HTTP message processing framework is designed to be expressive and flexible while remaining memory efficient and fast. HttpCore HTTP message processing code achieves near zero intermediate garbage and near zero-copy buffering for its parsing and formatting operations. The same HTTP message parsing and formatting API and implementations are used by both the blocking and non-blocking transport implementations, which helps ensure a consistent behavior of HTTP services regardless of the I/O model.

HttpCore utilizes a number of low level components for all its line parsing and formatting methods. CharArrayBuffer represents a sequence of characters, usually a single line in an HTTP message stream such as a request line, a status line or a header. Internally CharArrayBuffer is backed by an array of chars, which can be expanded to accommodate more input if needed. CharArrayBuffer also provides a number of utility methods for manipulating content of the buffer, storing more data and retrieving subsets of data. stdout > ParserCursor represents a context of a parsing operation: the bounds limiting the scope of the parsing operation and the current position the parsing operation is expected to start at. stdout > 7>14] ]]> LineParser is the interface for parsing lines in the head section of an HTTP message. There are individual methods for parsing a request line, a status line, or a header line. The lines to parse are passed in-memory, the parser does not depend on any specific I/O mechanism. stdout > stdout > LineFormatter for formatting elements of the head section of an HTTP message. This is the complement to LineParser . There are individual methods for formatting a request line, a status line, or a header line. Please note the formatting does not include the trailing line break sequence CR-LF. stdout > HeaderValueParser is the interface for parsing header values into elements. stdout > HeaderValueFormatter is the interface for formatting elements of a header value. This is the complement to HeaderValueParser . stdout >

HttpCore provides a number of utility classes for the blocking and non-blocking I/O models that facilitate the processing of HTTP message streams, simplify handling of CR-LF delimited lines in HTTP messages and manage intermediate data buffering. HTTP connection implementations usually rely on session input/output buffers for reading and writing data from and to an HTTP message stream. Session input/output buffer implementations are I/O model specific and are optimized either for blocking or non-blocking operations. Blocking HTTP connections use socket bound session buffers to transfer data. Session buffer interfaces are similar to java.io.InputStream / java.io.OutputStream classes, but they also provide methods for reading and writing CR-LF delimited lines. Non-blocking HTTP connections use session buffers optimized for reading and writing data from and to non-blocking NIO channels. NIO session input/output sessions help deal with CR-LF delimited lines in a non-blocking I/O mode.

HttpCore also provides coarse-grained facade type interfaces for parsing and formatting of HTTP messages. Default implementations of those interfaces build upon the functionality provided by SessionInputBuffer / SessionOutputBuffer and HttpLineParser / HttpLineFormatter implementations. Example of HTTP request parsing / writing for blocking HTTP connections: Example of HTTP response parsing / writing for blocking HTTP connections: Example of HTTP request parsing / writing for non-blocking HTTP connections: Example of HTTP response parsing / writing for non-blocking HTTP connections:

The default implementations of HttpMessageParser and NHttpMessageParser interfaces do not parse HTTP headers immediately. Parsing of header value is deferred until its properties are accessed. Those headers that are never used by the application will not be parsed at all. The CharArrayBuffer backing the header can be obtained through an optional FormattedHeader interface.

One can customize the way HTTP connections parse and format HTTP messages by extending the default implementations and overriding factory methods and replacing the default parser or formatter implementations with a custom one. For blocking HTTP connections one also can provide custom implementation of session input/output buffers. For non-blocking HTTP connection implementation one can replace the default HTTP message parser and formatter implementations. The session input/output buffer implementations can be overridden at the I/O reactor level.