Package org.apache.datasketches.tuple
Class Util
- java.lang.Object
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- org.apache.datasketches.tuple.Util
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public final class Util extends Object
Common utility functions for Tuples
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Constructor Summary
Constructors Constructor Description Util()
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Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static void
checkSeedHashes(short seedHashA, short seedHashB)
Checks the two given seed hashes.static short
computeSeedHash(long seed)
Computes and checks the 16-bit seed hash from the given long seed.static <S extends Summary>
S[]copySummaryArray(S[] summaryArr)
Will copy compact summary arrays as well as hashed summary tables (with nulls).static long[]
doubleToLongArray(double value)
Converts a double to a long[].static int
getStartingCapacity(int nomEntries, int lgResizeFactor)
Gets the starting capacity of a new sketch given the Nominal Entries and the log Resize Factor.static <S extends Summary>
S[]newSummaryArray(S[] summaryArr, int length)
Creates a new Summary Array with the specified lengthstatic long
stringArrHash(String[] strArray)
static String
stringConcat(String[] strArr)
Concatenate array of Strings to a single String.static long
stringHash(String s)
static byte[]
stringToByteArray(String value)
Converts a String to a UTF_8 byte array.
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Method Detail
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doubleToLongArray
public static final long[] doubleToLongArray(double value)
Converts a double to a long[].- Parameters:
value
- the given double value- Returns:
- the long array
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stringToByteArray
public static final byte[] stringToByteArray(String value)
Converts a String to a UTF_8 byte array. If the given value is either null or empty this method returns null.- Parameters:
value
- the given String value- Returns:
- the UTF_8 byte array
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computeSeedHash
public static short computeSeedHash(long seed)
Computes and checks the 16-bit seed hash from the given long seed. The seed hash may not be zero in order to maintain compatibility with older serialized versions that did not have this concept.- Parameters:
seed
- See Update Hash Seed- Returns:
- the seed hash.
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checkSeedHashes
public static final void checkSeedHashes(short seedHashA, short seedHashB)
Checks the two given seed hashes. If they are not equal, this method throws an Exception.- Parameters:
seedHashA
- given seed hash AseedHashB
- given seed hash B
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getStartingCapacity
public static int getStartingCapacity(int nomEntries, int lgResizeFactor)
Gets the starting capacity of a new sketch given the Nominal Entries and the log Resize Factor.- Parameters:
nomEntries
- the given Nominal EntrieslgResizeFactor
- the given log Resize Factor- Returns:
- the starting capacity
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stringConcat
public static String stringConcat(String[] strArr)
Concatenate array of Strings to a single String.- Parameters:
strArr
- the given String array- Returns:
- the concatenated String
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stringHash
public static long stringHash(String s)
- Parameters:
s
- the string to hash- Returns:
- the hash of the string
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stringArrHash
public static long stringArrHash(String[] strArray)
- Parameters:
strArray
- array of Strings- Returns:
- long hash of concatenated strings.
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copySummaryArray
public static <S extends Summary> S[] copySummaryArray(S[] summaryArr)
Will copy compact summary arrays as well as hashed summary tables (with nulls).- Type Parameters:
S
- type of summary- Parameters:
summaryArr
- the given summary array or table- Returns:
- the copy
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newSummaryArray
public static <S extends Summary> S[] newSummaryArray(S[] summaryArr, int length)
Creates a new Summary Array with the specified length- Type Parameters:
S
- the summary class type- Parameters:
summaryArr
- example array, only used to obtain the component type. It has no data.length
- the desired length of the returned array.- Returns:
- a new Summary Array with the specified length
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