Struct PageHeader

pub struct PageHeader {
    pub type_: PageType,
    pub uncompressed_page_size: i32,
    pub compressed_page_size: i32,
    pub crc: Option<i32>,
    pub data_page_header: Option<DataPageHeader>,
    pub index_page_header: Option<IndexPageHeader>,
    pub dictionary_page_header: Option<DictionaryPageHeader>,
    pub data_page_header_v2: Option<DataPageHeaderV2>,
}

Fields

type_: PageType

the type of the page: indicates which of the *_header fields is set *

uncompressed_page_size: i32

Uncompressed page size in bytes (not including this header) *

compressed_page_size: i32

Compressed (and potentially encrypted) page size in bytes, not including this header *

crc: Option<i32>

The 32-bit CRC checksum for the page, to be be calculated as follows:

• The standard CRC32 algorithm is used (with polynomial 0x04C11DB7, the same as in e.g. GZip).
• All page types can have a CRC (v1 and v2 data pages, dictionary pages, etc.).
• The CRC is computed on the serialization binary representation of the page (as written to disk), excluding the page header. For example, for v1 data pages, the CRC is computed on the concatenation of repetition levels, definition levels and column values (optionally compressed, optionally encrypted).
• The CRC computation therefore takes place after any compression and encryption steps, if any.

If enabled, this allows for disabling checksumming in HDFS if only a few pages need to be read.

data_page_header: Option<DataPageHeader>

index_page_header: Option<IndexPageHeader>

dictionary_page_header: Option<DictionaryPageHeader>

data_page_header_v2: Option<DataPageHeaderV2>

Implementations

impl PageHeader

pub fn new<F4, F5, F6, F7, F8>( type_: PageType, uncompressed_page_size: i32, compressed_page_size: i32, crc: F4, data_page_header: F5, index_page_header: F6, dictionary_page_header: F7, data_page_header_v2: F8, ) -> PageHeader

where F4: Into<Option<i32>>, F5: Into<Option<DataPageHeader>>, F6: Into<Option<IndexPageHeader>>, F7: Into<Option<DictionaryPageHeader>>, F8: Into<Option<DataPageHeaderV2>>,

pub fn read_from_in_protocol<T: TInputProtocol>( i_prot: &mut T, ) -> Result<PageHeader>

pub fn write_to_out_protocol<T: TOutputProtocol>( &self, o_prot: &mut T, ) -> Result<usize>

Trait Implementations

impl Clone for PageHeader

fn clone(&self) -> PageHeader

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for PageHeader

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for PageHeader

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for PageHeader

fn cmp(&self, other: &PageHeader) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for PageHeader

fn eq(&self, other: &PageHeader) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for PageHeader

fn partial_cmp(&self, other: &PageHeader) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl ReadThrift for PageHeader

fn read_from_in_protocol<T: TInputProtocol>( i_prot: &mut T, ) -> Result<PageHeader>

impl Eq for PageHeader

impl StructuralPartialEq for PageHeader