FS_HomeHelper.h

Go to the documentation of this file.

/*
 * Copyright (c) 2024
 *      Side Effects Software Inc.  All rights reserved.
 *
 * Redistribution and use of Houdini Development Kit samples in source and
 * binary forms, with or without modification, are permitted provided that the
 * following conditions are met:
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. The name of Side Effects Software may not be used to endorse or
 *    promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY SIDE EFFECTS SOFTWARE `AS IS' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 * NO EVENT SHALL SIDE EFFECTS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *----------------------------------------------------------------------------
 */

#ifndef __FS_HomeHelper__
#define __FS_HomeHelper__

#include <FS/FS_Reader.h>
#include <FS/FS_Writer.h>
#include <FS/FS_Info.h>
#include <FS/FS_Utils.h>
#include <UT/UT_String.h>
#include <UT/UT_StringArray.h>
#include <SYS/SYS_Types.h>
#include <time.h>

namespace HDK_Sample {

/// @file
/// This example shows how to add a custom file handler to Houdini. There are
/// three separate types of helpers that can be added. An FS_ReaderHelper is
/// used for reading files; an FS_WriterHelper is used for writing files; and
/// an FS_InfoHelper is used for getting file information and browsing
/// directories. In this example, we implement a subclass of each of these
/// classes to allow the user to specify a file name in the format
/// <tt>home:/foo/bar.hip</tt>. This file name will be reinterpreted by these
/// derived classes as if the user had entered <tt>$HOME/foo/bar.hip</tt>. This
/// example does not implement any subclasses of the FS_ReaderStream or
/// FS_WriterStream classes, but these classes can also be extended to provide
/// extra functionality (such as buffering of read and write operations).
/// @see FS_ReaderHelper, FS_InfoHelper, FS_WriterHelper

/// @brief Class to open a file as a read stream.  The class tests for a
/// "home:" prefix and replaces it with $HOME.
class FS_HomeReadHelper : public FS_ReaderHelper
{
public:
             FS_HomeReadHelper();
            ~FS_HomeReadHelper() override;

    /// If the filename starts with @c "home:", open an FS_ReaderStream
    FS_ReaderStream *createStream(const char *source,
                                  const UT_Options *options) override;

    /// Parse the source path into the index file path and the section name.
    /// Please, see the base class for more documentation.
    bool            splitIndexFileSectionPath(const char *source_section_path,
                                        UT_String &index_file_path,
                                        UT_String &section_name) override;

    /// Utility function to combine index file name and section name into the
    /// section path. Performs the reverse of splitIndexFileSectionPath().
    /// Please, see the base class for more documentation.
    bool            combineIndexFileSectionPath( 
                                        UT_String &source_section_path,
                                        const char *index_file_path,
                                        const char *section_name) override;
};

/// @brief Class to open a file as a write stream.  The class tests for a
/// "home:" prefix and replaces it with $HOME.
class FS_HomeWriteHelper : public FS_WriterHelper
{
public:
             FS_HomeWriteHelper();
            ~FS_HomeWriteHelper() override;

    /// If the filename begins with "home:" return a new write stream
    FS_WriterStream *createStream(const char *source) override;

    /// Whether this helper supports the given source path for makeDirectory().
    bool            canMakeDirectory(const char *source) override;

    /// Make a directory and all the parent directories needed.
    bool            makeDirectory(const char *source,
                                  mode_t mode = 0777,
                                  bool ignore_umask = false) override;
};

/// @brief Class to stat a file.  The class tests for a "home:" prefix and
/// replaces it with $HOME.
class FS_HomeInfoHelper : public FS_InfoHelper
{
public:
             FS_HomeInfoHelper();
            ~FS_HomeInfoHelper() override;

    bool                 canHandle(const char *source) override;
    bool                 hasAccess(const char *source, int mode) override;
    bool                 getIsDirectory(const char *source) override;
    time_t               getModTime(const char *source) override;
    int64                getSize(const char *source) override;
    UT_String            getExtension(const char *source) override;
    bool                 getContents(const char *source,
                                     UT_StringArray &contents,
                                     UT_StringArray *dirs) override;
};

}       // End HDK_Sample namespace

#endif