Fix analysis server caching edge case http://code.google.com/p/dart/issues/detail?id=3423

editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/analysis/CacheWriter.java

Index: editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/analysis/CacheWriter.java
===================================================================
--- editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/analysis/CacheWriter.java	(revision 0)
+++ editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/analysis/CacheWriter.java	(revision 0)
@@ -0,0 +1,94 @@
+package com.google.dart.tools.core.analysis;
+
+import java.io.File;
+import java.io.PrintWriter;
+import java.io.Writer;
+import java.util.ArrayList;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+
+/**
+ * Internal class for writing analysis state to disk between sessions.
+ */
+public class CacheWriter {
+  private PrintWriter writer;
+
+  public CacheWriter(Writer writer) {
+    this.writer = writer instanceof PrintWriter ? (PrintWriter) writer : new PrintWriter(writer);
+    this.writer.println(CacheReader.CACHE_VERSION_TAG);
+  }
+
+  /**
+   * Write a value that can be read by {@link CacheReader#readBoolean()}
+   */
+  public void writeBoolean(boolean value) {
+    writer.println(value ? "true" : "false");
+  }
+
+  /**
+   * Write a collection of file paths to be read by
+   * {@link CacheReader#readFilePaths(java.util.Collection, String)}
+   * 
+   * @param files the collection of files (not <code>null</code> )
+   * @param endTag the tag used to denote the end of the collection of file paths
+   */
+  public void writeFilePaths(ArrayList<File> files, String endTag) {
+    for (File libFile : files) {
+      writeString(libFile.getPath());
+    }
+    writeString(endTag);
+  }
+
+  /**
+   * Write a string that can be read by {@link CacheReader#readString()}
+   */
+  public void writeString(String string) {
+
+    // Normal case ... write a line
+
+    if (!string.startsWith("!") && string.indexOf('\r') == -1 && string.indexOf('\n') == -1) {
+      writer.println(string);
+      return;
+    }
+
+    // If the string contains a line separator, then string length is encoded
+    // preceding the string as bang-number-bang
+
+    writer.print('!');
+    writer.print(string.length());
+    writer.print('!');
+    writer.println(string);
+  }
+
+  /**
+   * Write a collection of key/value pairs to be read by
+   * {@link CacheReader#readStringFileMap(String)} where the keys are strings and the values are
+   * instances of {@link java.io.File}.
+   * 
+   * @param endTag the tag used to denote the end of the collection
+   * @return the collection (not <code>null</code>)
+   */
+  public void writeStringFileMap(Map<String, File> map, String endTag) {
+    for (Entry<String, File> entry : map.entrySet()) {
+      writeString(entry.getKey());
+      writeString(entry.getValue().getPath());
+    }
+    writeString(endTag);
+  }
+
+  /**
+   * Write a collection of strings that can be read by {@link CacheReader#readStringSet(String)}
+   * 
+   * @param strings the collection of strings to be written (not <code>null</code>, contains no
+   *          <code>null</code>s)
+   * @param endTag the tag used to denote the end of the collection of strings (not
+   *          <code>null</code>)
+   */
+  public void writeStringSet(Set<String> strings, String endTag) {
+    for (String string : strings) {
+      writeString(string);
+    }
+    writeString(endTag);
+  }
+}