Exception.cpp

/*
 * MIT License
 *
 * Copyright (c) 2025 Adriano dos Santos Fernandes
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
 
#include "Exception.h"
#include "Client.h"
#include <string>
#include <vector>
#include <cassert>
 
using namespace fbcpp;
using namespace fbcpp::impl;
 
 
void StatusWrapper::checkException(StatusWrapper* status)
{
    if (status->dirty && (status->getState() & fb::IStatus::STATE_ERRORS))
        throw DatabaseException{*status->client, status->getErrors()};
}
 
void StatusWrapper::catchException(fb::IStatus* status) noexcept
{
    assert(false);
}
 
 
std::string DatabaseException::buildMessage(Client& client, const std::intptr_t* statusVector)
{
    constexpr char DEFAULT_MESSAGE[] = "Unknown database error";
 
    if (!statusVector)
        return DEFAULT_MESSAGE;
 
    const auto util = client.getUtil();
 
    const auto status = client.newStatus();
    status->setErrors(statusVector);
 
    constexpr unsigned MAX_BUFFER_SIZE = 32u * 1024u;
    unsigned bufferSize = 256u;
    std::string message;
 
    while (bufferSize <= MAX_BUFFER_SIZE)
    {
        std::string buffer(bufferSize, '\0');
        const auto written = util->formatStatus(buffer.data(), bufferSize, status.get());
 
        if (written < bufferSize && buffer[0] != '\0')
        {
            message = written == 0 ? std::string{buffer.c_str()} : std::string{buffer.data(), written};
            break;
        }
 
        if (bufferSize == MAX_BUFFER_SIZE)
        {
            message = buffer.c_str();
            break;
        }
 
        bufferSize = (bufferSize > MAX_BUFFER_SIZE / 2u) ? MAX_BUFFER_SIZE : bufferSize * 2u;
    }
 
    if (message.empty())
        message = DEFAULT_MESSAGE;
 
    return message;
}
 
void DatabaseException::copyErrorVector(const std::intptr_t* statusVector)
{
    if (!statusVector)
        return;
 
    const auto* p = statusVector;
 
    while (*p != isc_arg_end)
    {
        const auto argType = *p++;
 
        switch (argType)
        {
            case isc_arg_gds:
            case isc_arg_number:
                errorVector.push_back(argType);
                errorVector.push_back(*p++);
                break;
 
            case isc_arg_string:
            case isc_arg_interpreted:
            case isc_arg_sql_state:
                errorVector.push_back(argType);
                errorStrings.emplace_back(reinterpret_cast<const char*>(*p++));
                errorVector.push_back(0);  // placeholder for string pointer
                break;
 
            case isc_arg_cstring:
            {
                const auto len = static_cast<size_t>(*p++);
                const auto str = reinterpret_cast<const char*>(*p++);
                errorVector.push_back(isc_arg_string);
                errorStrings.emplace_back(str, len);
                errorVector.push_back(0);  // placeholder for string pointer
                break;
            }
 
            default:
                errorVector.push_back(argType);
                errorVector.push_back(*p++);
                break;
        }
    }
 
    errorVector.push_back(isc_arg_end);
 
    fixupStringPointers();
}
 
void DatabaseException::fixupStringPointers()
{
    size_t strIdx = 0;
    size_t i = 0;
 
    while (i < errorVector.size() && errorVector[i] != isc_arg_end)
    {
        const auto argType = errorVector[i];
 
        if (argType == isc_arg_string || argType == isc_arg_interpreted || argType == isc_arg_sql_state)
            errorVector[i + 1] = reinterpret_cast<std::intptr_t>(errorStrings[strIdx++].c_str());
 
        i += 2;
    }
}
 
std::string DatabaseException::extractSqlState(const std::intptr_t* statusVector)
{
    if (!statusVector)
        return {};
 
    const auto* p = statusVector;
 
    while (*p != isc_arg_end)
    {
        const auto argType = *p++;
 
        if (argType == isc_arg_sql_state)
            return reinterpret_cast<const char*>(*p);
 
        if (argType == isc_arg_cstring)
            p += 2;
        else
            p++;
    }
 
    return {};
}