ollama/server/prompt.go
Michael Yang 22c5451fc2
fix system prompt (#5662)
* fix system prompt

* execute template when hitting previous roles

* fix tests

---------

Co-authored-by: jmorganca <jmorganca@gmail.com>
2024-07-12 21:04:44 -07:00

74 lines
2 KiB
Go

package server
import (
"bytes"
"context"
"log/slog"
"github.com/ollama/ollama/api"
"github.com/ollama/ollama/llm"
"github.com/ollama/ollama/template"
)
type tokenizeFunc func(context.Context, string) ([]int, error)
// chatPrompt accepts a list of messages and returns the prompt and images that should be used for the next chat turn.
// chatPrompt truncates any messages that exceed the context window of the model, making sure to always include 1) the
// latest message and 2) system messages
func chatPrompt(ctx context.Context, m *Model, tokenize tokenizeFunc, opts *api.Options, msgs []api.Message) (prompt string, images []llm.ImageData, _ error) {
var system []api.Message
// always include the last message
n := len(msgs) - 1
// in reverse, find all messages that fit into context window
for i := n - 1; i >= 0; i-- {
system = make([]api.Message, 0)
for j := range i {
if msgs[j].Role == "system" {
system = append(system, msgs[j])
}
}
var b bytes.Buffer
if err := m.Template.Execute(&b, template.Values{Messages: append(system, msgs[i:]...)}); err != nil {
return "", nil, err
}
s, err := tokenize(ctx, b.String())
if err != nil {
return "", nil, err
}
c := len(s)
if m.ProjectorPaths != nil {
for _, m := range msgs[i:] {
// images are represented as 768 sized embeddings
// TODO: get embedding length from project metadata
c += 768 * len(m.Images)
}
}
if c > opts.NumCtx {
slog.Debug("truncating input messages which exceed context length", "truncated", len(msgs[i:]))
break
} else {
n = i
}
}
// truncate any messages that do not fit into the context window
var b bytes.Buffer
if err := m.Template.Execute(&b, template.Values{Messages: append(system, msgs[n:]...)}); err != nil {
return "", nil, err
}
for _, m := range msgs[n:] {
for _, i := range m.Images {
images = append(images, llm.ImageData{
ID: len(images),
Data: i,
})
}
}
return b.String(), images, nil
}