Struct SchemaHeader 

pub struct SchemaHeader {
    pub flags: u8,
    pub root_key: Option<String>,
    pub row_count: usize,
    pub fields: Vec<FieldDef>,
    pub null_bitmap: Option<Vec<u8>>,
    pub metadata: Option<HashMap<String, String>>,
}

Schema header containing metadata about the encoded data

The header is self-describing and stores:

• Flags indicating optional features (nulls, root key, etc.)
• Optional root key for single-array JSON structures
• Row and field counts
• Field definitions (names and types)
• Optional null bitmap for tracking null values

Binary Format

[flags: u8]
[root_key?: varint_string]  // if FLAG_HAS_ROOT_KEY
[row_count: varint]
[field_count: varint]
[field_types: 4-bit packed]
[field_names: varint_strings]
[null_bitmap?: bytes]        // if FLAG_HAS_NULLS

Fields

flags: u8

root_key: Option<String>

row_count: usize

fields: Vec<FieldDef>

null_bitmap: Option<Vec<u8>>

metadata: Option<HashMap<String, String>>

Implementations

impl SchemaHeader

pub fn new(row_count: usize, fields: Vec<FieldDef>) -> Self

Create a new header

pub fn set_flag(&mut self, flag: u8)

Set a flag bit

pub fn has_flag(&self, flag: u8) -> bool

Check if a flag bit is set

pub fn total_value_count(&self) -> usize

Calculate total value count (row_count * field_count)

Trait Implementations

impl Clone for SchemaHeader

fn clone(&self) -> SchemaHeader

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SchemaHeader

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

Formats the value using the given formatter.

impl PartialEq for SchemaHeader

fn eq(&self, other: &SchemaHeader) -> 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 StructuralPartialEq for SchemaHeader