Setting up a checksum on user and team instances to lower connection delay

diff --git a/src/main/java/com/gitblit/auth/AuthenticationProvider.java b/src/main/java/com/gitblit/auth/AuthenticationProvider.java
index 29051df81acc8b6f87a45bf46d8cb76cc1f84ad9..6205fd75903df5e481b0168aac1b1e91d9342a71 100644 (file)
--- a/src/main/java/com/gitblit/auth/AuthenticationProvider.java
+++ b/src/main/java/com/gitblit/auth/AuthenticationProvider.java
@@ -15,7 +15,13 @@
  */
 package com.gitblit.auth;
 
+import java.io.ByteArrayOutputStream;
 import java.io.File;
+import java.io.IOException;
+import java.io.ObjectOutputStream;
+import java.math.BigInteger;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -77,25 +83,70 @@ public abstract class AuthenticationProvider {
                }
        }
 
-       protected void updateUser(UserModel userModel) {
-               // TODO implement user model change detection
-               // account for new user and revised user
+       /**
+        * Utility method to calculate the checksum of an object.
+        * @param sourceObject The object from which to establish the checksum.
+        * @return The checksum
+        * @throws IOException
+        * @throws NoSuchAlgorithmException
+        */
+       private BigInteger checksum(Object sourceObject) throws IOException, NoSuchAlgorithmException {
 
-               // username
-               // displayname
-               // email address
-               // cookie
+           if (sourceObject == null) {
+             return BigInteger.ZERO;   
+           }
 
-               userManager.updateUserModel(userModel);
-       }
+           ByteArrayOutputStream baos = new ByteArrayOutputStream();
+           ObjectOutputStream oos = new ObjectOutputStream(baos);
+           oos.writeObject(sourceObject);
+           oos.close();
 
-       protected void updateTeam(TeamModel teamModel) {
-               // TODO implement team model change detection
-               // account for new team and revised team
+           MessageDigest m = MessageDigest.getInstance("SHA1");
+           m.update(baos.toByteArray());
 
-               // memberships
+           return new BigInteger(1, m.digest());
+       }
+       
+       protected void updateUser(UserModel userModel) {
+               final UserModel userLocalDB = userManager.getUserModel(userModel.getName());
+               try {
+                       // Establish the checksum of the current version of the user
+                       final BigInteger userCurrentCheck = checksum(userModel);
+                       // Establish the checksum of the stored version of the user
+                       final BigInteger userLocalDBcheck = checksum(userLocalDB);
+                       // Compare the checksums
+                       if (!userCurrentCheck.equals(userLocalDBcheck))
+                       {
+                               // If mismatch, save the new instance.
+                               userManager.updateUserModel(userModel);
+                       }
+               } catch (NoSuchAlgorithmException | IOException e) {
+                       // Trace any potential error.
+                       if (logger.isErrorEnabled()) {
+                               logger.error(e.getMessage());
+                       }
+               }
+       }
 
-               userManager.updateTeamModel(teamModel);
+       protected void updateTeam(TeamModel teamModel) {
+               final TeamModel teamLocalDB = userManager.getTeamModel(teamModel.name);
+               try {
+                       // Establish the checksum of the current version of the team
+                       final BigInteger teamCurrentCheck = checksum(teamModel);
+                       // Establish the checksum of the stored version of the team
+                       final BigInteger teamLocalDBcheck = checksum(teamLocalDB);
+                       // Compare the checksums
+                       if (!teamCurrentCheck.equals(teamLocalDBcheck))
+                       {
+                               // If mismatch, save the new instance.
+                               userManager.updateTeamModel(teamModel);
+                       }
+               } catch (NoSuchAlgorithmException | IOException e) {
+                       // Trace any potential error.
+                       if (logger.isErrorEnabled()) {
+                               logger.error(e.getMessage());
+                       }
+               }
        }
 
        public abstract void setup();