fprime/Svc/ActiveTextLogger/LogFile.cpp

// \copyright
// Copyright 2009-2015, by the California Institute of Technology.
// ALL RIGHTS RESERVED.  United States Government Sponsorship
// acknowledged.

#include <Fw/Types/Assert.hpp>
#include <Fw/Types/StringUtils.hpp>
#include <Os/File.hpp>
#include <Os/FileSystem.hpp>
#include <Svc/ActiveTextLogger/LogFile.hpp>
#include <cstdio>
#include <cstring>
#include <limits>

namespace Svc {

// ----------------------------------------------------------------------
// Initialization/Exiting
// ----------------------------------------------------------------------

LogFile::LogFile() : m_fileName(), m_file(), m_maxFileSize(0), m_openFile(false), m_currentFileSize(0) {}

LogFile::~LogFile() {
    // Close the file if needed:
    if (this->m_openFile) {
        this->m_file.close();
    }
}

// ----------------------------------------------------------------------
// Member Functions
// ----------------------------------------------------------------------

bool LogFile::write_to_log(const char* const buf, const FwSizeType size) {
    FW_ASSERT(buf != nullptr);

    bool status = true;

    // Print to file if there is one, and given a valid size:
    if (this->m_openFile && size > 0) {
        // Make sure we won't exceed the maximum size:
        // Note: second condition in if statement is true if there is overflow
        // in the addition below
        FwSizeType projectedSize = this->m_currentFileSize + size;
        if (projectedSize > this->m_maxFileSize ||
            (this->m_currentFileSize > (std::numeric_limits<FwSizeType>::max() - size))) {
            status = false;
            this->m_openFile = false;
            this->m_file.close();
        }
        // Won't exceed max size, so write to file:
        else {
            FwSizeType writeSize = size;
            Os::File::Status stat = this->m_file.write(reinterpret_cast<const U8*>(buf), writeSize, Os::File::WAIT);

            // Assert that we are not trying to write to a file we never opened:
            FW_ASSERT(stat != Os::File::NOT_OPENED);

            // Only return a good status if the write was valid
            status = (stat == Os::File::OP_OK) && (static_cast<FwSizeType>(writeSize) == size);

            this->m_currentFileSize += static_cast<FwSizeType>(writeSize);
        }
    }

    return status;
}

bool LogFile::set_log_file(const char* fileName, const FwSizeType maxSize, const FwSizeType maxBackups) {
    FW_ASSERT(fileName != nullptr);

    // If there is already a previously open file then close it:
    if (this->m_openFile) {
        this->m_openFile = false;
        this->m_file.close();
    }
    Fw::FileNameString searchFilename;
    Fw::FormatStatus formatStatus = searchFilename.format("%s", fileName);

    // If file name is too large, return failure:
    if (formatStatus != Fw::FormatStatus::SUCCESS) {
        return false;
    }

    // Check if file already exists, and if it does try to tack on a suffix.
    // Quit after maxBackups suffix addition tries (first try is w/ the original name).
    U32 suffix = 0;
    bool failedSuffix = false;
    FwSizeType fileSize = 0;
    while (Os::FileSystem::getFileSize(searchFilename.toChar(), fileSize) == Os::FileSystem::OP_OK) {
        // Not able to create a new non-existing file in maxBackups tries, then mark that it failed:
        if (suffix >= maxBackups) {
            failedSuffix = true;
            break;
        }
        // Format and check for error and overflows
        formatStatus = searchFilename.format("%s%" PRIu32, fileName, suffix);
        if (formatStatus != Fw::FormatStatus::SUCCESS) {
            return false;
        }
        ++suffix;
    }

    // If failed trying to make a new file, just use the original file
    if (failedSuffix) {
        searchFilename = fileName;
    }

    // Open the file (using CREATE so that it truncates an already existing file):
    Os::File::Status stat =
        this->m_file.open(searchFilename.toChar(), Os::File::OPEN_CREATE, Os::File::OverwriteType::OVERWRITE);

    // Bad status when trying to open the file:
    if (stat != Os::File::OP_OK) {
        return false;
    }

    this->m_currentFileSize = 0;
    this->m_maxFileSize = maxSize;
    this->m_fileName = searchFilename;
    this->m_openFile = true;

    return true;
}

}  // namespace Svc