Class TextBuffer


  • public final class TextBuffer
    extends Object
    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.

    Author:
    Tatu Saloranta
    • Method Detail

      • createTemporaryBuffer

        public static TextBuffer createTemporaryBuffer()
      • 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 to resetWithEmpty(), but actively marks current text content to be empty string (whereas former method leaves content as undefined).
      • resetWithShared

        public 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. It also means that if anything is to be appended to the buffer, it will first have to unshare it (make a local copy).
      • 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.
      • resetWithIndentation

        public void resetWithIndentation​(int indCharCount,
                                         char indChar)
      • size

        public int size()
        Returns:
        Number of characters currently stored by this collector
      • getTextStart

        public int getTextStart()
      • getTextBuffer

        public char[] getTextBuffer()
      • 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
      • 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 data
        firstChunk - Whether this is the first segment fed or not; if it is, state needs to be fullt reset; if not, only partially.
      • contentsAsString

        public String contentsAsString()
      • contentsAsStringBuilder

        public StringBuilder contentsAsStringBuilder​(int extraSpace)
        Similar to contentsAsString(), 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
      • contentsToStringBuilder

        public void contentsToStringBuilder​(StringBuilder sb)
      • contentsAsArray

        public char[] contentsAsArray()
      • contentsToArray

        public int contentsToArray​(int srcStart,
                                   char[] dst,
                                   int dstStart,
                                   int len)
      • rawContentsTo

        public int rawContentsTo​(Writer w)
                          throws IOException
        Method that will stream contents of this buffer into specified Writer.
        Throws:
        IOException
      • isAllWhitespace

        public boolean isAllWhitespace()
      • endsWith

        public boolean endsWith​(String str)
        Method that can be used to check if the contents of the buffer end in specified String.
        Returns:
        True if the textual content buffer contains ends with the specified String; false otherwise
      • equalsString

        public boolean equalsString​(String str)
        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.
      • ensureNotShared

        public void ensureNotShared()
        Method called to make sure that buffer is not using shared input buffer; if it is, it will copy such contents to private buffer.
      • append

        public void append​(char c)
      • append

        public void append​(char[] c,
                           int start,
                           int len)
      • append

        public void append​(String str)
      • getCurrentSegment

        public char[] getCurrentSegment()
      • getCurrentSegmentSize

        public int getCurrentSegmentSize()
      • setCurrentLength

        public void setCurrentLength​(int len)
      • finishCurrentSegment

        public char[] finishCurrentSegment()
      • toString

        public String toString()
        Note: calling this method may not be as efficient as calling contentsAsString(), since it's not guaranteed that resulting String is cached.
        Overrides:
        toString in class Object
      • unshare

        public void unshare​(int needExtra)
        Method called if/when we need to append content when we have been initialized to use shared buffer.