Package com.ctc.wstx.util
Class TextBuffer
java.lang.Object
com.ctc.wstx.util.TextBuffer
TextBuffer is a class similar to
StringBuilder
, with
following differences:
- TextBuffer uses segments character arrays, to avoid having to do additional array copies when array is not big enough. This means that only reallocating that is necessary is done only once -- if and when caller wants to access contents in a linear array (char[], String).
- TextBuffer is not synchronized.
Over time more and more cruft has accumulated here, mostly to support efficient access to collected text. Since access is easiest to do efficiently using callbacks, this class now needs to known interfaces of SAX classes and validators.
Notes about usage: for debugging purposes, it's suggested to use
toString()
method, as opposed to
contentsAsArray()
or contentsAsString()
. Internally
resulting code paths may or may not be different, WRT caching.
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Nested Class Summary
Nested Classes -
Field Summary
FieldsModifier and TypeFieldDescription(package private) static final int
Size of the first text segment buffer to allocate; need not contain the biggest segment, since new ones will get allocated as needed.(package private) static final int
static final int
static final int
(package private) static final int
We will also restrict maximum length of individual segments to allocate (not including cases where we must return a single segment).private final ReaderConfig
private char[]
private int
Number of characters in currently active (last) segmentprivate boolean
private char[]
Shared input buffer; stored here in case some input can be returned as is, without being copied to collector's own buffers.private int
When using shared buffer, offset after the last character in shared bufferprivate int
Character offset of first char in input buffer; -1 to indicate that input buffer currently does not contain any useful char dataprivate char[]
private String
String that will be constructed when the whole contents are needed; will be temporarily stored in case asked for again.private ArrayList
<char[]> List of segments prior to currently active segment.private int
Amount of characters in segments inmSegments
private static final String
private static final char[]
private static final String[]
private static final String
private static final char[]
private static final String[]
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionprivate final char[]
allocBuffer
(int needed) void
append
(char c) void
append
(char[] c, int start, int len) void
private char[]
private int
calcNewSize
(int latestSize) Method used to determine size of the next segment to allocate to contain textual content.private final void
char[]
contentsAsStringBuilder
(int extraSpace) Similar tocontentsAsString()
, but constructs a StringBuilder for further appends.int
contentsToArray
(int srcStart, char[] dst, int dstStart, int len) void
static TextBuffer
static TextBuffer
void
decode
(org.codehaus.stax2.typed.TypedValueDecoder tvd) Generic pass-through method which call given decoder with accumulated dataint
decodeElements
(org.codehaus.stax2.typed.TypedArrayDecoder tad, InputProblemReporter rep) Pass-through decode method called to find find the next token, decode it, and repeat the process as long as there are more tokens and the array decoder accepts more entries.void
Method called to make sure that buffer is not using shared input buffer; if it is, it will copy such contents to private buffer.boolean
equalsString
(String str) Note: it is assumed that this method is not used often enough to be a bottleneck, or for long segments.private void
expand
(int roomNeeded) Method called when current segment is full, to allocate new segment.char[]
void
void
void
void
char[]
int
char[]
int
void
initBinaryChunks
(org.codehaus.stax2.typed.Base64Variant v, org.codehaus.stax2.ri.typed.CharArrayBase64Decoder dec, boolean firstChunk) Method that needs to be called to configure given base64 decoder with textual contents collected by this buffer.boolean
int
Method that will stream contents of this buffer into specified Writer.Deprecated.void
recycle
(boolean force) Method called to indicate that the underlying buffers should now be recycled if they haven't yet been recycled.void
Method called to make sure there is a non-shared segment to use, without appending any content yet.void
resetWithCopy
(char[] buf, int start, int len) void
Method called to clear out any content text buffer may have, and initializes buffer to use non-shared data.void
Similar toresetWithEmpty()
, but actively marks current text content to be empty string (whereas former method leaves content as undefined).void
resetWithIndentation
(int indCharCount, char indChar) void
resetWithShared
(char[] buf, int start, int len) Method called to initialize the buffer with a shared copy of data; this means that buffer will just have pointers to actual data.void
setCurrentLength
(int len) int
size()
toString()
Note: calling this method may not be as efficient as callingcontentsAsString()
, since it's not guaranteed that resulting String is cached.void
unshare
(int needExtra) Method called if/when we need to append content when we have been initialized to use shared buffer.void
validateText
(org.codehaus.stax2.validation.XMLValidator vld, boolean lastSegment)
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Field Details
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DEF_INITIAL_BUFFER_SIZE
static final int DEF_INITIAL_BUFFER_SIZESize of the first text segment buffer to allocate; need not contain the biggest segment, since new ones will get allocated as needed. However, it's sensible to use something that often is big enough to contain segments.- See Also:
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MAX_SEGMENT_LENGTH
static final int MAX_SEGMENT_LENGTHWe will also restrict maximum length of individual segments to allocate (not including cases where we must return a single segment). Value is somewhat arbitrary, let's use it so that memory used is no more than 1/2 megabytes.- See Also:
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INT_SPACE
static final int INT_SPACE- See Also:
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mConfig
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mInputBuffer
private char[] mInputBufferShared input buffer; stored here in case some input can be returned as is, without being copied to collector's own buffers. Note that this is read-only for this Objet. -
mInputStart
private int mInputStartCharacter offset of first char in input buffer; -1 to indicate that input buffer currently does not contain any useful char data -
mInputLen
private int mInputLenWhen using shared buffer, offset after the last character in shared buffer -
mHasSegments
private boolean mHasSegments -
mSegments
List of segments prior to currently active segment. -
mSegmentSize
private int mSegmentSizeAmount of characters in segments inmSegments
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mCurrentSegment
private char[] mCurrentSegment -
mCurrentSize
private int mCurrentSizeNumber of characters in currently active (last) segment -
mResultString
String that will be constructed when the whole contents are needed; will be temporarily stored in case asked for again. -
mResultArray
private char[] mResultArray -
MAX_INDENT_SPACES
public static final int MAX_INDENT_SPACES- See Also:
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MAX_INDENT_TABS
public static final int MAX_INDENT_TABS- See Also:
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sIndSpaces
- See Also:
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sIndSpacesArray
private static final char[] sIndSpacesArray -
sIndSpacesStrings
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sIndTabs
- See Also:
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sIndTabsArray
private static final char[] sIndTabsArray -
sIndTabsStrings
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Constructor Details
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TextBuffer
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Method Details
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createRecyclableBuffer
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createTemporaryBuffer
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recycle
public void recycle(boolean force) Method called to indicate that the underlying buffers should now be recycled if they haven't yet been recycled. Although caller can still use this text buffer, it is not advisable to call this method if that is likely, since next time a buffer is needed, buffers need to reallocated. Note: calling this method automatically also clears contents of the buffer. -
resetWithEmpty
public void resetWithEmpty()Method called to clear out any content text buffer may have, and initializes buffer to use non-shared data. -
resetWithEmptyString
public void resetWithEmptyString()Similar toresetWithEmpty()
, but actively marks current text content to be empty string (whereas former method leaves content as undefined). -
resetWithCopy
public void resetWithCopy(char[] buf, int start, int len) -
resetInitialized
public void resetInitialized()Method called to make sure there is a non-shared segment to use, without appending any content yet. -
allocBuffer
private final char[] allocBuffer(int needed) -
clearSegments
private final void clearSegments() -
resetWithIndentation
public void resetWithIndentation(int indCharCount, char indChar) -
size
public int size()- Returns:
- Number of characters currently stored by this collector
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getTextStart
public int getTextStart() -
getTextBuffer
public char[] getTextBuffer() -
decode
Generic pass-through method which call given decoder with accumulated data- Throws:
IllegalArgumentException
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decodeElements
public int decodeElements(org.codehaus.stax2.typed.TypedArrayDecoder tad, InputProblemReporter rep) throws org.codehaus.stax2.typed.TypedXMLStreamException Pass-through decode method called to find find the next token, decode it, and repeat the process as long as there are more tokens and the array decoder accepts more entries. All tokens processed will be "consumed", such that they will not be visible via buffer.- Returns:
- Number of tokens decoded; 0 means that no (more) tokens were found from this buffer.
- Throws:
org.codehaus.stax2.typed.TypedXMLStreamException
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initBinaryChunks
public void initBinaryChunks(org.codehaus.stax2.typed.Base64Variant v, org.codehaus.stax2.ri.typed.CharArrayBase64Decoder dec, boolean firstChunk) Method that needs to be called to configure given base64 decoder with textual contents collected by this buffer.- Parameters:
dec
- Decoder that will need datafirstChunk
- Whether this is the first segment fed or not; if it is, state needs to be fullt reset; if not, only partially.
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contentsAsString
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contentsAsStringBuilder
Similar tocontentsAsString()
, but constructs a StringBuilder for further appends.- Parameters:
extraSpace
- Number of extra characters to preserve in StringBuilder beyond space immediately needed to hold the contents
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contentsToStringBuilder
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contentsAsArray
public char[] contentsAsArray() -
contentsToArray
public int contentsToArray(int srcStart, char[] dst, int dstStart, int len) -
rawContentsTo
Method that will stream contents of this buffer into specified Writer.- Throws:
IOException
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rawContentsViaReader
Deprecated.- Throws:
IOException
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isAllWhitespace
public boolean isAllWhitespace() -
equalsString
Note: it is assumed that this method is not used often enough to be a bottleneck, or for long segments. Based on this, it is optimized for common simple cases where there is only one single character segment to use; fallback for other cases is to create such segment. -
fireSaxCharacterEvents
- Throws:
SAXException
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fireSaxSpaceEvents
- Throws:
SAXException
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fireSaxCommentEvent
- Throws:
SAXException
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fireDtdCommentEvent
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validateText
public void validateText(org.codehaus.stax2.validation.XMLValidator vld, boolean lastSegment) throws XMLStreamException - Throws:
XMLStreamException
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append
public void append(char c) -
append
public void append(char[] c, int start, int len) -
append
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getCurrentSegment
public char[] getCurrentSegment() -
getCurrentSegmentSize
public int getCurrentSegmentSize() -
setCurrentLength
public void setCurrentLength(int len) -
finishCurrentSegment
public char[] finishCurrentSegment() -
calcNewSize
private int calcNewSize(int latestSize) Method used to determine size of the next segment to allocate to contain textual content. -
toString
Note: calling this method may not be as efficient as callingcontentsAsString()
, since it's not guaranteed that resulting String is cached. -
expand
private void expand(int roomNeeded) Method called when current segment is full, to allocate new segment.- Parameters:
roomNeeded
- Number of characters that the resulting new buffer must have
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buildResultArray
private char[] buildResultArray()
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