Package com.fasterxml.aalto.in
Class CharBasedPNameTable
java.lang.Object
com.fasterxml.aalto.util.NameTable
com.fasterxml.aalto.in.CharBasedPNameTable
This is a symbol table implementation used for storing byte-based
PNames
, specifically, instances of
(PNameC
).-
Nested Class Summary
Nested ClassesModifier and TypeClassDescription(package private) static final class
This class is a symbol table entry. -
Field Summary
FieldsModifier and TypeFieldDescriptionprotected CharBasedPNameTable.Bucket[]
Overflow buckets; if primary doesn't match, lookup is done from here.protected boolean
Flag that indicates if any changes have been made to the data; used to both determine if bucket array needs to be copied when (first) change is made, and potentially if updated bucket list is to be resync'ed back to master instance.protected int
Mask used to get index from hash values; equal tomBuckets.length - 1
, when mBuckets.length is a power of two.protected int
Current size (number of entries); needed to know if and when rehash.protected int
Limit that indicates maximum size this instance can hold before it needs to be expanded and rehashed.protected PNameC[]
Primary matching symbols; it's expected most match occur from here.protected static final float
(package private) static final int
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Constructor Summary
ConstructorsConstructorDescriptionCharBasedPNameTable
(int initialSize) Main method for constructing a master symbol table instance; will be called by other public constructors. -
Method Summary
Modifier and TypeMethodDescriptionaddSymbol
(char[] buffer, int start, int len, int hash) private void
Method called when copy-on-write is needed; generally when first change is made to a derived symbol table.findSymbol
(char[] buffer, int start, int len, int hash) boolean
Method called to check to quickly see if a child symbol table may have gotten additional entries.void
Method that allows contents of child table to potentially be "merged in" with contents of this symbol table.private void
rehash()
Method called when size (number of entries) of symbol table grows so big that load factor is exceeded.int
size()
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Field Details
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MIN_HASH_SIZE
static final int MIN_HASH_SIZE- See Also:
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DEFAULT_FILL_FACTOR
protected static final float DEFAULT_FILL_FACTOR- See Also:
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_symbols
Primary matching symbols; it's expected most match occur from here. -
_buckets
Overflow buckets; if primary doesn't match, lookup is done from here.Note: Number of buckets is half of number of symbol entries, on assumption there's less need for buckets.
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_size
protected int _sizeCurrent size (number of entries); needed to know if and when rehash. -
_sizeThreshold
protected int _sizeThresholdLimit that indicates maximum size this instance can hold before it needs to be expanded and rehashed. Calculated using fill factor passed in to constructor. -
_indexMask
protected int _indexMaskMask used to get index from hash values; equal tomBuckets.length - 1
, when mBuckets.length is a power of two. -
_dirty
protected boolean _dirtyFlag that indicates if any changes have been made to the data; used to both determine if bucket array needs to be copied when (first) change is made, and potentially if updated bucket list is to be resync'ed back to master instance.
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Constructor Details
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CharBasedPNameTable
public CharBasedPNameTable(int initialSize) Main method for constructing a master symbol table instance; will be called by other public constructors.- Parameters:
initialSize
- Minimum initial size for bucket array; internally will always use a power of two equal to or bigger than this value.
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CharBasedPNameTable
CharBasedPNameTable(CharBasedPNameTable parent)
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Method Details
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mergeFromChild
Method that allows contents of child table to potentially be "merged in" with contents of this symbol table.Note that caller has to make sure symbol table passed in is really a child or sibling of this symbol table.
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size
public int size() -
maybeDirty
public boolean maybeDirty()Description copied from class:NameTable
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.- Specified by:
maybeDirty
in classNameTable
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findSymbol
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addSymbol
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copyArrays
private void copyArrays()Method called when copy-on-write is needed; generally when first change is made to a derived symbol table. -
rehash
private void rehash()Method called when size (number of entries) of symbol table grows so big that load factor is exceeded. Since size has to remain power of two, arrays will then always be doubled. Main work is really redistributing old entries into new String/Bucket entries.
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