content: /*
   * Copyright 2014-2025 Real Logic Limited.
   *
   * 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
   *
   * https://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 io.aeron.driver;
  
  import io.aeron.protocol.ResolutionEntryFlyweight;
  import org.agrona.collections.ArrayListUtil;
  import org.agrona.concurrent.status.AtomicCounter;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  
  final class DriverNameResolverCache implements AutoCloseable
  {
      private static final int INVALID_INDEX = -1;
  
      private final ArrayList<CacheEntry> entries = new ArrayList<>();
      private final long timeoutMs;
  
      DriverNameResolverCache(final long timeoutMs)
      {
          this.timeoutMs = timeoutMs;
      }
  
      /**
       * {@inheritDoc}
       */
      public void close()
      {
      }
  
      CacheEntry lookup(final String name, final byte type)
      {
          final int index = findEntryIndexByNameAndType(name, type);
  
          return INVALID_INDEX == index ? null : entries.get(index);
      }
  
      void addOrUpdateEntry(
          final byte[] name,
          final int nameLength,
          final long nowMs,
          final byte type,
          final byte[] address,
          final int port,
          final AtomicCounter cacheEntriesCounter)
      {
          final int existingEntryIndex = findEntryIndexByNameAndType(name, nameLength, type);
          final int addressLength = ResolutionEntryFlyweight.addressLength(type);
          final CacheEntry entry;
  
          if (INVALID_INDEX == existingEntryIndex)
          {
              entry = new CacheEntry(
                  Arrays.copyOf(name, nameLength),
                  type,
                  nowMs,
                  nowMs + timeoutMs,
                  Arrays.copyOf(address, addressLength),
                  port);
              entries.add(entry);
              cacheEntriesCounter.setRelease(entries.size());
          }
          else
          {
              entry = entries.get(existingEntryIndex);
              entry.timeOfLastActivityMs = nowMs;
              entry.deadlineMs = nowMs + timeoutMs;
  
              if (port != entry.port || !byteSubsetEquals(address, entry.address, addressLength))
              {
                  entry.address = Arrays.copyOf(address, addressLength);
                  entry.port = port;
              }
          }
      }
  
      int timeoutOldEntries(final long nowMs, final AtomicCounter cacheEntriesCounter)
      {
          int workCount = 0;
  
          final ArrayList<CacheEntry> listOfEntries = this.entries;
          for (int lastIndex = listOfEntries.size() - 1, i = lastIndex; i >= 0; i--)
          {
              final CacheEntry entry = listOfEntries.get(i);
  
              if (entry.deadlineMs - nowMs < 0)
              {
                  ArrayListUtil.fastUnorderedRemove(listOfEntries, i, lastIndex--);
                  cacheEntriesCounter.setRelease(listOfEntries.size());
                  workCount++;
              }
          }
  
          return workCount;
      }
  
      Iterator resetIterator()
      {
          iterator.cache = this;
          iterator.index = -1;
  
          return iterator;
      }
  
      static final class Iterator
      {
          int index = -1;
          DriverNameResolverCache cache;
  
          boolean hasNext()
          {
              return (index + 1) < cache.entries.size();
          }
  
          CacheEntry next()
          {
              return cache.entries.get(++index);
          }
  
          void rewindNext()
          {
              --index;
          }
      }
  
      private final Iterator iterator = new Iterator();
  
      static boolean byteSubsetEquals(final byte[] lhs, final byte[] rhs, final int length)
      {
          if (lhs.length < length || rhs.length < length)
          {
              return false;
          }
  
          for (int i = 0; i < length; i++)
          {
              if (lhs[i] != rhs[i])
              {
                  return false;
              }
          }
  
          return true;
      }
  
      static boolean byteSubsetEquals(final byte[] lhs, final String rhs)
      {
          final int length = rhs.length();
  
          if (lhs.length < length)
          {
              return false;
          }
  
          for (int i = 0; i < length; i++)
          {
              if (lhs[i] != rhs.charAt(i))
              {
                  return false;
              }
          }
  
          return true;
      }
  
      private int findEntryIndexByNameAndType(final byte[] name, final int nameLength, final byte type)
      {
          for (int i = 0; i < entries.size(); i++)
          {
              final CacheEntry entry = entries.get(i);
  
              if (type == entry.type && byteSubsetEquals(entry.name, name, nameLength))
              {
                  return i;
              }
          }
  
          return INVALID_INDEX;
      }
  
      private int findEntryIndexByNameAndType(final String name, final byte type)
      {
          for (int i = 0; i < entries.size(); i++)
          {
              final CacheEntry entry = entries.get(i);
  
              if (type == entry.type && byteSubsetEquals(entry.name, name))
              {
                  return i;
              }
          }
  
          return INVALID_INDEX;
      }
  
      static final class CacheEntry
      {
          long deadlineMs;
          long timeOfLastActivityMs;
          int port;
          final byte type;
          final byte[] name;
          byte[] address;
  
          CacheEntry(
              final byte[] name,
              final byte type,
              final long timeOfLastActivityMs,
              final long deadlineMs,
              final byte[] address,
              final int port)
          {
              this.name = name;
              this.type = type;
              this.timeOfLastActivityMs = timeOfLastActivityMs;
              this.deadlineMs = deadlineMs;
              this.address = address;
              this.port = port;
          }
      }
  }
  