materialize the manytomany relationship to have better control over queries

src/main/java/com/commafeed/backend/model/Feed.java

@@ -4,11 +4,10 @@ import java.util.Date;
 import java.util.Set;
 
 import javax.persistence.Cacheable;
+import javax.persistence.CascadeType;
 import javax.persistence.Column;
 import javax.persistence.Entity;
-import javax.persistence.ManyToMany;
 import javax.persistence.OneToMany;
-import javax.persistence.PreRemove;
 import javax.persistence.Table;
 import javax.persistence.Temporal;
 import javax.persistence.TemporalType;
@@ -17,8 +16,6 @@ import javax.persistence.Transient;
 import org.hibernate.annotations.Cache;
 import org.hibernate.annotations.CacheConcurrencyStrategy;
 
-import com.google.common.collect.Sets;
-
 @Entity
 @Table(name = "FEEDS")
 @SuppressWarnings("serial")
@@ -111,8 +108,8 @@ public class Feed extends AbstractModel {
 	@Column(length = 40)
 	private String lastContentHash;
 
-	@ManyToMany(mappedBy = "feeds")
-	private Set<FeedEntry> entries = Sets.newHashSet();
+	@OneToMany(mappedBy = "feed", cascade = CascadeType.REMOVE)
+	private Set<FeedFeedEntry> entryRelationships;
 
 	@OneToMany(mappedBy = "feed")
 	private Set<FeedSubscription> subscriptions;
@@ -145,13 +142,6 @@ public class Feed extends AbstractModel {
 	@Transient
 	private boolean urgent;
 
-	@PreRemove
-	private void removeEntriesFromFeed() {
-		for (FeedEntry entry : entries) {
-			entry.getFeeds().remove(this);
-		}
-	}
-
 	public Feed() {
 
 	}
@@ -176,14 +166,6 @@ public class Feed extends AbstractModel {
 		this.lastUpdated = lastUpdated;
 	}
 
-	public Set<FeedEntry> getEntries() {
-		return entries;
-	}
-
-	public void setEntries(Set<FeedEntry> entries) {
-		this.entries = entries;
-	}
-
 	public String getMessage() {
 		return message;
 	}
@@ -344,4 +326,12 @@ public class Feed extends AbstractModel {
 		this.normalizedUrlHash = normalizedUrlHash;
 	}
 
+	public Set<FeedFeedEntry> getEntryRelationships() {
+		return entryRelationships;
+	}
+
+	public void setEntryRelationships(Set<FeedFeedEntry> entryRelationships) {
+		this.entryRelationships = entryRelationships;
+	}
+
 }

src/main/java/com/commafeed/backend/model/FeedEntry.java

@@ -9,8 +9,6 @@ import javax.persistence.Column;
 import javax.persistence.Entity;
 import javax.persistence.FetchType;
 import javax.persistence.JoinColumn;
-import javax.persistence.JoinTable;
-import javax.persistence.ManyToMany;
 import javax.persistence.OneToMany;
 import javax.persistence.OneToOne;
 import javax.persistence.Table;
@@ -20,8 +18,6 @@ import javax.persistence.TemporalType;
 import org.hibernate.annotations.Cache;
 import org.hibernate.annotations.CacheConcurrencyStrategy;
 
-import com.google.api.client.util.Sets;
-
 @Entity
 @Table(name = "FEEDENTRIES")
 @SuppressWarnings("serial")
@@ -35,9 +31,8 @@ public class FeedEntry extends AbstractModel {
 	@Column(length = 40, nullable = false)
 	private String guidHash;
 
-	@ManyToMany
-	@JoinTable(name = "FEED_FEEDENTRIES", joinColumns = { @JoinColumn(name = "FEEDENTRY_ID", nullable = false, updatable = false) }, inverseJoinColumns = { @JoinColumn(name = "FEED_ID", nullable = false, updatable = false) })
-	private Set<Feed> feeds = Sets.newHashSet();
+	@OneToMany(mappedBy = "entry", cascade = CascadeType.REMOVE)
+	private Set<FeedFeedEntry> feedRelationships;
 
 	@OneToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY, optional = false)
 	@JoinColumn(nullable = false, updatable = false)
@@ -82,14 +77,6 @@ public class FeedEntry extends AbstractModel {
 		this.updated = updated;
 	}
 
-	public Set<Feed> getFeeds() {
-		return feeds;
-	}
-
-	public void setFeeds(Set<Feed> feeds) {
-		this.feeds = feeds;
-	}
-
 	public Set<FeedEntryStatus> getStatuses() {
 		return statuses;
 	}
@@ -130,4 +117,12 @@ public class FeedEntry extends AbstractModel {
 		this.author = author;
 	}
 
+	public Set<FeedFeedEntry> getFeedRelationships() {
+		return feedRelationships;
+	}
+
+	public void setFeedRelationships(Set<FeedFeedEntry> feedRelationships) {
+		this.feedRelationships = feedRelationships;
+	}
+
 }

src/main/java/com/commafeed/backend/model/FeedFeedEntry.java

@@ -0,0 +1,57 @@
+package com.commafeed.backend.model;
+
+import java.io.Serializable;
+
+import javax.persistence.Cacheable;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+import javax.persistence.Table;
+
+import org.hibernate.annotations.Cache;
+import org.hibernate.annotations.CacheConcurrencyStrategy;
+
+@Entity
+@Table(name = "FEED_FEEDENTRIES")
+@SuppressWarnings("serial")
+@Cacheable
+@Cache(usage = CacheConcurrencyStrategy.TRANSACTIONAL)
+public class FeedFeedEntry implements Serializable {
+
+	@Id
+	@ManyToOne
+	@JoinColumn(name = "FEED_ID")
+	private Feed feed;
+
+	@Id
+	@ManyToOne
+	@JoinColumn(name = "FEEDENTRY_ID")
+	private FeedEntry entry;
+
+	public FeedFeedEntry() {
+
+	}
+
+	public FeedFeedEntry(Feed feed, FeedEntry entry) {
+		this.feed = feed;
+		this.entry = entry;
+	}
+
+	public Feed getFeed() {
+		return feed;
+	}
+
+	public void setFeed(Feed feed) {
+		this.feed = feed;
+	}
+
+	public FeedEntry getEntry() {
+		return entry;
+	}
+
+	public void setEntry(FeedEntry entry) {
+		this.entry = entry;
+	}
+
+}