Optimize OAuthSignatureCalculator , close #1333

Motivation:

* `ThreadSafeHMAC` is synchronized. `NONCE_BUFFER` uses a
`ThreadLocal`, why not use a global one so Mac doesn't need
synchronization?
* `OAuthParameterSet. sortAndConcat` allocates a `StringBuilder`
* `OAuthParameterSet. sortAndConcat` allocates a an Array.

Modifications:

* Introduce OAuthSignatureCalculatorInstance and have
OAuthSignatureCalculator delegate
* Use `Collections.sort` to sort parameters

Result:

Less allocation. No more synchronized block.

Author: slandelle

client/src/main/java/org/asynchttpclient/oauth/OAuthSignatureCalculator.java

@@ -13,300 +13,47 @@
  */
 package org.asynchttpclient.oauth;
 
-import static java.nio.charset.StandardCharsets.UTF_8;
-import static org.asynchttpclient.util.MiscUtils.isNonEmpty;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
 
-import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.concurrent.ThreadLocalRandom;
-import java.util.regex.Pattern;
-
-import org.asynchttpclient.Param;
 import org.asynchttpclient.Request;
 import org.asynchttpclient.RequestBuilderBase;
 import org.asynchttpclient.SignatureCalculator;
-import org.asynchttpclient.uri.Uri;
-import org.asynchttpclient.util.Base64;
-import org.asynchttpclient.util.StringUtils;
-import org.asynchttpclient.util.Utf8UrlEncoder;
 
 /**
- * Simple OAuth signature calculator that can used for constructing client signatures for accessing services that use OAuth for authorization. <br>
- * Supports most common signature inclusion and calculation methods: HMAC-SHA1 for calculation, and Header inclusion as inclusion method. Nonce generation uses simple random
- * numbers with base64 encoding.
- *
- * @author tatu (tatu.saloranta@iki.fi)
+ * OAuth {@link SignatureCalculator} that delegates to {@link OAuthSignatureCalculatorInstance}s.
  */
 public class OAuthSignatureCalculator implements SignatureCalculator {
-    public final static String HEADER_AUTHORIZATION = "Authorization";
-
-    private static final String KEY_OAUTH_CONSUMER_KEY = "oauth_consumer_key";
-    private static final String KEY_OAUTH_NONCE = "oauth_nonce";
-    private static final String KEY_OAUTH_SIGNATURE = "oauth_signature";
-    private static final String KEY_OAUTH_SIGNATURE_METHOD = "oauth_signature_method";
-    private static final String KEY_OAUTH_TIMESTAMP = "oauth_timestamp";
-    private static final String KEY_OAUTH_TOKEN = "oauth_token";
-    private static final String KEY_OAUTH_VERSION = "oauth_version";
 
-    private static final String OAUTH_VERSION_1_0 = "1.0";
-    private static final String OAUTH_SIGNATURE_METHOD = "HMAC-SHA1";
-
-    protected static final ThreadLocal<byte[]> NONCE_BUFFER = new ThreadLocal<byte[]>() {
-        protected byte[] initialValue() {
-            return new byte[16];
-        }
+    private static final ThreadLocal<OAuthSignatureCalculatorInstance> INSTANCES = new ThreadLocal<OAuthSignatureCalculatorInstance>() {
+        protected OAuthSignatureCalculatorInstance initialValue() {
+            try {
+                return new OAuthSignatureCalculatorInstance();
+            } catch (NoSuchAlgorithmException e) {
+                throw new ExceptionInInitializerError(e);
+            }
+        };
     };
 
-    protected final ThreadSafeHMAC mac;
-
-    protected final ConsumerKey consumerAuth;
+    private final ConsumerKey consumerAuth;
 
-    protected final RequestToken userAuth;
+    private final RequestToken userAuth;
 
     /**
      * @param consumerAuth Consumer key to use for signature calculation
      * @param userAuth Request/access token to use for signature calculation
      */
     public OAuthSignatureCalculator(ConsumerKey consumerAuth, RequestToken userAuth) {
-        mac = new ThreadSafeHMAC(consumerAuth, userAuth);
         this.consumerAuth = consumerAuth;
         this.userAuth = userAuth;
     }
 
     @Override
     public void calculateAndAddSignature(Request request, RequestBuilderBase<?> requestBuilder) {
-        String nonce = generateNonce();
-        long timestamp = generateTimestamp();
-        String signature = calculateSignature(request, timestamp, nonce);
-        String headerValue = constructAuthHeader(signature, nonce, timestamp);
-        requestBuilder.setHeader(HEADER_AUTHORIZATION, headerValue);
-    }
-
-    private String encodedParams(long oauthTimestamp, String nonce, List<Param> formParams, List<Param> queryParams) {
-        /**
-         * List of all query and form parameters added to this request; needed for calculating request signature
-         */
-        int allParametersSize = 5 + (userAuth.getKey() != null ? 1 : 0) + (formParams != null ? formParams.size() : 0) + (queryParams != null ? queryParams.size() : 0);
-        OAuthParameterSet allParameters = new OAuthParameterSet(allParametersSize);
-
-        // start with standard OAuth parameters we need
-        allParameters.add(KEY_OAUTH_CONSUMER_KEY, Utf8UrlEncoder.percentEncodeQueryElement(consumerAuth.getKey()));
-        allParameters.add(KEY_OAUTH_NONCE, Utf8UrlEncoder.percentEncodeQueryElement(nonce));
-        allParameters.add(KEY_OAUTH_SIGNATURE_METHOD, OAUTH_SIGNATURE_METHOD);
-        allParameters.add(KEY_OAUTH_TIMESTAMP, String.valueOf(oauthTimestamp));
-        if (userAuth.getKey() != null) {
-            allParameters.add(KEY_OAUTH_TOKEN, Utf8UrlEncoder.percentEncodeQueryElement(userAuth.getKey()));
-        }
-        allParameters.add(KEY_OAUTH_VERSION, OAUTH_VERSION_1_0);
-
-        if (formParams != null) {
-            for (Param param : formParams) {
-                // formParams are not already encoded
-                allParameters.add(Utf8UrlEncoder.percentEncodeQueryElement(param.getName()), Utf8UrlEncoder.percentEncodeQueryElement(param.getValue()));
-            }
-        }
-        if (queryParams != null) {
-            for (Param param : queryParams) {
-                // queryParams are already form-url-encoded
-                // but OAuth1 uses RFC3986_UNRESERVED_CHARS so * and + have to be encoded
-                allParameters.add(percentEncodeAlreadyFormUrlEncoded(param.getName()), percentEncodeAlreadyFormUrlEncoded(param.getValue()));
-            }
-        }
-        return allParameters.sortAndConcat();
-    }
-
-    private String baseUrl(Uri uri) {
-        /*
-         * 07-Oct-2010, tatu: URL may contain default port number; if so, need to remove from base URL.
-         */
-        String scheme = uri.getScheme();
-
-        StringBuilder sb = StringUtils.stringBuilder();
-        sb.append(scheme).append("://").append(uri.getHost());
-
-        int port = uri.getPort();
-        if (scheme.equals("http")) {
-            if (port == 80)
-                port = -1;
-        } else if (scheme.equals("https")) {
-            if (port == 443)
-                port = -1;
-        }
-
-        if (port != -1)
-            sb.append(':').append(port);
-
-        if (isNonEmpty(uri.getPath()))
-            sb.append(uri.getPath());
-
-        return sb.toString();
-    }
-
-    private static final Pattern STAR_CHAR_PATTERN = Pattern.compile("*", Pattern.LITERAL);
-    private static final Pattern PLUS_CHAR_PATTERN = Pattern.compile("+", Pattern.LITERAL);
-    private static final Pattern ENCODED_TILDE_PATTERN = Pattern.compile("%7E", Pattern.LITERAL);
-
-    private String percentEncodeAlreadyFormUrlEncoded(String s) {
-        s = STAR_CHAR_PATTERN.matcher(s).replaceAll("%2A");
-        s = PLUS_CHAR_PATTERN.matcher(s).replaceAll("%20");
-        s = ENCODED_TILDE_PATTERN.matcher(s).replaceAll("~");
-        return s;
-    }
-
-    StringBuilder signatureBaseString(Request request, long oauthTimestamp, String nonce) {
-
-        // beware: must generate first as we're using pooled StringBuilder
-        String baseUrl = baseUrl(request.getUri());
-        String encodedParams = encodedParams(oauthTimestamp, nonce, request.getFormParams(), request.getQueryParams());
-
-        StringBuilder sb = StringUtils.stringBuilder();
-        sb.append(request.getMethod()); // POST / GET etc (nothing to URL encode)
-        sb.append('&');
-        Utf8UrlEncoder.encodeAndAppendPercentEncoded(sb, baseUrl);
-
-        // and all that needs to be URL encoded (... again!)
-        sb.append('&');
-        Utf8UrlEncoder.encodeAndAppendPercentEncoded(sb, encodedParams);
-        return sb;
-    }
-
-    String calculateSignature(Request request, long oauthTimestamp, String nonce) {
-
-        StringBuilder sb = signatureBaseString(request, oauthTimestamp, nonce);
-
-        ByteBuffer rawBase = StringUtils.charSequence2ByteBuffer(sb, UTF_8);
-        byte[] rawSignature = mac.digest(rawBase);
-        // and finally, base64 encoded... phew!
-        return Base64.encode(rawSignature);
-    }
-
-    String constructAuthHeader(String signature, String nonce, long oauthTimestamp) {
-        StringBuilder sb = StringUtils.stringBuilder();
-        sb.append("OAuth ");
-        sb.append(KEY_OAUTH_CONSUMER_KEY).append("=\"").append(consumerAuth.getKey()).append("\", ");
-        if (userAuth.getKey() != null) {
-            sb.append(KEY_OAUTH_TOKEN).append("=\"").append(userAuth.getKey()).append("\", ");
-        }
-        sb.append(KEY_OAUTH_SIGNATURE_METHOD).append("=\"").append(OAUTH_SIGNATURE_METHOD).append("\", ");
-
-        // careful: base64 has chars that need URL encoding:
-        sb.append(KEY_OAUTH_SIGNATURE).append("=\"");
-        Utf8UrlEncoder.encodeAndAppendPercentEncoded(sb, signature).append("\", ");
-        sb.append(KEY_OAUTH_TIMESTAMP).append("=\"").append(oauthTimestamp).append("\", ");
-
-        // also: nonce may contain things that need URL encoding (esp. when using base64):
-        sb.append(KEY_OAUTH_NONCE).append("=\"");
-        Utf8UrlEncoder.encodeAndAppendPercentEncoded(sb, nonce);
-        sb.append("\", ");
-
-        sb.append(KEY_OAUTH_VERSION).append("=\"").append(OAUTH_VERSION_1_0).append("\"");
-        return sb.toString();
-    }
-
-    long generateTimestamp() {
-        return System.currentTimeMillis() / 1000L;
-    }
-
-    String generateNonce() {
-        byte[] nonceBuffer = NONCE_BUFFER.get();
-        ThreadLocalRandom.current().nextBytes(nonceBuffer);
-        // let's use base64 encoding over hex, slightly more compact than hex or decimals
-        return Base64.encode(nonceBuffer);
-        // return String.valueOf(Math.abs(random.nextLong()));
-    }
-
-    /**
-     * Container for parameters used for calculating OAuth signature. About the only confusing aspect is that of whether entries are to be sorted before encoded or vice versa: if
-     * my reading is correct, encoding is to occur first, then sorting; although this should rarely matter (since sorting is primary by key, which usually has nothing to encode)...
-     * of course, rarely means that when it would occur it'd be harder to track down.
-     */
-    final static class OAuthParameterSet {
-        private final ArrayList<Parameter> allParameters;
-
-        public OAuthParameterSet(int size) {
-            allParameters = new ArrayList<>(size);
-        }
-
-        public OAuthParameterSet add(String key, String value) {
-            allParameters.add(new Parameter(key, value));
-            return this;
-        }
-
-        public String sortAndConcat() {
-            // then sort them (AFTER encoding, important)
-            Parameter[] params = allParameters.toArray(new Parameter[allParameters.size()]);
-            Arrays.sort(params);
-
-            // and build parameter section using pre-encoded pieces:
-            StringBuilder encodedParams = new StringBuilder(100);
-            for (Parameter param : params) {
-                if (encodedParams.length() > 0) {
-                    encodedParams.append('&');
-                }
-                encodedParams.append(param.key()).append('=').append(param.value());
-            }
-            return encodedParams.toString();
-        }
-    }
-
-    /**
-     * Helper class for sorting query and form parameters that we need
-     */
-    final static class Parameter implements Comparable<Parameter> {
-
-        private final String key, value;
-
-        public Parameter(String key, String value) {
-            this.key = key;
-            this.value = value;
-        }
-
-        public String key() {
-            return key;
-        }
-
-        public String value() {
-            return value;
-        }
-
-        @Override
-        public int compareTo(Parameter other) {
-            int diff = key.compareTo(other.key);
-            if (diff == 0) {
-                diff = value.compareTo(other.value);
-            }
-            return diff;
-        }
-
-        @Override
-        public String toString() {
-            return key + "=" + value;
-        }
-
-        @Override
-        public boolean equals(Object o) {
-            if (this == o)
-                return true;
-            if (o == null || getClass() != o.getClass())
-                return false;
-
-            Parameter parameter = (Parameter) o;
-
-            if (!key.equals(parameter.key))
-                return false;
-            if (!value.equals(parameter.value))
-                return false;
-
-            return true;
-        }
-
-        @Override
-        public int hashCode() {
-            int result = key.hashCode();
-            result = 31 * result + value.hashCode();
-            return result;
+        try {
+            INSTANCES.get().sign(consumerAuth, userAuth, request, requestBuilder);
+        } catch (InvalidKeyException e) {
+            throw new IllegalArgumentException("Failed to compute a valid key from consumer and user secrets", e);
         }
     }
 }