Modifier and Type	Class and Description
private static class	ByteQuadsCanonicalizer.TableInfo Immutable value class used for sharing information as efficiently as possible, by only require synchronization of reference manipulation but not access to contents.

Field Summary

Modifier and Type	Field and Description
protected int	_count Total number of Strings in the symbol table; only used for child tables.
protected final boolean	_failOnDoS Flag that indicates whether we should throw an exception if enough hash collisions are detected (true); or just worked around (false).
protected int[]	_hashArea Primary hash information area: consists of `2 * _hashSize` entries of 16 bytes (4 ints), arranged in a cascading lookup structure (details of which may be tweaked depending on expected rates of collisions).
protected boolean	_hashShared Flag that indicates whether underlying data structures for the main hash area are shared or not.
protected int	_hashSize Number of slots for primary entries within `_hashArea`; which is at most `1/8` of actual size of the underlying array (4-int slots, primary covers only half of the area; plus, additional area for longer symbols after hash area).
protected final InternCache	_interner Entity that knows how to `intern` Strings, if needed, or `null` if no interning is wanted.
protected int	_longNameOffset Offset within `_hashArea` that follows main slots and contains quads for longer names (13 bytes or longer), and points to the first available int that may be used for appending quads of the next long name.
protected String[]	_names Array that contains `String` instances matching entries in `_hashArea`.
protected final ByteQuadsCanonicalizer	_parent Reference to the root symbol table, for child tables, so that they can merge table information back as necessary.
protected int	_secondaryStart Offset within `_hashArea` where secondary entries start
protected final int	_seed Seed value we use as the base to make hash codes non-static between different runs, but still stable for lifetime of a single symbol table instance.
protected int	_spilloverEnd Pointer to the offset within spill-over area where there is room for more spilled over entries (if any).
protected final AtomicReference<ByteQuadsCanonicalizer.TableInfo>	_tableInfo Member that is only used by the root table instance: root passes immutable state info child instances, and children may return new state if they add entries to the table.
protected int	_tertiaryShift Constant that determines size of buckets for tertiary entries: `1 << _tertiaryShift` is the size, and shift value is also used for translating from primary offset into tertiary bucket (shift right by `4 + _tertiaryShift`).
protected int	_tertiaryStart Offset within `_hashArea` where tertiary entries start
private static final int	DEFAULT_T_SIZE Initial size of the primary hash area.
protected static final int	MAX_ENTRIES_FOR_REUSE Let's only share reasonably sized symbol tables.
private static final int	MAX_T_SIZE Let's not expand symbol tables past some maximum size; with unique (~= random) names.
private static final int	MIN_HASH_SIZE No point in trying to construct tiny tables, just need to resize soon.
private static final int	MULT
private static final int	MULT2
private static final int	MULT3

Constructor Summary

Access	Constructor and Description
private	ByteQuadsCanonicalizer(int Initial primary hash area size sz, int Random seed valued used to make it more difficult to cause collisions (used for collision-based DoS attacks). seed) Constructor used for creating per-`TokenStreamFactory` "root" symbol tables: ones used for merging and sharing common symbols
private	ByteQuadsCanonicalizer(ByteQuadsCanonicalizer parent, int seed, ByteQuadsCanonicalizer.TableInfo state, boolean intern, boolean failOnDoS) Constructor used when creating a child instance
private	ByteQuadsCanonicalizer(ByteQuadsCanonicalizer.TableInfo state) Alternate constructor used in cases where a "placeholder" child instance is needed when symbol table is not really used, but caller needs a non-null placeholder to keep code functioning with minimal awareness of distinction (all lookups fail to match any name without error; add methods should NOT be called).

Method Summary

Modifier and Type	Method and Description
private int	_appendLongName(int[] quads, int qlen)
private final int	_calcOffset(int hash)
pack-priv static int	_calcTertiaryShift(int primarySlots)
private boolean	_checkNeedForRehash()
private int	_findOffsetForAdd(int Hash of name for which to find location hash) Method called to find the location within hash table to add a new symbol in.
private String	_findSecondary(int origOffset, int q1)
private String	_findSecondary(int origOffset, int q1, int q2)
private String	_findSecondary(int origOffset, int q1, int q2, int q3)
private String	_findSecondary(int origOffset, int hash, int[] q, int qlen)
protected void	_reportTooManyCollisions()
private int	_resizeAndFindOffsetForAdd(int hash)
private final int	_spilloverStart() Helper method that calculates start of the spillover area
private boolean	_verifyLongName(int[] q, int qlen, int spillOffset)
private boolean	_verifyLongName2(int[] q, int qlen, int spillOffset)
private void	_verifySharing()
public String	Returns: name (possibly interned) addName(String Name to add name, int Quad representation of the name q1)
public String	Returns: name (possibly interned) addName(String Name to add name, int First quad of name representation q1, int Second quad of name representation q2)
public String	Returns: name (possibly interned) addName(String Name to add name, int First quad of name representation q1, int Second quad of name representation q2, int Third quad of name representation q3)
public String	Returns: name (possibly interned) addName(String Name to add name, int[] Quads of name representation q, int Number of quads in `q` qlen)
public int	Returns: number of primary slots table has currently bucketCount()
public int	calcHash(int q1)
public int	calcHash(int q1, int q2)
public int	calcHash(int q1, int q2, int q3)
public int	Returns: hash calcHash(int[] int array q, int length qlen)
public static ByteQuadsCanonicalizer	Returns: Root instance to use for constructing new child instances createRoot() Factory method to call to create a symbol table instance with a randomized seed value.
protected static ByteQuadsCanonicalizer	createRoot(int seed)
public String	findName(int q1)
public String	findName(int q1, int q2)
public String	findName(int q1, int q2, int q3)
public String	findName(int[] q, int qlen)
public int	hashSeed()
public boolean	Returns: True for "real", canonicalizing child tables; false for root table as well as placeholder "child" tables. isCanonicalizing()
public ByteQuadsCanonicalizer	Returns: Actual canonicalizer instance that can be used by a parser makeChild(int Bit flags of active `com.fasterxml.jackson.core.JsonFactory.Feature`s enabled. flags) Factory method used to create actual symbol table instance to use for parsing.
public ByteQuadsCanonicalizer	Returns: Actual canonicalizer instance that can be used by a parser if (and only if) canonicalization is enabled; otherwise a non-null "placeholder" instance. makeChildOrPlaceholder(int Bit flags of active `com.fasterxml.jackson.core.JsonFactory.Feature`s enabled. flags) Method similar to `makeChild` but one that only creates real instance of `com.fasterxml.jackson.core.JsonFactory.Feature#CANONICALIZE_FIELD_NAMES` is enabled: otherwise a "bogus" instance is created.
public boolean	Returns: Whether main hash area has been modified maybeDirty() Method called to check to quickly see if a child symbol table may have gotten additional entries.
private void	mergeChild(ByteQuadsCanonicalizer.TableInfo childState)
private void	nukeSymbols(boolean fill) Helper method called to empty all shared symbols, but to leave arrays allocated
public int	Returns: Number of entries in the primary hash area primaryCount() Method mostly needed by unit tests; calculates number of entries that are in the primary slot set.
private void	rehash()
public void	release() Method called by the using code to indicate it is done with this instance.
public int	Returns: Number of entries in the secondary hash area secondaryCount() Method mostly needed by unit tests; calculates number of entries in secondary buckets
public int	Returns: Number of symbol entries contained by this canonicalizer instance size()
public int	Returns: Number of entries in the linear spill-over areay spilloverCount() Method mostly needed by unit tests; calculates number of entries in shared spill-over area
public int	Returns: Number of entries in the tertiary hash area tertiaryCount() Method mostly needed by unit tests; calculates number of entries in tertiary buckets
public String	toString() Overrides java.lang.Object.toString. Returns a string representation of the object.
public int	totalCount()

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll wait wait wait

Field Detail

_count	back to summary
protected int _count Total number of Strings in the symbol table; only used for child tables.

_failOnDoS	back to summary
protected final boolean _failOnDoS Flag that indicates whether we should throw an exception if enough hash collisions are detected (true); or just worked around (false). Since 2.4

_failOnDoS

back to summary

protected final boolean _failOnDoS

Flag that indicates whether we should throw an exception if enough hash collisions are detected (true); or just worked around (false).

Since: 2.4

_hashArea	back to summary
protected int[] _hashArea Primary hash information area: consists of `2 * _hashSize` entries of 16 bytes (4 ints), arranged in a cascading lookup structure (details of which may be tweaked depending on expected rates of collisions).

_hashShared	back to summary
protected boolean _hashShared Flag that indicates whether underlying data structures for the main hash area are shared or not. If they are, then they need to be handled in copy-on-write way, i.e. if they need to be modified, a copy needs to be made first; at this point it will not be shared any more, and can be modified. This flag needs to be checked both when adding new main entries, and when adding new collision list queues (i.e. creating a new collision list head entry)

_hashShared

back to summary

protected boolean _hashShared

Flag that indicates whether underlying data structures for the main hash area are shared or not. If they are, then they need to be handled in copy-on-write way, i.e. if they need to be modified, a copy needs to be made first; at this point it will not be shared any more, and can be modified.

This flag needs to be checked both when adding new main entries, and when adding new collision list queues (i.e. creating a new collision list head entry)

_hashSize	back to summary
protected int _hashSize Number of slots for primary entries within `_hashArea`; which is at most `1/8` of actual size of the underlying array (4-int slots, primary covers only half of the area; plus, additional area for longer symbols after hash area).

_interner back to summary

_interner	back to summary
protected final InternCache _interner Entity that knows how to `intern` Strings, if needed, or `null` if no interning is wanted. Since 2.16

protected final InternCache _interner

Entity that knows how to intern Strings, if needed, or null if no interning is wanted.

Since: 2.16

_longNameOffset	back to summary
protected int _longNameOffset Offset within `_hashArea` that follows main slots and contains quads for longer names (13 bytes or longer), and points to the first available int that may be used for appending quads of the next long name. Note that long name area follows immediately after the fixed-size main hash area (`_hashArea`).

_names	back to summary
protected String[] _names Array that contains `String` instances matching entries in `_hashArea`. Contains nulls for unused entries. Note that this size is twice that of `_hashArea`

_parent	back to summary
protected final ByteQuadsCanonicalizer _parent Reference to the root symbol table, for child tables, so that they can merge table information back as necessary.

_secondaryStart	back to summary
protected int _secondaryStart Offset within `_hashArea` where secondary entries start

_seed	back to summary
protected final int _seed Seed value we use as the base to make hash codes non-static between different runs, but still stable for lifetime of a single symbol table instance. This is done for security reasons, to avoid potential DoS attack via hash collisions.

_spilloverEnd	back to summary
protected int _spilloverEnd Pointer to the offset within spill-over area where there is room for more spilled over entries (if any). Spill over area is within fixed-size portion of `_hashArea`.

_tableInfo	back to summary
protected final AtomicReference<ByteQuadsCanonicalizer.TableInfo> _tableInfo Member that is only used by the root table instance: root passes immutable state info child instances, and children may return new state if they add entries to the table. Child tables do NOT use the reference.

_tertiaryShift back to summary

_tertiaryShift	back to summary
protected int _tertiaryShift Constant that determines size of buckets for tertiary entries: `1 << _tertiaryShift` is the size, and shift value is also used for translating from primary offset into tertiary bucket (shift right by `4 + _tertiaryShift`). Default value is 2, for buckets of 4 slots; grows bigger with bigger table sizes.

protected int _tertiaryShift

Constant that determines size of buckets for tertiary entries: 1 << _tertiaryShift is the size, and shift value is also used for translating from primary offset into tertiary bucket (shift right by 4 + _tertiaryShift).

Default value is 2, for buckets of 4 slots; grows bigger with bigger table sizes.

_tertiaryStart	back to summary
protected int _tertiaryStart Offset within `_hashArea` where tertiary entries start

DEFAULT_T_SIZE	back to summary
private static final int DEFAULT_T_SIZE Initial size of the primary hash area. Each entry consumes 4 ints (16 bytes), and secondary area is same as primary; so default size will use 2kB of memory (plus 64x4 or 64x8 (256/512 bytes) for references to Strings, and Strings themselves).

MAX_ENTRIES_FOR_REUSE	back to summary
protected static final int MAX_ENTRIES_FOR_REUSE Let's only share reasonably sized symbol tables. Max size set to 3/4 of 8k; this corresponds to 256k main hash index. This should allow for enough distinct names for almost any case, while preventing ballooning for cases where names are unique (or close thereof).

MAX_T_SIZE	back to summary
private static final int MAX_T_SIZE Let's not expand symbol tables past some maximum size; with unique (~= random) names. Size is in

MIN_HASH_SIZE	back to summary
private static final int MIN_HASH_SIZE No point in trying to construct tiny tables, just need to resize soon.

MULT	back to summary
private static final int MULT

MULT2	back to summary
private static final int MULT2

MULT3	back to summary
private static final int MULT3

Constructor Detail

ByteQuadsCanonicalizer back to summary

ByteQuadsCanonicalizer	back to summary
private ByteQuadsCanonicalizer(int sz, int seed) Constructor used for creating per-`TokenStreamFactory` "root" symbol tables: ones used for merging and sharing common symbols Parameters sz:int Initial primary hash area size seed:int Random seed valued used to make it more difficult to cause collisions (used for collision-based DoS attacks).

private ByteQuadsCanonicalizer(int sz, int seed)

Constructor used for creating per-TokenStreamFactory "root" symbol tables: ones used for merging and sharing common symbols

Parameters

sz:int: Initial primary hash area size
seed:int: Random seed valued used to make it more difficult to cause collisions (used for collision-based DoS attacks).

ByteQuadsCanonicalizer	back to summary
private ByteQuadsCanonicalizer(ByteQuadsCanonicalizer parent, int seed, ByteQuadsCanonicalizer.TableInfo state, boolean intern, boolean failOnDoS) Constructor used when creating a child instance

ByteQuadsCanonicalizer	back to summary
private ByteQuadsCanonicalizer(ByteQuadsCanonicalizer.TableInfo state) Alternate constructor used in cases where a "placeholder" child instance is needed when symbol table is not really used, but caller needs a non-null placeholder to keep code functioning with minimal awareness of distinction (all lookups fail to match any name without error; add methods should NOT be called). Since 2.13

ByteQuadsCanonicalizer

back to summary

private ByteQuadsCanonicalizer(ByteQuadsCanonicalizer.TableInfo state)

Alternate constructor used in cases where a "placeholder" child instance is needed when symbol table is not really used, but caller needs a non-null placeholder to keep code functioning with minimal awareness of distinction (all lookups fail to match any name without error; add methods should NOT be called).

Since: 2.13

Method Detail

_appendLongName	back to summary
private int _appendLongName(int[] quads, int qlen)

_calcOffset	back to summary
private final int _calcOffset(int hash)

_calcTertiaryShift	back to summary
pack-priv static int _calcTertiaryShift(int primarySlots)

_checkNeedForRehash	back to summary
private boolean _checkNeedForRehash()

_findOffsetForAdd	back to summary
private int _findOffsetForAdd(int hash) throws StreamConstraintsException Method called to find the location within hash table to add a new symbol in. Parameters hash:int Hash of name for which to find location Exceptions StreamConstraintsException: If name length exceeds maximum allowed.

_findOffsetForAdd

back to summary

private int _findOffsetForAdd(int hash) throws StreamConstraintsException

Method called to find the location within hash table to add a new symbol in.

Parameters

hash:int: Hash of name for which to find location

Exceptions

StreamConstraintsException:: If name length exceeds maximum allowed.

_findSecondary	back to summary
private String _findSecondary(int origOffset, int q1)

_findSecondary	back to summary
private String _findSecondary(int origOffset, int q1, int q2)

_findSecondary	back to summary
private String _findSecondary(int origOffset, int q1, int q2, int q3)

_findSecondary	back to summary
private String _findSecondary(int origOffset, int hash, int[] q, int qlen)

_reportTooManyCollisions	back to summary
protected void _reportTooManyCollisions() throws StreamConstraintsException

_resizeAndFindOffsetForAdd	back to summary
private int _resizeAndFindOffsetForAdd(int hash) throws StreamConstraintsException

_spilloverStart	back to summary
private final int _spilloverStart() Helper method that calculates start of the spillover area

_verifyLongName	back to summary
private boolean _verifyLongName(int[] q, int qlen, int spillOffset)

_verifyLongName2	back to summary
private boolean _verifyLongName2(int[] q, int qlen, int spillOffset)

_verifySharing	back to summary
private void _verifySharing()

addName	back to summary
public String addName(String name, int q1) throws StreamConstraintsException Parameters name:String Name to add q1:int Quad representation of the name Returns:String name (possibly interned) Exceptions StreamConstraintsException: if the constraint exceptions

addName	back to summary
public String addName(String name, int q1, int q2) throws StreamConstraintsException Parameters name:String Name to add q1:int First quad of name representation q2:int Second quad of name representation Returns:String name (possibly interned) Exceptions StreamConstraintsException: if the constraint exceptions

addName	back to summary
public String addName(String name, int q1, int q2, int q3) throws StreamConstraintsException Parameters name:String Name to add q1:int First quad of name representation q2:int Second quad of name representation q3:int Third quad of name representation Returns:String name (possibly interned) Exceptions StreamConstraintsException: if the constraint exceptions

addName	back to summary
public String addName(String name, int[] q, int qlen) throws StreamConstraintsException Parameters name:String Name to add q:int[] Quads of name representation qlen:int Number of quads in `q` Returns:String name (possibly interned) Exceptions StreamConstraintsException: if the constraint exceptions

bucketCount	back to summary
public int bucketCount() Returns:int number of primary slots table has currently

calcHash	back to summary
public int calcHash(int q1)

calcHash	back to summary
public int calcHash(int q1, int q2)

calcHash	back to summary
public int calcHash(int q1, int q2, int q3)

calcHash	back to summary
public int calcHash(int[] q, int qlen) Parameters q:int[] int array qlen:int length Returns:int hash Exceptions IllegalArgumentException: if `qlen` is less than 4

createRoot

back to summary

public static ByteQuadsCanonicalizer createRoot()

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

Returns:ByteQuadsCanonicalizer: Root instance to use for constructing new child instances

createRoot	back to summary
protected static ByteQuadsCanonicalizer createRoot(int seed)

findName	back to summary
public String findName(int q1)

findName	back to summary
public String findName(int q1, int q2)

findName	back to summary
public String findName(int q1, int q2, int q3)

findName	back to summary
public String findName(int[] q, int qlen)

hashSeed	back to summary
public int hashSeed()

isCanonicalizing	back to summary
public boolean isCanonicalizing() Returns:boolean True for "real", canonicalizing child tables; false for root table as well as placeholder "child" tables. Since 2.13

makeChild back to summary

public ByteQuadsCanonicalizer makeChild(int flags)

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

Parameters

flags:int: Bit flags of active com.fasterxml.jackson.core.JsonFactory.Features enabled.

Returns:ByteQuadsCanonicalizer

Actual canonicalizer instance that can be used by a parser

makeChildOrPlaceholder back to summary

public ByteQuadsCanonicalizer makeChildOrPlaceholder(int flags)

Method similar to makeChild but one that only creates real instance of com.fasterxml.jackson.core.JsonFactory.Feature#CANONICALIZE_FIELD_NAMES is enabled: otherwise a "bogus" instance is created.

Parameters

flags:int: Bit flags of active com.fasterxml.jackson.core.JsonFactory.Features enabled.

Returns:ByteQuadsCanonicalizer

Actual canonicalizer instance that can be used by a parser if (and only if) canonicalization is enabled; otherwise a non-null "placeholder" instance.

Since

2.13

maybeDirty

back to summary

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.

Returns:boolean: Whether main hash area has been modified

mergeChild	back to summary
private void mergeChild(ByteQuadsCanonicalizer.TableInfo childState)

nukeSymbols	back to summary
private void nukeSymbols(boolean fill) Helper method called to empty all shared symbols, but to leave arrays allocated

primaryCount

back to summary

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

Returns:int: Number of entries in the primary hash area

rehash	back to summary
private void rehash() throws StreamConstraintsException

release	back to summary
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.

secondaryCount

back to summary

public int secondaryCount()

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

Returns:int: Number of entries in the secondary hash area

size	back to summary
public int size() Returns:int Number of symbol entries contained by this canonicalizer instance

spilloverCount

back to summary

public int spilloverCount()

Method mostly needed by unit tests; calculates number of entries in shared spill-over area

Returns:int: Number of entries in the linear spill-over areay

tertiaryCount

back to summary

public int tertiaryCount()

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

Returns:int: Number of entries in the tertiary hash area

toString

back to summary

public String toString()

Overrides java.lang.Object.toString.

Doc from java.lang.Object.toString.

Returns a string representation of the object.

Returns:String

a string representation of the object.

Annotations

@Override

totalCount	back to summary
public int totalCount()

com.fasterxml.jackson.core.sym back to summary

private final Class ByteQuadsCanonicalizer.TableInfo

Class Inheritance

extends Object

java.lang.Object
com.fasterxml.jackson.core.sym.ByteQuadsCanonicalizer.TableInfo

Immutable value class used for sharing information as efficiently as possible, by only require synchronization of reference manipulation but not access to contents.

Since: 2.1

Field Summary

Modifier and Type	Field and Description
public final int	count
public final int	longNameOffset
public final int[]	mainHash
public final String[]	names
public final int	size
public final int	spilloverEnd
public final int	tertiaryShift

Constructor Summary

Access	Constructor and Description
public	TableInfo(int size, int count, int tertiaryShift, int[] mainHash, String[] names, int spilloverEnd, int longNameOffset)
public	TableInfo(ByteQuadsCanonicalizer src)

Method Summary

Modifier and Type	Method and Description
public static ByteQuadsCanonicalizer.TableInfo	createInitial(int sz)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

count	back to summary
public final int count

longNameOffset	back to summary
public final int longNameOffset

mainHash	back to summary
public final int[] mainHash

names	back to summary
public final String[] names

size	back to summary
public final int size

spilloverEnd	back to summary
public final int spilloverEnd

tertiaryShift	back to summary
public final int tertiaryShift

Constructor Detail

TableInfo	back to summary
public TableInfo(int size, int count, int tertiaryShift, int[] mainHash, String[] names, int spilloverEnd, int longNameOffset)

TableInfo	back to summary
public TableInfo(ByteQuadsCanonicalizer src)

Method Detail

createInitial	back to summary
public static ByteQuadsCanonicalizer.TableInfo createInitial(int sz)

public final Class ByteQuadsCanonicalizer

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private final Class ByteQuadsCanonicalizer.TableInfo

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail