+ * Note that the keys field is synchronized using RCU. + * Writes to it are not synchronized by this object, the writers have to synchronize writes themselves. + *
+ * In short this means that you should not rely on this variable being the same value when read again and your should always + * copy it on writes. + *
+ * Further reading: + *
keys is null, clears existing key/value pairs.
+ * + * Note that this method, like all methods that modify keys, is not synchronized and may lead to data corruption when being used + * from multiple threads. * * @param keys the key/value pairs to set. If null, removes all existing key/value pairs. @@ -555,4 +570,7 @@ * Set the given value to the given key. If key is null, does nothing. If value is null, * removes the key and behaves like {@link #remove(String)}. + *
+ * Note that this method, like all methods that modify keys, is not synchronized and may lead to data corruption when being used + * from multiple threads. * * @param key The key, for which the value is to be set. Can be null or empty, does nothing in this case. @@ -572,15 +590,18 @@ keysChangedImpl(originalKeys); } else { - for (int i = 0; i < keys.length; i += 2) { - if (keys[i].equals(key)) { - // This modifies the keys array but it doesn't make it invalidate for any time so its ok (see note no top) - keys[i+1] = value; - keysChangedImpl(originalKeys); - return; - } + int keyIndex = indexOfKey(keys, key); + int tagArrayLength = keys.length; + if (keyIndex < 0) { + keyIndex = tagArrayLength; + tagArrayLength += 2; } - String[] newKeys = Arrays.copyOf(keys, keys.length + 2); - newKeys[keys.length] = key; - newKeys[keys.length + 1] = value; + + // Do not try to optimize this array creation if the key already exists. + // We would need to convert the keys array to be an AtomicReferenceArray + // Or we would at least need a volatile write after the array was modified to + // ensure that changes are visible by other threads. + String[] newKeys = Arrays.copyOf(keys, tagArrayLength); + newKeys[keyIndex] = key; + newKeys[keyIndex + 1] = value; keys = newKeys; keysChangedImpl(originalKeys); @@ -589,5 +610,26 @@ /** + * Scans a key/value array for a given key. + * @param keys The key array. It is not modified. It may be null to indicate an emtpy array. + * @param key The key to search for. + * @return The position of that key in the keys array - which is always a multiple of 2 - or -1 if it was not found. + */ + private static int indexOfKey(String[] keys, String key) { + if (keys == null) { + return -1; + } + for (int i = 0; i < keys.length; i += 2) { + if (keys[i].equals(key)) { + return i; + } + } + return -1; + } + + /** * Remove the given key from the list + *
+ * Note that this method, like all methods that modify keys, is not synchronized and may lead to data corruption when being used + * from multiple threads. * * @param key the key to be removed. Ignored, if key is null. @@ -618,4 +660,7 @@ /** * Removes all keys from this primitive. + *
+ * Note that this method, like all methods that modify keys, is not synchronized and may lead to data corruption when being used
+ * from multiple threads.
*/
@Override
@@ -681,4 +726,5 @@
public final int getNumKeys() {
+ String[] keys = this.keys;
return keys == null ? 0 : keys.length / 2;
}
@@ -719,11 +765,5 @@
*/
public boolean hasKey(String key) {
- String[] keys = this.keys;
- if (key == null) return false;
- if (keys == null) return false;
- for (int i = 0; i < keys.length; i += 2) {
- if (keys[i].equals(key)) return true;
- }
- return false;
+ return key != null && indexOfKey(keys, key) >= 0;
}
Index: trunk/src/org/openstreetmap/josm/data/osm/OsmPrimitive.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/osm/OsmPrimitive.java (revision 9266)
+++ trunk/src/org/openstreetmap/josm/data/osm/OsmPrimitive.java (revision 9267)
@@ -776,5 +776,5 @@
/**
* Returns {@link #getKeys()} for which {@code key} does not fulfill {@link #isUninterestingKey}.
- * @return list of interesting tags
+ * @return A map of interesting tags
*/
public Map