weichen
3a110a728c
Why: Some endpoints reject consecutive system messages or a run of the same role. The product already emits several system messages in one request. Evidence: go test is covered by PrepareMessages tests for merge, strict folding, and tool pairs. Empty MessageShape leaves the transcript unchanged. Impact: Callers opt in with StreamOptions.MessageShape. Tool calls and tool results are not merged. Refs: docs/records/2026-10-04-sillytavern-review.md
61 lines
1.5 KiB
Go
61 lines
1.5 KiB
Go
package llm
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// PrepareMessages 按 endpoint 整形消息。
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// merge 合并相邻、且不携带工具调用的同角色消息。
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// strict 在此之后把第一条之后的 system 收成 user，再合并，满足严格交替。
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// 工具消息和带 tool_calls 的助手消息保持原样，避免拆开调用与结果。
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func PrepareMessages(msgs []Message, shape string) []Message {
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switch shape {
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case "", "merge", "strict":
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default:
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return msgs
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}
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out := mergeSameRole(msgs)
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if shape == "strict" {
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out = foldExtraSystems(out)
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out = mergeSameRole(out)
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}
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return out
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}
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func mergeable(m Message) bool {
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return m.Role != RoleTool && len(m.ToolCalls) == 0 && m.ToolCallID == ""
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}
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func mergeSameRole(msgs []Message) []Message {
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if len(msgs) == 0 {
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return msgs
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}
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out := make([]Message, 0, len(msgs))
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for _, m := range msgs {
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if n := len(out); n > 0 && out[n-1].Role == m.Role && mergeable(out[n-1]) && mergeable(m) {
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if out[n-1].Content != "" && m.Content != "" {
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out[n-1].Content += "\n\n" + m.Content
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} else {
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out[n-1].Content += m.Content
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}
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continue
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}
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out = append(out, m)
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}
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return out
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}
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func foldExtraSystems(msgs []Message) []Message {
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seenSystem := false
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out := make([]Message, 0, len(msgs))
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for _, m := range msgs {
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if m.Role == RoleSystem {
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if seenSystem {
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m.Role = RoleUser
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if m.Content != "" {
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m.Content = "[system]\n" + m.Content
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}
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}
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seenSystem = true
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}
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out = append(out, m)
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}
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return out
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}
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