[SDL] [OT] Sound and Music - memory mapped files boost.org
post at andre-krause.net
Mon Sep 19 13:23:08 PDT 2005
Tyler Montbriand wrote:
>On September 18, 2005 09:56 pm, Simon Roby wrote:
>>I fully agree, a portable mmap abstraction would be an incredible
>>addition to SDL. There should be a decent fallback on platforms that
>>don't support it though...
>Now there's a toughie. How does one emulate memory mapping without
>actually /doing/ memory mapping? The only sane thing I can think of is using
>size-limited, allocated buffers; but that's no good for writing, and for any
>decently sized file, forces people to do all the seek-abstraction they'd be
>doing without mmap in the first place.
>Worst case, emulated mmap would be slower and waste more memory than plain
>file operations. It might end up just being something that's either
>supported or not, like CDROMs and timers. If it ever becomes internal to
>SDL, maybye it can be used for optimizations there when present...
>Interestingly, while Palm doesn't support mmap /yet/ afaik, future versions
>ought to via a linux kernel. http://www.palmsource.com/opensource/
>SDL mailing list
>SDL at libsdl.org
i just want to note that the latest boost library ( www.boost.org ) adds
a set of iostream classes, that include abstraction for memory mapped
"Boost.Iostreams has three aims:
To make it easy to create standard C++ streams and stream buffers for
accessing new Sources and Sinks.
To provide a framework for defining Filters and attaching them to
standard streams and stream buffers.
To provide a collection of ready-to-use Filters, Sources and Sinks.
For example, Boost.Iostreams can be used to create streams to access TCP
connections or as a framework for cryptography and data compression. The
library includes components for accessing
!!!!!!!!!!!! memory-mapped files, !!!!!!!!!!!!!!
for file access using operating system file descriptors, for code
conversion, for text filtering with regular expressions, for line-ending
conversion and for compression and decompression in the zlib, gzip and
"The classes mapped_file_source, mapped_file_sink and mapped_file
provide access to memory-mapped files on Windows and POSIX systems. "
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