gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/Change.java - gerrit - Git at Google

 // Copyright (C) 2008 The Android Open Source Project
 //
 // 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
 //
 // http://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 com.google.gerrit.reviewdb.client;

 import static com.google.gerrit.reviewdb.client.RefNames.REFS_CHANGES;

 import com.google.gerrit.extensions.client.ChangeStatus;
 import com.google.gwtorm.client.Column;
 import com.google.gwtorm.client.IntKey;
 import com.google.gwtorm.client.RowVersion;
 import com.google.gwtorm.client.StringKey;

 import java.sql.Timestamp;
 import java.util.Arrays;

 /**
  * A change proposed to be merged into a {@link Branch}.
  * <p>
  * The data graph rooted below a Change can be quite complex:
  *
  * <pre>
  *   {@link Change}
  *     |
  *     +- {@link ChangeMessage}: &quot;cover letter&quot; or general comment.
  *     |
  *     +- {@link PatchSet}: a single variant of this change.
  *          |
  *          +- {@link PatchSetApproval}: a +/- vote on the change's current state.
  *          |
  *          +- {@link PatchSetAncestor}: parents of this change's commit.
  *          |
  *          +- {@link PatchLineComment}: comment about a specific line
  * </pre>
  * <p>
  * <h5>PatchSets</h5>
  * <p>
  * Every change has at least one PatchSet. A change starts out with one
  * PatchSet, the initial proposal put forth by the change owner. This
  * {@link Account} is usually also listed as the author and committer in the
  * PatchSetInfo.
  * <p>
  * The {@link PatchSetAncestor} entities are a mirror of the Git commit
  * metadata, providing access to the information without needing direct
  * accessing Git. These entities are actually legacy artifacts from Gerrit 1.x
  * and could be removed, replaced by direct RevCommit access.
  * <p>
  * Each PatchSet contains zero or more Patch records, detailing the file paths
  * impacted by the change (otherwise known as, the file paths the author
  * added/deleted/modified). Sometimes a merge commit can contain zero patches,
  * if the merge has no conflicts, or has no impact other than to cut off a line
  * of development.
  * <p>
  * Each PatchLineComment is a draft or a published comment about a single line
  * of the associated file. These are the inline comment entities created by
  * users as they perform a review.
  * <p>
  * When additional PatchSets appear under a change, these PatchSets reference
  * <i>replacement</i> commits; alternative commits that could be made to the
  * project instead of the original commit referenced by the first PatchSet.
  * <p>
  * A change has at most one current PatchSet. The current PatchSet is updated
  * when a new replacement PatchSet is uploaded. When a change is submitted, the
  * current patch set is what is merged into the destination branch.
  * <p>
  * <h5>ChangeMessage</h5>
  * <p>
  * The ChangeMessage entity is a general free-form comment about the whole
  * change, rather than PatchLineComment's file and line specific context. The
  * ChangeMessage appears at the start of any email generated by Gerrit, and is
  * shown on the change overview page, rather than in a file-specific context.
  * Users often use this entity to describe general remarks about the overall
  * concept proposed by the change.
  * <p>
  * <h5>PatchSetApproval</h5>
  * <p>
  * PatchSetApproval entities exist to fill in the <i>cells</i> of the approvals
  * table in the web UI. That is, a single PatchSetApproval record's key is the
  * tuple {@code (PatchSet,Account,ApprovalCategory)}. Each PatchSetApproval
  * carries with it a small score value, typically within the range -2..+2.
  * <p>
  * If an Account has created only PatchSetApprovals with a score value of 0, the
  * Change shows in their dashboard, and they are said to be CC'd (carbon copied)
  * on the Change, but are not a direct reviewer. This often happens when an
  * account was specified at upload time with the {@code --cc} command line flag,
  * or have published comments, but left the approval scores at 0 ("No Score").
  * <p>
  * If an Account has one or more PatchSetApprovals with a score != 0, the Change
  * shows in their dashboard, and they are said to be an active reviewer. Such
  * individuals are highlighted when notice of a replacement patch set is sent,
  * or when notice of the change submission occurs.
  */
 public final class Change {
   public static class Id extends IntKey<com.google.gwtorm.client.Key<?>> {
     private static final long serialVersionUID = 1L;

     @Column(id = 1)
     public int id;

     protected Id() {
     }

     public Id(final int id) {
       this.id = id;
     }

     @Override
     public int get() {
       return id;
     }

     @Override
     protected void set(int newValue) {
       id = newValue;
     }

     /** Parse a Change.Id out of a string representation. */
     public static Id parse(final String str) {
       final Id r = new Id();
       r.fromString(str);
       return r;
     }

     public static Id fromRef(String ref) {
       int cs = startIndex(ref);
       if (cs < 0) {
         return null;
       }
       int ce = nextNonDigit(ref, cs);
       if (ref.substring(ce).equals(RefNames.META_SUFFIX)
           || PatchSet.Id.fromRef(ref, ce) >= 0) {
         return new Change.Id(Integer.parseInt(ref.substring(cs, ce)));
       }
       return null;
     }

     static int startIndex(String ref) {
       if (ref == null || !ref.startsWith(REFS_CHANGES)) {
         return -1;
       }

       // Last 2 digits.
       int ls = REFS_CHANGES.length();
       int le = nextNonDigit(ref, ls);
       if (le - ls != 2 || le >= ref.length() || ref.charAt(le) != '/') {
         return -1;
       }

       // Change ID.
       int cs = le + 1;
       if (cs >= ref.length() || ref.charAt(cs) == '0') {
         return -1;
       }
       int ce = nextNonDigit(ref, cs);
       if (ce >= ref.length() || ref.charAt(ce) != '/') {
         return -1;
       }
       switch (ce - cs) {
         case 0:
           return -1;
         case 1:
           if (ref.charAt(ls) != '0'
               || ref.charAt(ls + 1) != ref.charAt(cs)) {
             return -1;
           }
           break;
         default:
           if (ref.charAt(ls) != ref.charAt(ce - 2)
               || ref.charAt(ls + 1) != ref.charAt(ce - 1)) {
             return -1;
           }
           break;
       }
       return cs;
     }

     static int nextNonDigit(String s, int i) {
       while (i < s.length() && s.charAt(i) >= '0' && s.charAt(i) <= '9') {
         i++;
       }
       return i;
     }
   }

   /** Globally unique identification of this change. */
   public static class Key extends StringKey<com.google.gwtorm.client.Key<?>> {
     private static final long serialVersionUID = 1L;

     @Column(id = 1, length = 60)
     protected String id;

     protected Key() {
     }

     public Key(final String id) {
       this.id = id;
     }

     @Override
     public String get() {
       return id;
     }

     @Override
     protected void set(String newValue) {
       id = newValue;
     }

     /** Construct a key that is after all keys prefixed by this key. */
     public Key max() {
       final StringBuilder revEnd = new StringBuilder(get().length() + 1);
       revEnd.append(get());
       revEnd.append('\u9fa5');
       return new Key(revEnd.toString());
     }

     /** Obtain a shorter version of this key string, using a leading prefix. */
     public String abbreviate() {
       final String s = get();
       return s.substring(0, Math.min(s.length(), 9));
     }

     /** Parse a Change.Key out of a string representation. */
     public static Key parse(final String str) {
       final Key r = new Key();
       r.fromString(str);
       return r;
     }
   }

   /** Minimum database status constant for an open change. */
   private static final char MIN_OPEN = 'a';
   /** Database constant for {@link Status#NEW}. */
   public static final char STATUS_NEW = 'n';
   /** Database constant for {@link Status#SUBMITTED}. */
   public static final char STATUS_SUBMITTED = 's';
   /** Database constant for {@link Status#DRAFT}. */
   public static final char STATUS_DRAFT = 'd';
   /** Maximum database status constant for an open change. */
   private static final char MAX_OPEN = 'z';

   /** Database constant for {@link Status#MERGED}. */
   public static final char STATUS_MERGED = 'M';

   /** ID number of the first patch set in a change. */
   public static final int INITIAL_PATCH_SET_ID = 1;

   /**
    * Current state within the basic workflow of the change.
    *
    * <p>
    * Within the database, lower case codes ('a'..'z') indicate a change that is
    * still open, and that can be modified/refined further, while upper case
    * codes ('A'..'Z') indicate a change that is closed and cannot be further
    * modified.
    * */
   public static enum Status {
     /**
      * Change is open and pending review, or review is in progress.
      *
      * <p>
      * This is the default state assigned to a change when it is first created
      * in the database. A change stays in the NEW state throughout its review
      * cycle, until the change is submitted or abandoned.
      *
      * <p>
      * Changes in the NEW state can be moved to:
      * <ul>
      * <li>{@link #SUBMITTED} - when the Submit Patch Set action is used;
      * <li>{@link #ABANDONED} - when the Abandon action is used.
      * </ul>
      */
     NEW(STATUS_NEW, ChangeStatus.NEW),

     /**
      * Change is open, but has been submitted to the merge queue.
      *
      * <p>
      * A change enters the SUBMITTED state when an authorized user presses the
      * "submit" action through the web UI, requesting that Gerrit merge the
      * change's current patch set into the destination branch.
      *
      * <p>
      * Typically a change resides in the SUBMITTED for only a brief sub-second
      * period while the merge queue fires and the destination branch is updated.
      * However, if a dependency commit (a {@link PatchSetAncestor}, directly or
      * transitively) is not yet merged into the branch, the change will hang in
      * the SUBMITTED state indefinitely.
      *
      * <p>
      * Changes in the SUBMITTED state can be moved to:
      * <ul>
      * <li>{@link #NEW} - when a replacement patch set is supplied, OR when a
      * merge conflict is detected;
      * <li>{@link #MERGED} - when the change has been successfully merged into
      * the destination branch;
      * <li>{@link #ABANDONED} - when the Abandon action is used.
      * </ul>
      */
     SUBMITTED(STATUS_SUBMITTED, ChangeStatus.SUBMITTED),

     /**
      * Change is a draft change that only consists of draft patchsets.
      *
      * <p>
      * This is a change that is not meant to be submitted or reviewed yet. If
      * the uploader publishes the change, it becomes a NEW change.
      * Publishing is a one-way action, a change cannot return to DRAFT status.
      * Draft changes are only visible to the uploader and those explicitly
      * added as reviewers.
      *
      * <p>
      * Changes in the DRAFT state can be moved to:
      * <ul>
      * <li>{@link #NEW} - when the change is published, it becomes a new change;
      * </ul>
      */
     DRAFT(STATUS_DRAFT, ChangeStatus.DRAFT),

     /**
      * Change is closed, and submitted to its destination branch.
      *
      * <p>
      * Once a change has been merged, it cannot be further modified by adding a
      * replacement patch set. Draft comments however may be published,
      * supporting a post-submit review.
      */
     MERGED(STATUS_MERGED, ChangeStatus.MERGED),

     /**
      * Change is closed, but was not submitted to its destination branch.
      *
      * <p>
      * Once a change has been abandoned, it cannot be further modified by adding
      * a replacement patch set, and it cannot be merged. Draft comments however
      * may be published, permitting reviewers to send constructive feedback.
      */
     ABANDONED('A', ChangeStatus.ABANDONED);

     static {
       boolean ok = true;
       if (Status.values().length != ChangeStatus.values().length) {
         ok = false;
       }
       for (Status s : Status.values()) {
         ok &= s.name().equals(s.changeStatus.name());
       }
       if (!ok) {
         throw new IllegalStateException("Mismatched status mapping: "
             + Arrays.asList(Status.values()) + " != "
             + Arrays.asList(ChangeStatus.values()));
       }
     }

     private final char code;
     private final boolean closed;
     private final ChangeStatus changeStatus;

     private Status(char c, ChangeStatus cs) {
       code = c;
       closed = !(MIN_OPEN <= c && c <= MAX_OPEN);
       changeStatus = cs;
     }

     public char getCode() {
       return code;
     }

     public boolean isOpen() {
       return !closed;
     }

     public boolean isClosed() {
       return closed;
     }

     public ChangeStatus asChangeStatus() {
       return changeStatus;
     }

     public static Status forCode(final char c) {
       for (final Status s : Status.values()) {
         if (s.code == c) {
           return s;
         }
       }
       return null;
     }

     public static Status forChangeStatus(ChangeStatus cs) {
       for (Status s : Status.values()) {
         if (s.changeStatus == cs) {
           return s;
         }
       }
       return null;
     }
   }

   /** Locally assigned unique identifier of the change */
   @Column(id = 1)
   protected Id changeId;

   /** Globally assigned unique identifier of the change */
   @Column(id = 2)
   protected Key changeKey;

   /** optimistic locking */
   @Column(id = 3)
   @RowVersion
   protected int rowVersion;

   /** When this change was first introduced into the database. */
   @Column(id = 4)
   protected Timestamp createdOn;

   /**
    * When was a meaningful modification last made to this record's data
    * <p>
    * Note, this update timestamp includes its children.
    */
   @Column(id = 5)
   protected Timestamp lastUpdatedOn;

   // DELETED: id = 6 (sortkey)

   @Column(id = 7, name = "owner_account_id")
   protected Account.Id owner;

   /** The branch (and project) this change merges into. */
   @Column(id = 8)
   protected Branch.NameKey dest;

   // DELETED: id = 9 (open)

   /** Current state code; see {@link Status}. */
   @Column(id = 10)
   protected char status;

   // DELETED: id = 11 (nbrPatchSets)

   /** The current patch set. */
   @Column(id = 12)
   protected int currentPatchSetId;

   /** Subject from the current patch set. */
   @Column(id = 13)
   protected String subject;

   /** Topic name assigned by the user, if any. */
   @Column(id = 14, notNull = false)
   protected String topic;

   // DELETED: id = 15 (lastSha1MergeTested)
   // DELETED: id = 16 (mergeable)

   /**
    * First line of first patch set's commit message.
    *
    * Unlike {@link #subject}, this string does not change if future patch sets
    * change the first line.
    */
   @Column(id = 17, notNull = false)
   protected String originalSubject;

   protected Change() {
   }

   public Change(Change.Key newKey, Change.Id newId, Account.Id ownedBy,
       Branch.NameKey forBranch, Timestamp ts) {
     changeKey = newKey;
     changeId = newId;
     createdOn = ts;
     lastUpdatedOn = createdOn;
     owner = ownedBy;
     dest = forBranch;
     setStatus(Status.NEW);
   }

   public Change(Change other) {
     changeId = other.changeId;
     changeKey = other.changeKey;
     rowVersion = other.rowVersion;
     createdOn = other.createdOn;
     lastUpdatedOn = other.lastUpdatedOn;
     owner = other.owner;
     dest = other.dest;
     status = other.status;
     currentPatchSetId = other.currentPatchSetId;
     subject = other.subject;
     originalSubject = other.originalSubject;
     topic = other.topic;
   }

   /** Legacy 32 bit integer identity for a change. */
   public Change.Id getId() {
     return changeId;
   }

   /** Legacy 32 bit integer identity for a change. */
   public int getChangeId() {
     return changeId.get();
   }

   /** The Change-Id tag out of the initial commit, or a natural key. */
   public Change.Key getKey() {
     return changeKey;
   }

   public void setKey(final Change.Key k) {
     changeKey = k;
   }

   public Timestamp getCreatedOn() {
     return createdOn;
   }

   public Timestamp getLastUpdatedOn() {
     return lastUpdatedOn;
   }

   public void setLastUpdatedOn(Timestamp now) {
     lastUpdatedOn = now;
   }

   public int getRowVersion() {
     return rowVersion;
   }

   public Account.Id getOwner() {
     return owner;
   }

   public Branch.NameKey getDest() {
     return dest;
   }

   public Project.NameKey getProject() {
     return dest.getParentKey();
   }

   public String getSubject() {
     return subject;
   }

   public String getOriginalSubject() {
     return originalSubject != null ? originalSubject : subject;
   }

   /** Get the id of the most current {@link PatchSet} in this change. */
   public PatchSet.Id currentPatchSetId() {
     if (currentPatchSetId > 0) {
       return new PatchSet.Id(changeId, currentPatchSetId);
     }
     return null;
   }

   public void setCurrentPatchSet(final PatchSetInfo ps) {
     if (originalSubject == null && subject != null) {
       // Change was created before schema upgrade. Use the last subject
       // associated with this change, as the most recent discussion will
       // be under that thread in an email client such as GMail.
       originalSubject = subject;
     }

     currentPatchSetId = ps.getKey().get();
     subject = ps.getSubject();

     if (originalSubject == null) {
       // Newly created changes remember the first commit's subject.
       originalSubject = subject;
     }
   }

   public Status getStatus() {
     return Status.forCode(status);
   }

   public void setStatus(Status newStatus) {
     status = newStatus.getCode();
   }

   public String getTopic() {
     return topic;
   }

   public void setTopic(String topic) {
     this.topic = topic;
   }

   @Override
   public String toString() {
     return new StringBuilder(getClass().getSimpleName())
         .append('{').append(changeId)
         .append(" (").append(changeKey).append("), ")
         .append("dest=").append(dest).append(", ")
         .append("status=").append(status).append('}')
         .toString();
   }
 }
	// Copyright (C) 2008 The Android Open Source Project
	//
	// 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
	//
	// http://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 com.google.gerrit.reviewdb.client;

	import static com.google.gerrit.reviewdb.client.RefNames.REFS_CHANGES;

	import com.google.gerrit.extensions.client.ChangeStatus;
	import com.google.gwtorm.client.Column;
	import com.google.gwtorm.client.IntKey;
	import com.google.gwtorm.client.RowVersion;
	import com.google.gwtorm.client.StringKey;

	import java.sql.Timestamp;
	import java.util.Arrays;

	/**
	* A change proposed to be merged into a {@link Branch}.
	* <p>
	* The data graph rooted below a Change can be quite complex:
	*
	* <pre>
	* {@link Change}
	* \|
	* +- {@link ChangeMessage}: "cover letter" or general comment.
	* \|
	* +- {@link PatchSet}: a single variant of this change.
	* \|
	* +- {@link PatchSetApproval}: a +/- vote on the change's current state.
	* \|
	* +- {@link PatchSetAncestor}: parents of this change's commit.
	* \|
	* +- {@link PatchLineComment}: comment about a specific line
	* </pre>
	* <p>
	* <h5>PatchSets</h5>
	* <p>
	* Every change has at least one PatchSet. A change starts out with one
	* PatchSet, the initial proposal put forth by the change owner. This
	* {@link Account} is usually also listed as the author and committer in the
	* PatchSetInfo.
	* <p>
	* The {@link PatchSetAncestor} entities are a mirror of the Git commit
	* metadata, providing access to the information without needing direct
	* accessing Git. These entities are actually legacy artifacts from Gerrit 1.x
	* and could be removed, replaced by direct RevCommit access.
	* <p>
	* Each PatchSet contains zero or more Patch records, detailing the file paths
	* impacted by the change (otherwise known as, the file paths the author
	* added/deleted/modified). Sometimes a merge commit can contain zero patches,
	* if the merge has no conflicts, or has no impact other than to cut off a line
	* of development.
	* <p>
	* Each PatchLineComment is a draft or a published comment about a single line
	* of the associated file. These are the inline comment entities created by
	* users as they perform a review.
	* <p>
	* When additional PatchSets appear under a change, these PatchSets reference
	* <i>replacement</i> commits; alternative commits that could be made to the
	* project instead of the original commit referenced by the first PatchSet.
	* <p>
	* A change has at most one current PatchSet. The current PatchSet is updated
	* when a new replacement PatchSet is uploaded. When a change is submitted, the
	* current patch set is what is merged into the destination branch.
	* <p>
	* <h5>ChangeMessage</h5>
	* <p>
	* The ChangeMessage entity is a general free-form comment about the whole
	* change, rather than PatchLineComment's file and line specific context. The
	* ChangeMessage appears at the start of any email generated by Gerrit, and is
	* shown on the change overview page, rather than in a file-specific context.
	* Users often use this entity to describe general remarks about the overall
	* concept proposed by the change.
	* <p>
	* <h5>PatchSetApproval</h5>
	* <p>
	* PatchSetApproval entities exist to fill in the <i>cells</i> of the approvals
	* table in the web UI. That is, a single PatchSetApproval record's key is the
	* tuple {@code (PatchSet,Account,ApprovalCategory)}. Each PatchSetApproval
	* carries with it a small score value, typically within the range -2..+2.
	* <p>
	* If an Account has created only PatchSetApprovals with a score value of 0, the
	* Change shows in their dashboard, and they are said to be CC'd (carbon copied)
	* on the Change, but are not a direct reviewer. This often happens when an
	* account was specified at upload time with the {@code --cc} command line flag,
	* or have published comments, but left the approval scores at 0 ("No Score").
	* <p>
	* If an Account has one or more PatchSetApprovals with a score != 0, the Change
	* shows in their dashboard, and they are said to be an active reviewer. Such
	* individuals are highlighted when notice of a replacement patch set is sent,
	* or when notice of the change submission occurs.
	*/
	public final class Change {
	public static class Id extends IntKey<com.google.gwtorm.client.Key<?>> {
	private static final long serialVersionUID = 1L;

	@Column(id = 1)
	public int id;

	protected Id() {
	}

	public Id(final int id) {
	this.id = id;
	}

	@Override
	public int get() {
	return id;
	}

	@Override
	protected void set(int newValue) {
	id = newValue;
	}

	/** Parse a Change.Id out of a string representation. */
	public static Id parse(final String str) {
	final Id r = new Id();
	r.fromString(str);
	return r;
	}

	public static Id fromRef(String ref) {
	int cs = startIndex(ref);
	if (cs < 0) {
	return null;
	}
	int ce = nextNonDigit(ref, cs);
	if (ref.substring(ce).equals(RefNames.META_SUFFIX)
	\|\| PatchSet.Id.fromRef(ref, ce) >= 0) {
	return new Change.Id(Integer.parseInt(ref.substring(cs, ce)));
	}
	return null;
	}

	static int startIndex(String ref) {
	if (ref == null \|\| !ref.startsWith(REFS_CHANGES)) {
	return -1;
	}

	// Last 2 digits.
	int ls = REFS_CHANGES.length();
	int le = nextNonDigit(ref, ls);
	if (le - ls != 2 \|\| le >= ref.length() \|\| ref.charAt(le) != '/') {
	return -1;
	}

	// Change ID.
	int cs = le + 1;
	if (cs >= ref.length() \|\| ref.charAt(cs) == '0') {
	return -1;
	}
	int ce = nextNonDigit(ref, cs);
	if (ce >= ref.length() \|\| ref.charAt(ce) != '/') {
	return -1;
	}
	switch (ce - cs) {
	case 0:
	return -1;
	case 1:
	if (ref.charAt(ls) != '0'
	\|\| ref.charAt(ls + 1) != ref.charAt(cs)) {
	return -1;
	}
	break;
	default:
	if (ref.charAt(ls) != ref.charAt(ce - 2)
	\|\| ref.charAt(ls + 1) != ref.charAt(ce - 1)) {
	return -1;
	}
	break;
	}
	return cs;
	}

	static int nextNonDigit(String s, int i) {
	while (i < s.length() && s.charAt(i) >= '0' && s.charAt(i) <= '9') {
	i++;
	}
	return i;
	}
	}

	/** Globally unique identification of this change. */
	public static class Key extends StringKey<com.google.gwtorm.client.Key<?>> {
	private static final long serialVersionUID = 1L;

	@Column(id = 1, length = 60)
	protected String id;

	protected Key() {
	}

	public Key(final String id) {
	this.id = id;
	}

	@Override
	public String get() {
	return id;
	}

	@Override
	protected void set(String newValue) {
	id = newValue;
	}

	/** Construct a key that is after all keys prefixed by this key. */
	public Key max() {
	final StringBuilder revEnd = new StringBuilder(get().length() + 1);
	revEnd.append(get());
	revEnd.append('\u9fa5');
	return new Key(revEnd.toString());
	}

	/** Obtain a shorter version of this key string, using a leading prefix. */
	public String abbreviate() {
	final String s = get();
	return s.substring(0, Math.min(s.length(), 9));
	}

	/** Parse a Change.Key out of a string representation. */
	public static Key parse(final String str) {
	final Key r = new Key();
	r.fromString(str);
	return r;
	}
	}

	/** Minimum database status constant for an open change. */
	private static final char MIN_OPEN = 'a';
	/** Database constant for {@link Status#NEW}. */
	public static final char STATUS_NEW = 'n';
	/** Database constant for {@link Status#SUBMITTED}. */
	public static final char STATUS_SUBMITTED = 's';
	/** Database constant for {@link Status#DRAFT}. */
	public static final char STATUS_DRAFT = 'd';
	/** Maximum database status constant for an open change. */
	private static final char MAX_OPEN = 'z';

	/** Database constant for {@link Status#MERGED}. */
	public static final char STATUS_MERGED = 'M';

	/** ID number of the first patch set in a change. */
	public static final int INITIAL_PATCH_SET_ID = 1;

	/**
	* Current state within the basic workflow of the change.
	*
	* <p>
	* Within the database, lower case codes ('a'..'z') indicate a change that is
	* still open, and that can be modified/refined further, while upper case
	* codes ('A'..'Z') indicate a change that is closed and cannot be further
	* modified.
	* */
	public static enum Status {
	/**
	* Change is open and pending review, or review is in progress.
	*
	* <p>
	* This is the default state assigned to a change when it is first created
	* in the database. A change stays in the NEW state throughout its review
	* cycle, until the change is submitted or abandoned.
	*
	* <p>
	* Changes in the NEW state can be moved to:
	* <ul>
	* <li>{@link #SUBMITTED} - when the Submit Patch Set action is used;
	* <li>{@link #ABANDONED} - when the Abandon action is used.
	* </ul>
	*/
	NEW(STATUS_NEW, ChangeStatus.NEW),

	/**
	* Change is open, but has been submitted to the merge queue.
	*
	* <p>
	* A change enters the SUBMITTED state when an authorized user presses the
	* "submit" action through the web UI, requesting that Gerrit merge the
	* change's current patch set into the destination branch.
	*
	* <p>
	* Typically a change resides in the SUBMITTED for only a brief sub-second
	* period while the merge queue fires and the destination branch is updated.
	* However, if a dependency commit (a {@link PatchSetAncestor}, directly or
	* transitively) is not yet merged into the branch, the change will hang in
	* the SUBMITTED state indefinitely.
	*
	* <p>
	* Changes in the SUBMITTED state can be moved to:
	* <ul>
	* <li>{@link #NEW} - when a replacement patch set is supplied, OR when a
	* merge conflict is detected;
	* <li>{@link #MERGED} - when the change has been successfully merged into
	* the destination branch;
	* <li>{@link #ABANDONED} - when the Abandon action is used.
	* </ul>
	*/
	SUBMITTED(STATUS_SUBMITTED, ChangeStatus.SUBMITTED),

	/**
	* Change is a draft change that only consists of draft patchsets.
	*
	* <p>
	* This is a change that is not meant to be submitted or reviewed yet. If
	* the uploader publishes the change, it becomes a NEW change.
	* Publishing is a one-way action, a change cannot return to DRAFT status.
	* Draft changes are only visible to the uploader and those explicitly
	* added as reviewers.
	*
	* <p>
	* Changes in the DRAFT state can be moved to:
	* <ul>
	* <li>{@link #NEW} - when the change is published, it becomes a new change;
	* </ul>
	*/
	DRAFT(STATUS_DRAFT, ChangeStatus.DRAFT),

	/**
	* Change is closed, and submitted to its destination branch.
	*
	* <p>
	* Once a change has been merged, it cannot be further modified by adding a
	* replacement patch set. Draft comments however may be published,
	* supporting a post-submit review.
	*/
	MERGED(STATUS_MERGED, ChangeStatus.MERGED),

	/**
	* Change is closed, but was not submitted to its destination branch.
	*
	* <p>
	* Once a change has been abandoned, it cannot be further modified by adding
	* a replacement patch set, and it cannot be merged. Draft comments however
	* may be published, permitting reviewers to send constructive feedback.
	*/
	ABANDONED('A', ChangeStatus.ABANDONED);

	static {
	boolean ok = true;
	if (Status.values().length != ChangeStatus.values().length) {
	ok = false;
	}
	for (Status s : Status.values()) {
	ok &= s.name().equals(s.changeStatus.name());
	}
	if (!ok) {
	throw new IllegalStateException("Mismatched status mapping: "
	+ Arrays.asList(Status.values()) + " != "
	+ Arrays.asList(ChangeStatus.values()));
	}
	}

	private final char code;
	private final boolean closed;
	private final ChangeStatus changeStatus;

	private Status(char c, ChangeStatus cs) {
	code = c;
	closed = !(MIN_OPEN <= c && c <= MAX_OPEN);
	changeStatus = cs;
	}

	public char getCode() {
	return code;
	}

	public boolean isOpen() {
	return !closed;
	}

	public boolean isClosed() {
	return closed;
	}

	public ChangeStatus asChangeStatus() {
	return changeStatus;
	}

	public static Status forCode(final char c) {
	for (final Status s : Status.values()) {
	if (s.code == c) {
	return s;
	}
	}
	return null;
	}

	public static Status forChangeStatus(ChangeStatus cs) {
	for (Status s : Status.values()) {
	if (s.changeStatus == cs) {
	return s;
	}
	}
	return null;
	}
	}

	/** Locally assigned unique identifier of the change */
	@Column(id = 1)
	protected Id changeId;

	/** Globally assigned unique identifier of the change */
	@Column(id = 2)
	protected Key changeKey;

	/** optimistic locking */
	@Column(id = 3)
	@RowVersion
	protected int rowVersion;

	/** When this change was first introduced into the database. */
	@Column(id = 4)
	protected Timestamp createdOn;

	/**
	* When was a meaningful modification last made to this record's data
	* <p>
	* Note, this update timestamp includes its children.
	*/
	@Column(id = 5)
	protected Timestamp lastUpdatedOn;

	// DELETED: id = 6 (sortkey)

	@Column(id = 7, name = "owner_account_id")
	protected Account.Id owner;

	/** The branch (and project) this change merges into. */
	@Column(id = 8)
	protected Branch.NameKey dest;

	// DELETED: id = 9 (open)

	/** Current state code; see {@link Status}. */
	@Column(id = 10)
	protected char status;

	// DELETED: id = 11 (nbrPatchSets)

	/** The current patch set. */
	@Column(id = 12)
	protected int currentPatchSetId;

	/** Subject from the current patch set. */
	@Column(id = 13)
	protected String subject;

	/** Topic name assigned by the user, if any. */
	@Column(id = 14, notNull = false)
	protected String topic;

	// DELETED: id = 15 (lastSha1MergeTested)
	// DELETED: id = 16 (mergeable)

	/**
	* First line of first patch set's commit message.
	*
	* Unlike {@link #subject}, this string does not change if future patch sets
	* change the first line.
	*/
	@Column(id = 17, notNull = false)
	protected String originalSubject;

	protected Change() {
	}

	public Change(Change.Key newKey, Change.Id newId, Account.Id ownedBy,
	Branch.NameKey forBranch, Timestamp ts) {
	changeKey = newKey;
	changeId = newId;
	createdOn = ts;
	lastUpdatedOn = createdOn;
	owner = ownedBy;
	dest = forBranch;
	setStatus(Status.NEW);
	}

	public Change(Change other) {
	changeId = other.changeId;
	changeKey = other.changeKey;
	rowVersion = other.rowVersion;
	createdOn = other.createdOn;
	lastUpdatedOn = other.lastUpdatedOn;
	owner = other.owner;
	dest = other.dest;
	status = other.status;
	currentPatchSetId = other.currentPatchSetId;
	subject = other.subject;
	originalSubject = other.originalSubject;
	topic = other.topic;
	}

	/** Legacy 32 bit integer identity for a change. */
	public Change.Id getId() {
	return changeId;
	}

	/** Legacy 32 bit integer identity for a change. */
	public int getChangeId() {
	return changeId.get();
	}

	/** The Change-Id tag out of the initial commit, or a natural key. */
	public Change.Key getKey() {
	return changeKey;
	}

	public void setKey(final Change.Key k) {
	changeKey = k;
	}

	public Timestamp getCreatedOn() {
	return createdOn;
	}

	public Timestamp getLastUpdatedOn() {
	return lastUpdatedOn;
	}

	public void setLastUpdatedOn(Timestamp now) {
	lastUpdatedOn = now;
	}

	public int getRowVersion() {
	return rowVersion;
	}

	public Account.Id getOwner() {
	return owner;
	}

	public Branch.NameKey getDest() {
	return dest;
	}

	public Project.NameKey getProject() {
	return dest.getParentKey();
	}

	public String getSubject() {
	return subject;
	}

	public String getOriginalSubject() {
	return originalSubject != null ? originalSubject : subject;
	}

	/** Get the id of the most current {@link PatchSet} in this change. */
	public PatchSet.Id currentPatchSetId() {
	if (currentPatchSetId > 0) {
	return new PatchSet.Id(changeId, currentPatchSetId);
	}
	return null;
	}

	public void setCurrentPatchSet(final PatchSetInfo ps) {
	if (originalSubject == null && subject != null) {
	// Change was created before schema upgrade. Use the last subject
	// associated with this change, as the most recent discussion will
	// be under that thread in an email client such as GMail.
	originalSubject = subject;
	}

	currentPatchSetId = ps.getKey().get();
	subject = ps.getSubject();

	if (originalSubject == null) {
	// Newly created changes remember the first commit's subject.
	originalSubject = subject;
	}
	}

	public Status getStatus() {
	return Status.forCode(status);
	}

	public void setStatus(Status newStatus) {
	status = newStatus.getCode();
	}

	public String getTopic() {
	return topic;
	}

	public void setTopic(String topic) {
	this.topic = topic;
	}

	@Override
	public String toString() {
	return new StringBuilder(getClass().getSimpleName())
	.append('{').append(changeId)
	.append(" (").append(changeKey).append("), ")
	.append("dest=").append(dest).append(", ")
	.append("status=").append(status).append('}')
	.toString();
	}
	}