Package org.eclipse.jgit.storage.pack
Class PackConfig
- java.lang.Object
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- org.eclipse.jgit.storage.pack.PackConfig
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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.
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Field Summary
Fields Modifier and Type Field Description static int
DEFAULT_BIG_FILE_THRESHOLD
Default big file threshold: 52428800static boolean
DEFAULT_BUILD_BITMAPS
Default value of the build bitmaps option: truestatic boolean
DEFAULT_DELTA_BASE_AS_OFFSET
Default value of delta base as offset option: falsestatic int
DEFAULT_DELTA_CACHE_LIMIT
Default delta cache limit: 100static long
DEFAULT_DELTA_CACHE_SIZE
Default delta cache size: 52428800Lstatic boolean
DEFAULT_DELTA_COMPRESS
Default value of delta compress option: truestatic int
DEFAULT_DELTA_SEARCH_WINDOW_SIZE
Default window size during packing: 10static int
DEFAULT_INDEX_VERSION
Default index version: 2static int
DEFAULT_MAX_DELTA_DEPTH
Default value of maximum delta chain depth: 50static boolean
DEFAULT_REUSE_DELTAS
Default value of deltas reuse option: truestatic boolean
DEFAULT_REUSE_OBJECTS
Default value of objects reuse option: true
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Constructor Summary
Constructors Constructor Description PackConfig()
Create a default configuration.PackConfig(Config cfg)
Create a configuration honoring settings in aConfig
.PackConfig(Repository db)
Create a configuration honoring the repository's settings.PackConfig(PackConfig cfg)
Copy an existing configuration to a new instance.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
fromConfig(Config rc)
Update properties by setting fields from the configuration.int
getBigFileThreshold()
Get the maximum file size that will be delta compressed.int
getCompressionLevel()
Get the compression level applied to objects in the pack.boolean
getCutDeltaChains()
int
getDeltaCacheLimit()
Maximum size in bytes of a delta to cache.long
getDeltaCacheSize()
Get the size of the in-memory delta cache.long
getDeltaSearchMemoryLimit()
Get maximum number of bytes to put into the delta search window.int
getDeltaSearchWindowSize()
Get the number of objects to try when looking for a delta base.Executor
getExecutor()
int
getIndexVersion()
Get the pack index file format version this instance creates.int
getMaxDeltaDepth()
Get maximum depth of delta chain set up for the writer.int
getThreads()
Get the number of threads used during delta compression.boolean
isBuildBitmaps()
True if writer is allowed to build bitmaps for indexes.boolean
isDeltaBaseAsOffset()
True if writer can use offsets to point to a delta base.boolean
isDeltaCompress()
Check whether the writer will create new deltas on the fly.boolean
isReuseDeltas()
Check whether to reuse deltas existing in repository.boolean
isReuseObjects()
Checks whether to reuse existing objects representation in repository.void
setBigFileThreshold(int bigFileThreshold)
Set the maximum file size that should be considered for deltas.void
setBuildBitmaps(boolean buildBitmaps)
Set writer to allow building bitmaps for supported pack files.void
setCompressionLevel(int level)
Set the compression level applied to objects in the pack.void
setCutDeltaChains(boolean cut)
Enable cutting existing delta chains atgetMaxDeltaDepth()
.void
setDeltaBaseAsOffset(boolean deltaBaseAsOffset)
Set writer delta base format.void
setDeltaCacheLimit(int size)
Set the maximum size of a delta that should be cached.void
setDeltaCacheSize(long size)
Set the maximum number of bytes of delta data to cache.void
setDeltaCompress(boolean deltaCompress)
Set whether or not the writer will create new deltas on the fly.void
setDeltaSearchMemoryLimit(long memoryLimit)
Set the maximum number of bytes to put into the delta search window.void
setDeltaSearchWindowSize(int objectCount)
Set the number of objects considered when searching for a delta base.void
setExecutor(Executor executor)
Set the executor to use when using threads.void
setIndexVersion(int version)
Set the pack index file format version this instance will create.void
setMaxDeltaDepth(int maxDeltaDepth)
Set up maximum depth of delta chain for the writer.void
setReuseDeltas(boolean reuseDeltas)
Set reuse deltas configuration option for the writer.void
setReuseObjects(boolean reuseObjects)
Set reuse objects configuration option for the writer.void
setThreads(int threads)
Set the number of threads to use for delta compression.String
toString()
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Field Detail
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DEFAULT_REUSE_DELTAS
public static final boolean DEFAULT_REUSE_DELTAS
Default value of deltas reuse option: true- See Also:
setReuseDeltas(boolean)
, Constant Field Values
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DEFAULT_REUSE_OBJECTS
public static final boolean DEFAULT_REUSE_OBJECTS
Default value of objects reuse option: true- See Also:
setReuseObjects(boolean)
, Constant Field Values
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DEFAULT_DELTA_COMPRESS
public static final boolean DEFAULT_DELTA_COMPRESS
Default value of delta compress option: true- See Also:
setDeltaCompress(boolean)
, Constant Field Values
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DEFAULT_DELTA_BASE_AS_OFFSET
public static final boolean DEFAULT_DELTA_BASE_AS_OFFSET
Default value of delta base as offset option: false
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DEFAULT_MAX_DELTA_DEPTH
public static final int DEFAULT_MAX_DELTA_DEPTH
Default value of maximum delta chain depth: 50- See Also:
setMaxDeltaDepth(int)
, Constant Field Values
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DEFAULT_DELTA_SEARCH_WINDOW_SIZE
public static final int DEFAULT_DELTA_SEARCH_WINDOW_SIZE
Default window size during packing: 10
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DEFAULT_BIG_FILE_THRESHOLD
public static final int DEFAULT_BIG_FILE_THRESHOLD
Default big file threshold: 52428800- See Also:
setBigFileThreshold(int)
, Constant Field Values
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DEFAULT_DELTA_CACHE_SIZE
public static final long DEFAULT_DELTA_CACHE_SIZE
Default delta cache size: 52428800L- See Also:
setDeltaCacheSize(long)
, Constant Field Values
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DEFAULT_DELTA_CACHE_LIMIT
public static final int DEFAULT_DELTA_CACHE_LIMIT
Default delta cache limit: 100- See Also:
setDeltaCacheLimit(int)
, Constant Field Values
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DEFAULT_INDEX_VERSION
public static final int DEFAULT_INDEX_VERSION
Default index version: 2- See Also:
setIndexVersion(int)
, Constant Field Values
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DEFAULT_BUILD_BITMAPS
public static final boolean DEFAULT_BUILD_BITMAPS
Default value of the build bitmaps option: true- Since:
- 3.0
- See Also:
setBuildBitmaps(boolean)
, Constant Field Values
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Constructor Detail
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PackConfig
public PackConfig()
Create a default configuration.
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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.
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PackConfig
public PackConfig(Config cfg)
Create a configuration honoring settings in aConfig
.- 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.
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PackConfig
public PackConfig(PackConfig cfg)
Copy an existing configuration to a new instance.- Parameters:
cfg
- the source configuration to copy from.
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Method Detail
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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 whenisReuseDeltas()
is false, or when a suitable delta isn't available for reuse. Set to false to write whole objects instead.
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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.
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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.
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getCutDeltaChains
public boolean getCutDeltaChains()
- 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
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setCutDeltaChains
public void setCutDeltaChains(boolean cut)
Enable cutting existing delta chains atgetMaxDeltaDepth()
. 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
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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.
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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.
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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 mostgetDeltaSearchWindowSize()
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.
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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 beforegetDeltaSearchWindowSize()
the window size is temporarily lowered.- Parameters:
memoryLimit
- Maximum number of bytes to load at once, 0 for unlimited.
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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.
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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.
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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.
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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 thegetDeltaCacheSize()
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.
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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.
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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.
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getCompressionLevel
public int getCompressionLevel()
Get the compression level applied to objects in the pack. Default setting: -1- Returns:
- current compression level, see
Deflater
.
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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 theDeflater
class.
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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.
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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 bysetExecutor(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.
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getExecutor
public Executor getExecutor()
- Returns:
- the preferred thread pool to execute delta search on.
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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 setsetThreads(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.
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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
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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
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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
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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
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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.
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