sdklib/src/main/java/com/android/sdklib/repository/FullRevision.java - platform/tools/base.git - Git at Google

 /*
  * Copyright (C) 2012 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.android.sdklib.repository;

 import com.android.annotations.NonNull;

 import java.util.regex.Matcher;
 import java.util.regex.Pattern;


 /**
  * Package multi-part revision number composed of a tuple
  * (major.minor.micro) and an optional preview revision
  * (the lack of a preview number indicates it's not a preview
  *  but a final package.)
  *
  *  @see MajorRevision
  */
 public class FullRevision implements Comparable<FullRevision> {

     public static final int MISSING_MAJOR_REV  = 0;
     public static final int IMPLICIT_MINOR_REV = 0;
     public static final int IMPLICIT_MICRO_REV = 0;
     public static final int NOT_A_PREVIEW      = 0;

     /** Only major revision specified: 1 term */
     protected static final int PRECISION_MAJOR = 1;
     /** Only major and minor revisions specified: 2 terms (x.y) */
     protected static final int PRECISION_MINOR = 2;
     /** Major, minor and micro revisions specified: 3 terms (x.y.z) */
     protected static final int PRECISION_MICRO = 3;
     /** Major, minor, micro and preview revisions specified: 4 terms (x.y.z-rcN) */
     protected static final int PRECISION_PREVIEW = 4;

     public static final FullRevision NOT_SPECIFIED = new FullRevision(MISSING_MAJOR_REV);

     private static final Pattern FULL_REVISION_PATTERN =
         //                   1=major       2=minor       3=micro     4=separator  5=previewType  6=preview
         Pattern.compile("\\s*([0-9]+)(?:\\.([0-9]+)(?:\\.([0-9]+))?)?([\\s-]*)?(?:(rc|alpha|beta)([0-9]+))?\\s*");

     protected static final String DEFAULT_SEPARATOR = " ";

     private final int mMajor;
     private final int mMinor;
     private final int mMicro;
     private final int mPreview;
     private final String mPreviewSeparator;
     private final PreviewType mPreviewType;

     public enum PreviewType {
         ALPHA("alpha"),
         BETA("beta"),
         RC("rc")
         ;

         final String name;

         PreviewType(String name) {
             this.name = name;
         }
     }

     public FullRevision(int major) {
         this(major, IMPLICIT_MINOR_REV, IMPLICIT_MICRO_REV);
     }

     public FullRevision(int major, int minor, int micro) {
         this(major, minor, micro, NOT_A_PREVIEW);
     }

     public FullRevision(int major, int minor, int micro, int preview) {
       this(major, minor, micro, PreviewType.RC, preview, DEFAULT_SEPARATOR);
     }

     public FullRevision(int major, int minor, int micro, @NonNull PreviewType previewType,
             int preview, @NonNull String previewSeparator) {
         mMajor = major;
         mMinor = minor;
         mMicro = micro;
         mPreview = preview;
         mPreviewSeparator = previewSeparator;
         mPreviewType = previewType;
     }

     public int getMajor() {
         return mMajor;
     }

     public int getMinor() {
         return mMinor;
     }

     public int getMicro() {
         return mMicro;
     }

     @NonNull
     protected String getSeparator() {
         return mPreviewSeparator;
     }

     public boolean isPreview() {
         return mPreview > NOT_A_PREVIEW;
     }

     public int getPreview() {
         return mPreview;
     }

     /**
      * Parses a string of format "major.minor.micro rcPreview" and returns
      * a new {@link FullRevision} for it. All the fields except major are
      * optional.
      * <p/>
      * The parsing is equivalent to the pseudo-BNF/regexp:
      * <pre>
      *   Major/Minor/Micro/Preview := [0-9]+
      *   Revision := Major ('.' Minor ('.' Micro)? )? \s* ('rc'Preview)?
      * </pre>
      *
      * @param revision A non-null revision to parse.
      * @return A new non-null {@link FullRevision}.
      * @throws NumberFormatException if the parsing failed.
      */
     @NonNull
     public static FullRevision parseRevision(@NonNull String revision)
             throws NumberFormatException {
         return parseRevisionImpl(revision, true /*supportMinorMicro*/, true /*supportPreview*/,
                 false /*keepPrevision*/);
     }

     @NonNull
     protected static FullRevision parseRevisionImpl(@NonNull String revision,
                                                     boolean supportMinorMicro,
                                                     boolean supportPreview,
                                                     boolean keepPrecision)
                                   throws NumberFormatException {
         if (revision == null) {
             throw new NumberFormatException("revision is <null>"); //$NON-NLS-1$
         }

         Throwable cause = null;
         String error = null;
         try {
             Matcher m = FULL_REVISION_PATTERN.matcher(revision);
             if (m != null && m.matches()) {
                 int major = Integer.parseInt(m.group(1));

                 int minor = IMPLICIT_MINOR_REV;
                 int micro = IMPLICIT_MICRO_REV;
                 int preview = NOT_A_PREVIEW;
                 int precision = PRECISION_MAJOR;
                 String previewSeparator = " ";
                 PreviewType previewType = PreviewType.RC;

                 String s = m.group(2);
                 if (s != null) {
                     if (!supportMinorMicro) {
                         error = " -- Minor number not supported";   //$NON-NLS-1$
                     } else {
                         minor = Integer.parseInt(s);
                         precision = PRECISION_MINOR;
                     }
                 }

                 s = m.group(3);
                 if (s != null) {
                     if (!supportMinorMicro) {
                         error = " -- Micro number not supported";   //$NON-NLS-1$
                     } else {
                         micro = Integer.parseInt(s);
                         precision = PRECISION_MICRO;
                     }
                 }

                 s = m.group(6);
                 if (s != null) {
                     if (!supportPreview) {
                         error = " -- Preview number not supported";   //$NON-NLS-1$
                     } else {
                         preview = Integer.parseInt(s);
                         previewSeparator = m.group(4);
                         precision = PRECISION_PREVIEW;

                         String previewTypeName = m.group(5);
                         for (PreviewType pt : PreviewType.values()) {
                             if (pt.name.equals(previewTypeName)) {
                                 previewType = pt;
                                 break;
                             }
                         }
                     }
                 }

                 if (error == null) {
                     if (keepPrecision) {
                         return new PreciseRevision(major, minor, micro, preview, precision,
                                 previewSeparator);
                     } else {
                         return new FullRevision(major, minor, micro, previewType, preview, previewSeparator);
                     }
                 }
             }
         } catch (Throwable t) {
             cause = t;
         }

         NumberFormatException n = new NumberFormatException(
                 "Invalid revision: "        //$NON-NLS-1$
                 + revision
                 + (error == null ? "" : error));
         if (cause != null) {
             n.initCause(cause);
         }
         throw n;
     }

     /**
      * Returns the version in a fixed format major.minor.micro
      * with an optional "rc preview#". For example it would
      * return "18.0.0", "18.1.0" or "18.1.2 rc5".
      */
     @Override
     public String toString() {
         StringBuilder sb = new StringBuilder();
         sb.append(mMajor)
           .append('.').append(mMinor)
           .append('.').append(mMicro);

         if (mPreview != NOT_A_PREVIEW) {
             sb.append(mPreviewSeparator).append(mPreviewType.name).append(mPreview);
         }

         return sb.toString();
     }

     /**
      * Returns the version in a dynamic format "major.minor.micro rc#".
      * This is similar to {@link #toString()} except it omits minor, micro
      * or preview versions when they are zero.
      * For example it would return "18 rc1" instead of "18.0.0 rc1",
      * or "18.1 rc2" instead of "18.1.0 rc2".
      */
     public String toShortString() {
         StringBuilder sb = new StringBuilder();
         sb.append(mMajor);
         if (mMinor > 0 || mMicro > 0) {
             sb.append('.').append(mMinor);
         }
         if (mMicro > 0) {
             sb.append('.').append(mMicro);
         }
         if (mPreview != NOT_A_PREVIEW) {
             sb.append(mPreviewSeparator).append(mPreviewType.name).append(mPreview);
         }

         return sb.toString();
     }

     /**
      * Returns the version number as an integer array, in the form
      * [major, minor, micro] or [major, minor, micro, preview].
      *
      * This is useful to initialize an instance of
      * {@code org.apache.tools.ant.util.DeweyDecimal} using a
      * {@link FullRevision}.
      *
      * @param includePreview If true the output will contain 4 fields
      *  to include the preview number (even if 0.) If false the output
      *  will contain only 3 fields (major, minor and micro.)
      * @return A new int array, never null, with either 3 or 4 fields.
      */
     public int[] toIntArray(boolean includePreview) {
         int size = includePreview ? 4 : 3;
         int[] result = new int[size];
         result[0] = mMajor;
         result[1] = mMinor;
         result[2] = mMicro;
         if (result.length > 3) {
             result[3] = mPreview;
         }
         return result;
     }

     @Override
     public int hashCode() {
         final int prime = 31;
         int result = 1;
         result = prime * result + mMajor;
         result = prime * result + mMinor;
         result = prime * result + mMicro;
         result = prime * result + mPreview;
         result = prime * result + mPreviewType.hashCode();
         return result;
     }

     @Override
     public boolean equals(Object rhs) {
         if (this == rhs) {
             return true;
         }
         if (rhs == null) {
             return false;
         }
         if (!(rhs instanceof FullRevision)) {
             return false;
         }
         FullRevision other = (FullRevision) rhs;
         if (mMajor != other.mMajor) {
             return false;
         }
         if (mMinor != other.mMinor) {
             return false;
         }
         if (mMicro != other.mMicro) {
             return false;
         }
         if (mPreview != other.mPreview) {
             return false;
         }
         if (mPreviewType != other.mPreviewType) {
             return false;
         }
         return true;
     }

     /**
      * Trivial comparison of a version, e.g 17.1.2 < 18.0.0.
      *
      * Note that preview/release candidate are released before their final version,
      * so "18.0.0 rc1" comes below "18.0.0". The best way to think of it as if the
      * lack of preview number was "+inf":
      * "18.1.2 rc5" => "18.1.2.5" so its less than "18.1.2.+INF" but more than "18.1.1.0"
      * and more than "18.1.2.4"
      *
      * @param rhs The right-hand side {@link FullRevision} to compare with.
      * @return &lt;0 if lhs &lt; rhs; 0 if lhs==rhs; &gt;0 if lhs &gt; rhs.
      */
     @Override
     public int compareTo(FullRevision rhs) {
         return compareTo(rhs, PreviewComparison.COMPARE_NUMBER);
     }

     /**
      * Trivial comparison of a version, e.g 17.1.2 < 18.0.0.
      *
      * Note that preview/release candidate are released before their final version,
      * so "18.0.0 rc1" comes below "18.0.0". The best way to think of it as if the
      * lack of preview number was "+inf":
      * "18.1.2 rc5" => "18.1.2.5" so its less than "18.1.2.+INF" but more than "18.1.1.0"
      * and more than "18.1.2.4"
      *
      * @param rhs The right-hand side {@link FullRevision} to compare with.
      * @param comparePreview How to compare the preview value.
      * @return &lt;0 if lhs &lt; rhs; 0 if lhs==rhs; &gt;0 if lhs &gt; rhs.
      */
     public int compareTo(FullRevision rhs, PreviewComparison comparePreview) {
         int delta = mMajor - rhs.mMajor;
         if (delta != 0) {
             return delta;
         }

         delta = mMinor - rhs.mMinor;
         if (delta != 0) {
             return delta;
         }

         delta = mMicro - rhs.mMicro;
         if (delta != 0) {
             return delta;
         }

         int p1, p2;
         switch (comparePreview) {
         case IGNORE:
             // Nothing to compare.
             break;

         case COMPARE_NUMBER:
             if (!mPreviewType.equals(rhs.mPreviewType)) {
                 return mPreviewType.compareTo(rhs.mPreviewType);
             }

             p1 =     mPreview == NOT_A_PREVIEW ? Integer.MAX_VALUE :     mPreview;
             p2 = rhs.mPreview == NOT_A_PREVIEW ? Integer.MAX_VALUE : rhs.mPreview;
             delta = p1 - p2;
             break;

         case COMPARE_TYPE:
             p1 =     mPreview == NOT_A_PREVIEW ? 1 : 0;
             p2 = rhs.mPreview == NOT_A_PREVIEW ? 1 : 0;
             delta = p1 - p2;
             break;
         }
         return delta;
     }

     /** Indicates how to compare the preview field in
      *  {@link FullRevision#compareTo(FullRevision, PreviewComparison)} */
     public enum PreviewComparison {
         /** Both revisions must have exactly the same preview number. */
         COMPARE_NUMBER,
         /** Both revisions must have the same preview type (both must be previews
          *  or both must not be previews, but the actual number is irrelevant.)
          *  This is the most typical choice used to find updates of the same type. */
         COMPARE_TYPE,
         /** The preview field is ignored and not used in the comparison. */
         IGNORE
     }


 }
	/*
	* Copyright (C) 2012 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.android.sdklib.repository;

	import com.android.annotations.NonNull;

	import java.util.regex.Matcher;
	import java.util.regex.Pattern;


	/**
	* Package multi-part revision number composed of a tuple
	* (major.minor.micro) and an optional preview revision
	* (the lack of a preview number indicates it's not a preview
	* but a final package.)
	*
	* @see MajorRevision
	*/
	public class FullRevision implements Comparable<FullRevision> {

	public static final int MISSING_MAJOR_REV = 0;
	public static final int IMPLICIT_MINOR_REV = 0;
	public static final int IMPLICIT_MICRO_REV = 0;
	public static final int NOT_A_PREVIEW = 0;

	/** Only major revision specified: 1 term */
	protected static final int PRECISION_MAJOR = 1;
	/** Only major and minor revisions specified: 2 terms (x.y) */
	protected static final int PRECISION_MINOR = 2;
	/** Major, minor and micro revisions specified: 3 terms (x.y.z) */
	protected static final int PRECISION_MICRO = 3;
	/** Major, minor, micro and preview revisions specified: 4 terms (x.y.z-rcN) */
	protected static final int PRECISION_PREVIEW = 4;

	public static final FullRevision NOT_SPECIFIED = new FullRevision(MISSING_MAJOR_REV);

	private static final Pattern FULL_REVISION_PATTERN =
	// 1=major 2=minor 3=micro 4=separator 5=previewType 6=preview
	Pattern.compile("\\s([0-9]+)(?:\\.([0-9]+)(?:\\.([0-9]+))?)?([\\s-])?(?:(rc\|alpha\|beta)([0-9]+))?\\s*");

	protected static final String DEFAULT_SEPARATOR = " ";

	private final int mMajor;
	private final int mMinor;
	private final int mMicro;
	private final int mPreview;
	private final String mPreviewSeparator;
	private final PreviewType mPreviewType;

	public enum PreviewType {
	ALPHA("alpha"),
	BETA("beta"),
	RC("rc")
	;

	final String name;

	PreviewType(String name) {
	this.name = name;
	}
	}

	public FullRevision(int major) {
	this(major, IMPLICIT_MINOR_REV, IMPLICIT_MICRO_REV);
	}

	public FullRevision(int major, int minor, int micro) {
	this(major, minor, micro, NOT_A_PREVIEW);
	}

	public FullRevision(int major, int minor, int micro, int preview) {
	this(major, minor, micro, PreviewType.RC, preview, DEFAULT_SEPARATOR);
	}

	public FullRevision(int major, int minor, int micro, @NonNull PreviewType previewType,
	int preview, @NonNull String previewSeparator) {
	mMajor = major;
	mMinor = minor;
	mMicro = micro;
	mPreview = preview;
	mPreviewSeparator = previewSeparator;
	mPreviewType = previewType;
	}

	public int getMajor() {
	return mMajor;
	}

	public int getMinor() {
	return mMinor;
	}

	public int getMicro() {
	return mMicro;
	}

	@NonNull
	protected String getSeparator() {
	return mPreviewSeparator;
	}

	public boolean isPreview() {
	return mPreview > NOT_A_PREVIEW;
	}

	public int getPreview() {
	return mPreview;
	}

	/**
	* Parses a string of format "major.minor.micro rcPreview" and returns
	* a new {@link FullRevision} for it. All the fields except major are
	* optional.
	* <p/>
	* The parsing is equivalent to the pseudo-BNF/regexp:
	* <pre>
	* Major/Minor/Micro/Preview := [0-9]+
	* Revision := Major ('.' Minor ('.' Micro)? )? \s* ('rc'Preview)?
	* </pre>
	*
	* @param revision A non-null revision to parse.
	* @return A new non-null {@link FullRevision}.
	* @throws NumberFormatException if the parsing failed.
	*/
	@NonNull
	public static FullRevision parseRevision(@NonNull String revision)
	throws NumberFormatException {
	return parseRevisionImpl(revision, true /supportMinorMicro/, true /supportPreview/,
	false /keepPrevision/);
	}

	@NonNull
	protected static FullRevision parseRevisionImpl(@NonNull String revision,
	boolean supportMinorMicro,
	boolean supportPreview,
	boolean keepPrecision)
	throws NumberFormatException {
	if (revision == null) {
	throw new NumberFormatException("revision is <null>"); //$NON-NLS-1$
	}

	Throwable cause = null;
	String error = null;
	try {
	Matcher m = FULL_REVISION_PATTERN.matcher(revision);
	if (m != null && m.matches()) {
	int major = Integer.parseInt(m.group(1));

	int minor = IMPLICIT_MINOR_REV;
	int micro = IMPLICIT_MICRO_REV;
	int preview = NOT_A_PREVIEW;
	int precision = PRECISION_MAJOR;
	String previewSeparator = " ";
	PreviewType previewType = PreviewType.RC;

	String s = m.group(2);
	if (s != null) {
	if (!supportMinorMicro) {
	error = " -- Minor number not supported"; //$NON-NLS-1$
	} else {
	minor = Integer.parseInt(s);
	precision = PRECISION_MINOR;
	}
	}

	s = m.group(3);
	if (s != null) {
	if (!supportMinorMicro) {
	error = " -- Micro number not supported"; //$NON-NLS-1$
	} else {
	micro = Integer.parseInt(s);
	precision = PRECISION_MICRO;
	}
	}

	s = m.group(6);
	if (s != null) {
	if (!supportPreview) {
	error = " -- Preview number not supported"; //$NON-NLS-1$
	} else {
	preview = Integer.parseInt(s);
	previewSeparator = m.group(4);
	precision = PRECISION_PREVIEW;

	String previewTypeName = m.group(5);
	for (PreviewType pt : PreviewType.values()) {
	if (pt.name.equals(previewTypeName)) {
	previewType = pt;
	break;
	}
	}
	}
	}

	if (error == null) {
	if (keepPrecision) {
	return new PreciseRevision(major, minor, micro, preview, precision,
	previewSeparator);
	} else {
	return new FullRevision(major, minor, micro, previewType, preview, previewSeparator);
	}
	}
	}
	} catch (Throwable t) {
	cause = t;
	}

	NumberFormatException n = new NumberFormatException(
	"Invalid revision: " //$NON-NLS-1$
	+ revision
	+ (error == null ? "" : error));
	if (cause != null) {
	n.initCause(cause);
	}
	throw n;
	}

	/**
	* Returns the version in a fixed format major.minor.micro
	* with an optional "rc preview#". For example it would
	* return "18.0.0", "18.1.0" or "18.1.2 rc5".
	*/
	@Override
	public String toString() {
	StringBuilder sb = new StringBuilder();
	sb.append(mMajor)
	.append('.').append(mMinor)
	.append('.').append(mMicro);

	if (mPreview != NOT_A_PREVIEW) {
	sb.append(mPreviewSeparator).append(mPreviewType.name).append(mPreview);
	}

	return sb.toString();
	}

	/**
	* Returns the version in a dynamic format "major.minor.micro rc#".
	* This is similar to {@link #toString()} except it omits minor, micro
	* or preview versions when they are zero.
	* For example it would return "18 rc1" instead of "18.0.0 rc1",
	* or "18.1 rc2" instead of "18.1.0 rc2".
	*/
	public String toShortString() {
	StringBuilder sb = new StringBuilder();
	sb.append(mMajor);
	if (mMinor > 0 \|\| mMicro > 0) {
	sb.append('.').append(mMinor);
	}
	if (mMicro > 0) {
	sb.append('.').append(mMicro);
	}
	if (mPreview != NOT_A_PREVIEW) {
	sb.append(mPreviewSeparator).append(mPreviewType.name).append(mPreview);
	}

	return sb.toString();
	}

	/**
	* Returns the version number as an integer array, in the form
	* [major, minor, micro] or [major, minor, micro, preview].
	*
	* This is useful to initialize an instance of
	* {@code org.apache.tools.ant.util.DeweyDecimal} using a
	* {@link FullRevision}.
	*
	* @param includePreview If true the output will contain 4 fields
	* to include the preview number (even if 0.) If false the output
	* will contain only 3 fields (major, minor and micro.)
	* @return A new int array, never null, with either 3 or 4 fields.
	*/
	public int[] toIntArray(boolean includePreview) {
	int size = includePreview ? 4 : 3;
	int[] result = new int[size];
	result[0] = mMajor;
	result[1] = mMinor;
	result[2] = mMicro;
	if (result.length > 3) {
	result[3] = mPreview;
	}
	return result;
	}

	@Override
	public int hashCode() {
	final int prime = 31;
	int result = 1;
	result = prime * result + mMajor;
	result = prime * result + mMinor;
	result = prime * result + mMicro;
	result = prime * result + mPreview;
	result = prime * result + mPreviewType.hashCode();
	return result;
	}

	@Override
	public boolean equals(Object rhs) {
	if (this == rhs) {
	return true;
	}
	if (rhs == null) {
	return false;
	}
	if (!(rhs instanceof FullRevision)) {
	return false;
	}
	FullRevision other = (FullRevision) rhs;
	if (mMajor != other.mMajor) {
	return false;
	}
	if (mMinor != other.mMinor) {
	return false;
	}
	if (mMicro != other.mMicro) {
	return false;
	}
	if (mPreview != other.mPreview) {
	return false;
	}
	if (mPreviewType != other.mPreviewType) {
	return false;
	}
	return true;
	}

	/**
	* Trivial comparison of a version, e.g 17.1.2 < 18.0.0.
	*
	* Note that preview/release candidate are released before their final version,
	* so "18.0.0 rc1" comes below "18.0.0". The best way to think of it as if the
	* lack of preview number was "+inf":
	* "18.1.2 rc5" => "18.1.2.5" so its less than "18.1.2.+INF" but more than "18.1.1.0"
	* and more than "18.1.2.4"
	*
	* @param rhs The right-hand side {@link FullRevision} to compare with.
	* @return <0 if lhs < rhs; 0 if lhs==rhs; >0 if lhs > rhs.
	*/
	@Override
	public int compareTo(FullRevision rhs) {
	return compareTo(rhs, PreviewComparison.COMPARE_NUMBER);
	}

	/**
	* Trivial comparison of a version, e.g 17.1.2 < 18.0.0.
	*
	* Note that preview/release candidate are released before their final version,
	* so "18.0.0 rc1" comes below "18.0.0". The best way to think of it as if the
	* lack of preview number was "+inf":
	* "18.1.2 rc5" => "18.1.2.5" so its less than "18.1.2.+INF" but more than "18.1.1.0"
	* and more than "18.1.2.4"
	*
	* @param rhs The right-hand side {@link FullRevision} to compare with.
	* @param comparePreview How to compare the preview value.
	* @return <0 if lhs < rhs; 0 if lhs==rhs; >0 if lhs > rhs.
	*/
	public int compareTo(FullRevision rhs, PreviewComparison comparePreview) {
	int delta = mMajor - rhs.mMajor;
	if (delta != 0) {
	return delta;
	}

	delta = mMinor - rhs.mMinor;
	if (delta != 0) {
	return delta;
	}

	delta = mMicro - rhs.mMicro;
	if (delta != 0) {
	return delta;
	}

	int p1, p2;
	switch (comparePreview) {
	case IGNORE:
	// Nothing to compare.
	break;

	case COMPARE_NUMBER:
	if (!mPreviewType.equals(rhs.mPreviewType)) {
	return mPreviewType.compareTo(rhs.mPreviewType);
	}

	p1 = mPreview == NOT_A_PREVIEW ? Integer.MAX_VALUE : mPreview;
	p2 = rhs.mPreview == NOT_A_PREVIEW ? Integer.MAX_VALUE : rhs.mPreview;
	delta = p1 - p2;
	break;

	case COMPARE_TYPE:
	p1 = mPreview == NOT_A_PREVIEW ? 1 : 0;
	p2 = rhs.mPreview == NOT_A_PREVIEW ? 1 : 0;
	delta = p1 - p2;
	break;
	}
	return delta;
	}

	/** Indicates how to compare the preview field in
	* {@link FullRevision#compareTo(FullRevision, PreviewComparison)} */
	public enum PreviewComparison {
	/** Both revisions must have exactly the same preview number. */
	COMPARE_NUMBER,
	/** Both revisions must have the same preview type (both must be previews
	* or both must not be previews, but the actual number is irrelevant.)
	* This is the most typical choice used to find updates of the same type. */
	COMPARE_TYPE,
	/** The preview field is ignored and not used in the comparison. */
	IGNORE
	}


	}