Merge pull request #1234 from square/jw/musings

Remove some needless allocations.

okhttp/src/main/java/com/squareup/okhttp/ConnectionPool.java

@@ -109,8 +109,8 @@ public final class ConnectionPool {
           }
         }
       }
-      for (Connection expiredConnection : expiredConnections) {
-        Util.closeQuietly(expiredConnection.getSocket());
+      for (int i = 0, size = expiredConnections.size(); i < size; i++) {
+        Util.closeQuietly(expiredConnections.get(i).getSocket());
       }
     }
   };

okhttp/src/main/java/com/squareup/okhttp/ConnectionSpec.java

@@ -149,10 +149,10 @@ public final class ConnectionSpec {
    * supported by {@code sslSocket}.
    */
   private ConnectionSpec supportedSpec(SSLSocket sslSocket) {
-    List<String> supportedCipherSuites = Util.intersect(Arrays.asList(cipherSuites),
-        Arrays.asList(sslSocket.getSupportedCipherSuites()));
-    List<String> supportedTlsVersions = Util.intersect(Arrays.asList(tlsVersions),
-        Arrays.asList(sslSocket.getSupportedProtocols()));
+    List<String> supportedCipherSuites =
+        Util.intersect(cipherSuites, sslSocket.getSupportedCipherSuites());
+    List<String> supportedTlsVersions =
+        Util.intersect(tlsVersions, sslSocket.getSupportedProtocols());
     return new Builder(this)
         .cipherSuites(supportedCipherSuites.toArray(new String[supportedCipherSuites.size()]))
         .tlsVersions(supportedTlsVersions.toArray(new String[supportedTlsVersions.size()]))

okhttp/src/main/java/com/squareup/okhttp/internal/Util.java

@@ -30,7 +30,6 @@ import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -270,16 +269,19 @@ public final class Util {
   }
 
   /**
-   * Returns a copy of {@code a} containing only elements also in {@code b}. The returned elements
-   * are in the same order as in {@code a}.
+   * Returns a mutable copy of {@code first} containing only elements also in {@code second}. The
+   * returned elements are in the same order as in {@code first}.
    */
-  public static <T> List<T> intersect(Collection<T> a, Collection<T> b) {
+  public static <T> List<T> intersect(T[] first, T[] second) {
     List<T> result = new ArrayList<>();
-    for (T t : a) {
-      if (b.contains(t)) {
-        result.add(t);
+    for (T a : first) {
+      for (T b : second) {
+        if (a.equals(b)) {
+          result.add(b);
+          break;
+        }
       }
     }
-    return Collections.unmodifiableList(result);
+    return result;
   }
 }

okhttp/src/main/java/com/squareup/okhttp/internal/http/RouteSelector.java

@@ -309,7 +309,9 @@ public final class RouteSelector {
   /** Prepares the connection specs to attempt. */
   private void resetConnectionSpecs() {
     connectionSpecs = new ArrayList<>();
-    for (ConnectionSpec spec : address.getConnectionSpecs()) {
+    List<ConnectionSpec> specs = address.getConnectionSpecs();
+    for (int i = 0, size = specs.size(); i < size; i++) {
+      ConnectionSpec spec = specs.get(i);
       if (request.isHttps() == spec.isTls()) {
         connectionSpecs.add(spec);
       }

okhttp/src/main/java/com/squareup/okhttp/internal/tls/OkHostnameVerifier.java

@@ -82,8 +82,9 @@ public final class OkHostnameVerifier implements HostnameVerifier {
    * Returns true if {@code certificate} matches {@code ipAddress}.
    */
   private boolean verifyIpAddress(String ipAddress, X509Certificate certificate) {
-    for (String altName : getSubjectAltNames(certificate, ALT_IPA_NAME)) {
-      if (ipAddress.equalsIgnoreCase(altName)) {
+    List<String> altNames = getSubjectAltNames(certificate, ALT_IPA_NAME);
+    for (int i = 0, size = altNames.size(); i < size; i++) {
+      if (ipAddress.equalsIgnoreCase(altNames.get(i))) {
         return true;
       }
     }
@@ -96,9 +97,10 @@ public final class OkHostnameVerifier implements HostnameVerifier {
   private boolean verifyHostName(String hostName, X509Certificate certificate) {
     hostName = hostName.toLowerCase(Locale.US);
     boolean hasDns = false;
-    for (String altName : getSubjectAltNames(certificate, ALT_DNS_NAME)) {
+    List<String> altNames = getSubjectAltNames(certificate, ALT_DNS_NAME);
+    for (int i = 0, size = altNames.size(); i < size; i++) {
       hasDns = true;
-      if (verifyHostName(hostName, altName)) {
+      if (verifyHostName(hostName, altNames.get(i))) {
         return true;
       }
     }
@@ -116,9 +118,11 @@ public final class OkHostnameVerifier implements HostnameVerifier {
   }
 
   public static List<String> allSubjectAltNames(X509Certificate certificate) {
-    List<String> result = new ArrayList<>();
-    result.addAll(getSubjectAltNames(certificate, ALT_IPA_NAME));
-    result.addAll(getSubjectAltNames(certificate, ALT_DNS_NAME));
+    List<String> altIpaNames = getSubjectAltNames(certificate, ALT_IPA_NAME);
+    List<String> altDnsNames = getSubjectAltNames(certificate, ALT_DNS_NAME);
+    List<String> result = new ArrayList<>(altIpaNames.size() + altDnsNames.size());
+    result.addAll(altIpaNames);
+    result.addAll(altDnsNames);
     return result;
   }