Struct CompressedPage 

pub struct CompressedPage {
    compressed_page: Page,
    uncompressed_size: usize,
}

Helper struct to represent pages with potentially compressed buffer (data page v1) or compressed and concatenated buffer (def levels + rep levels + compressed values for data page v2).

The difference with Page is that Page buffer is always uncompressed.

Fields

compressed_page: Page

uncompressed_size: usize

Implementations

impl CompressedPage

pub fn new(compressed_page: Page, uncompressed_size: usize) -> Self

Creates CompressedPage from a page with potentially compressed buffer and uncompressed size.

pub fn page_type(&self) -> PageType

Returns page type.

pub fn compressed_page(&self) -> &Page

Returns underlying page with potentially compressed buffer.

pub fn uncompressed_size(&self) -> usize

Returns uncompressed size in bytes.

pub fn compressed_size(&self) -> usize

Returns compressed size in bytes.

Note that it is assumed that buffer is compressed, but it may not be. In this case compressed size will be equal to uncompressed size.

pub fn num_values(&self) -> u32

Number of values in page.

pub fn encoding(&self) -> Encoding

Returns encoding for values in page.

pub fn data(&self) -> &[u8]

Returns slice of compressed buffer in the page.

pub fn memory_usage(&self) -> usize

Returns the number of heap bytes this page currently holds.

This is the page’s compressed buffer (the embedded [Bytes]); use it to account for a buffered page’s memory footprint rather than reaching for data().len() at each call site.

pub(crate) fn to_thrift_header(&self) -> Result<PageHeader>

Returns the thrift page header

pub(crate) fn with_new_compressed_buffer(self, new_buffer: Bytes) -> Self

Update the compressed buffer for a page. This might be required when encrypting page data for example. The size of uncompressed data must not change.