1 files changed, 238 insertions, 0 deletions
diff --git a/java/com/google/gerrit/common/data/ParameterizedString.java b/java/com/google/gerrit/common/data/ParameterizedString.java
new file mode 100644
index 0000000000..28e47ee67a
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+++ b/java/com/google/gerrit/common/data/ParameterizedString.java
@@ -0,0 +1,238 @@
+// 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.common.data;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/** Performs replacements on strings such as <code>Hello ${user}</code>. */
+public class ParameterizedString {
+  /** Obtain a string which has no parameters and always produces the value. */
+  public static ParameterizedString asis(String constant) {
+    return new ParameterizedString(new Constant(constant));
+  }
+
+  private final String pattern;
+  private final String rawPattern;
+  private final List<Format> patternOps;
+  private final List<Parameter> parameters;
+
+  protected ParameterizedString() {
+    this(new Constant(""));
+  }
+
+  private ParameterizedString(Constant c) {
+    pattern = c.text;
+    rawPattern = c.text;
+    patternOps = Collections.<Format>singletonList(c);
+    parameters = Collections.emptyList();
+  }
+
+  public ParameterizedString(String pattern) {
+    final StringBuilder raw = new StringBuilder();
+    final List<Parameter> prs = new ArrayList<>(4);
+    final List<Format> ops = new ArrayList<>(4);
+
+    int i = 0;
+    while (i < pattern.length()) {
+      final int b = pattern.indexOf("${", 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)));
+
+      // "${parameter[.functions...]}" -> "parameter[.functions...]"
+      final Parameter p = new Parameter(pattern.substring(b + 2, e));
+
+      raw.append("{").append(prs.size()).append("}");
+      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<>(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(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(Map<String, String> params) {
+    final StringBuilder r = new StringBuilder();
+    for (Format f : patternOps) {
+      f.format(r, params);
+    }
+    return r.toString();
+  }
+
+  public Builder replace(String name, 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<>();
+
+    public Builder replace(String name, String value) {
+      params.put(name, value);
+      return this;
+    }
+
+    @Override
+    public String toString() {
+      return ParameterizedString.this.replace(params);
+    }
+  }
+
+  private abstract static class Format {
+    abstract void format(StringBuilder b, Map<String, String> p);
+  }
+
+  private static class Constant extends Format {
+    private final String text;
+
+    Constant(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 List<Function> functions;
+
+    Parameter(String parameter) {
+      // "parameter[.functions...]" -> (parameter, functions...)
+      final List<String> names = Arrays.asList(parameter.split("\\."));
+      final List<Function> functs = new ArrayList<>(names.size());
+
+      if (names.isEmpty()) {
+        name = "";
+      } else {
+        name = names.get(0);
+
+        for (String fname : names.subList(1, names.size())) {
+          final Function function = FUNCTIONS.get(fname);
+          if (function != null) {
+            functs.add(function);
+          }
+        }
+      }
+
+      functions = Collections.unmodifiableList(functs);
+    }
+
+    @Override
+    void format(StringBuilder b, Map<String, String> p) {
+      String v = p.get(name);
+      if (v == null) {
+        v = "";
+      }
+      for (Function function : functions) {
+        v = function.apply(v);
+      }
+      b.append(v);
+    }
+  }
+
+  private abstract static class Function {
+    abstract String apply(String a);
+  }
+
+  private static final Map<String, Function> FUNCTIONS = initFunctions();
+
+  private static Map<String, Function> initFunctions() {
+    HashMap<String, Function> m = new HashMap<>();
+    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);
+  }
+}