82b2cda639
- added compress-level parameter to select a compression level for
file writing and changed the default for lz4 compression to do a
better job compressing. finished splitting glz input routines
apart from glz output routines and did a bit of other restructuring.
removed gzxfile struct-as-bytevector wrapper and moved its fd
into glzFile. moved DEACTIVATE to before glzdopen_input calls
in S_new_open_input_fd and S_compress_input_fd, since glzdopen_input
reads from the file and could block. the compress format and now
level are now recorded directly the thread context. replaced
as-gz? flag bit in compressed bytevector header word with a small
number of bits recording the compression format at the bottom of
the header word. flushed a couple of bytevector compression mats
that depended on the old representation. (these last few changes
should make adding new compression formats easier.) added
s-directory build options to choose whether to compress and, if
so, the format and level.
compress-io.h, compress-io.c, new-io.c, equates.h, system.h,
scheme.c, gc.c,
io.ss, cmacros.ss, back.ss, bytevector.ss, primdata.ss, s/Mf-base,
io.ms, mat.ss, bytevector.ms, root-experr*,
release_notes.stex, io.stex, system.stex, objects.stex
- improved the effectiveness of LZ4 boot-file compression to within
15% of gzip by increasing the lz4 output-port in_buffer size to
1<<18. With the previous size (1<<14) LZ4-compressed boot files
were about 50% larger. set the lz4 input-port in_buffer and
out_buffer sizes to 1<<12 and 1<<14. there's no clear win at
present for larger input-port buffer sizes.
compress-io.c
- To reduce the memory hit for the increased output-port in_buffer
size and the corresponding increase in computed out_buffer size,
one output-side out_buffer is now allocated (lazily) per thread
and stored in the thread context. The other buffers are now
directly a part of the lz4File_out and lz4File_in structures
rather than allocated separately.
compress-io.c, scheme.c, gc.c,
cmacros.ss
- split out the buffer emit code from glzwrite_lz4 into a
separate glzemit_lz4 helper that is now also used by gzclose
so we can avoid dealing with a NULL buffer in glzwrite_lz4.
glzwrite_lz4 also uses it to writing large buffers directly and
avoid the memcpy.
compress-io.c
- replaced lz4File_out and lz4File_in mode enumeration with the
compress format and inputp boolean. using switch to check and
raising exceptions for unexpected values to further simplify
adding new compression formats in the future.
compress-io.c
- replaced the never-defined struct lz4File pointer in glzFile
union with the more specific struct lz4File_in_r and Lz4File_out_r
pointers.
compress-io.h, compress-io.c
- added free of lz4 structures to gzclose. also changed file-close
logic generally so that (1) port is marked closed before anything is
freed to avoid dangling pointers in the case of an interrupt or
error, and (2) structures are freed even in the case of a write
or close error, before the error is reported. also now mallocing
glz and lz4 structures after possibility of errors have passed where
possible and freeing them when not.
compress-io.c,
io.ss
- added return-value checks to malloc calls and to a couple of other
C-library calls.
compress-io.c
- corrected EINTR checks to look at errno rather than return codes.
compress-io.c
- added S_ prefixes to the glz* exports
externs.h, compress-io.c, new-io.c, scheme.c, fasl.c
- added entries for mutex-name and mutex-thread
threads.stex
original commit: 722ffabef4c938bc92c0fe07f789a9ba350dc6c6
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| .travis | ||
| bintar | ||
| c | ||
| csug | ||
| examples | ||
| lz4@c438548312 | ||
| makefiles | ||
| mats | ||
| nanopass@1f7e80bcff | ||
| pkg | ||
| release_notes | ||
| rpm | ||
| s | ||
| stex@3bd2b86cc5 | ||
| unicode | ||
| wininstall | ||
| zlib@cacf7f1d4e | ||
| .gitattributes | ||
| .gitignore | ||
| .gitmodules | ||
| .travis.yml | ||
| BUILDING | ||
| CHARTER.md | ||
| checkin | ||
| configure | ||
| CONTRIBUTING.md | ||
| LICENSE | ||
| LOG | ||
| newrelease | ||
| NOTICE | ||
| README.md | ||
| scheme.1.in | ||
| workarea | ||
Chez Scheme is both a programming language and an implementation of that language, with supporting tools and documentation.
As a superset of the language described in the Revised6 Report on the Algorithmic Language Scheme (R6RS), Chez Scheme supports all standard features of Scheme, including first-class procedures, proper treatment of tail calls, continuations, user-defined records, libraries, exceptions, and hygienic macro expansion.
Chez Scheme also includes extensive support for interfacing with C and other languages, support for multiple threads possibly running on multiple cores, non-blocking I/O, and many other features.
The Chez Scheme implementation consists of a compiler, run-time system, and programming environment. Although an interpreter is available, all code is compiled by default. Source code is compiled on-the-fly when loaded from a source file or entered via the shell. A source file can also be precompiled into a stored binary form and automatically recompiled when its dependencies change. Whether compiling on the fly or precompiling, the compiler produces optimized machine code, with some optimization across separately compiled library boundaries. The compiler can also be directed to perform whole-program compilation, which does full cross-library optimization and also reduces a program and the libraries upon which it depends to a single binary.
The run-time system interfaces with the operating system and supports, among other things, binary and textual (Unicode) I/O, automatic storage management (dynamic memory allocation and generational garbage collection), library management, and exception handling. By default, the compiler is included in the run-time system, allowing programs to be generated and compiled at run time, and storage for dynamically compiled code, just like any other dynamically allocated storage, is automatically reclaimed by the garbage collector.
The programming environment includes a source-level debugger, a mechanism for producing HTML displays of profile counts and program "hot spots" when profiling is enabled during compilation, tools for inspecting memory usage, and an interactive shell interface (the expression editor, or "expeditor" for short) that supports multi-line expression editing.
The R6RS core of the Chez Scheme language is described in The Scheme Programming Language, which also includes an introduction to Scheme and a set of example programs. Chez Scheme's additional language, run-time system, and programming environment features are described in the Chez Scheme User's Guide. The latter includes a shared index and a shared summary of forms, with links where appropriate to the former, so it is often the best starting point.
Get started with Chez Scheme by Building Chez Scheme.
For more information see the Chez Scheme Project Page.