analysis server performance measurement driver first cut

pkg/analysis_server/test/performance/input_converter.dart

+library input.transformer;
+
+import 'dart:convert';
+
+import 'instrumentation_input_converter.dart';
+import 'operation.dart';
+
+final int NINE = '9'.codeUnitAt(0);
+final int ZERO = '0'.codeUnitAt(0);
+
+/**
+ * [InputConverter] converts an input stream
+ * into a series of operations to be sent to the analysis server.
+ * The input stream can be either an instrumenation or log file.
+ */
+class InputConverter extends Converter<String, Operation> {
+
+  /**
+   * The number of lines read before the underlying converter was determined
+   * or the end of file was reached.
+   */
+  int headerLineCount = 0;
+
+  /**
+   * The underlying converter used to translate lines into operations
+   * or `null` if it has not yet been determined.
+   */
+  Converter<String, Operation> converter;
+
+  @override
+  Operation convert(String line) {
+    if (converter != null) {
+      return converter.convert(line);
+    }
+    if (headerLineCount == 20) {
+      throw 'Failed to determine input file format';
+    }
+    if (InstrumentationInputConverter.isFormat(line)) {
+      converter = new InstrumentationInputConverter();
+    } else if (LogFileInputConverter.isFormat(line)) {
+      converter = new LogFileInputConverter();
+    }
+    if (converter != null) {
+      return converter.convert(line);
+    }
+    print(line);
+    return null;
+  }
+
+  @override
+  _InputSink startChunkedConversion(outSink) {
+    return new _InputSink(this, outSink);
+  }
+}
+
+/**
+ * [LogFileInputConverter] converts a log file stream
+ * into a series of operations to be sent to the analysis server.
+ */
+class LogFileInputConverter extends Converter<String, Operation> {
+  @override
+  Operation convert(String line) {
+    throw 'not implemented yet';
+  }
+
+  /**
+   * Determine if the given line is from an instrumentation file.
+   * For example:
+   * `1428347977499 <= {"event":"server.connected","params":{"version":"1.6.0"}}`
+   */
+  static bool isFormat(String line) {
+    String timeStampString = _parseTimeStamp(line);
+    int start = timeStampString.length;
+    int end = start + 5;
+    return start > 10 &&
+        line.length > end &&
+        line.substring(start, end) == ' <= {"event":"server.connected"';
+  }
+
+  /**
+   * Parse the given line and return the millisecond timestamp or `null`
+   * if it cannot be determined.
+   */
+  static String _parseTimeStamp(String line) {
+    int index = 0;
+    while (index < line.length) {
+      int code = line.codeUnitAt(index);
+      if (code < ZERO || NINE < code) {
+        return line.substring(0, index);
+      }
+      ++index;
+    }
+    return line;
+  }
+}
+
+class _InputSink extends ChunkedConversionSink<String> {
+  final Converter<String, Operation> converter;
+  final outSink;
+
+  _InputSink(this.converter, this.outSink);
+
+  @override
+  void add(String line) {
+    Operation op = converter.convert(line);
+    if (op != null) {
+      outSink.add(op);
+    }
+  }
+
+  @override
+  void close() {
+    outSink.close();
+  }
+}