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Mikhail Mazursky commented on LANG-993: --------------------------------------- [~britter], that was one of the ideas I had. The problem with such approach is the same as in description of this issue - Appendable.append(CharSequence) typical implementation will do CharSequence.toString() and process the resulting String. The idea is to avoid that allocation and data copy. > Add zero copy write methods to StrBuilder > ----------------------------------------- > > Key: LANG-993 > URL: https://issues.apache.org/jira/browse/LANG-993 > Project: Commons Lang > Issue Type: Improvement > Components: lang.text.* > Affects Versions: 3.3.1 > Reporter: Mikhail Mazursky > Fix For: Review Patch, Discussion, 3.4 > > Attachments: LANG-993.patch > > > Currently I have the following usecase: > {code} > StrBuilder builder = new StrBuilder(); > // add lots of stuff to builder > // in multiple invocations in several classes > // writer cannot be used directly > builder.append(...); > Writer writer = ....; > CharStreams.copy(builder.asReader(), writer); > {code} > [CharStreams|https://code.google.com/p/guava-libraries/source/browse/guava/src/com/google/common/io/CharStreams.java#177] > is a class from Guava lib that copies data between reader and writer using > temporary buffer. > There is a problem with such approach - two additional copies are performed: > 1) data is copied from the StrBuilder in chunks into temporary buffer > (CharBuffer) > 2) Writer.append(CharSequence) is called that is usually implemented as > write(CharSequence.toString()) - i.e. it makes another copy of data and > allocates an additional String object. > I want to avoid those copies by writing the internal buffer of the StrBuilder > directly to the writer. Also it is potentially more efficient because it > performs one I/O call instead of many. > So I propose to add the following methods: > {code} > public void writeTo(Writer writer) throws IOException { > writer.write(buffer, 0, size); > } > public void writeTo(StringBuilder builder) { > builder.append(buffer, 0, size); > } > public void writeTo(StringBuffer buffer) { > buffer.append(this.buffer, 0, size); > } > {code} > If there is interest I will provide patch (with JavaDocs and tests). -- This message was sent by Atlassian JIRA (v6.2#6252)