Package org.eclipse.jgit.storage.pack

Class PackConfig

  • public class PackConfig
extends Object
    Configuration used by a pack writer when constructing the stream. A configuration may be modified once created, but should not be modified while it is being used by a PackWriter. If a configuration is not modified it is safe to share the same configuration instance between multiple concurrent threads executing different PackWriters.

    • Field Detail

      • DEFAULT_WAIT_PREVENT_RACY_PACK

        public static final boolean DEFAULT_WAIT_PREVENT_RACY_PACK
        Default if we wait before opening a newly written pack to prevent its lastModified timestamp could be racy
        Since:
        5.1.8
        See Also:
        Constant Field Values

      • DEFAULT_MINSIZE_PREVENT_RACY_PACK

        public static final long DEFAULT_MINSIZE_PREVENT_RACY_PACK
        Default if we wait before opening a newly written pack to prevent its lastModified timestamp could be racy
        Since:
        5.1.8
        See Also:
        Constant Field Values

      • DEFAULT_BITMAP_CONTIGUOUS_COMMIT_COUNT

        public static final int DEFAULT_BITMAP_CONTIGUOUS_COMMIT_COUNT
        Default count of most recent commits to select for bitmaps. Only applies when bitmaps are enabled: 100
        Since:
        4.2
        See Also:
        setBitmapContiguousCommitCount(int), Constant Field Values

      • DEFAULT_BITMAP_RECENT_COMMIT_COUNT

        public static final int DEFAULT_BITMAP_RECENT_COMMIT_COUNT
        Count at which the span between selected commits changes from "bitmapRecentCommitSpan" to "bitmapDistantCommitSpan". Only applies when bitmaps are enabled: 20000
        Since:
        4.2
        See Also:
        setBitmapRecentCommitCount(int), Constant Field Values

      • DEFAULT_BITMAP_RECENT_COMMIT_SPAN

        public static final int DEFAULT_BITMAP_RECENT_COMMIT_SPAN
        Default spacing between commits in recent history when selecting commits for bitmaps. Only applies when bitmaps are enabled: 100
        Since:
        4.2
        See Also:
        setBitmapRecentCommitSpan(int), Constant Field Values

      • DEFAULT_BITMAP_DISTANT_COMMIT_SPAN

        public static final int DEFAULT_BITMAP_DISTANT_COMMIT_SPAN
        Default spacing between commits in distant history when selecting commits for bitmaps. Only applies when bitmaps are enabled: 5000
        Since:
        4.2
        See Also:
        setBitmapDistantCommitSpan(int), Constant Field Values

      • DEFAULT_BITMAP_EXCESSIVE_BRANCH_COUNT

        public static final int DEFAULT_BITMAP_EXCESSIVE_BRANCH_COUNT
        Default count of branches required to activate inactive branch commit selection. If the number of branches is less than this then bitmaps for the entire commit history of all branches will be created, otherwise branches marked as "inactive" will have coverage for only partial history: 100
        Since:
        4.2
        See Also:
        setBitmapExcessiveBranchCount(int), Constant Field Values

      • DEFAULT_BITMAP_INACTIVE_BRANCH_AGE_IN_DAYS

        public static final int DEFAULT_BITMAP_INACTIVE_BRANCH_AGE_IN_DAYS
        Default age at which a branch is considered inactive. Age is taken as the number of days ago that the most recent commit was made to a branch. Only affects bitmap processing if bitmaps are enabled and the "excessive branch count" has been exceeded: 90
        Since:
        4.2
        See Also:
        setBitmapInactiveBranchAgeInDays(int), Constant Field Values

      • DEFAULT_SEARCH_FOR_REUSE_TIMEOUT

        public static final Duration DEFAULT_SEARCH_FOR_REUSE_TIMEOUT
        Default max time to spend during the search for reuse phase. This optimization is disabled by default:
        Since:
        5.13
        See Also:
        setSearchForReuseTimeout(Duration)

    • Constructor Detail

      • PackConfig

        public PackConfig()
        Create a default configuration.

      • PackConfig

        public PackConfig​(Repository db)
        Create a configuration honoring the repository's settings.
        Parameters:
        db - the repository to read settings from. The repository is not retained by the new configuration, instead its settings are copied during the constructor.

      • PackConfig

        public PackConfig​(Config cfg)
        Create a configuration honoring settings in a Config.
        Parameters:
        cfg - the source to read settings from. The source is not retained by the new configuration, instead its settings are copied during the constructor.

      • PackConfig

        public PackConfig​(PackConfig cfg)
        Copy an existing configuration to a new instance.
        Parameters:
        cfg - the source configuration to copy from.

    • Method Detail

      • isReuseDeltas

        public boolean isReuseDeltas()
        Check whether to reuse deltas existing in repository. Default setting: true
        Returns:
        true if object is configured to reuse deltas; false otherwise.

      • setReuseDeltas

        public void setReuseDeltas​(boolean reuseDeltas)
        Set reuse deltas configuration option for the writer. When enabled, writer will search for delta representation of object in repository and use it if possible. Normally, only deltas with base to another object existing in set of objects to pack will be used. The exception however is thin-packs where the base object may exist on the other side. When raw delta data is directly copied from a pack file, its checksum is computed to verify the data is not corrupt. Default setting: true
        Parameters:
        reuseDeltas - boolean indicating whether or not try to reuse deltas.

      • isReuseObjects

        public boolean isReuseObjects()
        Checks whether to reuse existing objects representation in repository. Default setting: true
        Returns:
        true if writer is configured to reuse objects representation from pack; false otherwise.

      • setReuseObjects

        public void setReuseObjects​(boolean reuseObjects)
        Set reuse objects configuration option for the writer. If enabled, writer searches for compressed representation in a pack file. If possible, compressed data is directly copied from such a pack file. Data checksum is verified. Default setting: true
        Parameters:
        reuseObjects - boolean indicating whether or not writer should reuse existing objects representation.

      • isPreserveOldPacks

        public boolean isPreserveOldPacks()
        Checks whether to preserve old packs in a preserved directory Default setting: false
        Returns:
        true if repacking will preserve old pack files.
        Since:
        4.7

      • setPreserveOldPacks

        public void setPreserveOldPacks​(boolean preserveOldPacks)
        Set preserve old packs configuration option for repacking. If enabled, old pack files are moved into a preserved subdirectory instead of being deleted Default setting: false
        Parameters:
        preserveOldPacks - boolean indicating whether or not preserve old pack files
        Since:
        4.7

      • isPrunePreserved

        public boolean isPrunePreserved()
        Checks whether to remove preserved pack files in a preserved directory Default setting: false
        Returns:
        true if repacking will remove preserved pack files.
        Since:
        4.7

      • setPrunePreserved

        public void setPrunePreserved​(boolean prunePreserved)
        Set prune preserved configuration option for repacking. If enabled, preserved pack files are removed from a preserved subdirectory Default setting: false
        Parameters:
        prunePreserved - boolean indicating whether or not preserve old pack files
        Since:
        4.7

      • isDeltaBaseAsOffset

        public boolean isDeltaBaseAsOffset()
        True if writer can use offsets to point to a delta base. If true the writer may choose to use an offset to point to a delta base in the same pack, this is a newer style of reference that saves space. False if the writer has to use the older (and more compatible style) of storing the full ObjectId of the delta base. Default setting: false
        Returns:
        true if delta base is stored as an offset; false if it is stored as an ObjectId.

      • setDeltaBaseAsOffset

        public void setDeltaBaseAsOffset​(boolean deltaBaseAsOffset)
        Set writer delta base format. Delta base can be written as an offset in a pack file (new approach reducing file size) or as an object id (legacy approach, compatible with old readers). Default setting: false
        Parameters:
        deltaBaseAsOffset - boolean indicating whether delta base can be stored as an offset.

      • isDeltaCompress

        public boolean isDeltaCompress()
        Check whether the writer will create new deltas on the fly. Default setting: true
        Returns:
        true if the writer will create a new delta when either isReuseDeltas() is false, or no suitable delta is available for reuse.

      • setDeltaCompress

        public void setDeltaCompress​(boolean deltaCompress)
        Set whether or not the writer will create new deltas on the fly. Default setting: true
        Parameters:
        deltaCompress - true to create deltas when isReuseDeltas() is false, or when a suitable delta isn't available for reuse. Set to false to write whole objects instead.

      • getMaxDeltaDepth

        public int getMaxDeltaDepth()
        Get maximum depth of delta chain set up for the writer. Generated chains are not longer than this value. Default setting: 50
        Returns:
        maximum delta chain depth.

      • setMaxDeltaDepth

        public void setMaxDeltaDepth​(int maxDeltaDepth)
        Set up maximum depth of delta chain for the writer. Generated chains are not longer than this value. Too low value causes low compression level, while too big makes unpacking (reading) longer. Default setting: 50
        Parameters:
        maxDeltaDepth - maximum delta chain depth.

      • getCutDeltaChains

        public boolean getCutDeltaChains()
        Whether existing delta chains should be cut at getMaxDeltaDepth().
        Returns:
        true if existing delta chains should be cut at getMaxDeltaDepth(). Default is false, allowing existing chains to be of any length.
        Since:
        3.0

      • setCutDeltaChains

        public void setCutDeltaChains​(boolean cut)
        Enable cutting existing delta chains at getMaxDeltaDepth(). By default this is disabled and existing chains are kept at whatever length a prior packer was configured to create. This allows objects to be packed one with a large depth (for example 250), and later to quickly repack the repository with a shorter depth (such as 50), but reusing the complete delta chains created by the earlier 250 depth.
        Parameters:
        cut - true to cut existing chains.
        Since:
        3.0

      • getSinglePack

        public boolean getSinglePack()
        Whether all of refs/* should be packed in a single pack.
        Returns:
        true if all of refs/* should be packed in a single pack. Default is false, packing a separate GC_REST pack for references outside of refs/heads/* and refs/tags/*.
        Since:
        4.9

      • setSinglePack

        public void setSinglePack​(boolean single)
        If true, packs a single GC pack for all objects reachable from refs/*. Otherwise packs the GC pack with objects reachable from refs/heads/* and refs/tags/*, and a GC_REST pack with the remaining reachable objects. Disabled by default, packing GC and GC_REST.
        Parameters:
        single - true to pack a single GC pack rather than GC and GC_REST packs
        Since:
        4.9

      • getDeltaSearchWindowSize

        public int getDeltaSearchWindowSize()
        Get the number of objects to try when looking for a delta base. This limit is per thread, if 4 threads are used the actual memory used will be 4 times this value. Default setting: 10
        Returns:
        the object count to be searched.

      • setDeltaSearchWindowSize

        public void setDeltaSearchWindowSize​(int objectCount)
        Set the number of objects considered when searching for a delta base. Default setting: 10
        Parameters:
        objectCount - number of objects to search at once. Must be at least 2.

      • getDeltaSearchMemoryLimit

        public long getDeltaSearchMemoryLimit()
        Get maximum number of bytes to put into the delta search window. Default setting is 0, for an unlimited amount of memory usage. Actual memory used is the lower limit of either this setting, or the sum of space used by at most getDeltaSearchWindowSize() objects. This limit is per thread, if 4 threads are used the actual memory limit will be 4 times this value.
        Returns:
        the memory limit.

      • setDeltaSearchMemoryLimit

        public void setDeltaSearchMemoryLimit​(long memoryLimit)
        Set the maximum number of bytes to put into the delta search window. Default setting is 0, for an unlimited amount of memory usage. If the memory limit is reached before getDeltaSearchWindowSize() the window size is temporarily lowered.
        Parameters:
        memoryLimit - Maximum number of bytes to load at once, 0 for unlimited.

      • getDeltaCacheSize

        public long getDeltaCacheSize()
        Get the size of the in-memory delta cache. This limit is for the entire writer, even if multiple threads are used. Default setting: 52428800L
        Returns:
        maximum number of bytes worth of delta data to cache in memory. If 0 the cache is infinite in size (up to the JVM heap limit anyway). A very tiny size such as 1 indicates the cache is effectively disabled.

      • setDeltaCacheSize

        public void setDeltaCacheSize​(long size)
        Set the maximum number of bytes of delta data to cache. During delta search, up to this many bytes worth of small or hard to compute deltas will be stored in memory. This cache speeds up writing by allowing the cached entry to simply be dumped to the output stream. Default setting: 52428800L
        Parameters:
        size - number of bytes to cache. Set to 0 to enable an infinite cache, set to 1 (an impossible size for any delta) to disable the cache.

      • getDeltaCacheLimit

        public int getDeltaCacheLimit()
        Maximum size in bytes of a delta to cache. Default setting: 100
        Returns:
        maximum size (in bytes) of a delta that should be cached.

      • setDeltaCacheLimit

        public void setDeltaCacheLimit​(int size)
        Set the maximum size of a delta that should be cached. During delta search, any delta smaller than this size will be cached, up to the getDeltaCacheSize() maximum limit. This speeds up writing by allowing these cached deltas to be output as-is. Default setting: 100
        Parameters:
        size - maximum size (in bytes) of a delta to be cached.

      • getBigFileThreshold

        public int getBigFileThreshold()
        Get the maximum file size that will be delta compressed. Files bigger than this setting will not be delta compressed, as they are more than likely already highly compressed binary data files that do not delta compress well, such as MPEG videos. Default setting: 52428800
        Returns:
        the configured big file threshold.

      • setBigFileThreshold

        public void setBigFileThreshold​(int bigFileThreshold)
        Set the maximum file size that should be considered for deltas. Default setting: 52428800
        Parameters:
        bigFileThreshold - the limit, in bytes.

      • isWaitPreventRacyPack

        public boolean isWaitPreventRacyPack()
        Get whether we wait before opening a newly written pack to prevent its lastModified timestamp could be racy
        Returns:
        whether we wait before opening a newly written pack to prevent its lastModified timestamp could be racy
        Since:
        5.1.8

      • doWaitPreventRacyPack

        public boolean doWaitPreventRacyPack​(long packSize)
        Get whether we wait before opening a newly written pack to prevent its lastModified timestamp could be racy. Returns true if waitToPreventRacyPack = true and packSize > minSizePreventRacyPack, false otherwise.
        Parameters:
        packSize - size of the pack file
        Returns:
        whether we wait before opening a newly written pack to prevent its lastModified timestamp could be racy
        Since:
        5.1.8

      • setWaitPreventRacyPack

        public void setWaitPreventRacyPack​(boolean waitPreventRacyPack)
        Set whether we wait before opening a newly written pack to prevent its lastModified timestamp could be racy
        Parameters:
        waitPreventRacyPack - whether we wait before opening a newly written pack to prevent its lastModified timestamp could be racy
        Since:
        5.1.8

      • getMinSizePreventRacyPack

        public long getMinSizePreventRacyPack()
        Get minimum packfile size for which we wait before opening a newly written pack to prevent its lastModified timestamp could be racy if isWaitToPreventRacyPack is true.
        Returns:
        minimum packfile size, default is 100 MiB
        Since:
        5.1.8

      • setMinSizePreventRacyPack

        public void setMinSizePreventRacyPack​(long minSizePreventRacyPack)
        Set minimum packfile size for which we wait before opening a newly written pack to prevent its lastModified timestamp could be racy if isWaitToPreventRacyPack is true.
        Parameters:
        minSizePreventRacyPack - minimum packfile size, default is 100 MiB
        Since:
        5.1.8

      • getCompressionLevel

        public int getCompressionLevel()
        Get the compression level applied to objects in the pack. Default setting: -1
        Returns:
        current compression level, see Deflater.

      • setCompressionLevel

        public void setCompressionLevel​(int level)
        Set the compression level applied to objects in the pack. Default setting: -1
        Parameters:
        level - compression level, must be a valid level recognized by the Deflater class.

      • getThreads

        public int getThreads()
        Get the number of threads used during delta compression. Default setting: 0 (auto-detect processors)
        Returns:
        number of threads used for delta compression. 0 will auto-detect the threads to the number of available processors.

      • setThreads

        public void setThreads​(int threads)
        Set the number of threads to use for delta compression. During delta compression, if there are enough objects to be considered the writer will start up concurrent threads and allow them to compress different sections of the repository concurrently. An application thread pool can be set by setExecutor(Executor). If not set a temporary pool will be created by the writer, and torn down automatically when compression is over. Default setting: 0 (auto-detect processors)
        Parameters:
        threads - number of threads to use. If <= 0 the number of available processors for this JVM is used.

      • getExecutor

        public Executor getExecutor()
        Get the preferred thread pool to execute delta search on.
        Returns:
        the preferred thread pool to execute delta search on.

      • setExecutor

        public void setExecutor​(Executor executor)
        Set the executor to use when using threads. During delta compression if the executor is non-null jobs will be queued up on it to perform delta compression in parallel. Aside from setting the executor, the caller must set setThreads(int) to enable threaded delta search.
        Parameters:
        executor - executor to use for threads. Set to null to create a temporary executor just for the writer.

      • getIndexVersion

        public int getIndexVersion()
        Get the pack index file format version this instance creates. Default setting: 2
        Returns:
        the index version, the special version 0 designates the oldest (most compatible) format available for the objects.
        See Also:
        PackIndexWriter

      • setIndexVersion

        public void setIndexVersion​(int version)
        Set the pack index file format version this instance will create. Default setting: 2
        Parameters:
        version - the version to write. The special version 0 designates the oldest (most compatible) format available for the objects.
        See Also:
        PackIndexWriter

      • isBuildBitmaps

        public boolean isBuildBitmaps()
        True if writer is allowed to build bitmaps for indexes. Default setting: true
        Returns:
        true if delta base is the writer can choose to output an index with bitmaps.
        Since:
        3.0

      • setBuildBitmaps

        public void setBuildBitmaps​(boolean buildBitmaps)
        Set writer to allow building bitmaps for supported pack files. Index files can include bitmaps to speed up future ObjectWalks. Default setting: true
        Parameters:
        buildBitmaps - boolean indicating whether bitmaps may be included in the index.
        Since:
        3.0

      • getBitmapContiguousCommitCount

        public int getBitmapContiguousCommitCount()
        Get the count of most recent commits for which to build bitmaps. Default setting: 100
        Returns:
        the count of most recent commits for which to build bitmaps
        Since:
        4.2

      • setBitmapContiguousCommitCount

        public void setBitmapContiguousCommitCount​(int count)
        Set the count of most recent commits for which to build bitmaps. Default setting: 100
        Parameters:
        count - the count of most recent commits for which to build bitmaps
        Since:
        4.2

      • getBitmapRecentCommitCount

        public int getBitmapRecentCommitCount()
        Get the count at which to switch from "bitmapRecentCommitSpan" to "bitmapDistantCommitSpan". Default setting: 20000
        Returns:
        the count for switching between recent and distant spans
        Since:
        4.2

      • setBitmapRecentCommitCount

        public void setBitmapRecentCommitCount​(int count)
        Set the count at which to switch from "bitmapRecentCommitSpan" to "bitmapDistantCommitSpan". Default setting: 20000
        Parameters:
        count - the count for switching between recent and distant spans
        Since:
        4.2

      • getBitmapRecentCommitSpan

        public int getBitmapRecentCommitSpan()
        Get the span of commits when building bitmaps for recent history. Default setting: 100
        Returns:
        the span of commits when building bitmaps for recent history
        Since:
        4.2

      • setBitmapRecentCommitSpan

        public void setBitmapRecentCommitSpan​(int span)
        Set the span of commits when building bitmaps for recent history. Default setting: 100
        Parameters:
        span - the span of commits when building bitmaps for recent history
        Since:
        4.2

      • getBitmapDistantCommitSpan

        public int getBitmapDistantCommitSpan()
        Get the span of commits when building bitmaps for distant history. Default setting: 5000
        Returns:
        the span of commits when building bitmaps for distant history
        Since:
        4.2

      • setBitmapDistantCommitSpan

        public void setBitmapDistantCommitSpan​(int span)
        Set the span of commits when building bitmaps for distant history. Default setting: 5000
        Parameters:
        span - the span of commits when building bitmaps for distant history
        Since:
        4.2

      • getBitmapExcessiveBranchCount

        public int getBitmapExcessiveBranchCount()
        Get the count of branches deemed "excessive". If the count of branches in a repository exceeds this number and bitmaps are enabled, "inactive" branches will have fewer bitmaps than "active" branches. Default setting: 100
        Returns:
        the count of branches deemed "excessive"
        Since:
        4.2

      • setBitmapExcessiveBranchCount

        public void setBitmapExcessiveBranchCount​(int count)
        Set the count of branches deemed "excessive". If the count of branches in a repository exceeds this number and bitmaps are enabled, "inactive" branches will have fewer bitmaps than "active" branches. Default setting: 100
        Parameters:
        count - the count of branches deemed "excessive"
        Since:
        4.2

      • getBitmapInactiveBranchAgeInDays

        public int getBitmapInactiveBranchAgeInDays()
        Get the age in days that marks a branch as "inactive". Default setting: 90
        Returns:
        the age in days that marks a branch as "inactive"
        Since:
        4.2

      • getSearchForReuseTimeout

        public Duration getSearchForReuseTimeout()
        Get the max time to spend during the search for reuse phase. Default setting:
        Returns:
        the maximum time to spend during the search for reuse phase.
        Since:
        5.13

      • setBitmapInactiveBranchAgeInDays

        public void setBitmapInactiveBranchAgeInDays​(int ageInDays)
        Set the age in days that marks a branch as "inactive". Default setting: 90
        Parameters:
        ageInDays - the age in days that marks a branch as "inactive"
        Since:
        4.2

      • setSearchForReuseTimeout

        public void setSearchForReuseTimeout​(Duration timeout)
        Set the max time to spend during the search for reuse phase.
        Parameters:
        timeout - max time allowed during the search for reuse phase Default setting:
        Since:
        5.13

      • fromConfig

        public void fromConfig​(Config rc)
        Update properties by setting fields from the configuration. If a property's corresponding variable is not defined in the supplied configuration, then it is left unmodified.
        Parameters:
        rc - configuration to read properties from.