Struct MtmdInputChunk 

pub struct MtmdInputChunk<'chunks> { /* private fields */ }

A single tokenized input chunk (text, image, or audio).

Instances are borrowed from an MtmdInputChunks list and live as long as that list.

Implementations

impl<'chunks> MtmdInputChunk<'chunks>

pub fn chunk_type(&self) -> MtmdInputChunkType

The type of this chunk.

pub fn n_tokens(&self) -> usize

Total number of tokens in this chunk.

pub fn n_pos(&self) -> i32

Number of temporal positions (equals n_tokens for non-M-RoPE models).

pub fn save(&self) -> Result<Vec<u8>>

Serialize this chunk’s metadata to a byte buffer.

Only metadata is saved — never the image or audio payload. A chunk restored with MtmdInputChunks::load_chunk is a placeholder: it carries the token and position counts needed to line a cached KV state back up with its prompt, but cannot be re-encoded. That is the intended use, and it is why this is cheap enough to store alongside a session file written by state_seq_save_file.

Wraps mtmd_input_chunk_save.

Errors

Returns MtmdError::ChunkSaveFailed if llama.cpp cannot serialize this chunk.

pub fn to_owned_chunk(&self) -> Result<OwnedMtmdInputChunk>

Copy this chunk, payload and all, into an owned handle.

MtmdInputChunk borrows from the MtmdInputChunks list holding it, so it dies with that list. Take a copy when a chunk has to outlive the tokenization it came from — caching encoded media across requests, for instance. Unlike Self::to_placeholder, the result is still usable for encoding.

Wraps mtmd_input_chunk_copy.

Errors

Returns MtmdError::ChunkLoadFailed if llama.cpp returns null.

pub fn to_placeholder(&self) -> Result<OwnedMtmdInputChunk>

Copy this chunk as a standalone placeholder — metadata only, no payload.

Same shape as a round trip through Self::save and MtmdInputChunks::load_chunk, without the serialization. Useful for keeping a prompt’s structure alive after the pixels have been dropped.

Wraps mtmd_input_chunk_get_placeholder.

Errors

Returns MtmdError::ChunkLoadFailed if llama.cpp returns null.

pub fn text_tokens(&self) -> Option<&[i32]>

Return the raw llama token IDs for a text chunk.

Returns None if this chunk is not a text chunk.

pub fn image_tokens(&self) -> Option<MtmdImageTokens<'chunks>>

Return the image token metadata for an image or audio chunk.

Returns None for text chunks.

pub fn id(&self) -> Option<&str>

Optional ID attached to this chunk (used for KV cache tracking).

pub fn as_ptr(&self) -> *const mtmd_input_chunk

Returns the raw *const mtmd_input_chunk pointer.

Safety

The returned pointer is valid for the lifetime of the parent MtmdInputChunks.

Trait Implementations

impl<'chunks> Debug for MtmdInputChunk<'chunks>

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

Formats the value using the given formatter.