llama.cpp/common/chat-template.hpp
2025-01-22 16:16:27 +00:00

269 lines
11 KiB
C++

/*
Copyright 2024 Google LLC
Use of this source code is governed by an MIT-style
license that can be found in the LICENSE file or at
https://opensource.org/licenses/MIT.
*/
// SPDX-License-Identifier: MIT
#pragma once
#include "minja.hpp"
#include <json.hpp>
#include <string>
#include <vector>
using json = nlohmann::ordered_json;
namespace minja {
class chat_template {
public:
private:
bool supports_tools_ = true;
// Meta-Llama-3.1-8B-Instruct's template expects arguments to be an object.
// Most other templates (and OpenAI's API) expect the arguments object to be stringified.
bool requires_object_arguments_ = false;
bool requires_typed_content_ = false;
bool supports_system_role_ = true;
bool supports_parallel_tool_calls_ = false;
std::string source_;
std::string bos_token_;
std::string eos_token_;
std::shared_ptr<minja::TemplateNode> template_root_;
std::string try_raw_render(
const nlohmann::ordered_json & messages,
const nlohmann::ordered_json & tools,
bool add_generation_prompt,
const nlohmann::ordered_json & extra_context = nlohmann::ordered_json()) const
{
try {
auto prompt = apply(messages, tools, add_generation_prompt, extra_context, /* adjust_inputs= */ false);
// fprintf(stderr, "Prompt: %s\n", prompt.c_str());
return prompt;
} catch (const std::exception & e) {
// fprintf(stderr, "Error: %s\n", e.what());
return "";
}
}
public:
chat_template(const std::string & source, const std::string & bos_token, const std::string & eos_token)
: source_(source), bos_token_(bos_token), eos_token_(eos_token)
{
template_root_ = minja::Parser::parse(source_, {
/* .trim_blocks = */ true,
/* .lstrip_blocks = */ true,
/* .keep_trailing_newline = */ false,
});
supports_tools_ = source.find("tools") != std::string::npos;
auto renders_string_arguments =
try_raw_render({
{
{"role", "user"},
{"content", "Hey"}
},
{
{"role", "assistant"},
{"tool_calls", json::array({
{
{"id", "call_1___"},
{"type", "function"},
{"function", {
{"arguments", "{\"code\": \"print('Hello, World!')\"}"},
{"name", "ipython"},
}},
},
})},
}
}, {}, false).find("{\"code\": \"print") != std::string::npos;
if (!renders_string_arguments) {
auto renders_object_arguments =
try_raw_render({
{
{"role", "user"},
{"content", "Hey"}
},
{
{"role", "assistant"},
{"tool_calls", json::array({
{
{"id", "call_1___"},
{"type", "function"},
{"function", {
{"arguments", {
{"code", "print('Hello, World!')"},
}},
{"name", "ipython"},
}},
},
})},
}
}, {}, false).find("{\"code\": \"print") != std::string::npos;
requires_object_arguments_ = renders_object_arguments;
}
supports_parallel_tool_calls_ = source.find("tool_call_id") != std::string::npos;
supports_system_role_ = try_raw_render({
{{"role", "system"}, {"content", "<System Needle>"}},
{{"role", "user"}, {"content", "Hey"}}
}, {}, false).find("<System Needle>") != std::string::npos;
requires_typed_content_ = try_raw_render({{{"role", "user"}, {"content", "Hey"}}}, {}, false).find("Hey") == std::string::npos
&& try_raw_render({{{"role", "user"}, {"content", {{{"type", "text"}, {"text", "Hey"}}}}}}, {}, false).find("Hey") != std::string::npos;
}
const std::string & source() const { return source_; }
const std::string & bos_token() const { return bos_token_; }
const std::string & eos_token() const { return eos_token_; }
bool supports_tools() const { return supports_tools_; }
bool supports_parallel_tool_calls() const { return supports_parallel_tool_calls_; }
std::string apply(
const nlohmann::ordered_json & messages,
const nlohmann::ordered_json & tools,
bool add_generation_prompt,
const nlohmann::ordered_json & extra_context = nlohmann::ordered_json(),
bool adjust_inputs = true) const
{
json actual_messages;
// First, "fix" messages so they have a chance to be rendered correctly by the template
if (adjust_inputs && (requires_object_arguments_ || !supports_system_role_ || !supports_tools_ || requires_typed_content_)) {
actual_messages = json::array();
auto add_message = [&](const json & msg) {
if (requires_typed_content_ && msg.contains("content") && !msg.at("content").is_null() && msg.at("content").is_string()) {
actual_messages.push_back({
{"role", msg.at("role")},
{"content", {{
{"type", "text"},
{"text", msg.at("content")},
}}},
});
} else {
actual_messages.push_back(msg);
}
};
std::string pending_system;
auto flush_sys = [&]() {
if (!pending_system.empty()) {
add_message({
{"role", "user"},
{"content", pending_system},
});
pending_system.clear();
}
};
for (const auto & message_ : messages) {
auto message = message_;
if (!message.contains("role") || !message.contains("content")) {
throw std::runtime_error("message must have 'role' and 'content' fields: " + message.dump());
}
std::string role = message.at("role");
if (message.contains("tool_calls")) {
if (requires_object_arguments_ || !supports_tools_) {
for (auto & tool_call : message.at("tool_calls")) {
if (tool_call["type"] == "function") {
auto & function = tool_call.at("function");
std::string arguments = function.at("arguments");
function["arguments"] = json::parse(arguments);
}
}
}
if (!supports_tools_) {
auto content = message.at("content");
auto tool_calls = json::array();
for (const auto & tool_call : message.at("tool_calls")) {
if (tool_call.at("type") != "function") {
continue;
}
const auto & function = tool_call.at("function");
auto tc = json {
{"name", function.at("name")},
{"arguments", function.at("arguments")},
};
if (tool_call.contains("id")) {
tc["id"] = tool_call["id"];
}
tool_calls.push_back(tc);
}
auto obj = json {
{"tool_calls", tool_calls},
};
if (!content.is_null() && content != "") {
obj["content"] = content;
}
message["content"] = obj.dump(2);
message.erase("tool_calls");
}
}
if (!supports_tools_ && role == "tool") {
message["role"] = "user";
auto obj = json {
{"tool_response", {
{"tool", message.at("name")},
{"content", message.at("content")},
}},
};
if (message.contains("tool_call_id")) {
obj["tool_response"]["tool_call_id"] = message.at("tool_call_id");
}
message["content"] = obj.dump(2);
message.erase("name");
}
if (!message["content"].is_null() && !supports_system_role_) {
std::string content = message.at("content");
if (role == "system") {
if (!pending_system.empty()) pending_system += "\n";
pending_system += content;
continue;
} else {
if (role == "user") {
if (!pending_system.empty()) {
message["content"] = pending_system + (content.empty() ? "" : "\n" + content);
pending_system.clear();
}
} else {
flush_sys();
}
}
}
add_message(message);
}
flush_sys();
} else {
actual_messages = messages;
}
auto context = minja::Context::make(json({
{"messages", actual_messages},
{"add_generation_prompt", add_generation_prompt},
{"bos_token", bos_token_},
{"eos_token", eos_token_},
}));
if (!tools.is_null()) {
auto tools_val = minja::Value(tools);
context->set("tools", tools_val);
}
if (!extra_context.is_null()) {
for (auto & kv : extra_context.items()) {
minja::Value val(kv.value());
context->set(kv.key(), val);
}
}
return template_root_->render(context);
}
};
} // namespace minja