Struct parquet::format::PageHeader

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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>,
}

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§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§

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impl PageHeader

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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

Trait Implementations§

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impl Clone for PageHeader

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fn clone(&self) -> PageHeader

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for PageHeader

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

Formats the value using the given formatter. Read more
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impl Hash for PageHeader

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

Feeds this value into the given Hasher. Read more
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fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
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impl Ord for PageHeader

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

This method returns an Ordering between self and other. Read more
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fn max(self, other: Self) -> Self
where Self: Sized,

Compares and returns the maximum of two values. Read more
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fn min(self, other: Self) -> Self
where Self: Sized,

Compares and returns the minimum of two values. Read more
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fn clamp(self, min: Self, max: Self) -> Self
where Self: Sized + PartialOrd,

Restrict a value to a certain interval. Read more
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impl PartialEq for PageHeader

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

Tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

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

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

This method returns an ordering between self and other values if one exists. Read more
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fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator. Read more
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fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator. Read more
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fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator. Read more
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fn ge(&self, other: &Rhs) -> bool

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

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impl TryFrom<&PageHeader> for PageMetadata

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type Error = ParquetError

The type returned in the event of a conversion error.
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fn try_from(value: &PageHeader) -> Result<Self, Self::Error>

Performs the conversion.
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impl Eq for PageHeader

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impl StructuralPartialEq for PageHeader

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impl<T> Any for T
where T: 'static + ?Sized,

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Gets the TypeId of self. Read more
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where T: ?Sized,

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where T: Clone,

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default unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
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impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

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fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more
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Returns the argument unchanged.

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where U: From<T>,

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Calls U::from(self).

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where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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type Error = Infallible

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Performs the conversion.
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type Error = <U as TryFrom<T>>::Error

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