2.5.1 Abstract Data Model

This section describes a conceptual model of possible data organization that an implementation maintains to participate in this algorithm. The described organization is provided to facilitate the explanation of how the algorithm behaves. This document does not mandate that implementations adhere to this model as long as their external behavior is consistent with that described in this document.

The following elements are specific to this algorithm.

Chunks: Segments of data that are compressed, uncompressed, or that denote the end of the buffer.

Chunk header: The header for a compressed or uncompressed chunk of data.

Flag bytes: A bit flag whose bits, read from low order to high order, specify the formats of the data elements that follow. For example, bit 0 corresponds to the first data element, bit 1 to the second, and so on. If the bit corresponding to a data element is set, the element is a 2-byte compressed word; otherwise, it is a 1-byte literal value.

Flag group: A flag byte followed by zero or more data elements, each of which is a single literal byte or a 2-byte compressed word.