1 files changed, 172 insertions, 0 deletions
diff --git a/java/com/android/voicemail/impl/mail/PackedString.java b/java/com/android/voicemail/impl/mail/PackedString.java
new file mode 100644
index 000000000..701dab62b
--- /dev/null
+++ b/java/com/android/voicemail/impl/mail/PackedString.java
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2015 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.android.voicemail.impl.mail;
+
+import android.util.ArrayMap;
+import java.util.Map;
+
+/**
+ * A utility class for creating and modifying Strings that are tagged and packed together.
+ *
+ * <p>Uses non-printable (control chars) for internal delimiters; Intended for regular displayable
+ * strings only, so please use base64 or other encoding if you need to hide any binary data here.
+ *
+ * <p>Binary compatible with Address.pack() format, which should migrate to use this code.
+ */
+public class PackedString {
+
+  /**
+   * Packing format is: element : [ value ] or [ value TAG-DELIMITER tag ] packed-string : [ element
+   * ] [ ELEMENT-DELIMITER [ element ] ]*
+   */
+  private static final char DELIMITER_ELEMENT = '\1';
+
+  private static final char DELIMITER_TAG = '\2';
+
+  private String mString;
+  private ArrayMap<String, String> mExploded;
+  private static final ArrayMap<String, String> EMPTY_MAP = new ArrayMap<String, String>();
+
+  /**
+   * Create a packed string using an already-packed string (e.g. from database)
+   *
+   * @param string packed string
+   */
+  public PackedString(String string) {
+    mString = string;
+    mExploded = null;
+  }
+
+  /**
+   * Get the value referred to by a given tag. If the tag does not exist, return null.
+   *
+   * @param tag identifier of string of interest
+   * @return returns value, or null if no string is found
+   */
+  public String get(String tag) {
+    if (mExploded == null) {
+      mExploded = explode(mString);
+    }
+    return mExploded.get(tag);
+  }
+
+  /**
+   * Return a map of all of the values referred to by a given tag. This is a shallow copy, don't
+   * edit the values.
+   *
+   * @return a map of the values in the packed string
+   */
+  public Map<String, String> unpack() {
+    if (mExploded == null) {
+      mExploded = explode(mString);
+    }
+    return new ArrayMap<String, String>(mExploded);
+  }
+
+  /** Read out all values into a map. */
+  private static ArrayMap<String, String> explode(String packed) {
+    if (packed == null || packed.length() == 0) {
+      return EMPTY_MAP;
+    }
+    ArrayMap<String, String> map = new ArrayMap<String, String>();
+
+    int length = packed.length();
+    int elementStartIndex = 0;
+    int elementEndIndex = 0;
+    int tagEndIndex = packed.indexOf(DELIMITER_TAG);
+
+    while (elementStartIndex < length) {
+      elementEndIndex = packed.indexOf(DELIMITER_ELEMENT, elementStartIndex);
+      if (elementEndIndex == -1) {
+        elementEndIndex = length;
+      }
+      String tag;
+      String value;
+      if (tagEndIndex == -1 || elementEndIndex <= tagEndIndex) {
+        // in this case the DELIMITER_PERSONAL is in a future pair (or not found)
+        // so synthesize a positional tag for the value, and don't update tagEndIndex
+        value = packed.substring(elementStartIndex, elementEndIndex);
+        tag = Integer.toString(map.size());
+      } else {
+        value = packed.substring(elementStartIndex, tagEndIndex);
+        tag = packed.substring(tagEndIndex + 1, elementEndIndex);
+        // scan forward for next tag, if any
+        tagEndIndex = packed.indexOf(DELIMITER_TAG, elementEndIndex + 1);
+      }
+      map.put(tag, value);
+      elementStartIndex = elementEndIndex + 1;
+    }
+
+    return map;
+  }
+
+  /**
+   * Builder class for creating PackedString values. Can also be used for editing existing
+   * PackedString representations.
+   */
+  public static class Builder {
+    ArrayMap<String, String> mMap;
+
+    /** Create a builder that's empty (for filling) */
+    public Builder() {
+      mMap = new ArrayMap<String, String>();
+    }
+
+    /** Create a builder using the values of an existing PackedString (for editing). */
+    public Builder(String packed) {
+      mMap = explode(packed);
+    }
+
+    /**
+     * Add a tagged value
+     *
+     * @param tag identifier of string of interest
+     * @param value the value to record in this position. null to delete entry.
+     */
+    public void put(String tag, String value) {
+      if (value == null) {
+        mMap.remove(tag);
+      } else {
+        mMap.put(tag, value);
+      }
+    }
+
+    /**
+     * Get the value referred to by a given tag. If the tag does not exist, return null.
+     *
+     * @param tag identifier of string of interest
+     * @return returns value, or null if no string is found
+     */
+    public String get(String tag) {
+      return mMap.get(tag);
+    }
+
+    /** Pack the values and return a single, encoded string */
+    @Override
+    public String toString() {
+      StringBuilder sb = new StringBuilder();
+      for (Map.Entry<String, String> entry : mMap.entrySet()) {
+        if (sb.length() > 0) {
+          sb.append(DELIMITER_ELEMENT);
+        }
+        sb.append(entry.getValue());
+        sb.append(DELIMITER_TAG);
+        sb.append(entry.getKey());
+      }
+      return sb.toString();
+    }
+  }
+}