DefaultHeaders#valueIterator doesn't remove from the in bucket list (#9090)

Motivation:
DefaultHeaders entries maintains two linked lists. 1 for overall insertion order
and 1 for "in bucket" order. DefaultHeaders#valueIterator removal (introduced in 1d9090aab2) only reliably
removes the entry from the overall insertion order, but may not remove from the
bucket unless the element is the first entry.

Modifications:
- DefaultHeaders$ValueIterator should track 2 elements behind the next entry so
that the single linked "in bucket" list can be patched up when removing the
previous entry.

Result:
More correct DefaultHeaders#valueIterator removal.
This commit is contained in:
Scott Mitchell 2019-04-27 11:32:50 -07:00 committed by GitHub
parent 2c12f09ec9
commit 2d33d1493e
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 44 additions and 10 deletions

View File

@ -1012,14 +1012,18 @@ public class DefaultHeaders<K, V, T extends Headers<K, V, T>> implements Headers
return value;
}
private void remove0(HeaderEntry<K, V> entry) {
private HeaderEntry<K, V> remove0(HeaderEntry<K, V> entry, HeaderEntry<K, V> previous) {
int i = index(entry.hash);
HeaderEntry<K, V> e = entries[i];
if (e == entry) {
entries[i] = entry.next;
previous = entries[i];
} else {
previous.next = entry.next;
}
entry.remove();
--size;
return previous;
}
@SuppressWarnings("unchecked")
@ -1065,6 +1069,7 @@ public class DefaultHeaders<K, V, T extends Headers<K, V, T>> implements Headers
private final class ValueIterator implements Iterator<V> {
private final K name;
private final int hash;
private HeaderEntry<K, V> removalPrevious;
private HeaderEntry<K, V> previous;
private HeaderEntry<K, V> next;
@ -1084,6 +1089,9 @@ public class DefaultHeaders<K, V, T extends Headers<K, V, T>> implements Headers
if (!hasNext()) {
throw new NoSuchElementException();
}
if (previous != null) {
removalPrevious = previous;
}
previous = next;
calculateNext(next.next);
return previous.value;
@ -1094,7 +1102,7 @@ public class DefaultHeaders<K, V, T extends Headers<K, V, T>> implements Headers
if (previous == null) {
throw new IllegalStateException();
}
remove0(previous);
removalPrevious = remove0(previous, removalPrevious);
previous = null;
}

View File

@ -110,24 +110,50 @@ public class DefaultHeadersTest {
}
@Test
public void multipleValuesPerNameIterator() {
public void multipleValuesPerNameIteratorWithOtherNames() {
TestDefaultHeaders headers = newInstance();
headers.add(of("name"), of("value1"));
headers.add(of("name"), of("value2"));
headers.add(of("name"), of("value3"));
assertEquals(3, headers.size());
headers.add(of("name1"), of("value1"));
headers.add(of("name1"), of("value2"));
headers.add(of("name2"), of("value4"));
headers.add(of("name1"), of("value3"));
assertEquals(4, headers.size());
List<CharSequence> values = new ArrayList<CharSequence>();
Iterator<CharSequence> itr = headers.valueIterator(of("name"));
Iterator<CharSequence> itr = headers.valueIterator(of("name1"));
while (itr.hasNext()) {
values.add(itr.next());
itr.remove();
}
assertEquals(3, values.size());
assertEquals(1, headers.size());
assertFalse(headers.isEmpty());
assertTrue(values.containsAll(asList(of("value1"), of("value2"), of("value3"))));
itr = headers.valueIterator(of("name1"));
assertFalse(itr.hasNext());
itr = headers.valueIterator(of("name2"));
assertTrue(itr.hasNext());
assertEquals(of("value4"), itr.next());
assertFalse(itr.hasNext());
}
@Test
public void multipleValuesPerNameIterator() {
TestDefaultHeaders headers = newInstance();
headers.add(of("name1"), of("value1"));
headers.add(of("name1"), of("value2"));
assertEquals(2, headers.size());
List<CharSequence> values = new ArrayList<CharSequence>();
Iterator<CharSequence> itr = headers.valueIterator(of("name1"));
while (itr.hasNext()) {
values.add(itr.next());
itr.remove();
}
assertEquals(2, values.size());
assertEquals(0, headers.size());
assertTrue(headers.isEmpty());
assertTrue(values.containsAll(asList(of("value1"), of("value2"), of("value3"))));
itr = headers.valueIterator(of("name"));
assertTrue(values.containsAll(asList(of("value1"), of("value2"))));
itr = headers.valueIterator(of("name1"));
assertFalse(itr.hasNext());
}