Improve code coverage generation.

tools/full-coverage.dart

Index: tools/full-coverage.dart
diff --git a/tools/full-coverage.dart b/tools/full-coverage.dart
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+++ b/tools/full-coverage.dart
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+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import "dart:async";
+import "dart:convert";
+import "dart:io";
+import "dart:isolate";
+import "dart:mirrors";
+
+import "package:args/args.dart";
+import "package:path/path.dart";
+
+/// [Environment] stores gathered arguments information.
+class Environment {
+  String sdkRoot;
+  String pkgRoot;
+  var input;
+  var output;
+  int workers;
+  bool prettyPrint;
+  bool lcov;
+  bool expectMarkers;
+  bool verbose;
+}
+
+/// [Resolver] resolves imports with respect to a given environment.
+class Resolver {
+  const DART_PREFIX = "dart:";
+  const PACKAGE_PREFIX = "package:";
+  const FILE_PREFIX = "file://";
+  const HTTP_PREFIX = "http://";
+
+  Map _env;
+  List failed = [];
+
+  Resolver(this._env);
+
+  /// Returns the absolute path wrt. to the given environment or null, if the
+  /// import could not be resolved.
+  resolve(String import) {
+    if (import.startsWith(DART_PREFIX)) {
+      var slashPos = import.indexOf("/");
+      var filePath;
+      if (slashPos != -1) {
+        var path = import.substring(DART_PREFIX.length, slashPos);
+        // Drop patch files, since we don't have their source in the compiled
+        // SDK.
+        if (path.endsWith("-patch")) {
+          failed.add(import);
+          return null;
+        }
+        // Canonicalize path. For instance: _collection-dev => _collection_dev.
+        path = path.replaceAll("-", "_");
+        filePath = "${_env["sdkRoot"]}"
+                   "/${path}${import.substring(slashPos, import.length)}";
+      } else {
+        // Resolve 'dart:something' to be something/something.dart in the SDK.
+        var lib = import.substring(DART_PREFIX.length, import.length);
+        filePath = "${_env["sdkRoot"]}/${lib}/${lib}.dart";
+      }
+      return filePath;
+    }
+    if (import.startsWith(PACKAGE_PREFIX)) {
+      var filePath =
+          "${_env["pkgRoot"]}"
+          "/${import.substring(PACKAGE_PREFIX.length, import.length)}"; 
+      return filePath;
+    }
+    if (import.startsWith(FILE_PREFIX)) {
+      var filePath = fromUri(Uri.parse(import));
+      return filePath;
+    }
+    if (import.startsWith(HTTP_PREFIX)) {
+      return import;
+    }
+    // We cannot deal with anything else.
+    failed.add(import);
+    return null;
+  }
+}
+
+/// Converts the given hitmap to lcov format and appends the result to
+/// env.output.
+///
+/// Returns a [Future] that completes as soon as all map entries have been
+/// emitted. 
+Future lcov(Map hitmap) {
+  var emitOne = (key) {
+    var v = hitmap[key];
+    StringBuffer entry = new StringBuffer();
+    entry.write("SF:${key}\n");
+    v.keys.toList()
+          ..sort()
+          ..forEach((k) {
+      entry.write("DA:${k},${v[k]}\n");
+    });
+    entry.write("end_of_record\n");
+    env.output.write(entry.toString());
+    return new Future.value(null);
+  };
+
+  return Future.forEach(hitmap.keys, emitOne);
+}
+
+/// Converts the given hitmap to a pretty-print format and appends the result
+/// to env.output.
+///
+/// Returns a [Future] that completes as soon as all map entries have been
+/// emitted. 
+Future prettyPrint(Map hitMap, List failedLoads) {
+  var emitOne = (key) {
+    var v = hitMap[key];
+    var c = new Completer();
+    loadResource(key).then((lines) {
+      if (lines == null) {
+        failedLoads.add(key);
+        c.complete();
+        return;
+      }
+      env.output.write("${key}\n");
+      for (var line = 1; line <= lines.length; line++) {
+        String prefix = "       ";
+        if (v.containsKey(line)) {
+          prefix = v[line].toString();
+          StringBuffer b = new StringBuffer();
+          for (int i = prefix.length; i < 7; i++) {
+            b.write(" ");
+          }
+          b.write(prefix);
+          prefix = b.toString();
+        }
+        env.output.write("${prefix}|${lines[line-1]}\n");
+      } 
+      c.complete();
+    });
+    return c.future;
+  };
+
+  return Future.forEach(hitMap.keys, emitOne);
+}
+
+/// Load an import resource and return a [Future] with a [List] of its lines.
+/// Returns [null] instead of a list if the resource could not be loaded.
+Future<List> loadResource(String import) {
+  if (import.startsWith("http")) {
+    Completer c = new Completer();
+    HttpClient client = new HttpClient();
+    client.getUrl(Uri.parse(import))
+        .then((HttpClientRequest request) {
+          return request.close();
+        })
+        .then((HttpClientResponse response) {
+          response.transform(new StringDecoder()).toList().then((data) {
+            c.complete(data);
+            httpClient.close();
+          });
+        })
+        .catchError((e) {
+          c.complete(null);
+        });
+    return c.future;
+  } else {
+    File f = new File(import);
+    return f.readAsLines()
+        .catchError((e) {
+          return new Future.value(null);
+        });
+  }
+}
+
+/// Creates a single hitmap from a raw json object. Throws away all entries that
+/// are not resolvable.
+Map createHitmap(String rawJson, Resolver resolver) {
+  Map<String, Map<int,int>> hitMap = {};
+
+  addToMap(source, line, count) {
+    if (!hitMap[source].containsKey(line)) {
+      hitMap[source][line] = 0;
+    }
+    hitMap[source][line] += count;
+  }
+
+  JSON.decode(rawJson).forEach((Map e) {
+    String source = resolver.resolve(e["source"]);
+    if (source == null) { 
+      // Couldnt resolve import, so skip this entry.
+      return;
+    }
+    if (!hitMap.containsKey(source)) {
+      hitMap[source] = {};
+    }
+    var hits = e["hits"];
+    // hits is a flat array of the following format:
+    // [ <line|linerange>, <hitcount>,...]
+    // line: number.
+    // linerange: "<line>-<line>".
+    for (var i = 0; i < hits.length; i += 2) {
+      var k = hits[i];
+      if (k is num) {
+        // Single line.
+        addToMap(source, k, hits[i+1]);
+      }
+      if (k is String) {
+        // Linerange. We expand line ranges to actual lines at this point.
+        var splitPos = k.indexOf("-");
+        int start = int.parse(k.substring(0, splitPos));
+        int end = int.parse(k.substring(splitPos + 1, k.length));
+        for (var j = start; j <= end; j++) {
+          addToMap(source, j, hits[i+1]);
+        }
+      }
+    }
+  });
+  return hitMap;
+}
+
+/// Merges [newMap] into [result].
+mergeHitmaps(Map newMap, Map result) {
+  newMap.forEach((String file, Map v) {
+    if (result.containsKey(file)) {
+      v.forEach((int line, int cnt) {
+        if (result[file][line] == null) {
+          result[file][line] = cnt;
+        } else {
+          result[file][line] += cnt;
+        }
+      }); 
+    } else {
+      result[file] = v;
+    }
+  });
+}
+
+/// Given an absolute path absPath, this function returns a [List] of files
+/// are contained by it if it is a directory, or a [List] containing the file if
+/// it is a file.
+List filesToProcess(String absPath) {
+  if (FileSystemEntity.isDirectorySync(absPath)) {
+    Directory d = new Directory(absPath);
+    List files = [];
+    d.listSync(recursive: true).forEach((FileSystemEntity entity) {
+      if (entity is File) {
+        files.add(entity as File);
+      }
+    });
+    return files;
+  } else if (FileSystemEntity.isFileSync(absPath)) {
+    return [ new File(absPath) ];
+  } 
+}
+
+worker() {
+  final start = new DateTime.now().millisecondsSinceEpoch;
+  String me = currentMirrorSystem().isolate.debugName;
+
+  port.receive((Message message, reply) {
+    if (message.type == Message.SHUTDOWN) {
+      port.close();
+    }
+
+    if (message.type == Message.WORK) {
+      var env = message.payload[0];
+      List files = message.payload[1];
+      Resolver resolver = new Resolver(env);
+      var workerHitmap = {};
+      files.forEach((File fileEntry) {
+        // Read file sync, as it only contains 1 object.
+        String contents = fileEntry.readAsStringSync();
+        if (contents.length > 0) {
+          mergeHitmaps(createHitmap(contents, resolver), workerHitmap);
+        }
+      }); 
+      if (env["verbose"]) {
+        final end = new DateTime.now().millisecondsSinceEpoch;
+        print("worker[${me}]: Finished processing files. "
+              "Took ${end - start} ms.");
+      }
+      reply.send(new Message(Message.RESULT, [workerHitmap, resolver.failed]));
+    }
+
+  });
+}
+
+class Message {
+  static const int SHUTDOWN = 1;
+  static const int RESULT = 2;
+  static const int WORK = 3;
+
+  final int type;
+  final payload;
+
+  Message(this.type, this.payload);
+}
+
+final env = new Environment();
+
+main() {
+  parseArgs();
+
+  List files = filesToProcess(env.input);
+  int filesPerWorker = files.length ~/ env.workers;
+  List workerPorts = [];
+  int doneCnt = 0;
+
+  List failedResolves = [];
+  List failedLoads = [];
+  Map globalHitmap = {};
+  int start = new DateTime.now().millisecondsSinceEpoch;
+
+  if (env.verbose) {
+    print("Environment:");
+    print("  # files: ${files.length}");
+    print("  # workers: ${env.workers}");
+    print("  sdk-root: ${env.sdkRoot}");
+    print("  package-root: ${env.pkgRoot}");
+  }
+
+  port.receive((Message message, reply) {
+    if (message.type == Message.RESULT) {
+      mergeHitmaps(message.payload[0], globalHitmap);  
+      failedResolves.addAll(message.payload[1]);
+      doneCnt++;
+    }
+
+    // All workers are done. Process the data.
+    if (doneCnt == env.workers) {
+      workerPorts.forEach((p) => p.send(new Message(Message.SHUTDOWN, null)));
+      if (env.verbose) {
+        final end = new DateTime.now().millisecondsSinceEpoch;
+        print("Done creating a global hitmap. Took ${end - start} ms.");
+      }
+
+      Future out;
+      if (env.prettyPrint) {
+        out = prettyPrint(globalHitmap, failedLoads);
+      }
+      if (env.lcov) {
+        out = lcov(globalHitmap);
+      }
+
+      out.then((_) {
+        env.output.close().then((_) {
+          if (env.verbose) {
+            final end = new DateTime.now().millisecondsSinceEpoch;
+            print("Done flushing output. Took ${end - start} ms.");
+          }
+        });
+        port.close();
+
+        if (env.verbose) {
+          if (failedResolves.length > 0) {
+            print("Failed to resolve:");
+            failedResolves.toSet().forEach((e) {
+              print("  ${e}");
+            });
+          }
+          if (failedLoads.length > 0) {
+            print("Failed to load:");
+            failedLoads.toSet().forEach((e) {
+              print("  ${e}");
+            });
+          }
+        }
+
+      });
+    }
+  });
+
+  Map sharedEnv = {
+    "sdkRoot": env.sdkRoot,
+    "pkgRoot": env.pkgRoot,
+    "verbose": env.verbose,
+  };
+
+  // Create workers.
+  for (var i = 1; i < env.workers; i++) {
+    var p = spawnFunction(worker);
+    workerPorts.add(p);
+    var start = files.length - filesPerWorker;
+    var end = files.length;
+    var workerFiles = files.getRange(start, end).toList();
+    files.removeRange(start, end);
+    p.send(new Message(Message.WORK, [sharedEnv, workerFiles]), port);
+  }
+  // Let the last worker deal with the rest of the files (which should be only
+  // off by at max (#workers - 1).
+  var p = spawnFunction(worker);
+  workerPorts.add(p);
+  p.send(new Message(Message.WORK, [sharedEnv, files]), port);
+
+  return 0;
+}
+
+/// Checks the validity of the provided arguments. Does not initialize actual
+/// processing.
+parseArgs() {
+  var parser = new ArgParser();
+
+  parser.addOption("sdk-root", abbr: "s",
+                   help: "path to the SDK root");
+  parser.addOption("package-root", abbr: "p",
+                   help: "path to the package root",
+                   defaultsTo: ".");
+  parser.addOption("in", abbr: "i",
+                   help: "input(s): may be file or directory",
+                   defaultsTo: "stdin");
+  parser.addOption("out", abbr: "o",
+                   help: "output: may be file or stdout",
+                   defaultsTo: "stdout");
+  parser.addOption("workers", abbr: "j",
+                   help: "number of workers",
+                   defaultsTo: "1");
+  parser.addFlag("pretty-print", abbr: "r",
+                 help: "convert coverage data to pretty print format",
+                 negatable: false);
+  parser.addFlag("lcov", abbr :"l",
+                 help: "convert coverage data to lcov format",
+                 negatable: false);
+  parser.addFlag("verbose", abbr :"v",
+                 help: "verbose output",
+                 negatable: false);
+  parser.addFlag("help", abbr: "h",
+                 help: "show this help",
+                 negatable: false);
+
+  var args = parser.parse(new Options().arguments);
+
+  if (args["help"]) {
+    print("Usage: coverage [OPTION...]\n");
+    print(parser.getUsage());
+    exit(0);
+  }
+
+  if (args["sdk-root"] == null) {
+    if (Platform.environment.containsKey("SDK_ROOT")) {
+      env.sdkRoot =
+        join(absolute(normalize(Platform.environment["SDK_ROOT"])), "lib");
+    } else {
+      throw "No SDK root found, please specify one using --sdk-root.";
+    }
+  } else {
+    env.sdkRoot = join(absolute(normalize(args["sdk-root"])), "lib");
+  }
+  if (!FileSystemEntity.isDirectorySync(env.sdkRoot)) {
+    throw "Provided SDK root ${args["sdk-root"]} is not a valid SDK "
+          "top-level directory";
+  }
+
+  if (args["package-root"] == null) {
+    env.pkgRoot = absolute(normalize("./packages"));
+  } else {
+    env.pkgRoot = absolute(normalize(args["package-root"]));
+    if (!FileSystemEntity.isDirectorySync(env.pkgRoot)) {
+      throw "Provided package root ${args["package-root"]} is not directory.";
+    }
+  }
+
+  if (args["in"] == "stdin") {
+    env.input = "stdin";
+  } else {
+    env.input = absolute(normalize(args["in"]));
+    if (!FileSystemEntity.isDirectorySync(env.input) &&
+        !FileSystemEntity.isFileSync(env.input)) {
+      throw "Provided input ${args["in"]} is neither a directory, nor a file.";
+    }
+  }
+
+  if (args["out"] == "stdout") {
+    env.output = stdout;
+  } else {
+    env.output = absolute(normalize(args["out"]));
+    env.output = new File(env.output).openWrite();
+  }
+
+  if (args["pretty-print"] &&
+      args["lcov"]) {
+    throw "Choose either pretty-print or lcov output";
+  }
+
+  env.prettyPrint = args["pretty-print"];
+  env.lcov = args["lcov"];
+  env.verbose = args["verbose"];
+  env.workers = int.parse("${args["workers"]}");
+}