MANIFEST_ONLY" with value "1", this method returns a
    * manifest-based implementation. The manifest's path is defined by the "RUNFILES_MANIFEST_FILE"
    * key's value in {@code env}.
    *
    * <p>Otherwise this method returns a directory-based implementation. The directory's path is
    * defined by the value in {@code env} under the "RUNFILES_DIR" key, or if absent, then under the
    * "JAVA_RUNFILES" key.
    *
    * <p>Note about performance: the manifest-based implementation eagerly reads and caches the whole
    * manifest file upon instantiation.
    *
    * @throws IOException if RUNFILES_MANIFEST_ONLY=1 is in {@code env} but there's no
    *     "RUNFILES_MANIFEST_FILE", "RUNFILES_DIR", or "JAVA_RUNFILES" key in {@code env} or their
    *     values are empty, or some IO error occurs
    */
   public static Runfiles create(Map<String, String> env) throws IOException {
     if (isManifestOnly(env)) {
       // On Windows, Bazel sets RUNFILES_MANIFEST_ONLY=1.
       // On every platform, Bazel also sets RUNFILES_MANIFEST_FILE, but on Linux and macOS it's
       // faster to use RUNFILES_DIR.
       return new ManifestBased(getManifestPath(env));
     } else {
       return new DirectoryBased(getRunfilesDir(env));
     }
   }

   /**
    * Returns the runtime path of a runfile (a Bazel-built binary's/test's data-dependency).
    *
    * <p>The returned path may not be valid. The caller should check the path's validity and that the
    * path exists.
    *
    * <p>The function may return null. In that case the caller can be sure that the rule does not
    * know about this data-dependency.
    *
    * @param path runfiles-root-relative path of the runfile
    * @throws IllegalArgumentException if {@code path} fails validation, for example if it's null or
    *     empty, or not normalized (contains "./", "../", or "//")
    */
   public final String rlocation(String path) {
     Util.checkArgument(path != null);
     Util.checkArgument(!path.isEmpty());
     Util.checkArgument(
         !path.startsWith("../")
             && !path.contains("/..")
             && !path.startsWith("./")
             && !path.contains("/./")
             && !path.endsWith("/.")
             && !path.contains("//"),
         "path is not normalized: \"%s\"",
         path);
     Util.checkArgument(
         !path.startsWith("\\"), "path is absolute without a drive letter: \"%s\"", path);
     if (new File(path).isAbsolute()) {
       return path;
     }
     return rlocationChecked(path);
   }

   /**
    * Returns environment variables for subprocesses.
    *
    * <p>The caller should add the returned key-value pairs to the environment of subprocesses in
    * case those subprocesses are also Bazel-built binaries that need to use runfiles.
    */
   public abstract Map<String, String> getEnvVars();

   /** Returns true if the platform supports runfiles only via manifests. */
   private static boolean isManifestOnly(Map<String, String> env) {
     return "1".equals(env.get("RUNFILES_MANIFEST_ONLY"));
   }

   private static String getManifestPath(Map<String, String> env) throws IOException {
     String value = env.get("RUNFILES_MANIFEST_FILE");
     if (Util.isNullOrEmpty(value)) {
       throw new IOException(
           "Cannot load runfiles manifest: $RUNFILES_MANIFEST_ONLY is 1 but"
               + " $RUNFILES_MANIFEST_FILE is empty or undefined");
     }
     return value;
   }

   private static String getRunfilesDir(Map<String, String> env) throws IOException {
     String value = env.get("RUNFILES_DIR");
     if (Util.isNullOrEmpty(value)) {
       value = env.get("JAVA_RUNFILES");
     }
     if (Util.isNullOrEmpty(value)) {
       throw new IOException(
           "Cannot find runfiles: $RUNFILES_DIR and $JAVA_RUNFILES are both unset or empty");
     }
     return value;
   }

   abstract String rlocationChecked(String path);

   /** {@link Runfiles} implementation that parses a runfiles-manifest file to look up runfiles. */
   private static final class ManifestBased extends Runfiles {
     private final Map<String, String> runfiles;
     private final String manifestPath;

     ManifestBased(String manifestPath) throws IOException {
       Util.checkArgument(manifestPath != null);
       Util.checkArgument(!manifestPath.isEmpty());
       this.manifestPath = manifestPath;
       this.runfiles = loadRunfiles(manifestPath);
     }

     private static Map<String, String> loadRunfiles(String path) throws IOException {
       HashMap<String, String> result = new HashMap<>();
       try (BufferedReader r =
           new BufferedReader(
               new InputStreamReader(new FileInputStream(path), StandardCharsets.UTF_8))) {
         String line = null;
         while ((line = r.readLine()) != null) {
           int index = line.indexOf(' ');
           String runfile = (index == -1) ? line : line.substring(0, index);
           String realPath = (index == -1) ? line : line.substring(index + 1);
           result.put(runfile, realPath);
         }
       }
       return Collections.unmodifiableMap(result);
     }

     private static String findRunfilesDir(String manifest) {
       if (manifest.endsWith("/MANIFEST")
           || manifest.endsWith("\\MANIFEST")
           || manifest.endsWith(".runfiles_manifest")) {
         String path = manifest.substring(0, manifest.length() - 9);
         if (new File(path).isDirectory()) {
           return path;
         }
       }
       return "";
     }

     @Override
     public String rlocationChecked(String path) {
       String exactMatch = runfiles.get(path);
       if (exactMatch != null) {
         return exactMatch;
       }
       // If path references a runfile that lies under a directory that itself is a runfile, then
       // only the directory is listed in the manifest. Look up all prefixes of path in the manifest
       // and append the relative path from the prefix if there is a match.
       int prefixEnd = path.length();
       while ((prefixEnd = path.lastIndexOf('/', prefixEnd - 1)) != -1) {
         String prefixMatch = runfiles.get(path.substring(0, prefixEnd));
         if (prefixMatch != null) {
           return prefixMatch + '/' + path.substring(prefixEnd + 1);
         }
       }
       return null;
     }

     @Override
     public Map<String, String> getEnvVars() {
       HashMap<String, String> result = new HashMap<>(4);
       result.put("RUNFILES_MANIFEST_ONLY", "1");
       result.put("RUNFILES_MANIFEST_FILE", manifestPath);
       String runfilesDir = findRunfilesDir(manifestPath);
       result.put("RUNFILES_DIR", runfilesDir);
       // TODO(laszlocsomor): remove JAVA_RUNFILES once the Java launcher can pick up RUNFILES_DIR.
       result.put("JAVA_RUNFILES", runfilesDir);
       return result;
     }
   }

   /** {@link Runfiles} implementation that appends runfiles paths to the runfiles root. */
   private static final class DirectoryBased extends Runfiles {
     private final String runfilesRoot;

     DirectoryBased(String runfilesDir) {
       Util.checkArgument(!Util.isNullOrEmpty(runfilesDir));
       Util.checkArgument(new File(runfilesDir).isDirectory());
       this.runfilesRoot = runfilesDir;
     }

     @Override
     String rlocationChecked(String path) {
       return runfilesRoot + "/" + path;
     }

     @Override
     public Map<String, String> getEnvVars() {
       HashMap<String, String> result = new HashMap<>(2);
       result.put("RUNFILES_DIR", runfilesRoot);
       // TODO(laszlocsomor): remove JAVA_RUNFILES once the Java launcher can pick up RUNFILES_DIR.
       result.put("JAVA_RUNFILES", runfilesRoot);
       return result;
     }
   }

   static Runfiles createManifestBasedForTesting(String manifestPath) throws IOException {
     return new ManifestBased(manifestPath);
   }

   static Runfiles createDirectoryBasedForTesting(String runfilesDir) {
     return new DirectoryBased(runfilesDir);
   }
 }
	// 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.runfiles;

	import java.io.BufferedReader;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.IOException;
	import java.io.InputStreamReader;
	import java.nio.charset.StandardCharsets;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.Map;

	/**
	* Runfiles lookup library for Bazel-built Java binaries and tests.
	*
	* <p>USAGE:
	*
	* <p>1. Depend on this runfiles library from your build rule:
	*
	* <pre>
	* java_binary(
	* name = "my_binary",
	* ...
	* deps = ["@bazel_tools//tools/java/runfiles"],
	* )
	* </pre>
	*
	* <p>2. Import the runfiles library.
	*
	* <pre>
	* import com.google.devtools.build.runfiles.Runfiles;
	* </pre>
	*
	* <p>3. Create a Runfiles object and use rlocation to look up runfile paths:
	*
	* <pre>
	* public void myFunction() {
	* Runfiles runfiles = Runfiles.create();
	* String path = runfiles.rlocation("my_workspace/path/to/my/data.txt");
	* ...
	* </pre>
	*
	* <p>If you want to start subprocesses that also need runfiles, you need to set the right
	* environment variables for them:
	*
	* <pre>
	* String path = r.rlocation("path/to/binary");
	* ProcessBuilder pb = new ProcessBuilder(path);
	* pb.environment().putAll(r.getEnvVars());
	* ...
	* Process p = pb.start();
	* </pre>
	*/
	public abstract class Runfiles {

	// Package-private constructor, so only package-private classes may extend it.
	private Runfiles() {}

	/**
	* Returns a new {@link Runfiles} instance.
	*
	* <p>This method passes the JVM's environment variable map to {@link #create(Map)}.
	*/
	public static Runfiles create() throws IOException {
	return create(System.getenv());
	}

	/**
	* Returns a new {@link Runfiles} instance.
	*
	* <p>The returned object is either:
	*
	* <ul>
	* <li>manifest-based, meaning it looks up runfile paths from a manifest file, or
	* <li>directory-based, meaning it looks up runfile paths under a given directory path
	* </ul>
	*
	* <p>If {@code env} contains "RUNFILES_MANIFEST_ONLY" with value "1", this method returns a
	* manifest-based implementation. The manifest's path is defined by the "RUNFILES_MANIFEST_FILE"
	* key's value in {@code env}.
	*
	* <p>Otherwise this method returns a directory-based implementation. The directory's path is
	* defined by the value in {@code env} under the "RUNFILES_DIR" key, or if absent, then under the
	* "JAVA_RUNFILES" key.
	*
	* <p>Note about performance: the manifest-based implementation eagerly reads and caches the whole
	* manifest file upon instantiation.
	*
	* @throws IOException if RUNFILES_MANIFEST_ONLY=1 is in {@code env} but there's no
	* "RUNFILES_MANIFEST_FILE", "RUNFILES_DIR", or "JAVA_RUNFILES" key in {@code env} or their
	* values are empty, or some IO error occurs
	*/
	public static Runfiles create(Map<String, String> env) throws IOException {
	if (isManifestOnly(env)) {
	// On Windows, Bazel sets RUNFILES_MANIFEST_ONLY=1.
	// On every platform, Bazel also sets RUNFILES_MANIFEST_FILE, but on Linux and macOS it's
	// faster to use RUNFILES_DIR.
	return new ManifestBased(getManifestPath(env));
	} else {
	return new DirectoryBased(getRunfilesDir(env));
	}
	}

	/**
	* Returns the runtime path of a runfile (a Bazel-built binary's/test's data-dependency).
	*
	* <p>The returned path may not be valid. The caller should check the path's validity and that the
	* path exists.
	*
	* <p>The function may return null. In that case the caller can be sure that the rule does not
	* know about this data-dependency.
	*
	* @param path runfiles-root-relative path of the runfile
	* @throws IllegalArgumentException if {@code path} fails validation, for example if it's null or
	* empty, or not normalized (contains "./", "../", or "//")
	*/
	public final String rlocation(String path) {
	Util.checkArgument(path != null);
	Util.checkArgument(!path.isEmpty());
	Util.checkArgument(
	!path.startsWith("../")
	&& !path.contains("/..")
	&& !path.startsWith("./")
	&& !path.contains("/./")
	&& !path.endsWith("/.")
	&& !path.contains("//"),
	"path is not normalized: \"%s\"",
	path);
	Util.checkArgument(
	!path.startsWith("\\"), "path is absolute without a drive letter: \"%s\"", path);
	if (new File(path).isAbsolute()) {
	return path;
	}
	return rlocationChecked(path);
	}

	/**
	* Returns environment variables for subprocesses.
	*
	* <p>The caller should add the returned key-value pairs to the environment of subprocesses in
	* case those subprocesses are also Bazel-built binaries that need to use runfiles.
	*/
	public abstract Map<String, String> getEnvVars();

	/** Returns true if the platform supports runfiles only via manifests. */
	private static boolean isManifestOnly(Map<String, String> env) {
	return "1".equals(env.get("RUNFILES_MANIFEST_ONLY"));
	}

	private static String getManifestPath(Map<String, String> env) throws IOException {
	String value = env.get("RUNFILES_MANIFEST_FILE");
	if (Util.isNullOrEmpty(value)) {
	throw new IOException(
	"Cannot load runfiles manifest: $RUNFILES_MANIFEST_ONLY is 1 but"
	+ " $RUNFILES_MANIFEST_FILE is empty or undefined");
	}
	return value;
	}

	private static String getRunfilesDir(Map<String, String> env) throws IOException {
	String value = env.get("RUNFILES_DIR");
	if (Util.isNullOrEmpty(value)) {
	value = env.get("JAVA_RUNFILES");
	}
	if (Util.isNullOrEmpty(value)) {
	throw new IOException(
	"Cannot find runfiles: $RUNFILES_DIR and $JAVA_RUNFILES are both unset or empty");
	}
	return value;
	}

	abstract String rlocationChecked(String path);

	/** {@link Runfiles} implementation that parses a runfiles-manifest file to look up runfiles. */
	private static final class ManifestBased extends Runfiles {
	private final Map<String, String> runfiles;
	private final String manifestPath;

	ManifestBased(String manifestPath) throws IOException {
	Util.checkArgument(manifestPath != null);
	Util.checkArgument(!manifestPath.isEmpty());
	this.manifestPath = manifestPath;
	this.runfiles = loadRunfiles(manifestPath);
	}

	private static Map<String, String> loadRunfiles(String path) throws IOException {
	HashMap<String, String> result = new HashMap<>();
	try (BufferedReader r =
	new BufferedReader(
	new InputStreamReader(new FileInputStream(path), StandardCharsets.UTF_8))) {
	String line = null;
	while ((line = r.readLine()) != null) {
	int index = line.indexOf(' ');
	String runfile = (index == -1) ? line : line.substring(0, index);
	String realPath = (index == -1) ? line : line.substring(index + 1);
	result.put(runfile, realPath);
	}
	}
	return Collections.unmodifiableMap(result);
	}

	private static String findRunfilesDir(String manifest) {
	if (manifest.endsWith("/MANIFEST")
	\|\| manifest.endsWith("\\MANIFEST")
	\|\| manifest.endsWith(".runfiles_manifest")) {
	String path = manifest.substring(0, manifest.length() - 9);
	if (new File(path).isDirectory()) {
	return path;
	}
	}
	return "";
	}

	@Override
	public String rlocationChecked(String path) {
	String exactMatch = runfiles.get(path);
	if (exactMatch != null) {
	return exactMatch;
	}
	// If path references a runfile that lies under a directory that itself is a runfile, then
	// only the directory is listed in the manifest. Look up all prefixes of path in the manifest
	// and append the relative path from the prefix if there is a match.
	int prefixEnd = path.length();
	while ((prefixEnd = path.lastIndexOf('/', prefixEnd - 1)) != -1) {
	String prefixMatch = runfiles.get(path.substring(0, prefixEnd));
	if (prefixMatch != null) {
	return prefixMatch + '/' + path.substring(prefixEnd + 1);
	}
	}
	return null;
	}

	@Override
	public Map<String, String> getEnvVars() {
	HashMap<String, String> result = new HashMap<>(4);
	result.put("RUNFILES_MANIFEST_ONLY", "1");
	result.put("RUNFILES_MANIFEST_FILE", manifestPath);
	String runfilesDir = findRunfilesDir(manifestPath);
	result.put("RUNFILES_DIR", runfilesDir);
	// TODO(laszlocsomor): remove JAVA_RUNFILES once the Java launcher can pick up RUNFILES_DIR.
	result.put("JAVA_RUNFILES", runfilesDir);
	return result;
	}
	}

	/** {@link Runfiles} implementation that appends runfiles paths to the runfiles root. */
	private static final class DirectoryBased extends Runfiles {
	private final String runfilesRoot;

	DirectoryBased(String runfilesDir) {
	Util.checkArgument(!Util.isNullOrEmpty(runfilesDir));
	Util.checkArgument(new File(runfilesDir).isDirectory());
	this.runfilesRoot = runfilesDir;
	}

	@Override
	String rlocationChecked(String path) {
	return runfilesRoot + "/" + path;
	}

	@Override
	public Map<String, String> getEnvVars() {
	HashMap<String, String> result = new HashMap<>(2);
	result.put("RUNFILES_DIR", runfilesRoot);
	// TODO(laszlocsomor): remove JAVA_RUNFILES once the Java launcher can pick up RUNFILES_DIR.
	result.put("JAVA_RUNFILES", runfilesRoot);
	return result;
	}
	}

	static Runfiles createManifestBasedForTesting(String manifestPath) throws IOException {
	return new ManifestBased(manifestPath);
	}

	static Runfiles createDirectoryBasedForTesting(String runfilesDir) {
	return new DirectoryBased(runfilesDir);
	}
	}