Files
the-biergarten-app/pipeline/src/data_generation/llama/helpers.cpp
Aaron Po e4e16a5084 fix: address critical correctness, reliability, and design issues in pipeline
CORRECTNESS FIXES:
- json_loader: Add RollbackTransaction() and call it on exception instead of
  CommitTransaction(). Prevents partial data corruption on parse/disk errors.
- wikipedia_service: Fix invalid MediaWiki API parameter explaintext=true ->
  explaintext=1. Now returns plain text instead of HTML markup in contexts.
- helpers: Fix ParseTwoLineResponse filter to only remove known thinking tags
  (<think>, <reasoning>, <reflect>) instead of any <...> pattern. Prevents
  silently removing legitimate output like <username>content</username>.

RELIABILITY & DESIGN IMPROVEMENTS:
- load/main: Make n_ctx (context window size) configurable via --n-ctx flag
  (default 2048, range 1-32768) to support larger models like Qwen3-14B.
- generate_brewery: Prevent retry prompt growth by extracting location context
  into constant and using compact retry format (error + schema + location only).
  Avoids token truncation on final retry attempts.
- database: Fix data representativeness by changing QueryCities from
  ORDER BY name (alphabetic bias) to ORDER BY RANDOM() for unbiased sampling.
  Convert all SQLITE_STATIC to SQLITE_TRANSIENT to prevent use-after-free risks.

POLISH:
- infer: Advance sampling seed between generation calls to improve diversity
  across brewery and user generation.
- data_downloader: Remove unnecessary commit hash truncation; use full hash.
- json_loader: Fix misleading log message from "RapidJSON" to "Boost.JSON".
2026-04-03 11:58:00 -04:00

442 lines
14 KiB
C++

/**
* Helper Functions Module
* Provides utility functions for text processing, parsing, and chat template
* formatting. Functions handle whitespace normalization, response parsing, and
* conversion of prompts to proper chat format using the model's built-in
* template.
*/
#include <algorithm>
#include <array>
#include <boost/json.hpp>
#include <cctype>
#include <sstream>
#include <stdexcept>
#include <string>
#include <vector>
#include "data_generation/llama_generator.h"
#include "llama.h"
namespace {
/**
* String trimming: removes leading and trailing whitespace
*/
std::string Trim(std::string value) {
auto not_space = [](unsigned char ch) { return !std::isspace(ch); };
value.erase(value.begin(),
std::find_if(value.begin(), value.end(), not_space));
value.erase(std::find_if(value.rbegin(), value.rend(), not_space).base(),
value.end());
return value;
}
/**
* Normalize whitespace: collapses multiple spaces/tabs/newlines into single
* spaces
*/
std::string CondenseWhitespace(std::string text) {
std::string out;
out.reserve(text.size());
bool in_whitespace = false;
for (unsigned char ch : text) {
if (std::isspace(ch)) {
if (!in_whitespace) {
out.push_back(' ');
in_whitespace = true;
}
continue;
}
in_whitespace = false;
out.push_back(static_cast<char>(ch));
}
return Trim(std::move(out));
}
/**
* Truncate region context to fit within max length while preserving word
* boundaries
*/
std::string PrepareRegionContext(std::string_view region_context,
std::size_t max_chars) {
std::string normalized = CondenseWhitespace(std::string(region_context));
if (normalized.size() <= max_chars) {
return normalized;
}
normalized.resize(max_chars);
const std::size_t last_space = normalized.find_last_of(' ');
if (last_space != std::string::npos && last_space > max_chars / 2) {
normalized.resize(last_space);
}
normalized += "...";
return normalized;
}
/**
* Remove common bullet points, numbers, and field labels added by LLM in output
*/
std::string StripCommonPrefix(std::string line) {
line = Trim(std::move(line));
if (!line.empty() && (line[0] == '-' || line[0] == '*')) {
line = Trim(line.substr(1));
} else {
std::size_t i = 0;
while (i < line.size() &&
std::isdigit(static_cast<unsigned char>(line[i]))) {
++i;
}
if (i > 0 && i < line.size() && (line[i] == '.' || line[i] == ')')) {
line = Trim(line.substr(i + 1));
}
}
auto strip_label = [&line](const std::string& label) {
if (line.size() >= label.size()) {
bool matches = true;
for (std::size_t i = 0; i < label.size(); ++i) {
if (std::tolower(static_cast<unsigned char>(line[i])) !=
std::tolower(static_cast<unsigned char>(label[i]))) {
matches = false;
break;
}
}
if (matches) {
line = Trim(line.substr(label.size()));
}
}
};
strip_label("name:");
strip_label("brewery name:");
strip_label("description:");
strip_label("username:");
strip_label("bio:");
return Trim(std::move(line));
}
/**
* Parse two-line response from LLM: normalize line endings, strip formatting,
* filter spurious output, and combine remaining lines if needed
*/
std::pair<std::string, std::string> ParseTwoLineResponse(
const std::string& raw, const std::string& error_message) {
std::string normalized = raw;
std::replace(normalized.begin(), normalized.end(), '\r', '\n');
std::vector<std::string> lines;
std::stringstream stream(normalized);
std::string line;
while (std::getline(stream, line)) {
line = StripCommonPrefix(std::move(line));
if (!line.empty()) lines.push_back(std::move(line));
}
std::vector<std::string> filtered;
for (auto& l : lines) {
std::string low = l;
std::transform(low.begin(), low.end(), low.begin(), [](unsigned char c) {
return static_cast<char>(std::tolower(c));
});
// Filter known thinking tags like <think>...</think>, but be conservative
// to avoid removing legitimate output. Only filter specific known
// patterns.
if (!l.empty() && l.front() == '<' && low.back() == '>') {
// Only filter if it's a known thinking tag: <think>, <reasoning>, etc.
if (low.find("think") != std::string::npos ||
low.find("reasoning") != std::string::npos ||
low.find("reflect") != std::string::npos) {
continue;
}
}
if (low.rfind("okay,", 0) == 0 || low.rfind("hmm", 0) == 0) continue;
filtered.push_back(std::move(l));
}
if (filtered.size() < 2) throw std::runtime_error(error_message);
std::string first = Trim(filtered.front());
std::string second;
for (size_t i = 1; i < filtered.size(); ++i) {
if (!second.empty()) second += ' ';
second += filtered[i];
}
second = Trim(std::move(second));
if (first.empty() || second.empty()) throw std::runtime_error(error_message);
return {first, second};
}
/**
* Apply model's chat template to user-only prompt, formatting it for the model
*/
std::string ToChatPrompt(const llama_model* model,
const std::string& user_prompt) {
const char* tmpl = llama_model_chat_template(model, nullptr);
if (tmpl == nullptr) {
return user_prompt;
}
const llama_chat_message message{"user", user_prompt.c_str()};
std::vector<char> buffer(
std::max<std::size_t>(1024, user_prompt.size() * 4));
int32_t required =
llama_chat_apply_template(tmpl, &message, 1, true, buffer.data(),
static_cast<int32_t>(buffer.size()));
if (required < 0) {
throw std::runtime_error("LlamaGenerator: failed to apply chat template");
}
if (required >= static_cast<int32_t>(buffer.size())) {
buffer.resize(static_cast<std::size_t>(required) + 1);
required =
llama_chat_apply_template(tmpl, &message, 1, true, buffer.data(),
static_cast<int32_t>(buffer.size()));
if (required < 0) {
throw std::runtime_error(
"LlamaGenerator: failed to apply chat template");
}
}
return std::string(buffer.data(), static_cast<std::size_t>(required));
}
/**
* Apply model's chat template to system+user prompt pair, formatting for the
* model
*/
std::string ToChatPrompt(const llama_model* model,
const std::string& system_prompt,
const std::string& user_prompt) {
const char* tmpl = llama_model_chat_template(model, nullptr);
if (tmpl == nullptr) {
return system_prompt + "\n\n" + user_prompt;
}
const llama_chat_message messages[2] = {{"system", system_prompt.c_str()},
{"user", user_prompt.c_str()}};
std::vector<char> buffer(std::max<std::size_t>(
1024, (system_prompt.size() + user_prompt.size()) * 4));
int32_t required =
llama_chat_apply_template(tmpl, messages, 2, true, buffer.data(),
static_cast<int32_t>(buffer.size()));
if (required < 0) {
throw std::runtime_error("LlamaGenerator: failed to apply chat template");
}
if (required >= static_cast<int32_t>(buffer.size())) {
buffer.resize(static_cast<std::size_t>(required) + 1);
required =
llama_chat_apply_template(tmpl, messages, 2, true, buffer.data(),
static_cast<int32_t>(buffer.size()));
if (required < 0) {
throw std::runtime_error(
"LlamaGenerator: failed to apply chat template");
}
}
return std::string(buffer.data(), static_cast<std::size_t>(required));
}
void AppendTokenPiece(const llama_vocab* vocab, llama_token token,
std::string& output) {
std::array<char, 256> buffer{};
int32_t bytes =
llama_token_to_piece(vocab, token, buffer.data(),
static_cast<int32_t>(buffer.size()), 0, true);
if (bytes < 0) {
std::vector<char> dynamic_buffer(static_cast<std::size_t>(-bytes));
bytes = llama_token_to_piece(vocab, token, dynamic_buffer.data(),
static_cast<int32_t>(dynamic_buffer.size()),
0, true);
if (bytes < 0) {
throw std::runtime_error(
"LlamaGenerator: failed to decode sampled token piece");
}
output.append(dynamic_buffer.data(), static_cast<std::size_t>(bytes));
return;
}
output.append(buffer.data(), static_cast<std::size_t>(bytes));
}
bool ExtractFirstJsonObject(const std::string& text, std::string& json_out) {
std::size_t start = std::string::npos;
int depth = 0;
bool in_string = false;
bool escaped = false;
for (std::size_t i = 0; i < text.size(); ++i) {
const char ch = text[i];
if (in_string) {
if (escaped) {
escaped = false;
} else if (ch == '\\') {
escaped = true;
} else if (ch == '"') {
in_string = false;
}
continue;
}
if (ch == '"') {
in_string = true;
continue;
}
if (ch == '{') {
if (depth == 0) {
start = i;
}
++depth;
continue;
}
if (ch == '}') {
if (depth == 0) {
continue;
}
--depth;
if (depth == 0 && start != std::string::npos) {
json_out = text.substr(start, i - start + 1);
return true;
}
}
}
return false;
}
std::string ValidateBreweryJson(const std::string& raw, std::string& name_out,
std::string& description_out) {
auto validate_object = [&](const boost::json::value& jv,
std::string& error_out) -> bool {
if (!jv.is_object()) {
error_out = "JSON root must be an object";
return false;
}
const auto& obj = jv.get_object();
if (!obj.contains("name") || !obj.at("name").is_string()) {
error_out = "JSON field 'name' is missing or not a string";
return false;
}
if (!obj.contains("description") || !obj.at("description").is_string()) {
error_out = "JSON field 'description' is missing or not a string";
return false;
}
name_out = Trim(std::string(obj.at("name").as_string().c_str()));
description_out =
Trim(std::string(obj.at("description").as_string().c_str()));
if (name_out.empty()) {
error_out = "JSON field 'name' must not be empty";
return false;
}
if (description_out.empty()) {
error_out = "JSON field 'description' must not be empty";
return false;
}
std::string name_lower = name_out;
std::string description_lower = description_out;
std::transform(
name_lower.begin(), name_lower.end(), name_lower.begin(),
[](unsigned char c) { return static_cast<char>(std::tolower(c)); });
std::transform(description_lower.begin(), description_lower.end(),
description_lower.begin(), [](unsigned char c) {
return static_cast<char>(std::tolower(c));
});
if (name_lower == "string" || description_lower == "string") {
error_out = "JSON appears to be a schema placeholder, not content";
return false;
}
error_out.clear();
return true;
};
boost::system::error_code ec;
boost::json::value jv = boost::json::parse(raw, ec);
std::string validation_error;
if (ec) {
std::string extracted;
if (!ExtractFirstJsonObject(raw, extracted)) {
return "JSON parse error: " + ec.message();
}
ec.clear();
jv = boost::json::parse(extracted, ec);
if (ec) {
return "JSON parse error: " + ec.message();
}
if (!validate_object(jv, validation_error)) {
return validation_error;
}
return {};
}
if (!validate_object(jv, validation_error)) {
return validation_error;
}
return {};
}
} // namespace
// Forward declarations for helper functions exposed to other translation units
std::string PrepareRegionContextPublic(std::string_view region_context,
std::size_t max_chars) {
return PrepareRegionContext(region_context, max_chars);
}
std::pair<std::string, std::string> ParseTwoLineResponsePublic(
const std::string& raw, const std::string& error_message) {
return ParseTwoLineResponse(raw, error_message);
}
std::string ToChatPromptPublic(const llama_model* model,
const std::string& user_prompt) {
return ToChatPrompt(model, user_prompt);
}
std::string ToChatPromptPublic(const llama_model* model,
const std::string& system_prompt,
const std::string& user_prompt) {
return ToChatPrompt(model, system_prompt, user_prompt);
}
void AppendTokenPiecePublic(const llama_vocab* vocab, llama_token token,
std::string& output) {
AppendTokenPiece(vocab, token, output);
}
std::string ValidateBreweryJsonPublic(const std::string& raw,
std::string& name_out,
std::string& description_out) {
return ValidateBreweryJson(raw, name_out, description_out);
}