1.1 --- a/TODO	Fri Aug 31 21:47:59 2012 +0200
     1.2 +++ b/TODO	Sat Sep 01 00:57:52 2012 +0200
     1.3 @@ -122,3 +122,58 @@
     1.4  * (strerror)
     1.5  * (unchange)
     1.6  * (unchange_all)
     1.7 +
     1.8 +
     1.9 +I/O Methods
    1.10 +===========
    1.11 +One major headache for libzip portability (especially to Windows) is
    1.12 +I/O, i.e. reading and writing from the file system.  Also, there
    1.13 +have been requests to open zip archives from a memory buffer.  To
    1.14 +address these issues, we'll introduce an I/O abstraction layer.
    1.15 +
    1.16 +  We'll reuse zip_source, since it already provides support for
    1.17 +the reading part, adding high level abstraction of the additional
    1.18 +operations needed. This way, newly written zip_sources can be used
    1.19 +both for adding files into an archive as well as for accessing archives
    1.20 +themselves.
    1.21 +
    1.22 +Specifically, we'll add these commands:
    1.23 +
    1.24 +ZIP_SOURCE_BEGIN_WRITE
    1.25 +        Prepare for writing.  The written data will replace all
    1.26 +        original data.  The file position is reset to 0.  (On POSIX
    1.27 +        systems, this will create a temporary file and open it for
    1.28 +        writing.)
    1.29 +
    1.30 +ZIP_SOURCE_WRITE
    1.31 +        Write bytes of data, a la fwrite(3) (does not need to know
    1.32 +        anything about the zip archive structure).
    1.33 +
    1.34 +ZIP_SOURCE_COMMIT_WRITE
    1.35 +        Used after all data has been written successfully. (On
    1.36 +        POSIX systems, this will replace the original file with
    1.37 +        the temporary file, adapting permissions etc.)
    1.38 +ZIP_SOURCE_ROLLBACK_WRITE
    1.39 +        because writing failed) to restore original data if possible;
    1.40 +        return an errohis will
    1.41 +        delete the temporary file.)
    1.42 +
    1.43 +ZIP_SOURCE_SEEK
    1.44 +        Set postion for next read or write, a la fseek(3).
    1.45 +
    1.46 +ZIP_SOURCE_SUPPORTS
    1.47 +        Query which commands are supported for this stream.  If a
    1.48 +        file cannot be written to, this will report ZIP_SOURCE_BEGIN_WRITE
    1.49 +        as not supported, even if the source type would support
    1.50 +        write.  (This is used in zip_open to set global flags like
    1.51 +        ZIP_AFL_RDONLY.)
    1.52 +
    1.53 +  We'll provide a zip_open variant that takes a zip_source argument
    1.54 +used for reading/writing archives.  Using an enhanced version of
    1.55 +zip_source_buffer, this can be used to read zip archives from memory.
    1.56 +
    1.57 +  zip_open itself will create a source from the file using a
    1.58 +port-specific default implementation (POSIX vs. Windows vs. ...).
    1.59 +
    1.60 +  Once the details are finalized, we'll ask for volunteers for writing
    1.61 +a Windows specific implementation.