common.cpp

#if defined(_MSC_VER)
#define _SILENCE_CXX17_CODECVT_HEADER_DEPRECATION_WARNING
#endif

#include "ggml.h"
#include "gguf.h"

#include "common.h"
#include "log.h"
// Change JSON_ASSERT from assert() to GGML_ASSERT:
#define JSON_ASSERT GGML_ASSERT
#include "json.hpp"
#include "json-schema-to-grammar.h"
#include "llama.h"
#include "chat.hpp"
#include "chat-template.hpp"

#include <algorithm>
#include <cinttypes>
#include <climits>
#include <cmath>
#include <codecvt>
#include <cstdarg>
#include <cstring>
#include <ctime>
#include <filesystem>
#include <fstream>
#include <iostream>
#include <iterator>
#include <regex>
#include <sstream>
#include <string>
#include <thread>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#if defined(__APPLE__) && defined(__MACH__)
#include <sys/types.h>
#include <sys/sysctl.h>
#endif

#if defined(_WIN32)
#define WIN32_LEAN_AND_MEAN
#ifndef NOMINMAX
#   define NOMINMAX
#endif
#include <locale>
#include <windows.h>
#include <fcntl.h>
#include <io.h>
#else
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <unistd.h>
#endif
#if defined(LLAMA_USE_CURL)
#include <curl/curl.h>
#include <curl/easy.h>
#include <future>
#endif

#if defined(_MSC_VER)
#pragma warning(disable: 4244 4267) // possible loss of data
#endif

#if defined(LLAMA_USE_CURL)
#ifdef __linux__
#include <linux/limits.h>
#elif defined(_WIN32)
#   if !defined(PATH_MAX)
#   define PATH_MAX MAX_PATH
#   endif
#else
#include <sys/syslimits.h>
#endif
#define LLAMA_CURL_MAX_URL_LENGTH 2084 // Maximum URL Length in Chrome: 2083

//
// CURL utils
//

using curl_ptr = std::unique_ptr<CURL, decltype(&curl_easy_cleanup)>;

// cannot use unique_ptr for curl_slist, because we cannot update without destroying the old one
struct curl_slist_ptr {
    struct curl_slist * ptr = nullptr;
    ~curl_slist_ptr() {
        if (ptr) {
            curl_slist_free_all(ptr);
        }
    }
};
#endif // LLAMA_USE_CURL

using json = nlohmann::ordered_json;

//
// CPU utils
//

int32_t cpu_get_num_physical_cores() {
#ifdef __linux__
    // enumerate the set of thread siblings, num entries is num cores
    std::unordered_set<std::string> siblings;
    for (uint32_t cpu=0; cpu < UINT32_MAX; ++cpu) {
        std::ifstream thread_siblings("/sys/devices/system/cpu/cpu"
            + std::to_string(cpu) + "/topology/thread_siblings");
        if (!thread_siblings.is_open()) {
            break; // no more cpus
        }
        std::string line;
        if (std::getline(thread_siblings, line)) {
            siblings.insert(line);
        }
    }
    if (!siblings.empty()) {
        return static_cast<int32_t>(siblings.size());
    }
#elif defined(__APPLE__) && defined(__MACH__)
    int32_t num_physical_cores;
    size_t len = sizeof(num_physical_cores);
    int result = sysctlbyname("hw.perflevel0.physicalcpu", &num_physical_cores, &len, NULL, 0);
    if (result == 0) {
        return num_physical_cores;
    }
    result = sysctlbyname("hw.physicalcpu", &num_physical_cores, &len, NULL, 0);
    if (result == 0) {
        return num_physical_cores;
    }
#elif defined(_WIN32) && (_WIN32_WINNT >= 0x0601) && !defined(__MINGW64__) // windows 7 and later
    // TODO: windows + arm64 + mingw64
    unsigned int n_threads_win = std::thread::hardware_concurrency();
    unsigned int default_threads = n_threads_win > 0 ? (n_threads_win <= 4 ? n_threads_win : n_threads_win / 2) : 4;

    DWORD buffer_size = 0;
    if (!GetLogicalProcessorInformationEx(RelationProcessorCore, nullptr, &buffer_size)) {
        if (GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
            return default_threads;
        }
    }

    std::vector<char> buffer(buffer_size);
    if (!GetLogicalProcessorInformationEx(RelationProcessorCore, reinterpret_cast<PSYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX>(buffer.data()), &buffer_size)) {
        return default_threads;
    }

    int32_t num_physical_cores = 0;
    PSYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX info = reinterpret_cast<PSYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX>(buffer.data());
    while (buffer_size > 0) {
        if (info->Relationship == RelationProcessorCore) {
            num_physical_cores += info->Processor.GroupCount;
        }
        buffer_size -= info->Size;
        info = reinterpret_cast<PSYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX>(reinterpret_cast<char*>(info) + info->Size);
    }

    return num_physical_cores > 0 ? num_physical_cores : default_threads;
#endif
    unsigned int n_threads = std::thread::hardware_concurrency();
    return n_threads > 0 ? (n_threads <= 4 ? n_threads : n_threads / 2) : 4;
}

#if defined(__x86_64__) && defined(__linux__) && !defined(__ANDROID__)
#include <pthread.h>

static void cpuid(unsigned leaf, unsigned subleaf,
                  unsigned *eax, unsigned *ebx, unsigned *ecx, unsigned *edx) {
    __asm__("movq\t%%rbx,%%rsi\n\t"
            "cpuid\n\t"
            "xchgq\t%%rbx,%%rsi"
            : "=a"(*eax), "=S"(*ebx), "=c"(*ecx), "=d"(*edx)
            : "0"(leaf), "2"(subleaf));
}

static int pin_cpu(int cpu) {
    cpu_set_t mask;
    CPU_ZERO(&mask);
    CPU_SET(cpu, &mask);
    return pthread_setaffinity_np(pthread_self(), sizeof(mask), &mask);
}

static bool is_hybrid_cpu(void) {
    unsigned eax, ebx, ecx, edx;
    cpuid(7, 0, &eax, &ebx, &ecx, &edx);
    return !!(edx & (1u << 15));
}

static bool is_running_on_efficiency_core(void) {
    unsigned eax, ebx, ecx, edx;
    cpuid(0x1a, 0, &eax, &ebx, &ecx, &edx);
    int intel_atom = 0x20;
    int core_type = (eax & 0xff000000u) >> 24;
    return core_type == intel_atom;
}

static int cpu_count_math_cpus(int n_cpu) {
    int result = 0;
    for (int cpu = 0; cpu < n_cpu; ++cpu) {
        if (pin_cpu(cpu)) {
            return -1;
        }
        if (is_running_on_efficiency_core()) {
            continue; // efficiency cores harm lockstep threading
        }
        ++cpu; // hyperthreading isn't useful for linear algebra
        ++result;
    }
    return result;
}

#endif // __x86_64__ && __linux__

/**
 * Returns number of CPUs on system that are useful for math.
 */
int32_t cpu_get_num_math() {
#if defined(__x86_64__) && defined(__linux__) && !defined(__ANDROID__)
    int n_cpu = sysconf(_SC_NPROCESSORS_ONLN);
    if (n_cpu < 1) {
        return cpu_get_num_physical_cores();
    }
    if (is_hybrid_cpu()) {
        cpu_set_t affinity;
        if (!pthread_getaffinity_np(pthread_self(), sizeof(affinity), &affinity)) {
            int result = cpu_count_math_cpus(n_cpu);
            pthread_setaffinity_np(pthread_self(), sizeof(affinity), &affinity);
            if (result > 0) {
                return result;
            }
        }
    }
#endif
    return cpu_get_num_physical_cores();
}

// Helper for setting process priority

#if defined(_WIN32)

bool set_process_priority(enum ggml_sched_priority prio) {
    if (prio == GGML_SCHED_PRIO_NORMAL) {
        return true;
    }

    DWORD p = NORMAL_PRIORITY_CLASS;
    switch (prio) {
        case GGML_SCHED_PRIO_NORMAL:   p = NORMAL_PRIORITY_CLASS;       break;
        case GGML_SCHED_PRIO_MEDIUM:   p = ABOVE_NORMAL_PRIORITY_CLASS; break;
        case GGML_SCHED_PRIO_HIGH:     p = HIGH_PRIORITY_CLASS;         break;
        case GGML_SCHED_PRIO_REALTIME: p = REALTIME_PRIORITY_CLASS;     break;
    }

    if (!SetPriorityClass(GetCurrentProcess(), p)) {
        LOG_WRN("failed to set process priority class %d : (%d)\n", prio, (int) GetLastError());
        return false;
    }

    return true;
}

#else // MacOS and POSIX
#include <sys/types.h>
#include <sys/resource.h>

bool set_process_priority(enum ggml_sched_priority prio) {
    if (prio == GGML_SCHED_PRIO_NORMAL) {
        return true;
    }

    int p = 0;
    switch (prio) {
        case GGML_SCHED_PRIO_NORMAL:   p =  0;  break;
        case GGML_SCHED_PRIO_MEDIUM:   p = -5;  break;
        case GGML_SCHED_PRIO_HIGH:     p = -10; break;
        case GGML_SCHED_PRIO_REALTIME: p = -20; break;
    }

    if (!setpriority(PRIO_PROCESS, 0, p)) {
        LOG_WRN("failed to set process priority %d : %s (%d)\n", prio, strerror(errno), errno);
        return false;
    }
    return true;
}

#endif

//
// CLI argument parsing
//


void postprocess_cpu_params(cpu_params& cpuparams, const cpu_params* role_model) {
    int32_t n_set = 0;

    if (cpuparams.n_threads < 0) {
        // Assuming everything about cpuparams is invalid
        if (role_model != nullptr) {
            cpuparams = *role_model;
        } else {
            cpuparams.n_threads = cpu_get_num_math();
        }
    }

    for (int32_t i = 0; i < GGML_MAX_N_THREADS; i++) {
        if (cpuparams.cpumask[i]) {
            n_set++;
        }
    }

    if (n_set && n_set < cpuparams.n_threads) {
        // Not enough set bits, may experience performance issues.
        LOG_WRN("Not enough set bits in CPU mask (%d) to satisfy requested thread count: %d\n", n_set, cpuparams.n_threads);
    }
}

bool parse_cpu_range(const std::string & range, bool (&boolmask)[GGML_MAX_N_THREADS]) {
    size_t dash_loc = range.find('-');
    if (dash_loc == std::string::npos) {
        LOG_ERR("Format of CPU range is invalid! Expected [<start>]-[<end>].\n");
        return false;
    }

    size_t start_i;
    size_t end_i;

    if (dash_loc == 0) {
        start_i = 0;
    } else {
        start_i = std::stoull(range.substr(0, dash_loc));
        if (start_i >= GGML_MAX_N_THREADS) {
            LOG_ERR("Start index out of bounds!\n");
            return false;
        }
    }

    if (dash_loc == range.length() - 1) {
        end_i = GGML_MAX_N_THREADS - 1;
    } else {
        end_i = std::stoull(range.substr(dash_loc + 1));
        if (end_i >= GGML_MAX_N_THREADS) {
            LOG_ERR("End index out of bounds!\n");
            return false;
        }
    }

    for (size_t i = start_i; i <= end_i; i++) {
        boolmask[i] = true;
    }

    return true;
}

bool parse_cpu_mask(const std::string & mask, bool (&boolmask)[GGML_MAX_N_THREADS]) {
    // Discard potential 0x prefix
    size_t start_i = 0;
    if (mask.length() >= 2 && mask.substr(0, 2) == "0x") {
        start_i = 2;
    }

    size_t num_digits = mask.length() - start_i;
    if (num_digits > 128) num_digits = 128;

    size_t end_i = num_digits + start_i;

    for (size_t i = start_i, n = (num_digits*4 - 1); i < end_i; i++, n-=4) {
        char c = mask.at(i);
        int8_t id = c;

        if ((c >= '0' && c <= '9')) {
            id -= '0';
        } else if (c >= 'a' && c <= 'f') {
            id -= 'a' - 10;
        } else if (c >= 'A' && c <= 'F') {
            id -= 'A' - 10;
        } else {
            LOG_ERR("Invalid hex character '%c' at position %d\n", c, int32_t(i));
            return false;
        }

        boolmask[  n  ] = boolmask[  n  ] || ((id & 8) != 0);
        boolmask[n - 1] = boolmask[n - 1] || ((id & 4) != 0);
        boolmask[n - 2] = boolmask[n - 2] || ((id & 2) != 0);
        boolmask[n - 3] = boolmask[n - 3] || ((id & 1) != 0);
    }

    return true;
}

void common_init() {
    llama_log_set([](ggml_log_level level, const char * text, void * /*user_data*/) {
        if (LOG_DEFAULT_LLAMA <= common_log_verbosity_thold) {
            common_log_add(common_log_main(), level, "%s", text);
        }
    }, NULL);

#ifdef NDEBUG
    const char * build_type = "";
#else
    const char * build_type = " (debug)";
#endif

    LOG_INF("build: %d (%s) with %s for %s%s\n", LLAMA_BUILD_NUMBER, LLAMA_COMMIT, LLAMA_COMPILER, LLAMA_BUILD_TARGET, build_type);
}

std::string common_params_get_system_info(const common_params & params) {
    std::ostringstream os;

    os << "system_info: n_threads = " << params.cpuparams.n_threads;
    if (params.cpuparams_batch.n_threads != -1) {
        os << " (n_threads_batch = " << params.cpuparams_batch.n_threads << ")";
    }
#if defined(_WIN32) && (_WIN32_WINNT >= 0x0601) && !defined(__MINGW64__) // windows 7 and later
    // TODO: windows + arm64 + mingw64
    DWORD logicalProcessorCount = GetActiveProcessorCount(ALL_PROCESSOR_GROUPS);
    os << " / " << logicalProcessorCount << " | " << llama_print_system_info();
#else
    os << " / " << std::thread::hardware_concurrency() << " | " << llama_print_system_info();
#endif

    return os.str();
}

//
// String utils
//

std::string string_format(const char * fmt, ...) {
    va_list ap;
    va_list ap2;
    va_start(ap, fmt);
    va_copy(ap2, ap);
    int size = vsnprintf(NULL, 0, fmt, ap);
    GGML_ASSERT(size >= 0 && size < INT_MAX); // NOLINT
    std::vector<char> buf(size + 1);
    int size2 = vsnprintf(buf.data(), size + 1, fmt, ap2);
    GGML_ASSERT(size2 == size);
    va_end(ap2);
    va_end(ap);
    return std::string(buf.data(), size);
}

std::string string_strip(const std::string & str) {
    size_t start = 0;
    size_t end = str.size();
    while (start < end && std::isspace(str[start])) {
        start++;
    }
    while (end > start && std::isspace(str[end - 1])) {
        end--;
    }
    return str.substr(start, end - start);
}

std::string string_get_sortable_timestamp() {
    using clock = std::chrono::system_clock;

    const clock::time_point current_time = clock::now();
    const time_t as_time_t = clock::to_time_t(current_time);
    char timestamp_no_ns[100];
    std::strftime(timestamp_no_ns, 100, "%Y_%m_%d-%H_%M_%S", std::localtime(&as_time_t));

    const int64_t ns = std::chrono::duration_cast<std::chrono::nanoseconds>(
        current_time.time_since_epoch() % 1000000000).count();
    char timestamp_ns[11];
    snprintf(timestamp_ns, 11, "%09" PRId64, ns);

    return std::string(timestamp_no_ns) + "." + std::string(timestamp_ns);
}

void string_replace_all(std::string & s, const std::string & search, const std::string & replace) {
    if (search.empty()) {
        return;
    }
    std::string builder;
    builder.reserve(s.length());
    size_t pos = 0;
    size_t last_pos = 0;
    while ((pos = s.find(search, last_pos)) != std::string::npos) {
        builder.append(s, last_pos, pos - last_pos);
        builder.append(replace);
        last_pos = pos + search.length();
    }
    builder.append(s, last_pos, std::string::npos);
    s = std::move(builder);
}

std::string string_join(const std::vector<std::string> & values, const std::string & separator) {
    std::ostringstream result;
    for (size_t i = 0; i < values.size(); ++i) {
        if (i > 0) {
            result << separator;
        }
        result << values[i];
    }
    return result.str();
}

std::vector<std::string> string_split(const std::string & str, const std::string & delimiter) {
    std::vector<std::string> parts;
    size_t start = 0;
    size_t end = str.find(delimiter);

    while (end != std::string::npos) {
        parts.push_back(str.substr(start, end - start));
        start = end + delimiter.length();
        end = str.find(delimiter, start);
    }

    parts.push_back(str.substr(start));

    return parts;
}

std::string string_repeat(const std::string & str, size_t n) {
    if (n == 0) {
        return "";
    }

    std::string result;
    result.reserve(str.length() * n);

    for (size_t i = 0; i < n; ++i) {
        result += str;
    }

    return result;
}

std::string string_from(bool value) {
    return value ? "true" : "false";
}

std::string string_from(const std::vector<int> & values) {
    std::stringstream buf;

    buf << "[ ";
    bool first = true;
    for (auto e : values) {
        if (first) {
            first = false;
        } else {
            buf << ", ";
        }
        buf << std::to_string(e);
    }
    buf << " ]";

    return buf.str();
}

std::string string_from(const struct llama_context * ctx, const std::vector<llama_token> & tokens) {
    std::stringstream buf;

    buf << "[ ";

    bool first = true;
    for (const auto & token : tokens) {
        if (!first) {
            buf << ", ";
        } else {
            first = false;
        }

        auto detokenized = common_token_to_piece(ctx, token);

        detokenized.erase(
            std::remove_if(
                detokenized.begin(),
                detokenized.end(),
                [](const unsigned char c) { return !std::isprint(c); }),
            detokenized.end());

        buf << "'" << detokenized << "'"
            << ":" << std::to_string(token);
    }

    buf << " ]";

    return buf.str();
}

std::string string_from(const struct llama_context * ctx, const struct llama_batch & batch) {
    std::stringstream buf;

    buf << "[ ";

    bool first = true;
    for (int i = 0; i < batch.n_tokens; ++i) {
        if (!first) {
            buf << ", ";
        } else {
            first = false;
        }

        auto detokenized = common_token_to_piece(ctx, batch.token[i]);

        detokenized.erase(
                std::remove_if(
                    detokenized.begin(),
                    detokenized.end(),
                    [](const unsigned char c) { return !std::isprint(c); }),
                detokenized.end());

        buf << "\n"          << std::to_string(i)
            << ", token '"   << detokenized << "'"
            << ", pos "      << std::to_string(batch.pos[i])
            << ", n_seq_id " << std::to_string(batch.n_seq_id[i])
            << ", seq_id "   << std::to_string(batch.seq_id[i][0])
            << ", logits "   << std::to_string(batch.logits[i]);
    }

    buf << " ]";

    return buf.str();
}

void string_process_escapes(std::string & input) {
    std::size_t input_len = input.length();
    std::size_t output_idx = 0;

    for (std::size_t input_idx = 0; input_idx < input_len; ++input_idx) {
        if (input[input_idx] == '\\' && input_idx + 1 < input_len) {
            switch (input[++input_idx]) {
                case 'n':  input[output_idx++] = '\n'; break;
                case 'r':  input[output_idx++] = '\r'; break;
                case 't':  input[output_idx++] = '\t'; break;
                case '\'': input[output_idx++] = '\''; break;
                case '\"': input[output_idx++] = '\"'; break;
                case '\\': input[output_idx++] = '\\'; break;
                case 'x':
                    // Handle \x12, etc
                    if (input_idx + 2 < input_len) {
                        const char x[3] = { input[input_idx + 1], input[input_idx + 2], 0 };
                        char *err_p = nullptr;
                        const long val = std::strtol(x, &err_p, 16);
                        if (err_p == x + 2) {
                            input_idx += 2;
                            input[output_idx++] = char(val);
                            break;
                        }
                    }
                    // fall through
                default:   input[output_idx++] = '\\';
                           input[output_idx++] = input[input_idx]; break;
            }
        } else {
            input[output_idx++] = input[input_idx];
        }
    }

    input.resize(output_idx);
}

bool string_parse_kv_override(const char * data, std::vector<llama_model_kv_override> & overrides) {
    const char * sep = strchr(data, '=');
    if (sep == nullptr || sep - data >= 128) {
        LOG_ERR("%s: malformed KV override '%s'\n", __func__, data);
        return false;
    }
    llama_model_kv_override kvo;
    std::strncpy(kvo.key, data, sep - data);
    kvo.key[sep - data] = 0;
    sep++;
    if (strncmp(sep, "int:", 4) == 0) {
        sep += 4;
        kvo.tag = LLAMA_KV_OVERRIDE_TYPE_INT;
        kvo.val_i64 = std::atol(sep);
    } else if (strncmp(sep, "float:", 6) == 0) {
        sep += 6;
        kvo.tag = LLAMA_KV_OVERRIDE_TYPE_FLOAT;
        kvo.val_f64 = std::atof(sep);
    } else if (strncmp(sep, "bool:", 5) == 0) {
        sep += 5;
        kvo.tag = LLAMA_KV_OVERRIDE_TYPE_BOOL;
        if (std::strcmp(sep, "true") == 0) {
            kvo.val_bool = true;
        } else if (std::strcmp(sep, "false") == 0) {
            kvo.val_bool = false;
        } else {
            LOG_ERR("%s: invalid boolean value for KV override '%s'\n", __func__, data);
            return false;
        }
    } else if (strncmp(sep, "str:", 4) == 0) {
        sep += 4;
        kvo.tag = LLAMA_KV_OVERRIDE_TYPE_STR;
        if (strlen(sep) > 127) {
            LOG_ERR("%s: malformed KV override '%s', value cannot exceed 127 chars\n", __func__, data);
            return false;
        }
        strncpy(kvo.val_str, sep, 127);
        kvo.val_str[127] = '\0';
    } else {
        LOG_ERR("%s: invalid type for KV override '%s'\n", __func__, data);
        return false;
    }
    overrides.emplace_back(std::move(kvo));
    return true;
}

//
// Filesystem utils
//

// Validate if a filename is safe to use
// To validate a full path, split the path by the OS-specific path separator, and validate each part with this function
bool fs_validate_filename(const std::string & filename) {
    if (!filename.length()) {
        // Empty filename invalid
        return false;
    }
    if (filename.length() > 255) {
        // Limit at common largest possible filename on Linux filesystems
        // to avoid unnecessary further validation
        // (On systems with smaller limits it will be caught by the OS)
        return false;
    }

    std::u32string filename_utf32;
    try {
#if defined(__clang__)
        // disable C++17 deprecation warning for std::codecvt_utf8
#    pragma clang diagnostic push
#    pragma clang diagnostic ignored "-Wdeprecated-declarations"
#endif
        std::wstring_convert<std::codecvt_utf8<char32_t>, char32_t> converter;

#if defined(__clang__)
#    pragma clang diagnostic pop
#endif

        filename_utf32 = converter.from_bytes(filename);

        // If the reverse conversion mismatches, it means overlong UTF-8 sequences were used,
        // or invalid encodings were encountered. Reject such attempts
        std::string filename_reencoded = converter.to_bytes(filename_utf32);
        if (filename_reencoded != filename) {
            return false;
        }
    } catch (const std::exception &) {
        return false;
    }

    // Check for forbidden codepoints:
    // - Control characters
    // - Unicode equivalents of illegal characters
    // - UTF-16 surrogate pairs
    // - UTF-8 replacement character
    // - Byte order mark (BOM)
    // - Illegal characters: / \ : * ? " < > |
    for (char32_t c : filename_utf32) {
        if (c <= 0x1F // Control characters (C0)
            || c == 0x7F // Control characters (DEL)
            || (c >= 0x80 && c <= 0x9F) // Control characters (C1)
            || c == 0xFF0E // Fullwidth Full Stop (period equivalent)
            || c == 0x2215 // Division Slash (forward slash equivalent)
            || c == 0x2216 // Set Minus (backslash equivalent)
            || (c >= 0xD800 && c <= 0xDFFF) // UTF-16 surrogate pairs
            || c == 0xFFFD // Replacement Character (UTF-8)
            || c == 0xFEFF // Byte Order Mark (BOM)
            || c == '/' || c == '\\' || c == ':' || c == '*' // Illegal characters
            || c == '?' || c == '"' || c == '<' || c == '>' || c == '|') {
            return false;
        }
    }

    // Reject any leading or trailing ' ', or any trailing '.', these are stripped on Windows and will cause a different filename
    // Unicode and other whitespace is not affected, only 0x20 space
    if (filename.front() == ' ' || filename.back() == ' ' || filename.back() == '.') {
        return false;
    }

    // Reject any ".." (currently stricter than necessary, it should be fine to just check for == ".." instead)
    if (filename.find("..") != std::string::npos) {
        return false;
    }

    // Reject "."
    if (filename == ".") {
        return false;
    }

    return true;
}

// returns true if successful, false otherwise
bool fs_create_directory_with_parents(const std::string & path) {
#ifdef _WIN32
    std::wstring_convert<std::codecvt_utf8<wchar_t>> converter;
    std::wstring wpath = converter.from_bytes(path);

    // if the path already exists, check whether it's a directory
    const DWORD attributes = GetFileAttributesW(wpath.c_str());
    if ((attributes != INVALID_FILE_ATTRIBUTES) && (attributes & FILE_ATTRIBUTE_DIRECTORY)) {
        return true;
    }

    size_t pos_slash = 0;

    // process path from front to back, procedurally creating directories
    while ((pos_slash = path.find('\\', pos_slash)) != std::string::npos) {
        const std::wstring subpath = wpath.substr(0, pos_slash);
        const wchar_t * test = subpath.c_str();

        const bool success = CreateDirectoryW(test, NULL);
        if (!success) {
            const DWORD error = GetLastError();

            // if the path already exists, ensure that it's a directory
            if (error == ERROR_ALREADY_EXISTS) {
                const DWORD attributes = GetFileAttributesW(subpath.c_str());
                if (attributes == INVALID_FILE_ATTRIBUTES || !(attributes & FILE_ATTRIBUTE_DIRECTORY)) {
                    return false;
                }
            } else {
                return false;
            }
        }

        pos_slash += 1;
    }

    return true;
#else
    // if the path already exists, check whether it's a directory
    struct stat info;
    if (stat(path.c_str(), &info) == 0) {
        return S_ISDIR(info.st_mode);
    }

    size_t pos_slash = 1; // skip leading slashes for directory creation

    // process path from front to back, procedurally creating directories
    while ((pos_slash = path.find('/', pos_slash)) != std::string::npos) {
        const std::string subpath = path.substr(0, pos_slash);
        struct stat info;

        // if the path already exists, ensure that it's a directory
        if (stat(subpath.c_str(), &info) == 0) {
            if (!S_ISDIR(info.st_mode)) {
                return false;
            }
        } else {
            // create parent directories
            const int ret = mkdir(subpath.c_str(), 0755);
            if (ret != 0) {
                return false;
            }
        }

        pos_slash += 1;
    }

    return true;
#endif // _WIN32
}

std::string fs_get_cache_directory() {
    std::string cache_directory = "";
    auto ensure_trailing_slash = [](std::string p) {
        // Make sure to add trailing slash
        if (p.back() != DIRECTORY_SEPARATOR) {
            p += DIRECTORY_SEPARATOR;
        }
        return p;
    };
    if (getenv("LLAMA_CACHE")) {
        cache_directory = std::getenv("LLAMA_CACHE");
    } else {
#ifdef __linux__
        if (std::getenv("XDG_CACHE_HOME")) {
            cache_directory = std::getenv("XDG_CACHE_HOME");
        } else {
            cache_directory = std::getenv("HOME") + std::string("/.cache/");
        }
#elif defined(__APPLE__)
        cache_directory = std::getenv("HOME") + std::string("/Library/Caches/");
#elif defined(_WIN32)
        cache_directory = std::getenv("LOCALAPPDATA");
#endif // __linux__
        cache_directory = ensure_trailing_slash(cache_directory);
        cache_directory += "llama.cpp";
    }
    return ensure_trailing_slash(cache_directory);
}

std::string fs_get_cache_file(const std::string & filename) {
    GGML_ASSERT(filename.find(DIRECTORY_SEPARATOR) == std::string::npos);
    std::string cache_directory = fs_get_cache_directory();
    const bool success = fs_create_directory_with_parents(cache_directory);
    if (!success) {
        throw std::runtime_error("failed to create cache directory: " + cache_directory);
    }
    return cache_directory + filename;
}


//
// Model utils
//
struct common_init_result common_init_from_params(common_params & params) {
    common_init_result iparams;
    auto mparams = common_model_params_to_llama(params);

    llama_model * model = nullptr;

    if (!params.hf_repo.empty() && !params.hf_file.empty()) {
        model = common_load_model_from_hf(params.hf_repo, params.hf_file, params.model, params.hf_token, mparams);
    } else if (!params.model_url.empty()) {
        model = common_load_model_from_url(params.model_url, params.model, params.hf_token, mparams);
    } else {
        model = llama_model_load_from_file(params.model.c_str(), mparams);
    }

    if (model == NULL) {
        LOG_ERR("%s: failed to load model '%s'\n", __func__, params.model.c_str());
        return iparams;
    }

    const llama_vocab * vocab = llama_model_get_vocab(model);

    if (params.reranking) {
        bool ok = true;

        if (llama_vocab_bos(vocab) == LLAMA_TOKEN_NULL) {
            LOG_WRN("%s: warning: vocab does not have a  BOS token, reranking will not work\n", __func__);
            ok = false;
        }

        if (llama_vocab_eos(vocab) == LLAMA_TOKEN_NULL) {
            LOG_WRN("%s: warning: vocab does not have an EOS token, reranking will not work\n", __func__);
            ok = false;
        }

        if (llama_vocab_sep(vocab) == LLAMA_TOKEN_NULL) {
            LOG_WRN("%s: warning: vocab does not have a  SEP token, reranking will not work\n", __func__);
            ok = false;
        }

        if (!ok) {
            llama_model_free(model);

            return iparams;
        }
    }

    auto cparams = common_context_params_to_llama(params);

    llama_context * lctx = llama_init_from_model(model, cparams);
    if (lctx == NULL) {
        LOG_ERR("%s: failed to create context with model '%s'\n", __func__, params.model.c_str());
        llama_model_free(model);
        return iparams;
    }

    if (params.ctx_shift && !llama_kv_cache_can_shift(lctx)) {
        LOG_WRN("%s: KV cache shifting is not supported for this model, disabling KV cache shifting\n", __func__);
        params.ctx_shift = false;
    }

    if (!params.control_vectors.empty()) {
        if (params.control_vector_layer_start <= 0) params.control_vector_layer_start = 1;
        if (params.control_vector_layer_end   <= 0) params.control_vector_layer_end   = llama_model_n_layer(model);

        const auto cvec = common_control_vector_load(params.control_vectors);
        if (cvec.n_embd == -1) {
            llama_free(lctx);
            llama_model_free(model);

            return iparams;
        }

        int err = llama_apply_adapter_cvec(
                lctx,
                cvec.data.data(),
                cvec.data.size(),
                cvec.n_embd,
                params.control_vector_layer_start,
                params.control_vector_layer_end);
        if (err) {
            llama_free(lctx);
            llama_model_free(model);

            return iparams;
        }
    }

    // load and optionally apply lora adapters
    for (auto & la : params.lora_adapters) {
        llama_adapter_lora_ptr lora;
        lora.reset(llama_adapter_lora_init(model, la.path.c_str()));
        if (lora == nullptr) {
            LOG_ERR("%s: failed to apply lora adapter '%s'\n", __func__, la.path.c_str());
            llama_free(lctx);
            llama_model_free(model);
            return iparams;
        }

        la.ptr = lora.get();
        iparams.lora.emplace_back(std::move(lora)); // copy to list of loaded adapters
    }

    if (!params.lora_init_without_apply) {
        common_set_adapter_lora(lctx, params.lora_adapters);
    }

    if (params.sampling.ignore_eos && llama_vocab_eos(vocab) == LLAMA_TOKEN_NULL) {
        LOG_WRN("%s: warning: vocab does not have an EOS token, ignoring --ignore-eos\n", __func__);
        params.sampling.ignore_eos = false;
    }

    if (params.sampling.ignore_eos) {
        for (llama_token i = 0; i < llama_vocab_n_tokens(vocab); i++) {
            if (llama_vocab_is_eog(vocab, i)) {
                LOG_INF("%s: added %s logit bias = %f\n", __func__, common_token_to_piece(lctx, i).c_str(), -INFINITY);
                params.sampling.logit_bias.push_back({i, -INFINITY});
            }
        }
    }

    if (params.sampling.penalty_last_n == -1) {
        LOG_INF("%s: setting penalty_last_n to ctx_size = %d\n", __func__, llama_n_ctx(lctx));
        params.sampling.penalty_last_n = llama_n_ctx(lctx);
    }

    if (params.sampling.dry_penalty_last_n == -1) {
        LOG_INF("%s: setting dry_penalty_last_n to ctx_size = %d\n", __func__, llama_n_ctx(lctx));
        params.sampling.dry_penalty_last_n = llama_n_ctx(lctx);
    }

    if (params.warmup) {
        LOG_WRN("%s: warming up the model with an empty run - please wait ... (--no-warmup to disable)\n", __func__);

        std::vector<llama_token> tmp;
        llama_token bos = llama_vocab_bos(vocab);
        llama_token eos = llama_vocab_eos(vocab);

        // some models (e.g. T5) don't have a BOS token
        if (bos != LLAMA_TOKEN_NULL) {
            tmp.push_back(bos);
        }
        if (eos != LLAMA_TOKEN_NULL) {
            tmp.push_back(eos);
        }
        if (tmp.empty()) {
            tmp.push_back(0);
        }

        if (llama_model_has_encoder(model)) {
            llama_encode(lctx, llama_batch_get_one(tmp.data(), tmp.size()));
            llama_token decoder_start_token_id = llama_model_decoder_start_token(model);
            if (decoder_start_token_id == LLAMA_TOKEN_NULL) {
                decoder_start_token_id = bos;
            }
            tmp.clear();
            tmp.push_back(decoder_start_token_id);
        }
        if (llama_model_has_decoder(model)) {
            llama_decode(lctx, llama_batch_get_one(tmp.data(), std::min(tmp.size(), (size_t) params.n_batch)));
        }
        llama_kv_cache_clear(lctx);
        llama_synchronize(lctx);
        llama_perf_context_reset(lctx);
    }

    iparams.model.reset(model);
    iparams.context.reset(lctx);

    return iparams;
}

void common_set_adapter_lora(struct llama_context * ctx, std::vector<common_adapter_lora_info> & lora) {
    llama_clear_adapter_lora(ctx);
    for (auto & la : lora) {
        if (la.scale != 0.0f) {
            llama_set_adapter_lora(ctx, la.ptr, la.scale);
        }
    }
}

struct llama_model_params common_model_params_to_llama(common_params & params) {
    auto mparams = llama_model_default_params();

    if (!params.devices.empty()) {
        mparams.devices = params.devices.data();
    }
    if (params.n_gpu_layers != -1) {
        mparams.n_gpu_layers = params.n_gpu_layers;
    }
    mparams.main_gpu        = params.main_gpu;
    mparams.split_mode      = params.split_mode;
    mparams.tensor_split    = params.tensor_split;
    mparams.use_mmap        = params.use_mmap;
    mparams.use_mlock       = params.use_mlock;
    mparams.check_tensors   = params.check_tensors;
    if (params.kv_overrides.empty()) {
        mparams.kv_overrides = NULL;
    } else {
        GGML_ASSERT(params.kv_overrides.back().key[0] == 0 && "KV overrides not terminated with empty key");
        mparams.kv_overrides = params.kv_overrides.data();
    }

    return mparams;
}

struct llama_context_params common_context_params_to_llama(const common_params & params) {
    auto cparams = llama_context_default_params();

    cparams.n_ctx             = params.n_ctx;
    cparams.n_seq_max         = params.n_parallel;
    cparams.n_batch           = params.n_batch;
    cparams.n_ubatch          = params.n_ubatch;
    cparams.n_threads         = params.cpuparams.n_threads;
    cparams.n_threads_batch   = params.cpuparams_batch.n_threads == -1 ?
                                params.cpuparams.n_threads : params.cpuparams_batch.n_threads;
    cparams.logits_all        = params.logits_all;
    cparams.embeddings        = params.embedding;
    cparams.rope_scaling_type = params.rope_scaling_type;
    cparams.rope_freq_base    = params.rope_freq_base;
    cparams.rope_freq_scale   = params.rope_freq_scale;
    cparams.yarn_ext_factor   = params.yarn_ext_factor;
    cparams.yarn_attn_factor  = params.yarn_attn_factor;
    cparams.yarn_beta_fast    = params.yarn_beta_fast;
    cparams.yarn_beta_slow    = params.yarn_beta_slow;
    cparams.yarn_orig_ctx     = params.yarn_orig_ctx;
    cparams.pooling_type      = params.pooling_type;
    cparams.attention_type    = params.attention_type;
    cparams.defrag_thold      = params.defrag_thold;
    cparams.cb_eval           = params.cb_eval;
    cparams.cb_eval_user_data = params.cb_eval_user_data;
    cparams.offload_kqv       = !params.no_kv_offload;
    cparams.flash_attn        = params.flash_attn;
    cparams.no_perf           = params.no_perf;

    if (params.reranking) {
        cparams.embeddings    = true;
        cparams.pooling_type  = LLAMA_POOLING_TYPE_RANK;
    }

    cparams.type_k = params.cache_type_k;
    cparams.type_v = params.cache_type_v;

    return cparams;
}

struct ggml_threadpool_params ggml_threadpool_params_from_cpu_params(const cpu_params & params) {
    struct ggml_threadpool_params tpp;

    ggml_threadpool_params_init(&tpp, params.n_threads); // setup the defaults

    if (params.mask_valid) {
        std::memcpy(&tpp.cpumask, &params.cpumask, GGML_MAX_N_THREADS);
    }

    tpp.prio       = params.priority;
    tpp.poll       = params.poll;
    tpp.strict_cpu = params.strict_cpu;

    return tpp;
}

#ifdef LLAMA_USE_CURL

#define CURL_MAX_RETRY 3
#define CURL_RETRY_DELAY_SECONDS 2

static bool curl_perform_with_retry(const std::string & url, CURL * curl, int max_attempts, int retry_delay_seconds) {
    int remaining_attempts = max_attempts;

    while (remaining_attempts > 0) {
        LOG_INF("%s: Trying to download from %s (attempt %d of %d)...\n", __func__ , url.c_str(), max_attempts - remaining_attempts + 1, max_attempts);

        CURLcode res = curl_easy_perform(curl);
        if (res == CURLE_OK) {
            return true;
        }

        int exponential_backoff_delay = std::pow(retry_delay_seconds, max_attempts - remaining_attempts) * 1000;
        LOG_WRN("%s: curl_easy_perform() failed: %s, retrying after %d milliseconds...\n", __func__, curl_easy_strerror(res), exponential_backoff_delay);

        remaining_attempts--;
        std::this_thread::sleep_for(std::chrono::milliseconds(exponential_backoff_delay));
    }

    LOG_ERR("%s: curl_easy_perform() failed after %d attempts\n", __func__, max_attempts);

    return false;
}

static bool common_download_file(const std::string & url, const std::string & path, const std::string & hf_token) {
    // Initialize libcurl
    curl_ptr       curl(curl_easy_init(), &curl_easy_cleanup);
    curl_slist_ptr http_headers;
    if (!curl) {
        LOG_ERR("%s: error initializing libcurl\n", __func__);
        return false;
    }

    bool force_download = false;

    // Set the URL, allow to follow http redirection
    curl_easy_setopt(curl.get(), CURLOPT_URL, url.c_str());
    curl_easy_setopt(curl.get(), CURLOPT_FOLLOWLOCATION, 1L);

    // Check if hf-token or bearer-token was specified
    if (!hf_token.empty()) {
        std::string auth_header = "Authorization: Bearer " + hf_token;
        http_headers.ptr = curl_slist_append(http_headers.ptr, auth_header.c_str());
        curl_easy_setopt(curl.get(), CURLOPT_HTTPHEADER, http_headers.ptr);
    }

#if defined(_WIN32)
    // CURLSSLOPT_NATIVE_CA tells libcurl to use standard certificate store of
    //   operating system. Currently implemented under MS-Windows.
    curl_easy_setopt(curl.get(), CURLOPT_SSL_OPTIONS, CURLSSLOPT_NATIVE_CA);
#endif

    // Check if the file already exists locally
    auto file_exists = std::filesystem::exists(path);

    // If the file exists, check its JSON metadata companion file.
    std::string metadata_path = path + ".json";
    nlohmann::json metadata;
    std::string etag;
    std::string last_modified;

    if (file_exists) {
        // Try and read the JSON metadata file (note: stream autoclosed upon exiting this block).
        std::ifstream metadata_in(metadata_path);
        if (metadata_in.good()) {
            try {
                metadata_in >> metadata;
                LOG_INF("%s: previous metadata file found %s: %s\n", __func__, metadata_path.c_str(), metadata.dump().c_str());
                if (metadata.contains("url") && metadata.at("url").is_string()) {
                    auto previous_url = metadata.at("url").get<std::string>();
                    if (previous_url != url) {
                        LOG_ERR("%s: Model URL mismatch: %s != %s\n", __func__, url.c_str(), previous_url.c_str());
                        return false;
                    }
                }
                if (metadata.contains("etag") && metadata.at("etag").is_string()) {
                    etag = metadata.at("etag");
                }
                if (metadata.contains("lastModified") && metadata.at("lastModified").is_string()) {
                    last_modified = metadata.at("lastModified");
                }
            } catch (const nlohmann::json::exception & e) {
            LOG_ERR("%s: error reading metadata file %s: %s\n", __func__, metadata_path.c_str(), e.what());
                return false;
            }
        }
    } else {
        LOG_INF("%s: no previous model file found %s\n", __func__, path.c_str());
    }

    // Send a HEAD request to retrieve the etag and last-modified headers
    struct common_load_model_from_url_headers {
        std::string etag;
        std::string last_modified;
    };

    common_load_model_from_url_headers headers;

    {
        typedef size_t(*CURLOPT_HEADERFUNCTION_PTR)(char *, size_t, size_t, void *);
        auto header_callback = [](char * buffer, size_t /*size*/, size_t n_items, void * userdata) -> size_t {
            common_load_model_from_url_headers * headers = (common_load_model_from_url_headers *) userdata;

            static std::regex header_regex("([^:]+): (.*)\r\n");
            static std::regex etag_regex("ETag", std::regex_constants::icase);
            static std::regex last_modified_regex("Last-Modified", std::regex_constants::icase);

            std::string header(buffer, n_items);
            std::smatch match;
            if (std::regex_match(header, match, header_regex)) {
                const std::string & key = match[1];
                const std::string & value = match[2];
                if (std::regex_match(key, match, etag_regex)) {
                    headers->etag = value;
                } else if (std::regex_match(key, match, last_modified_regex)) {
                    headers->last_modified = value;
                }
            }
            return n_items;
        };

        curl_easy_setopt(curl.get(), CURLOPT_NOBODY, 1L); // will trigger the HEAD verb
        curl_easy_setopt(curl.get(), CURLOPT_NOPROGRESS, 1L); // hide head request progress
        curl_easy_setopt(curl.get(), CURLOPT_HEADERFUNCTION, static_cast<CURLOPT_HEADERFUNCTION_PTR>(header_callback));
        curl_easy_setopt(curl.get(), CURLOPT_HEADERDATA, &headers);

        bool was_perform_successful = curl_perform_with_retry(url, curl.get(), CURL_MAX_RETRY, CURL_RETRY_DELAY_SECONDS);
        if (!was_perform_successful) {
            return false;
        }

        long http_code = 0;
        curl_easy_getinfo(curl.get(), CURLINFO_RESPONSE_CODE, &http_code);
        if (http_code != 200) {
            // HEAD not supported, we don't know if the file has changed
            // force trigger downloading
            force_download = true;
            LOG_ERR("%s: HEAD invalid http status code received: %ld\n", __func__, http_code);
        }
    }

    bool should_download = !file_exists || force_download;
    if (!should_download) {
        if (!etag.empty() && etag != headers.etag) {
            LOG_WRN("%s: ETag header is different (%s != %s): triggering a new download\n", __func__, etag.c_str(), headers.etag.c_str());
            should_download = true;
        } else if (!last_modified.empty() && last_modified != headers.last_modified) {
            LOG_WRN("%s: Last-Modified header is different (%s != %s): triggering a new download\n", __func__, last_modified.c_str(), headers.last_modified.c_str());
            should_download = true;
        }
    }
    if (should_download) {
        std::string path_temporary = path + ".downloadInProgress";
        if (file_exists) {
            LOG_WRN("%s: deleting previous downloaded file: %s\n", __func__, path.c_str());
            if (remove(path.c_str()) != 0) {
                LOG_ERR("%s: unable to delete file: %s\n", __func__, path.c_str());
                return false;
            }
        }

        // Set the output file

        struct FILE_deleter {
            void operator()(FILE * f) const {
                fclose(f);
            }
        };

        std::unique_ptr<FILE, FILE_deleter> outfile(fopen(path_temporary.c_str(), "wb"));
        if (!outfile) {
            LOG_ERR("%s: error opening local file for writing: %s\n", __func__, path.c_str());
            return false;
        }

        typedef size_t(*CURLOPT_WRITEFUNCTION_PTR)(void * data, size_t size, size_t nmemb, void * fd);
        auto write_callback = [](void * data, size_t size, size_t nmemb, void * fd) -> size_t {
            return fwrite(data, size, nmemb, (FILE *)fd);
        };
        curl_easy_setopt(curl.get(), CURLOPT_NOBODY, 0L);
        curl_easy_setopt(curl.get(), CURLOPT_WRITEFUNCTION, static_cast<CURLOPT_WRITEFUNCTION_PTR>(write_callback));
        curl_easy_setopt(curl.get(), CURLOPT_WRITEDATA, outfile.get());

        //  display download progress
        curl_easy_setopt(curl.get(), CURLOPT_NOPROGRESS, 0L);

        // helper function to hide password in URL
        auto llama_download_hide_password_in_url = [](const std::string & url) -> std::string {
            std::size_t protocol_pos = url.find("://");
            if (protocol_pos == std::string::npos) {
                return url;  // Malformed URL
            }

            std::size_t at_pos = url.find('@', protocol_pos + 3);
            if (at_pos == std::string::npos) {
                return url;  // No password in URL
            }

            return url.substr(0, protocol_pos + 3) + "********" + url.substr(at_pos);
        };

        // start the download
        LOG_INF("%s: trying to download model from %s to %s (server_etag:%s, server_last_modified:%s)...\n", __func__,
            llama_download_hide_password_in_url(url).c_str(), path.c_str(), headers.etag.c_str(), headers.last_modified.c_str());
        bool was_perform_successful = curl_perform_with_retry(url, curl.get(), CURL_MAX_RETRY, CURL_RETRY_DELAY_SECONDS);
        if (!was_perform_successful) {
            return false;
        }

        long http_code = 0;
        curl_easy_getinfo (curl.get(), CURLINFO_RESPONSE_CODE, &http_code);
        if (http_code < 200 || http_code >= 400) {
            LOG_ERR("%s: invalid http status code received: %ld\n", __func__, http_code);
            return false;
        }

        // Causes file to be closed explicitly here before we rename it.
        outfile.reset();

        // Write the updated JSON metadata file.
        metadata.update({
            {"url", url},
            {"etag", headers.etag},
            {"lastModified", headers.last_modified}
        });
        std::ofstream(metadata_path) << metadata.dump(4);
        LOG_INF("%s: file metadata saved: %s\n", __func__, metadata_path.c_str());

        if (rename(path_temporary.c_str(), path.c_str()) != 0) {
            LOG_ERR("%s: unable to rename file: %s to %s\n", __func__, path_temporary.c_str(), path.c_str());
            return false;
        }
    }

    return true;
}

struct llama_model * common_load_model_from_url(
        const std::string & model_url,
        const std::string & local_path,
        const std::string & hf_token,
        const struct llama_model_params & params) {
    // Basic validation of the model_url
    if (model_url.empty()) {
        LOG_ERR("%s: invalid model_url\n", __func__);
        return NULL;
    }

    if (!common_download_file(model_url, local_path, hf_token)) {
        return NULL;
    }

    // check for additional GGUFs split to download
    int n_split = 0;
    {
        struct gguf_init_params gguf_params = {
            /*.no_alloc = */ true,
            /*.ctx      = */ NULL,
        };
        auto * ctx_gguf = gguf_init_from_file(local_path.c_str(), gguf_params);
        if (!ctx_gguf) {
            LOG_ERR("\n%s:  failed to load input GGUF from %s\n", __func__, local_path.c_str());
            return NULL;
        }

        auto key_n_split = gguf_find_key(ctx_gguf, LLM_KV_SPLIT_COUNT);
        if (key_n_split >= 0) {
            n_split = gguf_get_val_u16(ctx_gguf, key_n_split);
        }

        gguf_free(ctx_gguf);
    }

    if (n_split > 1) {
        char split_prefix[PATH_MAX] = {0};
        char split_url_prefix[LLAMA_CURL_MAX_URL_LENGTH] = {0};

        // Verify the first split file format
        // and extract split URL and PATH prefixes
        {
            if (!llama_split_prefix(split_prefix, sizeof(split_prefix), local_path.c_str(), 0, n_split)) {
                LOG_ERR("\n%s: unexpected model file name: %s n_split=%d\n", __func__, local_path.c_str(), n_split);
                return NULL;
            }

            if (!llama_split_prefix(split_url_prefix, sizeof(split_url_prefix), model_url.c_str(), 0, n_split)) {
                LOG_ERR("\n%s: unexpected model url: %s n_split=%d\n", __func__, model_url.c_str(), n_split);
                return NULL;
            }
        }

        // Prepare download in parallel
        std::vector<std::future<bool>> futures_download;
        for (int idx = 1; idx < n_split; idx++) {
            futures_download.push_back(std::async(std::launch::async, [&split_prefix, &split_url_prefix, &n_split, hf_token](int download_idx) -> bool {
                char split_path[PATH_MAX] = {0};
                llama_split_path(split_path, sizeof(split_path), split_prefix, download_idx, n_split);

                char split_url[LLAMA_CURL_MAX_URL_LENGTH] = {0};
                llama_split_path(split_url, sizeof(split_url), split_url_prefix, download_idx, n_split);

                return common_download_file(split_url, split_path, hf_token);
            }, idx));
        }

        // Wait for all downloads to complete
        for (auto & f : futures_download) {
            if (!f.get()) {
                return NULL;
            }
        }
    }

    return llama_model_load_from_file(local_path.c_str(), params);
}

struct llama_model * common_load_model_from_hf(
        const std::string & repo,
        const std::string & remote_path,
        const std::string & local_path,
        const std::string & hf_token,
        const struct llama_model_params & params) {
    // construct hugging face model url:
    //
    //  --repo ggml-org/models --file tinyllama-1.1b/ggml-model-f16.gguf
    //    https://huggingface.co/ggml-org/models/resolve/main/tinyllama-1.1b/ggml-model-f16.gguf
    //
    //  --repo TheBloke/Mixtral-8x7B-v0.1-GGUF --file mixtral-8x7b-v0.1.Q4_K_M.gguf
    //    https://huggingface.co/TheBloke/Mixtral-8x7B-v0.1-GGUF/resolve/main/mixtral-8x7b-v0.1.Q4_K_M.gguf
    //

    std::string model_url = "https://huggingface.co/";
    model_url += repo;
    model_url += "/resolve/main/";
    model_url += remote_path;

    return common_load_model_from_url(model_url, local_path, hf_token, params);
}

/**
 * Allow getting the HF file from the HF repo with tag (like ollama), for example:
 * - bartowski/Llama-3.2-3B-Instruct-GGUF:q4
 * - bartowski/Llama-3.2-3B-Instruct-GGUF:Q4_K_M
 * - bartowski/Llama-3.2-3B-Instruct-GGUF:q5_k_s
 * Tag is optional, default to "latest" (meaning it checks for Q4_K_M first, then Q4, then if not found, return the first GGUF file in repo)
 *
 * Return pair of <repo, file> (with "repo" already having tag removed)
 *
 * Note: we use the Ollama-compatible HF API, but not using the blobId. Instead, we use the special "ggufFile" field which returns the value for "hf_file". This is done to be backward-compatible with existing cache files.
 */
std::pair<std::string, std::string> common_get_hf_file(const std::string & hf_repo_with_tag, const std::string & hf_token) {
    auto parts = string_split<std::string>(hf_repo_with_tag, ':');
    std::string tag = parts.size() > 1 ? parts.back() : "latest";
    std::string hf_repo = parts[0];
    if (string_split<std::string>(hf_repo, '/').size() != 2) {
        throw std::invalid_argument("error: invalid HF repo format, expected <user>/<model>[:quant]\n");
    }

    // fetch model info from Hugging Face Hub API
    json model_info;
    curl_ptr       curl(curl_easy_init(), &curl_easy_cleanup);
    curl_slist_ptr http_headers;
    std::string res_str;
    std::string url = "https://huggingface.co/v2/" + hf_repo + "/manifests/" + tag;
    curl_easy_setopt(curl.get(), CURLOPT_URL, url.c_str());
    curl_easy_setopt(curl.get(), CURLOPT_NOPROGRESS, 1L);
    typedef size_t(*CURLOPT_WRITEFUNCTION_PTR)(void * ptr, size_t size, size_t nmemb, void * data);
    auto write_callback = [](void * ptr, size_t size, size_t nmemb, void * data) -> size_t {
        static_cast<std::string *>(data)->append((char * ) ptr, size * nmemb);
        return size * nmemb;
    };
    curl_easy_setopt(curl.get(), CURLOPT_WRITEFUNCTION, static_cast<CURLOPT_WRITEFUNCTION_PTR>(write_callback));
    curl_easy_setopt(curl.get(), CURLOPT_WRITEDATA, &res_str);
#if defined(_WIN32)
    curl_easy_setopt(curl.get(), CURLOPT_SSL_OPTIONS, CURLSSLOPT_NATIVE_CA);
#endif
    if (!hf_token.empty()) {
        std::string auth_header = "Authorization: Bearer " + hf_token;
        http_headers.ptr = curl_slist_append(http_headers.ptr, auth_header.c_str());
    }
    // Important: the User-Agent must be "llama-cpp" to get the "ggufFile" field in the response
    http_headers.ptr = curl_slist_append(http_headers.ptr, "User-Agent: llama-cpp");
    http_headers.ptr = curl_slist_append(http_headers.ptr, "Accept: application/json");
    curl_easy_setopt(curl.get(), CURLOPT_HTTPHEADER, http_headers.ptr);

    CURLcode res = curl_easy_perform(curl.get());

    if (res != CURLE_OK) {
        throw std::runtime_error("error: cannot make GET request to HF API");
    }

    long res_code;
    curl_easy_getinfo(curl.get(), CURLINFO_RESPONSE_CODE, &res_code);
    if (res_code == 200) {
        model_info = json::parse(res_str);
    } else if (res_code == 401) {
        throw std::runtime_error("error: model is private or does not exist; if you are accessing a gated model, please provide a valid HF token");
    } else {
        throw std::runtime_error(string_format("error from HF API, response code: %ld, data: %s", res_code, res_str.c_str()));
    }

    // check response
    if (!model_info.contains("ggufFile")) {
        throw std::runtime_error("error: model does not have ggufFile");
    }
    json & gguf_file = model_info.at("ggufFile");
    if (!gguf_file.contains("rfilename")) {
        throw std::runtime_error("error: ggufFile does not have rfilename");
    }

    return std::make_pair(hf_repo, gguf_file.at("rfilename"));
}

#else

struct llama_model * common_load_model_from_url(
        const std::string & /*model_url*/,
        const std::string & /*local_path*/,
        const std::string & /*hf_token*/,
        const struct llama_model_params & /*params*/) {
    LOG_WRN("%s: llama.cpp built without libcurl, downloading from an url not supported.\n", __func__);
    return nullptr;
}

struct llama_model * common_load_model_from_hf(
        const std::string & /*repo*/,
        const std::string & /*remote_path*/,
        const std::string & /*local_path*/,
        const std::string & /*hf_token*/,
        const struct llama_model_params & /*params*/) {
    LOG_WRN("%s: llama.cpp built without libcurl, downloading from Hugging Face not supported.\n", __func__);
    return nullptr;
}

std::pair<std::string, std::string> common_get_hf_file(const std::string &, const std::string &) {
    LOG_WRN("%s: llama.cpp built without libcurl, downloading from Hugging Face not supported.\n", __func__);
    return std::make_pair("", "");
}

#endif // LLAMA_USE_CURL

//
// Batch utils
//

void common_batch_clear(struct llama_batch & batch) {
    batch.n_tokens = 0;
}

void common_batch_add(
                 struct llama_batch & batch,
                        llama_token   id,
                          llama_pos   pos,
    const std::vector<llama_seq_id> & seq_ids,
                               bool   logits) {
    GGML_ASSERT(batch.seq_id[batch.n_tokens] && "llama_batch size exceeded");

    batch.token   [batch.n_tokens] = id;
    batch.pos     [batch.n_tokens] = pos;
    batch.n_seq_id[batch.n_tokens] = seq_ids.size();
    for (size_t i = 0; i < seq_ids.size(); ++i) {
        batch.seq_id[batch.n_tokens][i] = seq_ids[i];
    }
    batch.logits  [batch.n_tokens] = logits;

    batch.n_tokens++;
}

//
// Token utils
//

size_t common_lcp(const llama_tokens & a, const llama_tokens & b) {
    size_t i;
    for (i = 0; i < a.size() && i < b.size() && a[i] == b[i]; i++) {}

    return i;
}

size_t common_lcs(const llama_tokens & a, const llama_tokens & b) {
    // check for empty sequences
    if (a.empty() || b.empty()) {
        return 0;
    }

    // get the lengths of the input sequences
    size_t a_len = a.size();
    size_t b_len = b.size();

    // initialize the maximum length of the longest common subsequence (LCS)
    size_t max_length = 0;

    // use two rows instead of a 2D matrix to optimize space
    std::vector<size_t> prev_row(b_len + 1, 0);
    std::vector<size_t> curr_row(b_len + 1, 0);

    // iterate through the elements of a
    for (size_t i = 1; i <= a_len; i++) {
        // iterate through the elements of b
        for (size_t j = 1; j <= b_len; j++) {
            // if elements at the current positions match
            if (a[i - 1] == b[j - 1]) {
                // if it's the first element of either sequences, set LCS length to 1
                if (i == 1 || j == 1) {
                    curr_row[j] = 1;
                } else {
                    // increment LCS length by 1 compared to the previous element
                    curr_row[j] = prev_row[j - 1] + 1;
                }

                // update max_length if necessary
                if (curr_row[j] > max_length) {
                    max_length = curr_row[j];
                }
            } else {
                // reset LCS length if elements don't match
                curr_row[j] = 0;
            }
        }

        // update the previous row for the next iteration
        prev_row = curr_row;
    }

    // return the maximum length of the LCS
    return max_length;
}

//
// Vocab utils
//

std::vector<llama_token> common_tokenize(
  const struct llama_context * ctx,
           const std::string & text,
                        bool   add_special,
                        bool   parse_special) {
    const llama_model * model = llama_get_model(ctx);
    const llama_vocab * vocab = llama_model_get_vocab(model);
    return common_tokenize(vocab, text, add_special, parse_special);
}

std::vector<llama_token> common_tokenize(
    const struct llama_vocab * vocab,
           const std::string & text,
                        bool   add_special,
                        bool   parse_special) {
    // upper limit for the number of tokens
    int n_tokens = text.length() + 2 * add_special;
    std::vector<llama_token> result(n_tokens);
    n_tokens = llama_tokenize(vocab, text.data(), text.length(), result.data(), result.size(), add_special, parse_special);
    if (n_tokens < 0) {
        result.resize(-n_tokens);
        int check = llama_tokenize(vocab, text.data(), text.length(), result.data(), result.size(), add_special, parse_special);
        GGML_ASSERT(check == -n_tokens);
    } else {
        result.resize(n_tokens);
    }
    return result;
}

std::string common_token_to_piece(const struct llama_context * ctx, llama_token token, bool special) {
    const llama_model * model = llama_get_model(ctx);
    const llama_vocab * vocab = llama_model_get_vocab(model);
    return common_token_to_piece(vocab, token, special);
}

std::string common_token_to_piece(const struct llama_vocab * vocab, llama_token token, bool special) {
    std::string piece;
    piece.resize(piece.capacity());  // using string internal cache, 15 bytes + '\n'
    const int n_chars = llama_token_to_piece(vocab, token, &piece[0], piece.size(), 0, special);
    if (n_chars < 0) {
        piece.resize(-n_chars);
        int check = llama_token_to_piece(vocab, token, &piece[0], piece.size(), 0, special);
        GGML_ASSERT(check == -n_chars);
    }
    else {
        piece.resize(n_chars);
    }

    return piece;
}

std::string common_detokenize(const struct llama_context * ctx, const std::vector<llama_token> & tokens, bool special) {
    const llama_model * model = llama_get_model(ctx);
    const llama_vocab * vocab = llama_model_get_vocab(model);
    return common_detokenize(vocab, tokens, special);
}

std::string common_detokenize(const struct llama_vocab * vocab, const std::vector<llama_token> & tokens, bool special) {
    std::string text;
    text.resize(std::max(text.capacity(), tokens.size()));
    int32_t n_chars = llama_detokenize(vocab, tokens.data(), (int32_t)tokens.size(), &text[0], (int32_t)text.size(), false, special);
    if (n_chars < 0) {
        text.resize(-n_chars);
        n_chars = llama_detokenize(vocab, tokens.data(), (int32_t)tokens.size(), &text[0], (int32_t)text.size(), false, special);
        GGML_ASSERT(n_chars <= (int32_t)text.size());  // whitespace trimming is performed after per-token detokenization
    }

    text.resize(n_chars);

    // NOTE: the original tokenizer decodes bytes after collecting the pieces.
    return text;
}

//
// Chat template utils
//

bool common_chat_verify_template(const std::string & tmpl, bool use_jinja) {
    if (use_jinja) {
        try {
            auto chat_template = common_chat_template(tmpl, "<s>", "</s>");
            common_chat_inputs inputs;
            inputs.messages = json::array({{
                {"role", "user"},
                {"content", "test"},
            }});
            common_chat_params_init(chat_template, inputs);
            return true;
        } catch (const std::exception & e) {
            LOG_ERR("%s: failed to apply template: %s\n", __func__, e.what());
            return false;
        }
    }
    llama_chat_message chat[] = {{"user", "test"}};
    const int res = llama_chat_apply_template(tmpl.c_str(), chat, 1, true, nullptr, 0);
    return res >= 0;
}

std::string common_chat_apply_template(
        const common_chat_template & tmpl,
        const std::vector<common_chat_msg> & msgs,
        bool add_ass,
        bool use_jinja) {
    if (use_jinja) {
        auto messages = json::array();
        for (const auto & msg : msgs) {
            messages.push_back({{"role", msg.role}, {"content", msg.content}});
        }
        common_chat_inputs inputs;
        inputs.messages = messages;
        inputs.add_generation_prompt = add_ass;
        return common_chat_params_init(tmpl, inputs).prompt;
    }

    int alloc_size = 0;
    std::vector<llama_chat_message> chat;
    for (const auto & msg : msgs) {
        chat.push_back({msg.role.c_str(), msg.content.c_str()});
        alloc_size += (msg.role.size() + msg.content.size()) * 1.25;
    }

    std::vector<char> buf(alloc_size);

    // run the first time to get the total output length
    int32_t res = llama_chat_apply_template(tmpl.source().c_str(), chat.data(), chat.size(), add_ass, buf.data(), buf.size());

    // error: chat template is not supported
    if (res < 0) {
        // if the custom "tmpl" is not supported, we throw an error
        // this is a bit redundant (for good), since we're not sure if user validated the custom template with llama_chat_verify_template()
        throw std::runtime_error("this custom template is not supported");
    }

    // if it turns out that our buffer is too small, we resize it
    if ((size_t) res > buf.size()) {
        buf.resize(res);
        res = llama_chat_apply_template(tmpl.source().c_str(), chat.data(), chat.size(), add_ass, buf.data(), buf.size());
    }

    std::string formatted_chat(buf.data(), res);
    return formatted_chat;
}

std::string common_chat_format_single(
        const common_chat_template & tmpl,
        const std::vector<common_chat_msg> & past_msg,
        const common_chat_msg & new_msg,
        bool add_ass,
        bool use_jinja) {
    std::ostringstream ss;
    auto fmt_past_msg = past_msg.empty() ? "" : common_chat_apply_template(tmpl, past_msg, false, use_jinja);
    std::vector<common_chat_msg> chat_new(past_msg);
    // if the past_msg ends with a newline, we must preserve it in the formatted version
    if (add_ass && !fmt_past_msg.empty() && fmt_past_msg.back() == '\n') {
        ss << "\n";
    };
    // format chat with new_msg
    chat_new.push_back(new_msg);
    auto fmt_new_msg = common_chat_apply_template(tmpl, chat_new, add_ass, use_jinja);
    // get the diff part
    ss << fmt_new_msg.substr(fmt_past_msg.size(), fmt_new_msg.size() - fmt_past_msg.size());
    return ss.str();
}

std::string common_chat_format_example(const common_chat_template & tmpl, bool use_jinja) {
    std::vector<common_chat_msg> msgs = {
        {"system",    "You are a helpful assistant", {}},
        {"user",      "Hello", {}},
        {"assistant", "Hi there", {}},
        {"user",      "How are you?", {}},
    };
    return common_chat_apply_template(tmpl, msgs, true, use_jinja);
}

#define CHATML_TEMPLATE_SRC \
    "{%- for message in messages -%}\n" \
    "  {{- '<|im_start|>' + message.role + '\n' + message.content + '<|im_end|>\n' -}}\n" \
    "{%- endfor -%}\n" \
    "{%- if add_generation_prompt -%}\n" \
    "  {{- '<|im_start|>assistant\n' -}}\n" \
    "{%- endif -%}"

common_chat_templates common_chat_templates_from_model(const struct llama_model * model, const std::string & chat_template_override)
{
    std::string default_template_src;
    std::string template_tool_use_src;

    bool has_explicit_template = !chat_template_override.empty();
    if (chat_template_override.empty()) {
        auto str = llama_model_chat_template(model, /* name */ nullptr);
        if (str) {
            default_template_src = str;
            has_explicit_template = true;
        }
        str = llama_model_chat_template(model, /* name */ "tool_use");
        if (str) {
            template_tool_use_src = str;
            has_explicit_template = true;
        }
    } else {
        default_template_src = chat_template_override;
    }
    if (default_template_src.empty() || default_template_src == "chatml") {
        if (!template_tool_use_src.empty()) {
            default_template_src = template_tool_use_src;
        } else {
            default_template_src = CHATML_TEMPLATE_SRC;
        }
    }
    auto vocab = llama_model_get_vocab(model);
    const auto get_token = [&](llama_token token, const char * name, const char * jinja_variable_name) {
        if (token == LLAMA_TOKEN_NULL) {
            if (default_template_src.find(jinja_variable_name) != std::string::npos
                || template_tool_use_src.find(jinja_variable_name) != std::string::npos) {
                LOG_WRN("%s: warning: vocab does not have a %s token, jinja template won't work as intended.\n", __func__, name);
            }
            return std::string();
        } else {
            return common_token_to_piece(vocab, token, true);
        }
    };
    auto token_bos = get_token(llama_vocab_bos(vocab), "BOS", "bos_token");
    auto token_eos = get_token(llama_vocab_eos(vocab), "EOS", "eos_token");
    try {
        return {
            has_explicit_template,
            std::make_unique<minja::chat_template>(default_template_src, token_bos, token_eos),
            template_tool_use_src.empty()
                ? nullptr
                : std::make_unique<minja::chat_template>(template_tool_use_src, token_bos, token_eos),
        };
    } catch (const std::exception & e) {
        LOG_ERR("%s: failed to parse chat template: %s\n", __func__, e.what());
        return {
            has_explicit_template,
            std::make_unique<minja::chat_template>(CHATML_TEMPLATE_SRC, token_bos, token_eos),
            nullptr,
        };
    }
}

//
// KV cache utils
//

void common_kv_cache_dump_view(const llama_kv_cache_view & view, int row_size) {
    static const char slot_chars[] = ".123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+";

    printf("=== Dumping KV cache. total cells %d, max sequences per cell %d, populated cells %d, total tokens in cache %d, largest empty slot=%d @ %d",
        view.n_cells, view.n_seq_max, view.used_cells, view.token_count, view.max_contiguous, view.max_contiguous_idx);

    llama_kv_cache_view_cell * c_curr = view.cells;
    llama_seq_id * cs_curr = view.cells_sequences;

    for (int i = 0; i < view.n_cells; i++, c_curr++, cs_curr += view.n_seq_max) {
        if (i % row_size == 0) {
            printf("\n%5d: ", i);
        }
        int seq_count = 0;
        for (int j = 0; j < view.n_seq_max; j++) {
            if (cs_curr[j] >= 0) { seq_count++; }
        }
        putchar(slot_chars[std::min(sizeof(slot_chars) - 2, size_t(seq_count))]);
    }

    printf("\n=== Done dumping\n");
}

void common_kv_cache_dump_view_seqs(const llama_kv_cache_view & view, int row_size) {
    static const char slot_chars[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

    printf("=== Dumping KV cache. total cells %d, max sequences per cell %d, populated cells %d, total tokens in cache %d, largest empty slot=%d @ %d\n",
        view.n_cells, view.n_seq_max, view.used_cells, view.token_count, view.max_contiguous, view.max_contiguous_idx);

    std::unordered_map<llama_seq_id, size_t> seqs;
    llama_kv_cache_view_cell * c_curr = view.cells;
    llama_seq_id * cs_curr = view.cells_sequences;

    for (int i = 0; i < view.n_cells; i++, c_curr++, cs_curr += view.n_seq_max) {
        for (int j = 0; j < view.n_seq_max; j++) {
            if (cs_curr[j] < 0) { continue; }
            if (seqs.find(cs_curr[j]) == seqs.end()) {
                if (seqs.size() + 1 >= sizeof(slot_chars)) { break; }
                const size_t sz = seqs.size();
                seqs[cs_curr[j]] = sz;
            }
        }
        if (seqs.size() + 1 >= sizeof(slot_chars)) { break; }
    }

    printf("=== Sequence legend: ");
    for (const auto & it : seqs) {
        printf("%zu=%d, ", it.second, it.first);
    }
    printf("'+'=other sequence ids");

    c_curr = view.cells;
    cs_curr = view.cells_sequences;
    for (int i = 0; i < view.n_cells; i++, c_curr++, cs_curr += view.n_seq_max) {
        if (i % row_size == 0) {
            printf("\n%5d: ", i);
        }
        for (int j = 0; j < view.n_seq_max; j++) {
            if (cs_curr[j] >= 0) {
                const auto & it = seqs.find(cs_curr[j]);
                putchar(it != seqs.end() ? int(slot_chars[it->second]) : '+');
            } else {
                putchar('.');
            }
        }
        putchar(' ');
    }

    printf("\n=== Done dumping\n");
}

//
// Embedding utils
//

void common_embd_normalize(const float * inp, float * out, int n, int embd_norm) {
    double sum = 0.0;

    switch (embd_norm) {
        case -1: // no normalisation
            sum = 1.0;
            break;
        case 0: // max absolute
            for (int i = 0; i < n; i++) {
                if (sum < std::abs(inp[i])) {
                    sum = std::abs(inp[i]);
                }
            }
            sum /= 32760.0; // make an int16 range
            break;
        case 2: // euclidean
            for (int i = 0; i < n; i++) {
                sum += inp[i] * inp[i];
            }
            sum = std::sqrt(sum);
            break;
        default: // p-norm (euclidean is p-norm p=2)
            for (int i = 0; i < n; i++) {
                sum += std::pow(std::abs(inp[i]), embd_norm);
            }
            sum = std::pow(sum, 1.0 / embd_norm);
            break;
    }

    const float norm = sum > 0.0 ? 1.0 / sum : 0.0f;

    for (int i = 0; i < n; i++) {
        out[i] = inp[i] * norm;
    }
}

float common_embd_similarity_cos(const float * embd1, const float * embd2, int n){
    double sum  = 0.0;
    double sum1 = 0.0;
    double sum2 = 0.0;

    for (int i = 0; i < n; i++) {
        sum  += embd1[i] * embd2[i];
        sum1 += embd1[i] * embd1[i];
        sum2 += embd2[i] * embd2[i];
    }

    // Handle the case where one or both vectors are zero vectors
    if (sum1 == 0.0 || sum2 == 0.0) {
        if (sum1 == 0.0 && sum2 == 0.0) {
            return 1.0f; // two zero vectors are similar
        }
        return 0.0f;
    }

    return sum / (sqrt(sum1) * sqrt(sum2));
}

//
// Control vector utils
//

static common_control_vector_data common_control_vector_load_one(const common_control_vector_load_info & load_info) {
    common_control_vector_data result = { -1, {} };

    ggml_context * ctx = nullptr;
    struct gguf_init_params meta_gguf_params = {
        /* .no_alloc = */ false,
        /* .ctx      = */ &ctx,
    };
    struct gguf_context * ctx_gguf = gguf_init_from_file(load_info.fname.c_str(), meta_gguf_params);
    if (!ctx_gguf) {
        LOG_ERR("%s: failed to load control vector file from %s\n", __func__, load_info.fname.c_str());
        return result;
    }

    int32_t n_tensors = gguf_get_n_tensors(ctx_gguf);
    if (n_tensors == 0) {
        LOG_WRN("%s: no direction tensors found in %s\n", __func__, load_info.fname.c_str());
    }

    for (int i = 0; i < n_tensors; i++) {
        std::string name = gguf_get_tensor_name(ctx_gguf, i);

        int layer_idx = -1;

        // split on '.'
        size_t dotpos = name.find('.');
        if (dotpos != std::string::npos && name.substr(0, dotpos) == "direction") {
            try {
                layer_idx = std::stoi(name.substr(dotpos + 1));
            } catch (...) {
                layer_idx = -1;
            }
        }
        if (layer_idx < 0) {
            LOG_ERR("%s: invalid/unparsable direction tensor layer index in %s\n", __func__, load_info.fname.c_str());
            result.n_embd = -1;
            break;
        } else if (layer_idx == 0) {
            LOG_ERR("%s: invalid (zero) direction tensor layer index in %s\n", __func__, load_info.fname.c_str());
            result.n_embd = -1;
            break;
        }

        struct ggml_tensor * tensor = ggml_get_tensor(ctx, name.c_str());
        if (tensor->type != GGML_TYPE_F32) {
            LOG_ERR("%s: invalid (non-F32) direction tensor type in %s\n", __func__, load_info.fname.c_str());
            result.n_embd = -1;
            break;
        }
        if (ggml_n_dims(tensor) != 1) {
            LOG_ERR("%s: invalid (non-1D) direction tensor shape in %s\n", __func__, load_info.fname.c_str());
            result.n_embd = -1;
            break;
        }

        if (result.n_embd == -1) {
            result.n_embd = ggml_nelements(tensor);
        } else if (ggml_nelements(tensor) != result.n_embd) {
            LOG_ERR("%s: direction tensor in %s does not match previous dimensions\n", __func__, load_info.fname.c_str());
            result.n_embd = -1;
            break;
        }

        // extend if necessary - do not store data for layer 0 (it's not used)
        result.data.resize(std::max(result.data.size(), static_cast<size_t>(result.n_embd * layer_idx)), 0.0f);

        const float * src = (const float *) tensor->data;
        float * dst = result.data.data() + result.n_embd * (layer_idx - 1);  // layer 1 at [0]
        for (int j = 0; j < result.n_embd; j++) {
            dst[j] += src[j] * load_info.strength;  // allows multiple directions for same layer in same file
        }

    }

    if (result.n_embd == -1) {
        LOG_WRN("%s: skipping %s due to invalid direction tensors\n", __func__, load_info.fname.c_str());
        result.data.clear();
    }

    gguf_free(ctx_gguf);
    ggml_free(ctx);

    return result;
}

common_control_vector_data common_control_vector_load(const std::vector<common_control_vector_load_info> & load_infos) {
    common_control_vector_data result = { -1, {} };

    for (const auto & info : load_infos) {
        auto cur = common_control_vector_load_one(info);

        if (cur.n_embd == -1) {
            result.n_embd = -1;
            break;
        }
        if (result.n_embd != -1 && result.n_embd != cur.n_embd) {
            LOG_ERR("%s: control vectors in %s does not match previous dimensions\n", __func__, info.fname.c_str());
            result.n_embd = -1;
            break;
        }

        if (result.n_embd == -1) {
            result = std::move(cur);
        } else {
            result.data.resize(std::max(result.data.size(), cur.data.size()), 0.0f);  // extend if necessary
            for (size_t i = 0; i < cur.data.size(); i++) {
                result.data[i] += cur.data[i];
            }
        }
    }

    if (result.n_embd == -1) {
        LOG_ERR("%s: no valid control vector files passed\n", __func__);
        result.data.clear();
    }

    return result;
}