ollama/kvcache/cache.go
Jesse Gross a1cda80bcb model: Update encoder cache to use multimodal input processing handler
The encoder cache needs to know the position of images in the input
stream so that it knows when to delete them. Previously images didn't
have a position, so we implied one by breaking batches before an
image and then assuming the image was in the first position. However,
multimodal objects are now given explicit positions in the input
stream, so we can use that instead.

Breaking batches was also a way to simulate a cross attention mask
for mllama. However, given that it only supports a single sequence
and a single image, this mask doesn't serve any real purpose.
Removing the batch break does not appear to affect the quality of
the output.

Most of this is simply moving the input data structures to a new
package to avoid import cycles.
2025-03-09 17:05:26 -07:00

67 lines
2.1 KiB
Go

package kvcache
import (
"errors"
"github.com/ollama/ollama/ml"
"github.com/ollama/ollama/model/input"
)
var (
ErrKvCacheFull = errors.New("could not find a kv cache slot")
ErrNotSupported = errors.New("model does not support operation")
)
type Cache interface {
// ** used by model implementations **
// SetLayer sets the active layer of the cache
SetLayer(layer int)
// Get returns the history of key and value tensors plus a mask
//
// The shape of the tensors is documented in the specific
// cache implementation used.
Get(ctx ml.Context) (ml.Tensor, ml.Tensor, ml.Tensor)
// Put stores a batch of key and value in the cache
//
// The shape of the tensors is documented in the specific
// cache implementation used.
Put(ctx ml.Context, key, value ml.Tensor)
// SetConfig controls optimizations (mostly backend-specific) that may transform
// the output of the cache to work better with specific kernels. If not called,
// the backend settings will be used. This works well when calling Attention.
//
// The config can be overridden by models, especially if they require vanilla
// output when implementing their own version of attention. To do this, pass
// an empty ml.CacheConfig.
//
// Most models will not need to use this.
SetConfig(ml.CacheConfig)
// ** cache management **
// Init sets up runtime parameters
Init(backend ml.Backend, dtype ml.DType, capacity int32)
// Close closes the cache and frees resources associated with it
Close()
// StartForward is called before the start of the model's forward pass.
// For each token in the coming batch, there must be a corresponding
// entry in positions and seqs.
StartForward(ctx ml.Context, opts input.Options) error
// CopyPrefix copies tokens in the range [0, len) from srcSeq to dstSeq
CopyPrefix(srcSeq, dstSeq int, len int32)
// Remove deletes tokens in the range [beginIndex, endIndex) from seq. Set
// endIndex to math.MaxInt32 to remove everything starting at beginIndex.
//
// If an error occurs, the entire context for the sequence should be
// removed by calling Remove(seq, 0, math.MaxInt32)
Remove(seq int, beginIndex, endIndex int32) error
}