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    * Copyright (C) 2015, Google Inc.
    *
    * This program and the accompanying materials are made available
    * under the terms of the Eclipse Distribution License v1.0 which
    * accompanies this distribution, is reproduced below, and is
    * available at http://www.eclipse.org/org/documents/edl-v10.php
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  package org.eclipse.jgit.storage.pack;
  
  import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
  import static org.eclipse.jgit.lib.Constants.OBJ_COMMIT;
  import static org.eclipse.jgit.lib.Constants.OBJ_TAG;
  import static org.eclipse.jgit.lib.Constants.OBJ_TREE;
  
  import java.text.MessageFormat;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.internal.storage.pack.CachedPack;
  import org.eclipse.jgit.lib.ObjectId;
  
  /**
   * Statistics about {@link org.eclipse.jgit.internal.storage.pack.PackWriter}
   * pack creation.
   *
   * @since 4.1
   */
  public class PackStatistics {
  	/**
  	 * Statistics about a single type of object (commits, tags, trees and
  	 * blobs).
  	 */
  	public static class ObjectType {
  		/**
  		 * POJO for accumulating the ObjectType statistics.
  		 */
  		public static class Accumulator {
  			/** Count of objects of this type. */
  			public long cntObjects;
  
  			/** Count of deltas of this type. */
  			public long cntDeltas;
  
  			/** Count of reused objects of this type. */
  			public long reusedObjects;
  
  			/** Count of reused deltas of this type. */
  			public long reusedDeltas;
  
  			/** Count of bytes for all objects of this type. */
  			public long bytes;
  
  			/** Count of delta bytes for objects of this type. */
  			public long deltaBytes;
  		}
  
  		private ObjectType.Accumulator objectType;
  
  		/**
  		 * Creates a new {@link ObjectType} object from the accumulator.
  		 *
 		 * @param accumulator
 		 *            the accumulator of the statistics
 		 */
 		public ObjectType(ObjectType.Accumulator accumulator) {
 			/*
 			 * For efficiency this wraps and serves up the Accumulator object
 			 * rather than making a deep clone. Normal usage of PackWriter is to
 			 * create a single pack/index/bitmap and only call getStatistics()
 			 * after all work is complete.
 			 */
 			objectType = accumulator;
 		}
 
 		/**
 		 * @return total number of objects output. This total includes the value
 		 *         of {@link #getDeltas()}.
 		 */
 		public long getObjects() {
 			return objectType.cntObjects;
 		}
 
 		/**
 		 * @return total number of deltas output. This may be lower than the
 		 *         actual number of deltas if a cached pack was reused.
 		 */
 		public long getDeltas() {
 			return objectType.cntDeltas;
 		}
 
 		/**
 		 * @return number of objects whose existing representation was reused in
 		 *         the output. This count includes {@link #getReusedDeltas()}.
 		 */
 		public long getReusedObjects() {
 			return objectType.reusedObjects;
 		}
 
 		/**
 		 * @return number of deltas whose existing representation was reused in
 		 *         the output, as their base object was also output or was
 		 *         assumed present for a thin pack. This may be lower than the
 		 *         actual number of reused deltas if a cached pack was reused.
 		 */
 		public long getReusedDeltas() {
 			return objectType.reusedDeltas;
 		}
 
 		/**
 		 * @return total number of bytes written. This size includes the object
 		 *         headers as well as the compressed data. This size also
 		 *         includes all of {@link #getDeltaBytes()}.
 		 */
 		public long getBytes() {
 			return objectType.bytes;
 		}
 
 		/**
 		 * @return number of delta bytes written. This size includes the object
 		 *         headers for the delta objects.
 		 */
 		public long getDeltaBytes() {
 			return objectType.deltaBytes;
 		}
 	}
 
 	/**
 	 * POJO for accumulating the statistics.
 	 */
 	public static class Accumulator {
 		/**
 		 * The count of references in the ref advertisement.
 		 *
 		 * @since 4.11
 		 */
 		public long advertised;
 
 		/**
 		 * The count of client wants.
 		 *
 		 * @since 4.11
 		 */
 		public long wants;
 
 		/**
 		 * The count of client haves.
 		 *
 		 * @since 4.11
 		 */
 		public long haves;
 
 		/**
 		 * Time in ms spent in the negotiation phase. For non-bidirectional
 		 * transports (e.g., HTTP), this is only for the final request that
 		 * sends back the pack file.
 		 *
 		 * @since 4.11
 		 */
 		public long timeNegotiating;
 
 		/** The set of objects to be included in the pack. */
 		public Set<ObjectId> interestingObjects;
 
 		/** The set of objects to be excluded from the pack. */
 		public Set<ObjectId> uninterestingObjects;
 
 		/** The set of shallow commits on the client. */
 		public Set<ObjectId> clientShallowCommits;
 
 		/** The collection of reused packs in the upload. */
 		public List<CachedPack> reusedPacks;
 
 		/** Commits with no parents. */
 		public Set<ObjectId> rootCommits;
 
 		/** If a shallow pack, the depth in commits. */
 		public int depth;
 
 		/**
 		 * The count of objects in the pack that went through the delta search
 		 * process in order to find a potential delta base.
 		 */
 		public int deltaSearchNonEdgeObjects;
 
 		/**
 		 * The count of objects in the pack that went through delta base search
 		 * and found a suitable base. This is a subset of
 		 * deltaSearchNonEdgeObjects.
 		 */
 		public int deltasFound;
 
 		/** The total count of objects in the pack. */
 		public long totalObjects;
 
 		/**
 		 * The count of objects that needed to be discovered through an object
 		 * walk because they were not found in bitmap indices.
 		 */
 		public long bitmapIndexMisses;
 
 		/** The total count of deltas output. */
 		public long totalDeltas;
 
 		/** The count of reused objects in the pack. */
 		public long reusedObjects;
 
 		/** The count of reused deltas in the pack. */
 		public long reusedDeltas;
 
 		/** The count of total bytes in the pack. */
 		public long totalBytes;
 
 		/** The size of the thin pack in bytes, if a thin pack was generated. */
 		public long thinPackBytes;
 
 		/** Time in ms spent counting the objects that will go into the pack. */
 		public long timeCounting;
 
 		/** Time in ms spent searching for objects to reuse. */
 		public long timeSearchingForReuse;
 
 		/** Time in ms spent searching for sizes of objects. */
 		public long timeSearchingForSizes;
 
 		/** Time in ms spent compressing the pack. */
 		public long timeCompressing;
 
 		/** Time in ms spent writing the pack. */
 		public long timeWriting;
 
 		/** Number of trees traversed in the walk when writing the pack.
 		 * @since 5.4*/
 		public long treesTraversed;
 
 		/**
 		 * Amount of packfile uris sent to the client to download via HTTP.
 		 *
 		 * @since 5.6
 		 */
 		public long offloadedPackfiles;
 
 		/**
 		 * Total size (in bytes) offloaded to HTTP downloads.
 		 *
 		 * @since 5.6
 		 */
 		public long offloadedPackfileSize;
 
 		/**
 		 * Statistics about each object type in the pack (commits, tags, trees
 		 * and blobs.)
 		 */
 		public ObjectType.Accumulator[] objectTypes;
 
 		{
 			objectTypes = new ObjectType.Accumulator[5];
 			objectTypes[OBJ_COMMIT] = new ObjectType.Accumulator();
 			objectTypes[OBJ_TREE] = new ObjectType.Accumulator();
 			objectTypes[OBJ_BLOB] = new ObjectType.Accumulator();
 			objectTypes[OBJ_TAG] = new ObjectType.Accumulator();
 		}
 	}
 
 	private Accumulator statistics;
 
 	/**
 	 * Creates a new {@link org.eclipse.jgit.storage.pack.PackStatistics} object
 	 * from the accumulator.
 	 *
 	 * @param accumulator
 	 *            the accumulator of the statistics
 	 */
 	public PackStatistics(Accumulator accumulator) {
 		/*
 		 * For efficiency this wraps and serves up the Accumulator object rather
 		 * than making a deep clone. Normal usage of PackWriter is to create a
 		 * single pack/index/bitmap and only call getStatistics() after all work
 		 * is complete.
 		 */
 		statistics = accumulator;
 	}
 
 	/**
 	 * Get the count of references in the ref advertisement.
 	 *
 	 * @return count of refs in the ref advertisement.
 	 * @since 4.11
 	 */
 	public long getAdvertised() {
 		return statistics.advertised;
 	}
 
 	/**
 	 * Get the count of client wants.
 	 *
 	 * @return count of client wants.
 	 * @since 4.11
 	 */
 	public long getWants() {
 		return statistics.wants;
 	}
 
 	/**
 	 * Get the count of client haves.
 	 *
 	 * @return count of client haves.
 	 * @since 4.11
 	 */
 	public long getHaves() {
 		return statistics.haves;
 	}
 
 	/**
 	 * Time in ms spent in the negotiation phase. For non-bidirectional
 	 * transports (e.g., HTTP), this is only for the final request that sends
 	 * back the pack file.
 	 *
 	 * @return time for ref advertisement in ms.
 	 * @since 4.11
 	 */
 	public long getTimeNegotiating() {
 		return statistics.timeNegotiating;
 	}
 
 	/**
 	 * Get unmodifiable collection of objects to be included in the pack.
 	 *
 	 * @return unmodifiable collection of objects to be included in the pack.
 	 *         May be {@code null} if the pack was hand-crafted in a unit test.
 	 */
 	public Set<ObjectId> getInterestingObjects() {
 		return statistics.interestingObjects;
 	}
 
 	/**
 	 * Get unmodifiable collection of objects that should be excluded from the
 	 * pack
 	 *
 	 * @return unmodifiable collection of objects that should be excluded from
 	 *         the pack, as the peer that will receive the pack already has
 	 *         these objects.
 	 */
 	public Set<ObjectId> getUninterestingObjects() {
 		return statistics.uninterestingObjects;
 	}
 
 	/**
 	 * Get unmodifiable collection of objects that were shallow commits on the
 	 * client.
 	 *
 	 * @return unmodifiable collection of objects that were shallow commits on
 	 *         the client.
 	 */
 	public Set<ObjectId> getClientShallowCommits() {
 		return statistics.clientShallowCommits;
 	}
 
 	/**
 	 * Get unmodifiable list of the cached packs that were reused in the output
 	 *
 	 * @return unmodifiable list of the cached packs that were reused in the
 	 *         output, if any were selected for reuse.
 	 */
 	public List<CachedPack> getReusedPacks() {
 		return statistics.reusedPacks;
 	}
 
 	/**
 	 * Get unmodifiable collection of the root commits of the history.
 	 *
 	 * @return unmodifiable collection of the root commits of the history.
 	 */
 	public Set<ObjectId> getRootCommits() {
 		return statistics.rootCommits;
 	}
 
 	/**
 	 * Get number of objects in the output pack that went through the delta
 	 * search process in order to find a potential delta base.
 	 *
 	 * @return number of objects in the output pack that went through the delta
 	 *         search process in order to find a potential delta base.
 	 */
 	public int getDeltaSearchNonEdgeObjects() {
 		return statistics.deltaSearchNonEdgeObjects;
 	}
 
 	/**
 	 * Get number of objects in the output pack that went through delta base
 	 * search and found a suitable base.
 	 *
 	 * @return number of objects in the output pack that went through delta base
 	 *         search and found a suitable base. This is a subset of
 	 *         {@link #getDeltaSearchNonEdgeObjects()}.
 	 */
 	public int getDeltasFound() {
 		return statistics.deltasFound;
 	}
 
 	/**
 	 * Get total number of objects output.
 	 *
 	 * @return total number of objects output. This total includes the value of
 	 *         {@link #getTotalDeltas()}.
 	 */
 	public long getTotalObjects() {
 		return statistics.totalObjects;
 	}
 
 	/**
 	 * Get the count of objects that needed to be discovered through an object
 	 * walk because they were not found in bitmap indices.
 	 *
 	 * @return the count of objects that needed to be discovered through an
 	 *         object walk because they were not found in bitmap indices.
 	 *         Returns -1 if no bitmap indices were found.
 	 */
 	public long getBitmapIndexMisses() {
 		return statistics.bitmapIndexMisses;
 	}
 
 	/**
 	 * Get total number of deltas output.
 	 *
 	 * @return total number of deltas output. This may be lower than the actual
 	 *         number of deltas if a cached pack was reused.
 	 */
 	public long getTotalDeltas() {
 		return statistics.totalDeltas;
 	}
 
 	/**
 	 * Get number of objects whose existing representation was reused in the
 	 * output.
 	 *
 	 * @return number of objects whose existing representation was reused in the
 	 *         output. This count includes {@link #getReusedDeltas()}.
 	 */
 	public long getReusedObjects() {
 		return statistics.reusedObjects;
 	}
 
 	/**
 	 * Get number of deltas whose existing representation was reused in the
 	 * output.
 	 *
 	 * @return number of deltas whose existing representation was reused in the
 	 *         output, as their base object was also output or was assumed
 	 *         present for a thin pack. This may be lower than the actual number
 	 *         of reused deltas if a cached pack was reused.
 	 */
 	public long getReusedDeltas() {
 		return statistics.reusedDeltas;
 	}
 
 	/**
 	 * Get total number of bytes written.
 	 *
 	 * @return total number of bytes written. This size includes the pack
 	 *         header, trailer, thin pack, and reused cached pack(s).
 	 */
 	public long getTotalBytes() {
 		return statistics.totalBytes;
 	}
 
 	/**
 	 * Get size of the thin pack in bytes.
 	 *
 	 * @return size of the thin pack in bytes, if a thin pack was generated. A
 	 *         thin pack is created when the client already has objects and some
 	 *         deltas are created against those objects, or if a cached pack is
 	 *         being used and some deltas will reference objects in the cached
 	 *         pack. This size does not include the pack header or trailer.
 	 */
 	public long getThinPackBytes() {
 		return statistics.thinPackBytes;
 	}
 
 	/**
 	 * Get information about this type of object in the pack.
 	 *
 	 * @param typeCode
 	 *            object type code, e.g. OBJ_COMMIT or OBJ_TREE.
 	 * @return information about this type of object in the pack.
 	 */
 	public ObjectType byObjectType(int typeCode) {
 		return new ObjectType(statistics.objectTypes[typeCode]);
 	}
 
 	/**
 	 * Whether the resulting pack file was a shallow pack.
 	 *
 	 * @return {@code true} if the resulting pack file was a shallow pack.
 	 */
 	public boolean isShallow() {
 		return statistics.depth > 0;
 	}
 
 	/**
 	 * Get depth (in commits) the pack includes if shallow.
 	 *
 	 * @return depth (in commits) the pack includes if shallow.
 	 */
 	public int getDepth() {
 		return statistics.depth;
 	}
 
 	/**
 	 * Get time in milliseconds spent enumerating the objects that need to be
 	 * included in the output.
 	 *
 	 * @return time in milliseconds spent enumerating the objects that need to
 	 *         be included in the output. This time includes any restarts that
 	 *         occur when a cached pack is selected for reuse.
 	 */
 	public long getTimeCounting() {
 		return statistics.timeCounting;
 	}
 
 	/**
 	 * Get time in milliseconds spent matching existing representations against
 	 * objects that will be transmitted.
 	 *
 	 * @return time in milliseconds spent matching existing representations
 	 *         against objects that will be transmitted, or that the client can
 	 *         be assumed to already have.
 	 */
 	public long getTimeSearchingForReuse() {
 		return statistics.timeSearchingForReuse;
 	}
 
 	/**
 	 * Get time in milliseconds spent finding the sizes of all objects that will
 	 * enter the delta compression search window.
 	 *
 	 * @return time in milliseconds spent finding the sizes of all objects that
 	 *         will enter the delta compression search window. The sizes need to
 	 *         be known to better match similar objects together and improve
 	 *         delta compression ratios.
 	 */
 	public long getTimeSearchingForSizes() {
 		return statistics.timeSearchingForSizes;
 	}
 
 	/**
 	 * Get time in milliseconds spent on delta compression.
 	 *
 	 * @return time in milliseconds spent on delta compression. This is observed
 	 *         wall-clock time and does not accurately track CPU time used when
 	 *         multiple threads were used to perform the delta compression.
 	 */
 	public long getTimeCompressing() {
 		return statistics.timeCompressing;
 	}
 
 	/**
 	 * Get time in milliseconds spent writing the pack output, from start of
 	 * header until end of trailer.
 	 *
 	 * @return time in milliseconds spent writing the pack output, from start of
 	 *         header until end of trailer. The transfer speed can be
 	 *         approximated by dividing {@link #getTotalBytes()} by this value.
 	 */
 	public long getTimeWriting() {
 		return statistics.timeWriting;
 	}
 
 	/**
 	 * @return number of trees traversed in the walk when writing the pack.
 	 * @since 5.4
 	 */
 	public long getTreesTraversed() {
 		return statistics.treesTraversed;
 	}
 
 	/**
 	 * @return amount of packfiles offloaded (sent as "packfile-uri")/
 	 * @since 5.6
 	 */
 	public long getOffloadedPackfiles() {
 		return statistics.offloadedPackfiles;
 	}
 
 	/**
 	 * @return total size (in bytes) offloaded to HTTP downloads.
 	 * @since 5.6
 	 */
 	public long getOffloadedPackfilesSize() {
 		return statistics.offloadedPackfileSize;
 	}
 
 	/**
 	 * Get total time spent processing this pack.
 	 *
 	 * @return total time spent processing this pack.
 	 */
 	public long getTimeTotal() {
 		return statistics.timeCounting + statistics.timeSearchingForReuse
 				+ statistics.timeSearchingForSizes + statistics.timeCompressing
 				+ statistics.timeWriting;
 	}
 
 	/**
 	 * Get the average output speed in terms of bytes-per-second.
 	 *
 	 * @return the average output speed in terms of bytes-per-second.
 	 *         {@code getTotalBytes() / (getTimeWriting() / 1000.0)}.
 	 */
 	public double getTransferRate() {
 		return getTotalBytes() / (getTimeWriting() / 1000.0);
 	}
 
 	/**
 	 * Get formatted message string for display to clients.
 	 *
 	 * @return formatted message string for display to clients.
 	 */
 	public String getMessage() {
 		return MessageFormat.format(JGitText.get().packWriterStatistics,
 				Long.valueOf(statistics.totalObjects),
 				Long.valueOf(statistics.totalDeltas),
 				Long.valueOf(statistics.reusedObjects),
 				Long.valueOf(statistics.reusedDeltas));
 	}
 
 	/**
 	 * Get a map containing ObjectType statistics.
 	 *
 	 * @return a map containing ObjectType statistics.
 	 */
 	public Map<Integer, ObjectType> getObjectTypes() {
 		HashMap<Integer, ObjectType> map = new HashMap<>();
 		map.put(Integer.valueOf(OBJ_BLOB), new ObjectType(
 				statistics.objectTypes[OBJ_BLOB]));
 		map.put(Integer.valueOf(OBJ_COMMIT), new ObjectType(
 				statistics.objectTypes[OBJ_COMMIT]));
 		map.put(Integer.valueOf(OBJ_TAG), new ObjectType(
 				statistics.objectTypes[OBJ_TAG]));
 		map.put(Integer.valueOf(OBJ_TREE), new ObjectType(
 				statistics.objectTypes[OBJ_TREE]));
 		return map;
 	}
 }