Struct StringBuffer 

pub struct StringBuffer {
    pub id: usize,
    pub data: BufferData,
    pub stored_file_offset: Option<usize>,
}

A string buffer containing a chunk of text data and its line metadata This is the fundamental storage unit - piece tree nodes reference these buffers

Fields

id: usize

Unique identifier for this buffer

data: BufferData

The buffer data - either loaded or unloaded

stored_file_offset: Option<usize>

For buffers created by loading a chunk from a stored (on-disk) buffer: the original file offset. This allows rebuild_with_pristine_saved_root to recognize loaded chunks as saved content rather than user edits.

Implementations

impl StringBuffer

pub fn new(id: usize, data: Vec<u8>) -> Self

Create a new string buffer with line metadata (legacy constructor) Automatically computes line starts

pub fn new_loaded(id: usize, data: Vec<u8>, compute_lines: bool) -> Self

Create a loaded buffer with optional line indexing

pub fn new_unloaded( id: usize, file_path: PathBuf, file_offset: usize, bytes: usize, ) -> Self

Create buffer for file region (not yet loaded)

pub fn is_loaded(&self) -> bool

Check if buffer is loaded

pub fn unloaded_bytes(&self) -> Option<usize>

Returns the total byte count of an unloaded buffer, or None if loaded.

pub fn nth_line_start_in_piece( &self, piece_start: usize, piece_end: usize, line_in_piece: usize, ) -> Option<usize>

Find the byte offset where line_in_piece-th line starts within a piece. piece_start/piece_end define the piece’s byte range in this buffer. line_in_piece is 0-indexed: 0 means the first line of the piece (returns piece_start). Returns None if line starts aren’t available or the target line isn’t in this piece.

pub fn get_line_starts(&self) -> Option<&[usize]>

Get line starts if available

pub fn load(&mut self, fs: &dyn FileSystem) -> Result<()>

Load buffer data from file using a FileSystem (for unloaded buffers) Returns error if buffer is not unloaded or if I/O fails

pub fn create_chunk_buffer( &self, new_id: usize, chunk_offset: usize, chunk_bytes: usize, ) -> Option<StringBuffer>

Create a new unloaded buffer representing a chunk of this buffer This is used for splitting large unloaded buffers into smaller chunks

Arguments

• new_id - The ID for the new buffer
• chunk_offset - Offset within this buffer where the chunk starts
• chunk_bytes - Number of bytes in the chunk

Returns

A new StringBuffer referencing the chunk, or None if this buffer is not unloaded or if the chunk range is invalid

pub fn line_feed_count(&self) -> Option<usize>

Get the number of line feeds (newlines) in this buffer Returns None if line indexing was not computed or buffer is unloaded

pub fn append(&mut self, data_to_append: &[u8]) -> usize

Append data to this buffer and recompute line starts Returns the offset where the appended data starts Only works for loaded buffers with line starts

Trait Implementations

impl Clone for StringBuffer

fn clone(&self) -> StringBuffer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StringBuffer

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

Formats the value using the given formatter.