Modifier and Type	Class and Description
private abstract static class	AsciiStringInterner.BaseKey
private static class	AsciiStringInterner.Key Instance used for inserting values into the cache.
private class	AsciiStringInterner.StringReference Custom `SoftReference` implementation which maintains a reference to the key in the cache, which allows aggressive cleaning when garbage collector collects the `String` instance.
private static class	AsciiStringInterner.TempKey Only used for lookups, never to actually store entries.

Modifier and Type	Field and Description
pack-priv final ConcurrentMap<AsciiStringInterner.BaseKey, SoftReference<String>>	cache Contains the canonicalized values, keyed by the ascii `byte[]`.
pack-priv final ReferenceQueue<String>	refQueue Used for `Reference` as values in `cache`.

Access	Constructor and Description
pack-priv	AsciiStringInterner()

Method Summary

Modifier and Type	Method and Description
pack-priv static boolean	arrayEquals(byte[] a, int aOffset, int aLength, byte[] b, int bOffset, int bLength) Performs equality check between a and b (with corresponding offset/length values).
private void	cleanQueue() Process any entries in `refQueue` to purge from the `cache`.
public String	Returns: Decoded `String` from bytes. getString(byte[] The bytes of the String. Must not be `null`. bytes, int Offset into bytes to start. offset, int The number of bytes in bytes which are relevant. length, Encoding To use if non-ascii bytes seen. encoding) Produces a `String` instance for the given bytes.
public String	Returns: Decoded `String` from bytes. getStringIfPresent(byte[] The bytes of the String. Must not be `null`. bytes, int Offset into bytes to start. offset, int The number of bytes in bytes which are relevant. length, Encoding To use if non-ascii bytes seen. encoding) Produces a `String` instance for the given bytes.
private static int	Returns: hash code for relevant bytes, or `0` if non-ascii bytes present. hashKey(byte[] bytes, int offset, int length) Generates a hash value for the relevant entries in bytes as long as all values are ascii (`>= 0`).
public boolean	Returns: Indication if val is an ascii String and placed into cache. putString(String The value to intern. Must not be `null`. val) Preemptively populates a value into the cache.
public String	toString() Overrides java.lang.Object.toString. Returns a string representation of the object.

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

cache	back to summary
pack-priv final ConcurrentMap<AsciiStringInterner.BaseKey, SoftReference<String>> cache Contains the canonicalized values, keyed by the ascii `byte[]`.

refQueue	back to summary
pack-priv final ReferenceQueue<String> refQueue Used for `Reference` as values in `cache`.

AsciiStringInterner	back to summary
pack-priv AsciiStringInterner()

Method Detail

arrayEquals back to summary

arrayEquals	back to summary
pack-priv static boolean arrayEquals(byte[] a, int aOffset, int aLength, byte[] b, int bOffset, int bLength) Performs equality check between a and b (with corresponding offset/length values). The `static boolean equals(byte[].class, int, int, byte[], int, int` method in `java.util.Arrays` is optimized for longer `byte[]` instances than is expected to be seen here.

pack-priv static boolean arrayEquals(byte[] a, int aOffset, int aLength, byte[] b, int bOffset, int bLength)

Performs equality check between a and b (with corresponding offset/length values).

The static boolean equals(byte[].class, int, int, byte[], int, int method in java.util.Arrays is optimized for longer byte[] instances than is expected to be seen here.

cleanQueue back to summary

cleanQueue	back to summary
private void cleanQueue() Process any entries in `refQueue` to purge from the `cache`. See Also `StringReference#dispose()`

private void cleanQueue()

Process any entries in refQueue to purge from the cache.

See Also: StringReference#dispose()

getString back to summary

getString	back to summary
public String getString(byte[] bytes, int offset, int length, Encoding encoding) throws IOException Produces a `String` instance for the given bytes. If all are valid ascii (i.e. `>= 0`) either an existing value will be returned, or the newly created `String` will be stored before being returned. If non-ascii bytes are discovered, the encoding will be used to `decode` and that value will be returned (but not stored). Parameters bytes:byte[] The bytes of the String. Must not be `null`. offset:int Offset into bytes to start. length:int The number of bytes in bytes which are relevant. encoding:Encoding To use if non-ascii bytes seen. Returns:String Decoded `String` from bytes. Exceptions IOException: If error decoding from Encoding.

public String getString(byte[] bytes, int offset, int length, Encoding encoding) throws IOException

Produces a String instance for the given bytes. If all are valid ascii (i.e. >= 0) either an existing value will be returned, or the newly created String will be stored before being returned.

If non-ascii bytes are discovered, the encoding will be used to decode and that value will be returned (but not stored).

Parameters

bytes:byte[]: The bytes of the String. Must not be null.
offset:int: Offset into bytes to start.
length:int: The number of bytes in bytes which are relevant.
encoding:Encoding: To use if non-ascii bytes seen.

Returns:String

Decoded String from bytes.

Exceptions

IOException:: If error decoding from Encoding.

getStringIfPresent back to summary

getStringIfPresent	back to summary
public String getStringIfPresent(byte[] bytes, int offset, int length, Encoding encoding) throws IOException Produces a `String` instance for the given bytes. If all are valid ascii (i.e. `>= 0`) and a corresponding `String` value exists, it will be returned. If no value exists, a `String` will be created, but not stored. If non-ascii bytes are discovered, the encoding will be used to `decode` and that value will be returned (but not stored). Parameters bytes:byte[] The bytes of the String. Must not be `null`. offset:int Offset into bytes to start. length:int The number of bytes in bytes which are relevant. encoding:Encoding To use if non-ascii bytes seen. Returns:String Decoded `String` from bytes. Exceptions IOException: If error decoding from Encoding.

public String getStringIfPresent(byte[] bytes, int offset, int length, Encoding encoding) throws IOException

Produces a String instance for the given bytes.

If all are valid ascii (i.e. >= 0) and a corresponding String value exists, it will be returned. If no value exists, a String will be created, but not stored.

If non-ascii bytes are discovered, the encoding will be used to decode and that value will be returned (but not stored).

Parameters

bytes:byte[]: The bytes of the String. Must not be null.
offset:int: Offset into bytes to start.
length:int: The number of bytes in bytes which are relevant.
encoding:Encoding: To use if non-ascii bytes seen.

Returns:String

Decoded String from bytes.

Exceptions

IOException:: If error decoding from Encoding.

hashKey back to summary

hashKey	back to summary
private static int hashKey(byte[] bytes, int offset, int length) Generates a hash value for the relevant entries in bytes as long as all values are ascii (`>= 0`). Returns:int hash code for relevant bytes, or `0` if non-ascii bytes present.

private static int hashKey(byte[] bytes, int offset, int length)

Generates a hash value for the relevant entries in bytes as long as all values are ascii (>= 0).

Returns:int: hash code for relevant bytes, or 0 if non-ascii bytes present.

putString back to summary

putString	back to summary
public boolean putString(String val) Preemptively populates a value into the cache. This is intended to be used with `String` constants which are frequently used. While this can work with other `String` values, if val is ever garbage collected, it will not be actively removed from this instance. Parameters val:String The value to intern. Must not be `null`. Returns:boolean Indication if val is an ascii String and placed into cache.

public boolean putString(String val)

Preemptively populates a value into the cache. This is intended to be used with String constants which are frequently used. While this can work with other String values, if val is ever garbage collected, it will not be actively removed from this instance.

Parameters

val:String: The value to intern. Must not be null.

Returns:boolean

Indication if val is an ascii String and placed into cache.

toString back to summary

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. Satisfying this method's contract implies a non-`null` result must be returned. Returns:String a string representation of the object Annotations @Override

public String toString()

Overrides java.lang.Object.toString.

Doc from java.lang.Object.toString.

Returns a string representation of the object. Satisfying this method's contract implies a non-null result must be returned.

Returns:String

a string representation of the object

Annotations

@Override

org.postgresql.core back to summary

private abstract Class AsciiStringInterner.BaseKey

Class Inheritance

extends Object

java.lang.Object
org.postgresql.core.AsciiStringInterner.BaseKey

Known Direct Subclasses

org.postgresql.core.AsciiStringInterner.TempKey, org.postgresql.core.AsciiStringInterner.Key

Field Summary

Modifier and Type	Field and Description
private final int	hash

Constructor Summary

Access	Constructor and Description
pack-priv	BaseKey(int hash)

Method Summary

Modifier and Type	Method and Description
pack-priv abstract void	appendString(StringBuilder sb)
public final boolean	equals(@Nullable Object the reference object with which to compare. obj) Overrides java.lang.Object.equals. Indicates whether some other object is "equal to" this one.
pack-priv abstract boolean	equals(byte[] other, int offset, int length)
pack-priv abstract boolean	equalsBytes(AsciiStringInterner.BaseKey other)
public final int	hashCode() Overrides java.lang.Object.hashCode. Returns a hash code value for this object.

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

Field Detail

hash	back to summary
private final int hash

Constructor Detail

BaseKey	back to summary
pack-priv BaseKey(int hash)

Method Detail

appendString	back to summary
pack-priv abstract void appendString(StringBuilder sb)

equals back to summary

equals	back to summary
public final boolean equals(@Nullable Object obj) Overrides java.lang.Object.equals. Doc from java.lang.Object.equals. Indicates whether some other object is "equal to" this one. The `equals` method implements an equivalence relation on non-null object references: It is reflexive: for any non-null reference value `x`, `x.equals(x)` should return `true`. It is symmetric: for any non-null reference values `x` and `y`, `x.equals(y)` should return `true` if and only if `y.equals(x)` returns `true`. It is transitive: for any non-null reference values `x`, `y`, and `z`, if `x.equals(y)` returns `true` and `y.equals(z)` returns `true`, then `x.equals(z)` should return `true`. It is consistent: for any non-null reference values `x` and `y`, multiple invocations of `x.equals(y)` consistently return `true` or consistently return `false`, provided no information used in `equals` comparisons on the objects is modified. For any non-null reference value `x`, `x.equals(null)` should return `false`. An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes. Parameters obj:@Nullable Object the reference object with which to compare. Returns:boolean `true` if this object is the same as the obj argument; `false` otherwise. Annotations @Override

public final boolean equals(@Nullable Object obj)

Overrides java.lang.Object.equals.

Doc from java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

It is reflexive: for any non-null reference value x, x.equals(x) should return true.
It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters

obj:@Nullable Object: the reference object with which to compare.

Returns:boolean

true if this object is the same as the obj argument; false otherwise.

Annotations

@Override

equals	back to summary
pack-priv abstract boolean equals(byte[] other, int offset, int length)

equalsBytes	back to summary
pack-priv abstract boolean equalsBytes(AsciiStringInterner.BaseKey other)

hashCode back to summary

hashCode	back to summary
public final int hashCode() Overrides java.lang.Object.hashCode. Doc from java.lang.Object.hashCode. Returns a hash code value for this object. This method is supported for the benefit of hash tables such as those provided by `java.util.HashMap`. The general contract of `hashCode` is: Whenever it is invoked on the same object more than once during an execution of a Java application, the `hashCode` method must consistently return the same integer, provided no information used in `equals` comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. If two objects are equal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce the same integer result. It is not required that if two objects are unequal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables. Returns:int a hash code value for this object Annotations @Override

public final int hashCode()

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for this object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns:int

a hash code value for this object

Annotations

@Override

org.postgresql.core back to summary

private final Class AsciiStringInterner.Key

Class Inheritance

extends BaseKey

java.lang.Object
org.postgresql.core.AsciiStringInterner.BaseKey
org.postgresql.core.AsciiStringInterner.Key

Instance used for inserting values into the cache. The byte[] must be a copy that will never be mutated.

Field Summary

Modifier and Type	Field and Description
pack-priv final byte[]	key

Constructor Summary

Access	Constructor and Description
pack-priv	Key(byte[] key, int hash)

Method Summary

Modifier and Type	Method and Description
pack-priv void	appendString(StringBuilder sb) Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.appendString.
public boolean	equals(byte[] other, int offset, int length) Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.equals.
pack-priv boolean	equalsBytes(AsciiStringInterner.BaseKey other) Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.equalsBytes.

Inherited from org.postgresql.core.AsciiStringInterner.BaseKey:: equals hashCode

Field Detail

key	back to summary
pack-priv final byte[] key

Constructor Detail

Key	back to summary
pack-priv Key(byte[] key, int hash)

Method Detail

appendString	back to summary
pack-priv void appendString(StringBuilder sb) Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.appendString. Annotations @Override

appendString

back to summary

pack-priv void appendString(StringBuilder sb)

Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.appendString.

Annotations

@Override

equals	back to summary
public boolean equals(byte[] other, int offset, int length) Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.equals. Annotations @Override

equals

back to summary

public boolean equals(byte[] other, int offset, int length)

Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.equals.

Annotations

@Override

equalsBytes	back to summary
pack-priv boolean equalsBytes(AsciiStringInterner.BaseKey other) Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.equalsBytes. Annotations @Override

equalsBytes

back to summary

pack-priv boolean equalsBytes(AsciiStringInterner.BaseKey other)

Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.equalsBytes.

Annotations

@Override

org.postgresql.core back to summary

private final Class AsciiStringInterner.StringReference

Class Inheritance

extends SoftReference<String>

java.lang.Object
java.lang.ref.Reference
java.lang.ref.SoftReference
org.postgresql.core.AsciiStringInterner.StringReference

Custom SoftReference implementation which maintains a reference to the key in the cache, which allows aggressive cleaning when garbage collector collects the String instance.

Field Summary

Modifier and Type	Field and Description
private final AsciiStringInterner.BaseKey	key

Constructor Summary

Access	Constructor and Description
pack-priv	StringReference(AsciiStringInterner.BaseKey key, String referent)

Method Summary

Modifier and Type	Method and Description
pack-priv void	dispose()

Inherited from java.lang.ref.SoftReference:: get

Field Detail

key	back to summary
private final AsciiStringInterner.BaseKey key

Constructor Detail

StringReference	back to summary
pack-priv StringReference(AsciiStringInterner.BaseKey key, String referent)

Method Detail

dispose	back to summary
pack-priv void dispose()

org.postgresql.core back to summary

private Class AsciiStringInterner.TempKey

Class Inheritance

extends BaseKey

java.lang.Object
org.postgresql.core.AsciiStringInterner.BaseKey
org.postgresql.core.AsciiStringInterner.TempKey

Only used for lookups, never to actually store entries.

Field Summary

Modifier and Type	Field and Description
pack-priv final byte[]	bytes
pack-priv final int	length
pack-priv final int	offset

Constructor Summary

Access	Constructor and Description
pack-priv	TempKey(int hash, byte[] bytes, int offset, int length)

Method Summary

Modifier and Type	Method and Description
pack-priv void	appendString(StringBuilder sb) Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.appendString.
public boolean	equals(byte[] other, int offset, int length) Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.equals.
pack-priv boolean	equalsBytes(AsciiStringInterner.BaseKey other) Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.equalsBytes.

Inherited from org.postgresql.core.AsciiStringInterner.BaseKey:: equals hashCode

Field Detail

bytes	back to summary
pack-priv final byte[] bytes

length	back to summary
pack-priv final int length

offset	back to summary
pack-priv final int offset

Constructor Detail

TempKey	back to summary
pack-priv TempKey(int hash, byte[] bytes, int offset, int length)

Method Detail

appendString	back to summary
pack-priv void appendString(StringBuilder sb) Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.appendString. Annotations @Override

appendString

back to summary

pack-priv void appendString(StringBuilder sb)

Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.appendString.

Annotations

@Override

equals	back to summary
public boolean equals(byte[] other, int offset, int length) Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.equals. Annotations @Override

equals

back to summary

public boolean equals(byte[] other, int offset, int length)

Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.equals.

Annotations

@Override

equalsBytes	back to summary
pack-priv boolean equalsBytes(AsciiStringInterner.BaseKey other) Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.equalsBytes. Annotations @Override

equalsBytes

back to summary

pack-priv boolean equalsBytes(AsciiStringInterner.BaseKey other)

Implements abstract org.postgresql.core.AsciiStringInterner.BaseKey.equalsBytes.

Annotations

@Override

pack-priv final Class AsciiStringInterner

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private abstract Class AsciiStringInterner.BaseKey

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private final Class AsciiStringInterner.Key

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private final Class AsciiStringInterner.StringReference

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private Class AsciiStringInterner.TempKey

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail