LogReader.cpp

#include "LogReader.h"


bool CLogReader::Open(const wchar_t* const filename)
{
    this->Close();

    const bool succeeded = this->_lineReader.Open(filename);
    return succeeded;
}

void CLogReader::Close()
{
    this->_lineReader.Close();
}

bool CLogReader::SetFilter(const char* const filter)
{
    if (filter == nullptr)
    {
        return false;
    }

    const size_t patternLen = strlen(filter);
    const bool allocatedOk = this->_pattern.Allocate(patternLen);
    if (!allocatedOk)
    {
        return false;
    }

    memcpy(this->_pattern.ptr, filter, patternLen);

    return true;
}

__declspec(noinline) // noinline is added to help CPU profiling in release version
std::optional<std::string_view> CLogReader::GetNextLine()
{
    const std::string_view pattern = { this->_pattern.ptr, this->_pattern.size };

    while (true)
    {
        const auto line = this->_lineReader.GetNextLine();
        if (!line)
        {
            // error or end of file
            return {};
        }

        std::string_view matchView = *line;

        // Ignore CRLF/LF during matching:
        if (!matchView.empty() && matchView.back() == '\n')
        {
            matchView.remove_suffix(1);
            if (!matchView.empty() && matchView.back() == '\r')
            {
                matchView.remove_suffix(1);
            }
        }

        const bool matched = this->_lineMatcher.Match(matchView, pattern);
        if (matched)
        {
            // line matched
            return line;
        }
    }
}