1 files changed, 226 insertions, 0 deletions
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/ParamertizedString.java b/gerrit-server/src/main/java/com/google/gerrit/server/ParamertizedString.java
new file mode 100644
index 0000000000..6fa2450fe4
--- /dev/null
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/ParamertizedString.java
@@ -0,0 +1,226 @@
+// Copyright (C) 2009 The Android Open Source Project
+//
+// 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.gerrit.server;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/** Performs replacements on strings such as <code>Hello ${user}</code>. */
+public class ParamertizedString {
+  /** Obtain a string which has no parameters and always produces the value. */
+  public static ParamertizedString asis(final String constant) {
+    return new ParamertizedString(new Constant(constant));
+  }
+
+  private final String pattern;
+  private final String rawPattern;
+  private final List<Format> patternOps;
+  private final List<Parameter> parameters;
+
+  private ParamertizedString(final Constant c) {
+    pattern = c.text;
+    rawPattern = c.text;
+    patternOps = Collections.<Format> singletonList(c);
+    parameters = Collections.emptyList();
+  }
+
+  public ParamertizedString(final String pattern) {
+    final StringBuilder raw = new StringBuilder();
+    final List<Parameter> prs = new ArrayList<Parameter>(4);
+    final List<Format> ops = new ArrayList<Format>(4);
+
+    int i = 0;
+    while (i < pattern.length()) {
+      final int b = pattern.indexOf("${", i);
+      if (b < 0) {
+        break;
+      }
+      final int e = pattern.indexOf("}", b + 2);
+      if (e < 0) {
+        break;
+      }
+
+      raw.append(pattern.substring(i, b));
+      ops.add(new Constant(pattern.substring(i, b)));
+
+      String expr = pattern.substring(b + 2, e);
+      Function function;
+      int lastDot = expr.lastIndexOf('.');
+      if (lastDot < 0) {
+        function = NOOP;
+      } else {
+        function = FUNCTIONS.get(expr.substring(lastDot + 1));
+        if (function == null) {
+          function = NOOP;
+        } else {
+          expr = expr.substring(0, lastDot);
+        }
+      }
+
+      final Parameter p = new Parameter(expr, function);
+      raw.append("{" + prs.size() + "}");
+      prs.add(p);
+      ops.add(p);
+
+      i = e + 1;
+    }
+    if (i < pattern.length()) {
+      raw.append(pattern.substring(i));
+      ops.add(new Constant(pattern.substring(i)));
+    }
+
+    this.pattern = pattern;
+    this.rawPattern = raw.toString();
+    this.patternOps = Collections.unmodifiableList(ops);
+    this.parameters = Collections.unmodifiableList(prs);
+  }
+
+  /** Get the original pattern given to the constructor. */
+  public String getPattern() {
+    return pattern;
+  }
+
+  /** Get the pattern with variables replaced with {0}, {1}, ... */
+  public String getRawPattern() {
+    return rawPattern;
+  }
+
+  /** Get the list of parameter names, ordered by appearance in the pattern. */
+  public List<String> getParameterNames() {
+    final ArrayList<String> r = new ArrayList<String>(parameters.size());
+    for (Parameter p : parameters) {
+      r.add(p.name);
+    }
+    return Collections.unmodifiableList(r);
+  }
+
+  /** Convert a map of parameters into a value array for binding. */
+  public String[] bind(final Map<String, String> params) {
+    final String[] r = new String[parameters.size()];
+    for (int i = 0; i < r.length; i++) {
+      final StringBuilder b = new StringBuilder();
+      parameters.get(i).format(b, params);
+      r[i] = b.toString();
+    }
+    return r;
+  }
+
+  /** Format this string by performing the variable replacements. */
+  public String replace(final Map<String, String> params) {
+    final StringBuilder r = new StringBuilder();
+    for (final Format f : patternOps) {
+      f.format(r, params);
+    }
+    return r.toString();
+  }
+
+  public Builder replace(final String name, final String value) {
+    return new Builder().replace(name, value);
+  }
+
+  @Override
+  public String toString() {
+    return getPattern();
+  }
+
+  public final class Builder {
+    private final Map<String, String> params = new HashMap<String, String>();
+
+    public Builder replace(final String name, final String value) {
+      params.put(name, value);
+      return this;
+    }
+
+    @Override
+    public String toString() {
+      return ParamertizedString.this.replace(params);
+    }
+  }
+
+  private static abstract class Format {
+    abstract void format(StringBuilder b, Map<String, String> p);
+  }
+
+  private static class Constant extends Format {
+    private final String text;
+
+    Constant(final String text) {
+      this.text = text;
+    }
+
+    @Override
+    void format(StringBuilder b, Map<String, String> p) {
+      b.append(text);
+    }
+  }
+
+  private static class Parameter extends Format {
+    private final String name;
+    private final Function function;
+
+    Parameter(final String name, final Function function) {
+      this.name = name;
+      this.function = function;
+    }
+
+    @Override
+    void format(StringBuilder b, Map<String, String> p) {
+      String v = p.get(name);
+      if (v == null) {
+        v = "";
+      }
+      b.append(function.apply(v));
+    }
+  }
+
+  private static abstract class Function {
+    abstract String apply(String a);
+  }
+
+  private static final Map<String, Function> FUNCTIONS = initFunctions();
+  private static final Function NOOP = new Function() {
+    @Override
+    String apply(String a) {
+      return a;
+    }
+  };
+
+  private static Map<String, Function> initFunctions() {
+    final HashMap<String, Function> m = new HashMap<String, Function>();
+    m.put("toLowerCase", new Function() {
+      @Override
+      String apply(String a) {
+        return a.toLowerCase();
+      }
+    });
+    m.put("toUpperCase", new Function() {
+      @Override
+      String apply(String a) {
+        return a.toUpperCase();
+      }
+    });
+    m.put("localPart", new Function() {
+      @Override
+      String apply(String a) {
+        int at = a.indexOf('@');
+        return at < 0 ? a : a.substring(0, at);
+      }
+    });
+    return Collections.unmodifiableMap(m);
+  }
+}