/mordor/streams/file.cpp

// Copyright (c) 2009 - Mozy, Inc.

#include "file.h"

#include "mordor/assert.h"
#include "mordor/string.h"

namespace Mordor {

static Logger::ptr g_log = Log::lookup("mordor:streams:file");

FileStream::FileStream()
: m_supportsRead(false),
  m_supportsWrite(false),
  m_supportsSeek(false)
{}

void
FileStream::init(const std::string &path, AccessFlags accessFlags,
    CreateFlags createFlags, IOManager *ioManager, Scheduler *scheduler)
{
    NativeHandle handle;
#ifdef WINDOWS
    DWORD access = 0;
    if (accessFlags & READ)
        access |= GENERIC_READ;
    if (accessFlags & WRITE)
        access |= GENERIC_WRITE;
    if (accessFlags == APPEND)
        access = FILE_APPEND_DATA | SYNCHRONIZE;
    DWORD flags = 0;
    if (createFlags & DELETE_ON_CLOSE) {
        flags |= FILE_FLAG_DELETE_ON_CLOSE;
        createFlags = (CreateFlags)(createFlags & ~DELETE_ON_CLOSE);
    }
    if (ioManager)
        flags |= FILE_FLAG_OVERLAPPED;
    MORDOR_ASSERT(createFlags >= CREATE_NEW && createFlags <= TRUNCATE_EXISTING);
    unsigned long  shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE;
    handle = ::CreateFileW(Mordor::toUtf16(path).c_str(), access, shareMode, NULL, createFlags, flags, NULL);
    error_t error = lastError();
    MORDOR_LOG_VERBOSE(g_log) << "CreateFileW(" << path << ", "
        << access << ", " << createFlags << ", " << flags << "): " << handle
        << " (" << error << ")";
    if (handle == INVALID_HANDLE_VALUE) {
        try {
            MORDOR_THROW_EXCEPTION_FROM_ERROR_API(error, "CreateFileW");
        } catch (boost::exception &ex) {
            ex << boost::errinfo_file_name(path);
            throw;
        }
    }
#else
    int oflags = (int)accessFlags;
    switch (createFlags & ~DELETE_ON_CLOSE) {
        case OPEN:
            break;
        case CREATE:
            oflags |= O_CREAT | O_EXCL;
            break;
        case OPEN_OR_CREATE:
            oflags |= O_CREAT;
            break;
        case OVERWRITE:
            oflags |= O_TRUNC;
            break;
        case OVERWRITE_OR_CREATE:
            oflags |= O_CREAT | O_TRUNC;
            break;
        default:
            MORDOR_NOTREACHED();
    }
    handle = open(path.c_str(), oflags, 0777);
    error_t error = lastError();
    MORDOR_LOG_VERBOSE(g_log) << "open(" << path << ", " << oflags << "): "
        << handle << " (" << error << ")";
    if (handle < 0) {
        try {
            MORDOR_THROW_EXCEPTION_FROM_ERROR_API(error, "open");
        } catch (boost::exception &ex) {
            ex << boost::errinfo_file_name(path);
            throw;
        }
    }
    if (createFlags & DELETE_ON_CLOSE) {
        int rc = unlink(path.c_str());
        if (rc != 0) {
            error_t error = lastError();
            ::close(handle);
            MORDOR_THROW_EXCEPTION_FROM_ERROR_API(error, "unlink");
        }
    }
#endif

    NativeStream::init(handle, ioManager, scheduler);
    setSupportFlags(accessFlags);
    m_path = path;
}

void FileStream::setSupportFlags(AccessFlags accessFlags)
{
    m_supportsRead = accessFlags == READ || accessFlags == READWRITE;
    m_supportsWrite = accessFlags == WRITE || accessFlags == READWRITE || accessFlags == APPEND;
    m_supportsSeek = accessFlags != APPEND;
}

}