Enum OffsetSpec 

pub enum OffsetSpec {
    Absolute(i64),
    Indirect {
        base_offset: i64,
        pointer_type: TypeKind,
        adjustment: i64,
        endian: Endianness,
    },
    Relative(i64),
    FromEnd(i64),
}

Offset specification for locating data in files

Variants

Absolute(i64)

Absolute offset from file start (or from file end if negative)

Positive values are offsets from the start of the file. Negative values are offsets from the end of the file (same as FromEnd).

Examples

use libmagic_rs::parser::ast::OffsetSpec;

let offset = OffsetSpec::Absolute(0x10); // Read at byte 16 from start
let from_end = OffsetSpec::Absolute(-4); // 4 bytes before end of file

Indirect

Indirect offset through pointer dereferencing

Reads a pointer value at base_offset, interprets it according to pointer_type and endian, then adds adjustment to get the final offset.

Examples

use libmagic_rs::parser::ast::{OffsetSpec, TypeKind, Endianness};

let indirect = OffsetSpec::Indirect {
    base_offset: 0x20,
    pointer_type: TypeKind::Long { endian: Endianness::Little, signed: false },
    adjustment: 4,
    endian: Endianness::Little,
};

Fields

base_offset: i64

Base offset to read pointer from

pointer_type: TypeKind

Type of pointer value

adjustment: i64

Adjustment to add to pointer value

endian: Endianness

Endianness for pointer reading

Relative(i64)

Relative offset from previous match position

Examples

use libmagic_rs::parser::ast::OffsetSpec;

let relative = OffsetSpec::Relative(8); // 8 bytes after previous match

FromEnd(i64)

Offset from end of file (negative values move towards start)

Examples

use libmagic_rs::parser::ast::OffsetSpec;

let from_end = OffsetSpec::FromEnd(-16); // 16 bytes before end of file

Trait Implementations

impl Clone for OffsetSpec

fn clone(&self) -> OffsetSpec

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for OffsetSpec

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for OffsetSpec

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for OffsetSpec

fn eq(&self, other: &OffsetSpec) -> 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 Serialize for OffsetSpec

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for OffsetSpec

impl StructuralPartialEq for OffsetSpec