Struct Header 

pub struct Header {
    pub version: Version,
    pub text_offset: RangeInclusive<usize>,
    pub data_offset: RangeInclusive<usize>,
    pub analysis_offset: RangeInclusive<usize>,
}

Contains FCS version and byte offsets to text, data, and analysis segments

The header is the first segment of an FCS file (first 58 bytes) and contains:

• The FCS version string (e.g., “FCS3.1”)
• Byte offsets to the TEXT segment (contains metadata/keywords)
• Byte offsets to the DATA segment (contains event data)
• Byte offsets to the ANALYSIS segment (optional, contains analysis results)

Fields

version: Version

text_offset: RangeInclusive<usize>

data_offset: RangeInclusive<usize>

analysis_offset: RangeInclusive<usize>

Implementations

impl Header

pub const fn new() -> Self

pub fn from_mmap(mmap: &Mmap) -> Result<Self>

Returns a new Header struct from a memory map of an FCS file

Errors

Will return Err if:

• the FCS version is not valid
• the number of spaces in the header segment is not 4
• the byte offsets for the TEXT, DATA, or ANALYSIS segments are not valid

pub fn get_version(mmap: &Mmap) -> Result<Version>

Returns the FCS version from the first 6 bytes of the file

Errors

Will return Err if the version is not valid

pub fn check_fcs_version(version: &str) -> Result<Version>

Returns a valid FCS version enum after checking that the parsed string from the header is valid

Errors

Will return Err if the version is not valid

pub fn check_header_spaces(buffer: &[u8]) -> Result<()>

Check for valid number of spaces (4) in the HEADER segment

Errors

Will return Err if the number of spaces is not 4

pub fn check_fcs_offsets(mmap: &Mmap) -> Result<()>

Debug utility to print FCS file segment offsets

This function prints detailed information about the header segment and the byte offsets for TEXT, DATA, and ANALYSIS segments. Useful for debugging file parsing issues.

Arguments

• mmap - Memory-mapped view of the FCS file

Errors

Will return Err if offsets cannot be read from the header

Trait Implementations

impl Clone for Header

fn clone(&self) -> Header

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Header

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

Formats the value using the given formatter.

impl Default for Header

fn default() -> Self

Returns the “default value” for a type.

impl Hash for Header

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 Serialize for Header

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.