Package com.fasterxml.jackson.core.sym

Class ByteQuadsCanonicalizer

java.lang.Object

com.fasterxml.jackson.core.sym.ByteQuadsCanonicalizer

public final class ByteQuadsCanonicalizer
extends Object

Replacement for BytesToNameCanonicalizer which aims at more localized memory access due to flattening of name quad data. Performance improvement modest for simple JSON document data binding (maybe 3%), but should help more for larger symbol tables, or for binary formats like Smile.

Hash area is divided into 4 sections:

1. Primary area (1/2 of total size), direct match from hash (LSB)
2. Secondary area (1/4 of total size), match from hash (LSB) >> 1
3. Tertiary area (1/8 of total size), match from hash (LSB) >> 2
4. Spill-over area (remaining 1/8) with linear scan, insertion order

and within every area, entries are 4 ints, where 1 - 3 ints contain 1 - 12 UTF-8 encoded bytes of name (null-padded), and last int is offset in _names that contains actual name Strings.

Since:

2.6

Method Summary

Modifier and Type	Method	Description
String	addName(String name, int q1)
String	addName(String name, int[] q, int qlen)
String	addName(String name, int q1, int q2)
String	addName(String name, int q1, int q2, int q3)
int	bucketCount()	Returns number of primary slots table has currently
int	calcHash(int q1)
int	calcHash(int[] q, int qlen)
int	calcHash(int q1, int q2)
int	calcHash(int q1, int q2, int q3)
static ByteQuadsCanonicalizer	createRoot()	Factory method to call to create a symbol table instance with a randomized seed value.
String	findName(int q1)
String	findName(int[] q, int qlen)
String	findName(int q1, int q2)
String	findName(int q1, int q2, int q3)
int	hashSeed()
ByteQuadsCanonicalizer	makeChild(int flags)	Factory method used to create actual symbol table instance to use for parsing.
boolean	maybeDirty()	Method called to check to quickly see if a child symbol table may have gotten additional entries.
int	primaryCount()	Method mostly needed by unit tests; calculates number of entries that are in the primary slot set.
void	release()	Method called by the using code to indicate it is done with this instance.
int	secondaryCount()	Method mostly needed by unit tests; calculates number of entries in secondary buckets
int	size()
int	spilloverCount()	Method mostly needed by unit tests; calculates number of entries in shared spillover area
int	tertiaryCount()	Method mostly needed by unit tests; calculates number of entries in tertiary buckets
String	toString()
int	totalCount()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

createRoot

public static ByteQuadsCanonicalizer createRoot()

Factory method to call to create a symbol table instance with a randomized seed value.

makeChild

public ByteQuadsCanonicalizer makeChild(int flags)

Factory method used to create actual symbol table instance to use for parsing.

release

public void release()

Method called by the using code to indicate it is done with this instance. This lets instance merge accumulated changes into parent (if need be), safely and efficiently, and without calling code having to know about parent information.

size

public int size()

bucketCount

public int bucketCount()

Returns number of primary slots table has currently

maybeDirty

public boolean maybeDirty()

Method called to check to quickly see if a child symbol table may have gotten additional entries. Used for checking to see if a child table should be merged into shared table.

hashSeed

public int hashSeed()

primaryCount

public int primaryCount()

Method mostly needed by unit tests; calculates number of entries that are in the primary slot set. These are "perfect" entries, accessible with a single lookup

secondaryCount

public int secondaryCount()

Method mostly needed by unit tests; calculates number of entries in secondary buckets

tertiaryCount

public int tertiaryCount()

Method mostly needed by unit tests; calculates number of entries in tertiary buckets

spilloverCount

public int spilloverCount()

Method mostly needed by unit tests; calculates number of entries in shared spillover area

totalCount

public int totalCount()

toString

public String toString()

Overrides:

toString in class Object

findName

public String findName(int q1)

findName

public String findName(int q1,
                       int q2)

findName

public String findName(int q1,
                       int q2,
                       int q3)

findName

public String findName(int[] q,
                       int qlen)

addName

public String addName(String name,
                      int q1)

addName

public String addName(String name,
                      int q1,
                      int q2)

addName

public String addName(String name,
                      int q1,
                      int q2,
                      int q3)

addName

public String addName(String name,
                      int[] q,
                      int qlen)

calcHash

public int calcHash(int q1)

calcHash

public int calcHash(int q1,
                    int q2)

calcHash

public int calcHash(int q1,
                    int q2,
                    int q3)

calcHash

public int calcHash(int[] q,
                    int qlen)