"context"
"errors"
"fmt"
+ "slices"
"strings"
"unicode/utf8"
)
// compactorTries is the most calls for one node.
const compactorTries = 5
+// compactorBlock is the number of view lines in one block message.
+const compactorBlock = 4
+
// compactorRuler shows the model the size limit of a line. Models cannot count
// bytes, and a sample line as the ruler gets its content copied.
var compactorRuler = strings.Repeat("-", nodeBytes)
// Compactor builds the nodes of one agent with a model. A compaction is a call
// like a turn, with the same system prompt and tools, so it reads them from the
-// prompt cache of the turns. The tools are never called. After them comes one
-// user message with the compaction view up to the node and the task.
+// prompt cache of the turns. The tools are never called. After them come the
+// compaction view up to the node and the task, as the user messages that
+// compactorTexts gives. Each whole block of compactorBlock view lines is its
+// own message, and the last message holds the rest of the lines and the task.
+// The backend reads a cache entry only at a message end of a request, so a
+// compaction whose view begins with the same lines as an earlier one begins
+// with the same block messages.
//
-// When the line is over nodeBytes, the next try sends the same view and task,
-// plus a note with the size of the newest line and its cut at the limit. A try
-// never sends the model's earlier reply or reasoning back, so every try has the
-// same cached prefix and about the same size. After at most compactorTries
-// tries, the shortest line is the node. A few bytes over the limit is fine,
-// because the view measures the real sizes. A call that fails before any line
-// fails the build, and the core tries it again at the next message.
+// When the line is over nodeBytes, the next try sends the same messages, plus
+// one more user message with a note with the size of the newest line and its
+// cut at the limit. A try never sends the model's earlier reply or reasoning
+// back, so every try begins with the whole earlier try and has about the same
+// size. After at most compactorTries tries, the shortest line is the node. A
+// few bytes over the limit is fine, because the view measures the real sizes. A
+// call that fails before any line fails the build, and the core tries it again
+// at the next message.
type Compactor struct {
client *ModelClient
model ModelConfig
// Summarize returns the line of the node of task.
func (c *Compactor) Summarize(ctx context.Context, task Task) (string, error) {
- view := task.Context + "\n"
text, err := compactorTask(task)
if err != nil {
return "", err
instructions, err := c.instructions()
if err != nil {
- return "", fmt.Errorf("compact node (%d, %d): %w", task.Level, task.Index, err)
+ return "", err
+ }
+
+ var first []any
+
+ for _, message := range compactorTexts(task.Context, text) {
+ first = append(first, modelUserMessage(message))
}
var lines []string
+
note := ""
for len(lines) < compactorTries {
- parts := []string{view, text}
+ input := first
if note != "" {
- parts = append(parts, note)
+ input = append(slices.Clip(first), modelUserMessage(note))
}
var response ModelResponse
+
response, err = c.client.Create(ctx, ModelRequest{
Model: c.model.Model,
Effort: c.model.Effort,
Instructions: instructions,
Tools: c.tools,
- Input: []any{modelUserMessage(parts...)},
+ Input: input,
Node: &NodeKey{task.Level, task.Index},
})
if err != nil {
}
if len(lines) == 0 {
- return "", fmt.Errorf("compact node (%d, %d): %w", task.Level, task.Index, err)
+ return "", err
}
return compactorShortest(lines), nil
return "", fmt.Errorf("node (%d, %d) has %d inputs", task.Level, task.Index, len(task.Input))
}
+// compactorTexts returns the texts of the user messages of a first try for the
+// compaction view and the task text. Each whole block of compactorBlock lines,
+// counted from the first line of the view, is one message. The last message
+// holds the rest of the lines, the closing tag, a newline, and the task. The
+// first message starts with the opening tag. Joined, the texts are the view, a
+// newline, and the task.
+func compactorTexts(view, task string) []string {
+ body := strings.TrimSuffix(strings.TrimPrefix(view, "<chat>\n"), "</chat>")
+ lines := strings.SplitAfter(body, "\n")
+ lines = lines[:len(lines)-1]
+ whole := len(lines) - len(lines)%compactorBlock
+
+ var texts []string
+
+ for n := 0; n < whole; n += compactorBlock {
+ texts = append(texts, viewMessage(n == 0, lines[n:n+compactorBlock]))
+ }
+
+ return append(texts, viewMessage(whole == 0, lines[whole:])+"</chat>\n"+task)
+}
+
// compactorTooLong returns the note for a line over nodeBytes: its size and its
// first nodeBytes bytes, which show the model where the limit cuts it.
func compactorTooLong(line string) string {
projects / onechat / blobdiff