Merge pull request #418 from dybvig/compress-level

Add a compress-level parameter
original commit: 3ea6f8e4b166b033f1cb33293090ca78b8986db9

LOG

@@ -1268,3 +1268,72 @@
     externs.h, system.h, expeditor.c, configure, Mf-*, Makefile.*nt,
     workarea, mat.ss, io.ms, io.stex, objects.stex, release_notes.stex,
     root-experr*, patch*
+- 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

c/compress-io.h

@@ -1,5 +1,5 @@
 /* compress-io.h
- * Copyright 1984-2017 Cisco Systems, Inc.
+ * Copyright 1984-2019 Cisco Systems, Inc.
  * 
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,34 +14,13 @@
  * limitations under the License.
  */
 
-#include "zlib.h"
-
-struct lz4File;
-
 typedef struct glzFile_r {
-  int mode;
+  INT fd;
+  IBOOL inputp;
+  INT format;
   union {
-    gzFile gz;
+    struct gzFile_s *gz;
-    struct lz4File *lz4;
+    struct lz4File_in_r *lz4_in;
+    struct lz4File_out_r *lz4_out;
   };
 } *glzFile;
-
-glzFile glzdopen_gz(int fd, const char *mode);
-glzFile glzdopen_lz4(int fd, const char *mode);
-glzFile glzdopen(int fd, const char *mode);
-glzFile glzopen(const char *path, const char *mode);
-#ifdef WIN32
-glzFile glzopen_w(wchar_t *path, const char *mode);
-#endif
-int glzdirect(glzFile file);
-int glzclose(glzFile file);
-
-int glzread(glzFile file, void *buffer, unsigned int count);
-int glzwrite(glzFile file, void *buffer, unsigned int count);
-long glzseek(glzFile file, long offset, int whence);
-int glzgetc(glzFile file);
-int glzungetc(int c, glzFile file);
-int glzrewind(glzFile file);
-
-void glzerror(glzFile file, int *errnum);
-void glzclearerr(glzFile fdfile);

c/externs.h

@@ -169,6 +169,27 @@ extern wchar_t *S_malloc_wide_pathname PROTO((const char *inpath));
 #endif
 extern IBOOL S_fixedpathp PROTO((const char *inpath));
 
+/* compress-io.c */
+extern glzFile S_glzdopen_output PROTO((INT fd, INT compress_format, INT compress_level));
+extern glzFile S_glzdopen_input PROTO((INT fd));
+extern glzFile S_glzopen_input PROTO((const char *path));
+#ifdef WIN32
+extern glzFile S_glzopen_input_w PROTO((const wchar_t *path));
+#endif
+extern IBOOL S_glzdirect PROTO((glzFile file));
+extern INT S_glzclose PROTO((glzFile file));
+
+extern INT S_glzread PROTO((glzFile file, void *buffer, UINT count));
+extern INT S_glzwrite PROTO((glzFile file, void *buffer, UINT count));
+extern long S_glzseek PROTO((glzFile file, long offset, INT whence));
+extern INT S_glzgetc PROTO((glzFile file));
+extern INT S_glzungetc PROTO((INT c, glzFile file));
+extern INT S_glzrewind PROTO((glzFile file));
+
+extern void S_glzerror PROTO((glzFile file, INT *errnum));
+extern void S_glzclearerr PROTO((glzFile fdfile));
+
+
 /* new-io.c */
 extern INT S_gzxfile_fd PROTO((ptr x));
 extern glzFile S_gzxfile_gzfile PROTO((ptr x));
@@ -176,14 +197,14 @@ extern ptr S_new_open_input_fd PROTO((const char *filename, IBOOL compressed));
 extern ptr S_new_open_output_fd PROTO((
   const char *filename, INT mode,
   IBOOL no_create, IBOOL no_fail, IBOOL no_truncate,
-  IBOOL append, IBOOL lock, IBOOL replace, IBOOL compressed, IBOOL as_gz));
+  IBOOL append, IBOOL lock, IBOOL replace, IBOOL compressed));
 extern ptr S_new_open_input_output_fd PROTO((
   const char *filename, INT mode,
   IBOOL no_create, IBOOL no_fail, IBOOL no_truncate,
   IBOOL append, IBOOL lock, IBOOL replace, IBOOL compressed));
 extern ptr S_close_fd PROTO((ptr file, IBOOL gzflag));
 extern ptr S_compress_input_fd PROTO((INT fd, I64 fp));
-extern ptr S_compress_output_fd PROTO((INT fd, IBOOL as_gz));
+extern ptr S_compress_output_fd PROTO((INT fd));
 
 extern ptr S_bytevector_read PROTO((ptr file, ptr buffer, iptr start, iptr count, IBOOL gzflag));
 extern ptr S_bytevector_read_nb PROTO((ptr file, ptr buffer, iptr start, iptr count, IBOOL gzflag));
@@ -198,13 +219,13 @@ extern ptr S_get_fd_length PROTO((ptr file, IBOOL gzflag));
 extern ptr S_set_fd_length PROTO((ptr file, ptr length, IBOOL gzflag));
 extern void S_new_io_init PROTO((void));
 
-extern uptr S_bytevector_compress_size PROTO((iptr s_count, IBOOL as_gz));
+extern uptr S_bytevector_compress_size PROTO((iptr s_count, INT compress_format));
 extern ptr S_bytevector_compress PROTO((ptr dest_bv, iptr d_start, iptr d_count,
                                         ptr src_bv, iptr s_start, iptr s_count,
-                                        IBOOL as_gz));
+                                        INT compress_format));
 extern ptr S_bytevector_uncompress PROTO((ptr dest_bv, iptr d_start, iptr d_count,
                                           ptr src_bv, iptr s_start, iptr s_count,
-                                          IBOOL as_gz));
+                                          INT compress_format));
 
 /* thread.c */
 extern void S_thread_init PROTO((void));

c/fasl.c

@@ -177,6 +177,7 @@
  */
 
 #include "system.h"
+#include "zlib.h"
 
 #ifdef WIN32
 #include <io.h>
@@ -346,14 +347,14 @@ static INT uf_read(unbufFaslFile uf, octet *s, iptr n) {
 
     switch (uf->type) {
       case UFFO_TYPE_GZ:
-        k = glzread(uf->file, s, (GZ_IO_SIZE_T)nx);
+        k = S_glzread(uf->file, s, (GZ_IO_SIZE_T)nx);
         if (k > 0)
           n -= k;
         else if (k == 0)
           return -1;
         else {
-          glzerror(uf->file, &errnum);
+          S_glzerror(uf->file, &errnum);
-          glzclearerr(uf->file);
+          S_glzclearerr(uf->file);
           if (errnum != Z_ERRNO || errno != EINTR)
             S_error1("", "error reading from ~a", uf->path);
         }

c/gc.c

@@ -1515,6 +1515,9 @@ static void sweep_thread(p) ptr p; {
     /* immediate SUPPRESSPRIMITIVEINLINING */
     relocate(&DEFAULTRECORDEQUALPROCEDURE(tc))
     relocate(&DEFAULTRECORDHASHPROCEDURE(tc))
+    relocate(&COMPRESSFORMAT(tc))
+    relocate(&COMPRESSLEVEL(tc))
+    /* void* LZ4OUTBUFFER(tc) */
     /* U64 INSTRCOUNTER(tc) */
     /* U64 ALLOCCOUNTER(tc) */
     relocate(&PARAMETERS(tc))

c/new-io.c

@@ -52,9 +52,8 @@
 /* locally defined functions */
 static ptr new_open_output_fd_helper PROTO((const char *filename, INT mode,
              INT flags, INT no_create, INT no_fail, INT no_truncate,
-             INT append, INT lock, INT replace, INT compressed, INT as_gz));
+             INT append, INT lock, INT replace, INT compressed));
 static INT lockfile PROTO((INT fd));
-static ptr make_gzxfile PROTO((int fd, glzFile file));
 static int is_valid_zlib_length(iptr count);
 static int is_valid_lz4_length(iptr count);
 
@@ -78,8 +77,8 @@ static int is_valid_lz4_length(iptr count);
     if (ok) { flag = 0; }                               \
     else {                                              \
       INT errnum;                                       \
-      glzerror((fd),&errnum);                           \
+      S_glzerror((fd),&errnum);                         \
-      glzclearerr((fd));                                \
+      S_glzclearerr((fd));                              \
       if (errnum == Z_ERRNO) {                          \
         flag = errno != EINTR;                          \
       } else {                                          \
@@ -99,8 +98,8 @@ static int is_valid_lz4_length(iptr count);
     if (ok) { flag = 0; break; }                        \
     else {                                              \
       INT errnum;                                       \
-      glzerror((fd),&errnum);                           \
+      S_glzerror((fd),&errnum);                         \
-      glzclearerr((fd));                                \
+      S_glzclearerr((fd));                              \
       if (errnum == Z_ERRNO) {                          \
         if (errno != EINTR) { flag = 1; break; }        \
       } else {                                          \
@@ -117,8 +116,8 @@ static int is_valid_lz4_length(iptr count);
     if (ok) { flag = 0; }                               \
     else {                                              \
       INT errnum;                                       \
-      glzerror((fd),&errnum);                           \
+      S_glzerror((fd),&errnum);                         \
-      glzclearerr((fd));                                \
+      S_glzclearerr((fd));                              \
       if (errnum == Z_ERRNO) { flag = 1; }              \
       else {                                            \
         flag = not_ok_is_fatal || errnum != Z_OK;       \
@@ -145,26 +144,15 @@ static INT lockfile(INT fd) { return FLOCK(fd, LOCK_EX); }
 static INT lockfile(INT fd) { return lockf(fd, F_LOCK, (off_t)0); }
 #endif
 
-/* work around missing zlib API operation to extract a glzFile's fd */
+#define MAKE_GZXFILE(x) Sinteger((iptr)x)
-typedef struct {
+#define GZXFILE_GZFILE(x) ((glzFile)Sinteger_value(x))
-  int fd;
-  glzFile file;
-} gzxfile;
-#define gzxfile_fd(x) (((gzxfile *)&BVIT(x,0))->fd)
-#define gzxfile_gzfile(x) (((gzxfile *)&BVIT(x,0))->file)
-static ptr make_gzxfile(int fd, glzFile file) {
-  ptr bv;
 
-  bv = S_bytevector(sizeof(gzxfile));
-  gzxfile_fd(bv) = fd;
-  gzxfile_gzfile(bv) = file;
-  return bv;
-}
 INT S_gzxfile_fd(ptr x) {
-  return gzxfile_fd(x);
+  return GZXFILE_GZFILE(x)->fd;
 }
+
 glzFile S_gzxfile_gzfile(ptr x) {
-  return gzxfile_gzfile(x);
+  return GZXFILE_GZFILE(x);
 }
 
 ptr S_new_open_input_fd(const char *infilename, IBOOL compressed) {
@@ -209,25 +197,26 @@ ptr S_new_open_input_fd(const char *infilename, IBOOL compressed) {
     return Scons(FIX(OPEN_ERROR_OTHER), str);
   }
   
-  if ((file = glzdopen(dupfd, "rb")) == Z_NULL) {
+  DEACTIVATE(tc) /* glzdopen_input reads the magic word from the file */
+  if ((file = S_glzdopen_input(dupfd)) == Z_NULL) {
+    REACTIVATE(tc)
     FD_GUARD(result == 0, error, result = CLOSE(fd));
     FD_GUARD(result == 0, error, result = CLOSE(dupfd));
     return Scons(FIX(OPEN_ERROR_OTHER), Sstring("unable to allocate compression state (too many open files?)"));
   }
 
-  DEACTIVATE(tc)
+  compressed = !S_glzdirect(file);
-  compressed = !glzdirect(file);
   REACTIVATE(tc)
 
   if (compressed) {
     FD_GUARD(result == 0, error, result = CLOSE(fd));
-    /* box indicates gzip'd */
+    /* box indicates compressed */
-    return Sbox(make_gzxfile(dupfd, file));
+    return Sbox(MAKE_GZXFILE(file));
   }
 
-  GZ_GUARD(1, ok == 0 || ok == Z_BUF_ERROR, flag, file, ok = glzclose(file));
+  GZ_GUARD(1, ok == 0 || ok == Z_BUF_ERROR, flag, file, ok = S_glzclose(file));
   if (flag) {} /* make the compiler happy */
-  if (LSEEK(fd, 0, SEEK_SET) != 0) { /* glzdirect does not leave fd at position 0 */
+  if (LSEEK(fd, 0, SEEK_SET) != 0) { /* glzdopen and glzdirect might not leave fd at position 0 */
     FD_GUARD(result == 0, error, result = CLOSE(fd));
     return Scons(FIX(OPEN_ERROR_OTHER),Sstring("unable to reset after reading header bytes"));
   }
@@ -245,22 +234,24 @@ ptr S_compress_input_fd(INT fd, I64 pos) {
     return S_strerror(errno);
   }
   
-  if ((file = glzdopen(dupfd, "rb")) == Z_NULL) {
+  DEACTIVATE(tc)
+  if ((file = S_glzdopen_input(dupfd)) == Z_NULL) {
+    REACTIVATE(tc)
     FD_GUARD(result == 0, error, result = CLOSE(dupfd));
     return Sstring("unable to allocate compression state (too many open files?)");
   }
   
-  DEACTIVATE(tc)
+  compressed = !S_glzdirect(file);
-  compressed = !glzdirect(file);
   REACTIVATE(tc)
 
   if (compressed) {
     FD_GUARD(result == 0, error, result = CLOSE(fd));
     if (error) {} /* make the compiler happy */
-    return Sbox(make_gzxfile(dupfd, file));
+    /* box indicates compressed */
+    return Sbox(MAKE_GZXFILE(file));
   }
 
-  GZ_GUARD(1, ok == 0 || ok == Z_BUF_ERROR, flag, file, ok = glzclose(file));
+  GZ_GUARD(1, ok == 0 || ok == Z_BUF_ERROR, flag, file, ok = S_glzclose(file));
   if (flag) {} /* make the compiler happy */
   if (LSEEK(fd, pos, SEEK_SET) != pos) { /* glzdirect does not leave fd at same position */
     return Sstring("unable to reset after reading header bytes");
@@ -268,38 +259,28 @@ ptr S_compress_input_fd(INT fd, I64 pos) {
   return MAKE_FD(fd);
 }
 
-ptr S_compress_output_fd(INT fd, IBOOL as_gz) {
+ptr S_compress_output_fd(INT fd) {
   glzFile file;
-  int as_append;
+  ptr tc = get_thread_context();
 
-#ifdef WIN32
+  file = S_glzdopen_output(fd, (INT)UNFIX(COMPRESSFORMAT(tc)), (INT)UNFIX(COMPRESSLEVEL(tc)));
-  as_append = 0;
-#else
-  as_append = fcntl(fd, F_GETFL) & O_APPEND;
-#endif
-
-  if (as_gz)
-    file = glzdopen_gz(fd, as_append ? "ab" : "wb");
-  else
-    file = glzdopen_lz4(fd, as_append ? "ab" : "wb");
 
   if (file == Z_NULL)
     return Sstring("unable to allocate compression state (too many open files?)");
 
-  return Sbox(make_gzxfile(fd, file));
+  /* box indicates compressed */
+  return Sbox(MAKE_GZXFILE(file));
 }
 
 static ptr new_open_output_fd_helper(
   const char *infilename, INT mode, INT flags,
   IBOOL no_create, IBOOL no_fail, IBOOL no_truncate,
-  IBOOL append, IBOOL lock, IBOOL replace, IBOOL compressed, IBOOL as_gz) {
+  IBOOL append, IBOOL lock, IBOOL replace, IBOOL compressed) {
   char *filename;
   INT saved_errno = 0;
   iptr error;
   INT fd, result;
-#ifdef PTHREADS
   ptr tc = get_thread_context();
-#endif
 
   flags |=
     (no_create ? 0 : O_CREAT) |
@@ -358,26 +339,23 @@ static ptr new_open_output_fd_helper(
   }
 
   glzFile file;
-  if (as_gz)
+  file = S_glzdopen_output(fd, (INT)UNFIX(COMPRESSFORMAT(tc)), (INT)UNFIX(COMPRESSLEVEL(tc)));
-    file = glzdopen_gz(fd, append ? "ab" : "wb");
-  else
-    file = glzdopen_lz4(fd, append ? "ab" : "wb");
   if (file == Z_NULL) {
     FD_GUARD(result == 0, error, result = CLOSE(fd));
     return Scons(FIX(OPEN_ERROR_OTHER), Sstring("unable to allocate compression state"));
   }
 
-  return make_gzxfile(fd, file);
+  return MAKE_GZXFILE(file);
 }
 
 ptr S_new_open_output_fd(
   const char *filename, INT mode,
   IBOOL no_create, IBOOL no_fail, IBOOL no_truncate,
-  IBOOL append, IBOOL lock, IBOOL replace, IBOOL compressed, IBOOL as_gz) {
+  IBOOL append, IBOOL lock, IBOOL replace, IBOOL compressed) {
   return new_open_output_fd_helper(
     filename, mode, O_BINARY | O_WRONLY,
     no_create, no_fail, no_truncate,
-    append, lock, replace, compressed, as_gz);
+    append, lock, replace, compressed);
 }
 
 ptr S_new_open_input_output_fd(
@@ -390,14 +368,14 @@ ptr S_new_open_input_output_fd(
     return new_open_output_fd_helper(
       filename, mode, O_BINARY | O_RDWR,
       no_create, no_fail, no_truncate,
-      append, lock, replace, compressed, 0);
+      append, lock, replace, 0);
 }
 
 ptr S_close_fd(ptr file, IBOOL gzflag) {
   INT saved_errno = 0;
   INT ok, flag;
   INT fd = gzflag ? 0 : GET_FD(file);
-  glzFile gzfile = gzflag ? gzxfile_gzfile(file) : NULL;
+  glzFile gzfile = gzflag ? GZXFILE_GZFILE(file) : NULL;
 #ifdef PTHREADS
   ptr tc = get_thread_context();
 #endif
@@ -414,7 +392,7 @@ ptr S_close_fd(ptr file, IBOOL gzflag) {
     FD_GUARD(ok == 0, flag, ok = CLOSE(fd));
   } else {
    /* zlib 1.2.1 returns Z_BUF_ERROR when closing an empty file opened for reading */
-    GZ_GUARD(1, ok == 0 || ok == Z_BUF_ERROR, flag, gzfile, ok = glzclose(gzfile));
+    GZ_GUARD(1, ok == 0 || ok == Z_BUF_ERROR, flag, gzfile, ok = S_glzclose(gzfile));
   }
   saved_errno = errno;
   REACTIVATE(tc)
@@ -444,7 +422,7 @@ ptr S_bytevector_read(ptr file, ptr bv, iptr start, iptr count, IBOOL gzflag) {
   ptr tc = get_thread_context();
   iptr m, flag = 0;
   INT fd = gzflag ? 0 : GET_FD(file);
-  glzFile gzfile = gzflag ? gzxfile_gzfile(file) : NULL;
+  glzFile gzfile = gzflag ? GZXFILE_GZFILE(file) : NULL;
 
  /* file is not locked; do not reference after deactivating thread! */
   file = (ptr)-1;
@@ -477,7 +455,7 @@ ptr S_bytevector_read(ptr file, ptr bv, iptr start, iptr count, IBOOL gzflag) {
       GZ_EINTR_GUARD(
         1, m >= 0 || Sboolean_value(KEYBOARDINTERRUPTPENDING(tc)),
         flag, gzfile,
-        m = glzread(gzfile, &BVIT(bv,start), (GZ_IO_SIZE_T)count));
+        m = S_glzread(gzfile, &BVIT(bv,start), (GZ_IO_SIZE_T)count));
     }
   }
   saved_errno = errno;
@@ -561,7 +539,7 @@ ptr S_bytevector_write(ptr file, ptr bv, iptr start, iptr count, IBOOL gzflag) {
   ptr tc = get_thread_context();
   INT flag = 0, saved_errno = 0;
   INT fd = gzflag ? 0 : GET_FD(file);
-  glzFile gzfile = gzflag ? gzxfile_gzfile(file) : NULL;
+  glzFile gzfile = gzflag ? GZXFILE_GZFILE(file) : NULL;
 
   for (s = start, c = count; c > 0; s += i, c -= i) {
     iptr cx = c;
@@ -579,7 +557,7 @@ ptr S_bytevector_write(ptr file, ptr bv, iptr start, iptr count, IBOOL gzflag) {
       GZ_EINTR_GUARD(
         i < 0, i > 0 || Sboolean_value(KEYBOARDINTERRUPTPENDING(tc)),
         flag, gzfile,
-        i = glzwrite(gzfile, &BVIT(bv,s), (GZ_IO_SIZE_T)cx));
+        i = S_glzwrite(gzfile, &BVIT(bv,s), (GZ_IO_SIZE_T)cx));
     } else {
       FD_EINTR_GUARD(i >= 0 || Sboolean_value(KEYBOARDINTERRUPTPENDING(tc)),
                      flag, i = WRITE(fd, &BVIT(bv,s), (IO_SIZE_T)cx));
@@ -623,7 +601,7 @@ ptr S_put_byte(ptr file, INT byte, IBOOL gzflag) {
   ptr tc = get_thread_context();
   INT flag = 0, saved_errno = 0;
   INT fd = gzflag ? 0 : GET_FD(file);
-  glzFile gzfile = gzflag ? gzxfile_gzfile(file) : NULL;
+  glzFile gzfile = gzflag ? GZXFILE_GZFILE(file) : NULL;
   octet buf[1];
 
   buf[0] = (octet)byte;
@@ -634,7 +612,7 @@ ptr S_put_byte(ptr file, INT byte, IBOOL gzflag) {
     GZ_EINTR_GUARD(
       i < 0, i > 0 || Sboolean_value(KEYBOARDINTERRUPTPENDING(tc)),
       flag, gzfile,
-      i = glzwrite(gzfile, buf, 1));
+      i = S_glzwrite(gzfile, buf, 1));
   } else {
     FD_EINTR_GUARD(i >= 0 || Sboolean_value(KEYBOARDINTERRUPTPENDING(tc)),
                    flag, i = WRITE(fd, buf, 1));
@@ -664,7 +642,7 @@ ptr S_put_byte(ptr file, INT byte, IBOOL gzflag) {
 ptr S_get_fd_pos(ptr file, IBOOL gzflag) {
   errno = 0;
   if (gzflag) {
-    z_off_t offset = glzseek(gzxfile_gzfile(file), 0, SEEK_CUR);
+    z_off_t offset = S_glzseek(GZXFILE_GZFILE(file), 0, SEEK_CUR);
     if (offset != -1) return Sinteger64(offset);
   } else {
     OFF_T offset = LSEEK(GET_FD(file), 0, SEEK_CUR);
@@ -683,7 +661,7 @@ ptr S_set_fd_pos(ptr file, ptr pos, IBOOL gzflag) {
     if (sizeof(z_off_t) != sizeof(I64))
       if (offset != offset64) return Sstring("invalid position");
     errno = 0;
-    if (glzseek(gzxfile_gzfile(file),offset,SEEK_SET) == offset) return Strue;
+    if (S_glzseek(GZXFILE_GZFILE(file),offset,SEEK_SET) == offset) return Strue;
     if (errno == 0) return Sstring("compression failed");
     return S_strerror(errno);
   } else {
@@ -811,96 +789,115 @@ static int is_valid_lz4_length(iptr len) {
 /* Accept `iptr` because we expect it to represent a bytevector size,
    which always fits in `iptr`. Return `uptr`, because the result might
    not fit in `iptr`. */
-uptr S_bytevector_compress_size(iptr s_count, IBOOL as_gz) {
+uptr S_bytevector_compress_size(iptr s_count, INT compress_format) {
-  if (as_gz) {
+  switch (compress_format) {
-    if (is_valid_zlib_length(s_count))
+    case COMPRESS_GZIP:
-      return compressBound((uLong)s_count);
+      if (is_valid_zlib_length(s_count))
-    else {
+        return compressBound((uLong)s_count);
-      /* Compression will report "source too long" */
+      else {
+        /* Compression will report "source too long" */
+        return 0;
+      }
+    case COMPRESS_LZ4:
+      if (is_valid_lz4_length(s_count))
+        return LZ4_compressBound((uLong)s_count);
+      else {
+        /* Compression will report "source too long" */
+        return 0;
+      }
+    default:
+      S_error1("S_bytevector_compress_size", "unexpected compress format ~s", FIX(compress_format));
       return 0;
-    }
-  } else {
-    if (is_valid_lz4_length(s_count))
-      return LZ4_compressBound((uLong)s_count);
-    else {
-      /* Compression will report "source too long" */
-      return 0;
-    }
   }
 }
 
 ptr S_bytevector_compress(ptr dest_bv, iptr d_start, iptr d_count,
                           ptr src_bv, iptr s_start, iptr s_count,
-                          IBOOL as_gz) {
+                          INT compress_format) {
   /* On error, an message-template string with ~s for the bytevector */
-  if (as_gz) {
+  switch (compress_format) {
-    int r;
+    case COMPRESS_GZIP:
-    uLong destLen;
+      {
-    
+        int r;
-    if (!is_valid_zlib_length(s_count))
+        uLong destLen;
-      return Sstring("source bytevector ~s is too large");
-    
-    destLen = (uLong)d_count;
-    
-    r = compress(&BVIT(dest_bv, d_start), &destLen, &BVIT(src_bv, s_start), (uLong)s_count);
-    
-    if (r == Z_OK)
-      return FIX(destLen);
-    else if (r == Z_BUF_ERROR)
-      return Sstring("destination bytevector is too small for compressed form of ~s");
-    else
-      return Sstring("internal error compressing ~s");
-  } else {
-    int destLen;
 
-    if (!is_valid_lz4_length(s_count))
+        if (!is_valid_zlib_length(s_count))
-      return Sstring("source bytevector ~s is too large");
+          return Sstring("source bytevector ~s is too large");
 
-    destLen = (int)d_count;
+        destLen = (uLong)d_count;
 
-    destLen = LZ4_compress_default((char *)&BVIT(src_bv, s_start), (char *)&BVIT(dest_bv, d_start), (int)s_count, (int)d_count);
+        r = compress(&BVIT(dest_bv, d_start), &destLen, &BVIT(src_bv, s_start), (uLong)s_count);
 
-    if (destLen > 0)
+        if (r == Z_OK)
-      return Sfixnum(destLen);
+          return FIX(destLen);
-    else
+        else if (r == Z_BUF_ERROR)
-      return Sstring("compression failed for ~s");
+          return Sstring("destination bytevector is too small for compressed form of ~s");
+        else
+          return Sstring("internal error compressing ~s");
+      }
+    case COMPRESS_LZ4:
+      {
+        int destLen;
+
+        if (!is_valid_lz4_length(s_count))
+          return Sstring("source bytevector ~s is too large");
+
+        destLen = (int)d_count;
+
+        destLen = LZ4_compress_default((char *)&BVIT(src_bv, s_start), (char *)&BVIT(dest_bv, d_start), (int)s_count, (int)d_count);
+
+        if (destLen > 0)
+          return Sfixnum(destLen);
+        else
+          return Sstring("compression failed for ~s");
+      }
+    default:
+      S_error1("S_bytevector_compress", "unexpected compress format ~s", FIX(compress_format));
+      return Sfalse;
   }
 }
 
 ptr S_bytevector_uncompress(ptr dest_bv, iptr d_start, iptr d_count,
                             ptr src_bv, iptr s_start, iptr s_count,
-                            IBOOL as_gz) {
+                            INT compress_format) {
   /* On error, an message-template string with ~s for the bytevector */
-  if (as_gz) {
+  switch (compress_format) {
-    int r;
+    case COMPRESS_GZIP:
-    uLongf destLen;
+      {
+        int r;
+        uLongf destLen;
 
-    if (!is_valid_zlib_length(d_count))
+        if (!is_valid_zlib_length(d_count))
-      return Sstring("expected result size of uncompressed source ~s is too large");
+          return Sstring("expected result size of uncompressed source ~s is too large");
 
-    destLen = (uLongf)d_count;
+        destLen = (uLongf)d_count;
 
-    r = uncompress(&BVIT(dest_bv, d_start), &destLen, &BVIT(src_bv, s_start), (uLong)s_count);
+        r = uncompress(&BVIT(dest_bv, d_start), &destLen, &BVIT(src_bv, s_start), (uLong)s_count);
 
-    if (r == Z_OK)
+        if (r == Z_OK)
-      return FIX(destLen);
+          return FIX(destLen);
-    else if (r == Z_BUF_ERROR)
+        else if (r == Z_BUF_ERROR)
-      return Sstring("uncompressed ~s is larger than expected size");
+          return Sstring("uncompressed ~s is larger than expected size");
-    else if (r == Z_DATA_ERROR)
+        else if (r == Z_DATA_ERROR)
-      return Sstring("invalid data in source bytevector ~s");
+          return Sstring("invalid data in source bytevector ~s");
-    else
+        else
-      return Sstring("internal error uncompressing ~s");
+          return Sstring("internal error uncompressing ~s");
-  } else {
+      }
-    int r;
+    case COMPRESS_LZ4:
+      {
+        int r;
 
-    if (!is_valid_lz4_length(d_count))
+        if (!is_valid_lz4_length(d_count))
-      return Sstring("expected result size of uncompressed source ~s is too large");
+          return Sstring("expected result size of uncompressed source ~s is too large");
 
-    r = LZ4_decompress_safe((char *)&BVIT(src_bv, s_start), (char *)&BVIT(dest_bv, d_start), (int)s_count, (int)d_count);
+        r = LZ4_decompress_safe((char *)&BVIT(src_bv, s_start), (char *)&BVIT(dest_bv, d_start), (int)s_count, (int)d_count);
 
-    if (r >= 0)
+        if (r >= 0)
-      return Sfixnum(r);
+          return Sfixnum(r);
-    else
+        else
-      return Sstring("internal error uncompressing ~s");
+          return Sstring("internal error uncompressing ~s");
+      }
+    default:
+      return Sstring("unepxected compress format ~s");
   }
 }

c/scheme.c

@@ -585,17 +585,17 @@ static IBOOL find_boot(name, ext, fd, errorp) const char *name, *ext; int fd; IB
     path = name;
 
     if (fd != -1) {
-      file = glzdopen(fd, "rb");
+      file = S_glzdopen_input(fd);
     } else {
 #ifdef WIN32
       expandedpath = S_malloc_wide_pathname(path);
-      file = glzopen_w(expandedpath, "rb");
+      file = S_glzopen_input_w(expandedpath);
 #else
       expandedpath = S_malloc_pathname(path);
-      file = glzopen(expandedpath, "rb");
+      file = S_glzopen_input(expandedpath);
 #endif
       /* assumption (seemingly true based on a glance at the source code):
-         glzopen doesn't squirrel away a pointer to expandedpath. */
+         S_glzopen_input doesn't squirrel away a pointer to expandedpath. */
       free(expandedpath);
     }
 
@@ -611,14 +611,14 @@ static IBOOL find_boot(name, ext, fd, errorp) const char *name, *ext; int fd; IB
     if (verbose) fprintf(stderr, "trying %s...opened\n", path);
 
    /* check for magic number */
-    if (glzgetc(file) != fasl_type_header ||
+    if (S_glzgetc(file) != fasl_type_header ||
-        glzgetc(file) != 0 ||
+        S_glzgetc(file) != 0 ||
-        glzgetc(file) != 0 ||
+        S_glzgetc(file) != 0 ||
-        glzgetc(file) != 0 ||
+        S_glzgetc(file) != 0 ||
-        glzgetc(file) != 'c' ||
+        S_glzgetc(file) != 'c' ||
-        glzgetc(file) != 'h' ||
+        S_glzgetc(file) != 'h' ||
-        glzgetc(file) != 'e' ||
+        S_glzgetc(file) != 'e' ||
-        glzgetc(file) != 'z') {
+        S_glzgetc(file) != 'z') {
       fprintf(stderr, "malformed fasl-object header in %s\n", path);
       S_abnormal_exit();
     }
@@ -626,7 +626,7 @@ static IBOOL find_boot(name, ext, fd, errorp) const char *name, *ext; int fd; IB
    /* check version */
     if (zget_uptr(file, &n) != 0) {
       fprintf(stderr, "unexpected end of file on %s\n", path);
-      glzclose(file);
+      S_glzclose(file);
       S_abnormal_exit();
     }
 
@@ -634,21 +634,21 @@ static IBOOL find_boot(name, ext, fd, errorp) const char *name, *ext; int fd; IB
       fprintf(stderr, "%s is for Version %s; ", path, S_format_scheme_version(n));
      /* use separate fprintf since S_format_scheme_version returns static string */
       fprintf(stderr, "need Version %s\n", S_format_scheme_version(scheme_version));
-      glzclose(file);
+      S_glzclose(file);
       S_abnormal_exit();
     }
 
    /* check machine type */
     if (zget_uptr(file, &n) != 0) {
       fprintf(stderr, "unexpected end of file on %s\n", path);
-      glzclose(file);
+      S_glzclose(file);
       S_abnormal_exit();
     }
 
     if (n != machine_type) {
       fprintf(stderr, "%s is for machine-type %s; need machine-type %s\n", path,
               S_lookup_machine_type(n), S_lookup_machine_type(machine_type));
-      glzclose(file);
+      S_glzclose(file);
       S_abnormal_exit();
     }
   } else {
@@ -671,13 +671,13 @@ static IBOOL find_boot(name, ext, fd, errorp) const char *name, *ext; int fd; IB
 
 #ifdef WIN32
       expandedpath = S_malloc_wide_pathname(path);
-      file = glzopen_w(expandedpath, "rb");
+      file = S_glzopen_input_w(expandedpath);
 #else
       expandedpath = S_malloc_pathname(path);
-      file = glzopen(expandedpath, "rb");
+      file = S_glzopen_input(expandedpath);
 #endif
       /* assumption (seemingly true based on a glance at the source code):
-         glzopen doesn't squirrel away a pointer to expandedpath. */
+         S_glzopen_input doesn't squirrel away a pointer to expandedpath. */
       free(expandedpath);
       if (!file) {
         if (verbose) fprintf(stderr, "trying %s...cannot open\n", path);
@@ -687,23 +687,23 @@ static IBOOL find_boot(name, ext, fd, errorp) const char *name, *ext; int fd; IB
       if (verbose) fprintf(stderr, "trying %s...opened\n", path);
 
      /* check for magic number */
-      if (glzgetc(file) != fasl_type_header ||
+      if (S_glzgetc(file) != fasl_type_header ||
-          glzgetc(file) != 0 ||
+          S_glzgetc(file) != 0 ||
-          glzgetc(file) != 0 ||
+          S_glzgetc(file) != 0 ||
-          glzgetc(file) != 0 ||
+          S_glzgetc(file) != 0 ||
-          glzgetc(file) != 'c' ||
+          S_glzgetc(file) != 'c' ||
-          glzgetc(file) != 'h' ||
+          S_glzgetc(file) != 'h' ||
-          glzgetc(file) != 'e' ||
+          S_glzgetc(file) != 'e' ||
-          glzgetc(file) != 'z') {
+          S_glzgetc(file) != 'z') {
         if (verbose) fprintf(stderr, "malformed fasl-object header in %s\n", path);
-        glzclose(file);
+        S_glzclose(file);
         continue;
       }
 
      /* check version */
       if (zget_uptr(file, &n) != 0) {
         if (verbose) fprintf(stderr, "unexpected end of file on %s\n", path);
-        glzclose(file);
+        S_glzclose(file);
         continue;
       }
 
@@ -713,14 +713,14 @@ static IBOOL find_boot(name, ext, fd, errorp) const char *name, *ext; int fd; IB
          /* use separate fprintf since S_format_scheme_version returns static string */
           fprintf(stderr, "need Version %s\n", S_format_scheme_version(scheme_version));
         }
-        glzclose(file);
+        S_glzclose(file);
         continue;
       }
 
      /* check machine type */
       if (zget_uptr(file, &n) != 0) {
         if (verbose) fprintf(stderr, "unexpected end of file on %s\n", path);
-        glzclose(file);
+        S_glzclose(file);
         continue;
       }
 
@@ -728,7 +728,7 @@ static IBOOL find_boot(name, ext, fd, errorp) const char *name, *ext; int fd; IB
         if (verbose)
           fprintf(stderr, "%s is for machine-type %s; need machine-type %s\n", path,
                   S_lookup_machine_type(n), S_lookup_machine_type(machine_type));
-        glzclose(file);
+        S_glzclose(file);
         continue;
       }
 
@@ -738,56 +738,56 @@ static IBOOL find_boot(name, ext, fd, errorp) const char *name, *ext; int fd; IB
 
   if (verbose) fprintf(stderr, "version and machine type check\n");
 
-  if (glzgetc(file) != '(') {  /* ) */
+  if (S_glzgetc(file) != '(') {  /* ) */
     fprintf(stderr, "malformed boot file %s\n", path);
-    glzclose(file);
+    S_glzclose(file);
     S_abnormal_exit();
   }
 
   /* ( */
-  if ((c = glzgetc(file)) == ')') {
+  if ((c = S_glzgetc(file)) == ')') {
     if (boot_count != 0) {
       fprintf(stderr, "base boot file %s must come before other boot files\n", path);
-      glzclose(file);
+      S_glzclose(file);
       S_abnormal_exit();
     }
   } else {
     if (boot_count == 0) {
       for (;;) {
-        glzungetc(c, file);
+        S_glzungetc(c, file);
        /* try to load heap or boot file this boot file requires */
         if (zgetstr(file, buf, PATH_MAX) != 0) {
           fprintf(stderr, "unexpected end of file on %s\n", path);
-          glzclose(file);
+          S_glzclose(file);
           S_abnormal_exit();
         }
         if (find_boot(buf, ".boot", -1, 0)) break;
-        if ((c = glzgetc(file)) == ')') {
+        if ((c = S_glzgetc(file)) == ')') {
           char *sep; char *wastebuf[8];
           fprintf(stderr, "cannot find subordinate boot file ");
-          glzrewind(file);
+          S_glzrewind(file);
-          (void) glzread(file, wastebuf, 8); /* magic number */
+          (void) S_glzread(file, wastebuf, 8); /* magic number */
           (void) zget_uptr(file, &n); /* version */
           (void) zget_uptr(file, &n); /* machine type */
-          (void) glzgetc(file);        /* open paren */
+          (void) S_glzgetc(file);        /* open paren */
           for (sep = ""; ; sep = "or ") {
-            if ((c = glzgetc(file)) == ')') break;
+            if ((c = S_glzgetc(file)) == ')') break;
-            glzungetc(c, file);
+            S_glzungetc(c, file);
             (void) zgetstr(file, buf, PATH_MAX);
             fprintf(stderr, "%s%s.boot ", sep, buf);
           }
           fprintf(stderr, "required by %s\n", path);
-          glzclose(file);
+          S_glzclose(file);
           S_abnormal_exit();
         }
       }
     }
 
    /* skip to end of header */
-    while ((c = glzgetc(file)) != ')') {
+    while ((c = S_glzgetc(file)) != ')') {
       if (c < 0) {
         fprintf(stderr, "malformed boot file %s\n", path);
-        glzclose(file);
+        S_glzclose(file);
         S_abnormal_exit();
       }
     }
@@ -808,11 +808,11 @@ static IBOOL find_boot(name, ext, fd, errorp) const char *name, *ext; int fd; IB
 static uptr zget_uptr(glzFile file, uptr *pn) {
   uptr n, m; int c; octet k;
 
-  if ((c = glzgetc(file)) < 0) return -1;
+  if ((c = S_glzgetc(file)) < 0) return -1;
   k = (octet)c;
   n = k >> 1;
   while (k & 1) {
-    if ((c = glzgetc(file)) < 0) return -1;
+    if ((c = S_glzgetc(file)) < 0) return -1;
     k = (octet)c;
     m = n << 7;
     if (m >> 7 != n) return -1;
@@ -826,9 +826,9 @@ static INT zgetstr(file, s, max) glzFile file; char *s; iptr max; {
   ICHAR c;
 
   while (max-- > 0) {
-    if ((c = glzgetc(file)) < 0) return -1;
+    if ((c = S_glzgetc(file)) < 0) return -1;
     if (c == ' ' || c == ')') {
-      if (c == ')') glzungetc(c, file);
+      if (c == ')') S_glzungetc(c, file);
       *s = 0;
       return 0;
     }
@@ -923,7 +923,7 @@ static void load(tc, n, base) ptr tc; iptr n; IBOOL base; {
   }
 
   S_G.load_binary = Sfalse;
-  glzclose(bd[n].file);
+  S_glzclose(bd[n].file);
 }
 
 /***************************************************************************/
@@ -1137,6 +1137,8 @@ extern void Sbuild_heap(kernel, custom_init) const char *kernel; void (*custom_i
     /* #scheme-init enables interrupts */
     TRAP(tc) = (ptr)most_positive_fixnum;
     DISABLECOUNT(tc) = Sfixnum(1);
+    COMPRESSFORMAT(tc) = FIX(COMPRESS_LZ4);
+    COMPRESSLEVEL(tc) = FIX(COMPRESS_MEDIUM);
 
     load(tc, i++, 1);
     S_boot_time = 0;

c/system.h

@@ -24,13 +24,14 @@
 
 #include "version.h"
 #include <stdio.h>
-#include "compress-io.h"
 #include <stddef.h>
 
 #include "thread.h"
 
 #include "types.h"
 
+#include "compress-io.h"
+
 #ifndef EXTERN
 #define EXTERN extern
 #endif

c/thread.c

@@ -121,6 +121,8 @@ ptr S_create_thread_object(who, p_tc) const char *who; ptr p_tc; {
 
   GUARDIANENTRIES(tc) = Snil;
 
+  LZ4OUTBUFFER(tc) = NULL;
+
   tc_mutex_release()
 
   return thread;
@@ -224,7 +226,9 @@ static IBOOL destroy_thread(tc) ptr tc; {
         }
       }
 
-      free((void *)THREADTC(thread));
+      if (LZ4OUTBUFFER(tc) != NULL) free(LZ4OUTBUFFER(tc));
+
+      free((void *)tc);
       THREADTC(thread) = 0; /* mark it dead */
       status = 1;
       break;

checkin

@@ -294,7 +294,7 @@ endif
 
 delete:
 
-set tmpfiles = `(cd $W; find . -name zlib -prune -o -type f -print)`
+set tmpfiles = `(cd $W; find . -name zlib -prune -o -name lz4 -prune -o -type f -print)`
 set files = ()
 foreach x ($tmpfiles)
     set files = ($x $files)

csug/io.stex

@@ -208,8 +208,10 @@ Section~\ref{TSPL:SECTOPENINGFILES} of {\TSPLFOUR}.
 \item[\var{compressed}:]
 An output file should be compressed when written; and a compressed input
 file should be decompressed when read. The compression format for output
-is determined by the \scheme{compress-format} parameter, while the compression
+is determined by the \index{\scheme{compress-format}}\scheme{compress-format}
-format on input is inferred.
+parameter, while the compression format on input is inferred.
+The compression level, which is relevant only for output, is determined
+by the \index{\scheme{compress-level}}\scheme{compress-level} parameter.
 
 \item[\var{replace}:]
 For output files only, replace (remove and recreate) the existing file if
@@ -975,8 +977,10 @@ will be compressed.
 If the port is an input port, subsequent input will be decompressed
 if and only if the port is currently pointing at compressed data.
 The compression format for output
-is determined by the \scheme{compress-format} parameter, while the compression
+is determined by the \index{\scheme{compress-format}}\scheme{compress-format}
-format on input is inferred.
+parameter, while the compression format on input is inferred.
+The compression level, which is relevant only for output, is determined
+by the \index{\scheme{compress-level}}\scheme{compress-level} parameter.
 This procedure has no effect if the port is already set for compression.
 
 %----------------------------------------------------------------------------
@@ -986,23 +990,41 @@ This procedure has no effect if the port is already set for compression.
 \endnoskipentryheader
 
 \noindent
-\scheme{compress-format} is a parameter that determines the
+\scheme{compress-format} determines the
-compression algorithm and format that is used for output. Currently,
+compression algorithm and format used for output. Currently,
-the possible values of the parameter are \scheme{'lz4} (the default)
+the possible values of the parameter are the symbols \scheme{lz4} (the default)
-and \scheme{'gzip}.
+and \scheme{gzip}.
 
-The \scheme{'lz4} format uses the LZ4 compression library developed by
+The \scheme{lz4} format uses the LZ4 compression library developed by
 Yann Collet.
 It is therefore compatible with the \scheme{lz4} program, which
 means that \scheme{lz4} may be used to uncompress files produced
 by {\ChezScheme} and visa versa.
 
-The \scheme{'gzip} format uses the zlib compression library developed by
+The \scheme{gzip} format uses the zlib compression library developed by
 Jean-loup Gailly and Mark Adler.
 It is therefore compatible with the \scheme{gzip} program, which
 means that \scheme{gzip} may be used to uncompress files produced
 by {\ChezScheme} and visa versa.
 
+Reading \scheme{lz4}-compressed data tends to be much faster than reading
+\scheme{gzip}-compressed data, while \scheme{gzip}-compressed data tends to 
+be significantly smaller.
+
+%----------------------------------------------------------------------------
+\entryheader
+\formdef{compress-level}{\categorythreadparameter}{compress-level}
+\listlibraries
+\endnoskipentryheader
+
+\noindent
+\scheme{compress-level} determines the amount of effort spent on
+compression and is thus relevant only for output.
+It can be set to one of the symbols \scheme{low},
+\scheme{medium}, \scheme{high}, or \scheme{maximum}, which are
+listed in order from shortest to longest expected compression time
+and least to greatest expected effectiveness.
+Its default value is \scheme{medium}.
 
 \section{String Ports\label{SECTIOSTRINGPORTS}}
 
@@ -1858,7 +1880,11 @@ The default behavior is to raise an exception.
 The mutually exclusive \scheme{compressed} and
 \scheme{uncompressed} options determine whether the output file is to
 be compressed.
-The compression format is determined by the \scheme{compress-format} parameter.
+The compression format and level are determined by the
+\index{\scheme{compress-format}}\scheme{compress-format}
+and
+\index{\scheme{compress-level}}\scheme{compress-level}
+parameters.
 Files are uncompressed by default, so the \scheme{uncompressed}
 option is useful only as documentation.
 

csug/objects.stex

@@ -1179,7 +1179,12 @@ The result is the raw compressed data with a minimal header to record
 the uncompressed size and the compression mode. The result does not include
 the header that is written by port-based compression using the
 \scheme{compressed} option. The compression format is determined by the
-\scheme{compress-format} parameter.
+\index{\scheme{compress-format}}\scheme{compress-format}
+parameter.
+The compression level is fixed to some default determined by the
+format; it is not affected by the
+\index{\scheme{compress-level}}\scheme{compress-level}
+parameter.
 
 
 %----------------------------------------------------------------------------

csug/system.stex

@@ -2471,6 +2471,11 @@ When this parameter is \scheme{#t}, the default, \scheme{compile-file},
 \scheme{compile-program}, \scheme{compile-to-file},
 \scheme{compile-whole-program}, and \scheme{strip-fasl-file} compress
 the object files they create.
+The compression format and level are determined by the
+\index{\scheme{compress-format}}\scheme{compress-format}
+and
+\index{\scheme{compress-level}}\scheme{compress-level}
+parameters.
 
 
 %----------------------------------------------------------------------------

csug/threads.stex

@@ -208,6 +208,16 @@ continuation invocation, the mutex is reacquired.
 Using \scheme{with-mutex} is generally more convenient and safer than using
 \scheme{mutex-acquire} and \scheme{mutex-release} directly.
 
+%----------------------------------------------------------------------------
+\entryheader
+\formdef{mutex-name}{\categoryprocedure}{(mutex-name \var{mutex})}
+\returns the name associated with \var{mutex}, if any; otherwise \scheme{#f}
+\listlibraries
+\endentryheader
+
+\noindent
+\var{mutex} must be a mutex.
+
 \section{Conditions}
 
 %----------------------------------------------------------------------------
@@ -284,6 +294,16 @@ condition identified by \var{cond}.
 \scheme{condition-broadcast} releases all of the threads waiting for the
 condition identified by \var{cond}.
 
+%----------------------------------------------------------------------------
+\entryheader
+\formdef{condition-name}{\categoryprocedure}{(condition-name \var{condition})}
+\returns the name associated with \var{condition}, if any; otherwise \scheme{#f}
+\listlibraries
+\endentryheader
+
+\noindent
+\var{condition} must be a condition.
+
 \section{Locks\label{SECTTHREADLOCKS}}
 
 \index{locks}%

mats/bytevector.ms

@@ -11277,7 +11277,7 @@
 
 
 (mat bytevector-compress
-    (parameters [compress-format 'gzip] [compress-format 'lz4])
+    (parameters [compress-format 'gzip 'lz4])
     (error? (bytevector-compress 7))
     (error? (bytevector-compress "hello"))
     (error? (bytevector-uncompress 7))
@@ -11300,19 +11300,6 @@
     (error?
      ;; Need at least 8 bytes for result size
      (bytevector-uncompress '#vu8(0 0 0 0 0 0 255)))
-    (error?
-     ;; Fail if the uncompressed result is too big
-     (bytevector-uncompress (let ([bv (bytevector-compress (string->utf8 "hello"))])
-                              (bytevector-u64-set! bv 0 (sub1 (bytevector-u64-ref bv 0 (endianness big))) (endianness big))
-                              bv)))
-    (error?
-     ;; Fail if the uncompressed result is too small
-     (bytevector-uncompress (let ([bv (bytevector-compress (string->utf8 "hello"))])
-                              (bytevector-u64-set! bv 0 (add1 (bytevector-u64-ref bv 0 (endianness big)))  (endianness big))
-                              bv)))
-    (error?
-     ;; Compressed data always starts with 0x78, so this one isn't valid:
-     (bytevector-uncompress '#vu8(0 0 0 0 0 0 0 255 1 2 3)))
     (error?
      ;; Claming a too-large size in the header should fail with a suitable message:
      (bytevector-uncompress '#vu8(255 255 255 255 255 255 255 255 1 2 3)))

mats/io.ms

@@ -2126,8 +2126,63 @@
         (= q (custom-port-buffer-size)))))
 )
 
+(mat compress-parameters
+  (error? ; unsupported format
+    (compress-format 'foo))
+  (error? ; unsupported format
+    (compress-format "gzip"))
+  (eq? (compress-format) 'lz4)
+  (eq? (parameterize ([compress-format 'gzip]) (compress-format)) 'gzip)
+  (eq? (parameterize ([compress-format 'lz4]) (compress-format)) 'lz4)
+  (error? ; unsupported level
+    (compress-level 'foo))
+  (error? ; unsupported level
+    (compress-level 1))
+  (eq? (compress-level) 'medium)
+  (eq? (parameterize ([compress-level 'low]) (compress-level)) 'low)
+  (eq? (parameterize ([compress-level 'medium]) (compress-level)) 'medium)
+  (eq? (parameterize ([compress-level 'high]) (compress-level)) 'high)
+  (eq? (parameterize ([compress-level 'maximum]) (compress-level)) 'maximum)
+  (begin
+    (define (fnlength ifn) (call-with-port (open-file-input-port ifn) port-length))
+    (define (compress-file ifn ofn fmt lvl)
+      (call-with-port (open-file-input-port ifn)
+        (lambda (ip)
+          (call-with-port (parameterize ([compress-format fmt] [compress-level lvl])
+                            (open-file-output-port ofn (file-options compressed replace)))
+            (lambda (op) (put-bytevector op (get-bytevector-all ip))))))
+      (fnlength ofn))
+    (define (compress-file-test fmt)
+      (let ([orig (fnlength "prettytest.ss")]
+            [low (compress-file "prettytest.ss" "testfile.ss" fmt 'low)]
+            [medium (compress-file "prettytest.ss" "testfile.ss" fmt 'medium)]
+            [high (compress-file "prettytest.ss" "testfile.ss" fmt 'high)]
+            [maximum (compress-file "prettytest.ss" "testfile.ss" fmt 'maximum)])
+        (define-syntax test1
+          (syntax-rules ()
+            [(_ level)
+             (unless (< level orig) (errorf #f "~s ~s did not compress" fmt 'level))]))
+        (define-syntax test2
+          (syntax-rules ()
+            [(_ level1 level2)
+             (unless (<= level2 level1) (errorf #f "~s ~s did worse than ~s" fmt 'level2 'level1))]))
+        (test1 low)
+        (test1 medium)
+        (test1 high)
+        (test1 maximum)
+        (test2 low medium)
+        (test2 medium high)
+        (test2 high maximum)
+        (unless (< maximum low) (errorf #f "~s maximum didn't do better than low" fmt))))
+    (compress-file-test 'lz4)
+    (compress-file-test 'gzip)
+    #t)
+)
+
 (mat compression
-  (parameters [compress-format 'gzip] [compress-format 'lz4])
+  (parameters [compress-format 'gzip 'lz4] [compress-level 'low 'medium 'high 'maximum])
+  (and (memq (compress-format) '(gzip lz4)) #t)
+  (and (memq (compress-level) '(low medium high maximum)) #t)
   (let ()
     (define cp
       (lambda (src dst)
@@ -3072,7 +3127,7 @@
 )
 
 (mat compression-textual
-  (parameters [compress-format 'gzip] [compress-format 'lz4])
+  (parameters [compress-format 'gzip 'lz4] [compress-level 'low 'medium 'high 'maximum])
   (let ()
     (define cp
       (lambda (src dst)

mats/mat.ss

@@ -20,12 +20,16 @@
   (define-syntax mat
     (lambda (x)
       (syntax-case x (parameters)
-        [(_ x (parameters [param val] ...) e ...)
+        [(_ x (parameters [param val ...] ...) e ...)
-         #'(for-each (lambda (p v)
+         #'(let f ([p* (list param ...)] [v** (list (list val ...) ...)])
+             (if (null? p*)
+                 (mat x e ...)
+                 (let ([p (car p*)])
+                   (for-each
+                     (lambda (v)
                        (parameterize ([p v])
-                         (mat x e ...)))
+                         (f (cdr p*) (cdr v**))))
-                     (list param ...)
+                     (car v**)))))]
-                     (list val ...))]
         [(_ x e ...)
          (with-syntax ([(source ...)
                         (map (lambda (clause)

mats/root-experr-compile-0-f-f-f

@@ -3626,9 +3626,6 @@ bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress:
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: "hello" is not a bytevector".
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: invalid data in source bytevector #vu8()".
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: invalid data in source bytevector #vu8(0 0 0 0 0 0 ...)".
-bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: uncompressed #vu8(0 0 0 0 0 0 ...) is larger than expected size".
-bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: uncompressed size 5 for #vu8(0 0 0 0 0 0 ...) is smaller than expected size 6".
-bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: invalid data in source bytevector #vu8(0 0 0 0 0 0 ...)".
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: bytevector #vu8(255 255 255 255 255 255 ...) claims invalid uncompressed size <int>".
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-compress: 7 is not a bytevector".
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-compress: "hello" is not a bytevector".
@@ -3636,9 +3633,6 @@ bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress:
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: "hello" is not a bytevector".
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: invalid data in source bytevector #vu8()".
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: invalid data in source bytevector #vu8(0 0 0 0 0 0 ...)".
-bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: internal error uncompressing #vu8(128 0 0 0 0 0 ...)".
-bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: uncompressed size 5 for #vu8(128 0 0 0 0 0 ...) is smaller than expected size 6".
-bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: invalid data in source bytevector #vu8(0 0 0 0 0 0 ...)".
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: bytevector #vu8(255 255 255 255 255 255 ...) claims invalid uncompressed size <int>".
 misc.mo:Expected error in mat compiler1: "variable i-am-not-bound is not bound".
 misc.mo:Expected error in mat compiler1: "attempt to apply non-procedure oops".
@@ -6798,6 +6792,22 @@ io.mo:Expected error in mat custom-port-buffer-size: "custom-port-buffer-size: 0
 io.mo:Expected error in mat custom-port-buffer-size: "custom-port-buffer-size: -15 is not a positive fixnum".
 io.mo:Expected error in mat custom-port-buffer-size: "custom-port-buffer-size: <int> is not a positive fixnum".
 io.mo:Expected error in mat custom-port-buffer-size: "custom-port-buffer-size: 1024.0 is not a positive fixnum".
+io.mo:Expected error in mat compress-parameters: "compress-format: foo is not a supported format".
+io.mo:Expected error in mat compress-parameters: "compress-format: "gzip" is not a supported format".
+io.mo:Expected error in mat compress-parameters: "compress-level: foo is not a supported level".
+io.mo:Expected error in mat compress-parameters: "compress-level: 1 is not a supported level".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
 io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
 io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
 io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".

mats/root-experr-compile-2-f-f-f

@@ -3626,8 +3626,12 @@ bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress:
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: "hello" is not a bytevector".
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: invalid data in source bytevector #vu8()".
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: invalid data in source bytevector #vu8(0 0 0 0 0 0 ...)".
-bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: uncompressed #vu8(0 0 0 0 0 0 ...) is larger than expected size".
+bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: bytevector #vu8(255 255 255 255 255 255 ...) claims invalid uncompressed size <int>".
-bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: uncompressed size 5 for #vu8(0 0 0 0 0 0 ...) is smaller than expected size 6".
+bytevector.mo:Expected error in mat bytevector-compress: "bytevector-compress: 7 is not a bytevector".
+bytevector.mo:Expected error in mat bytevector-compress: "bytevector-compress: "hello" is not a bytevector".
+bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: 7 is not a bytevector".
+bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: "hello" is not a bytevector".
+bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: invalid data in source bytevector #vu8()".
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: invalid data in source bytevector #vu8(0 0 0 0 0 0 ...)".
 bytevector.mo:Expected error in mat bytevector-compress: "bytevector-uncompress: bytevector #vu8(255 255 255 255 255 255 ...) claims invalid uncompressed size <int>".
 misc.mo:Expected error in mat compiler1: "variable i-am-not-bound is not bound".
@@ -6788,6 +6792,24 @@ io.mo:Expected error in mat custom-port-buffer-size: "custom-port-buffer-size: 0
 io.mo:Expected error in mat custom-port-buffer-size: "custom-port-buffer-size: -15 is not a positive fixnum".
 io.mo:Expected error in mat custom-port-buffer-size: "custom-port-buffer-size: <int> is not a positive fixnum".
 io.mo:Expected error in mat custom-port-buffer-size: "custom-port-buffer-size: 1024.0 is not a positive fixnum".
+io.mo:Expected error in mat compress-parameters: "compress-format: foo is not a supported format".
+io.mo:Expected error in mat compress-parameters: "compress-format: "gzip" is not a supported format".
+io.mo:Expected error in mat compress-parameters: "compress-level: foo is not a supported level".
+io.mo:Expected error in mat compress-parameters: "compress-level: 1 is not a supported level".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
+io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
+io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
 io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
 io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
 io.mo:Expected error in mat bytevector-input-port: "incorrect argument count in call (open-bytevector-input-port)".

release_notes/release_notes.stex

@@ -58,16 +58,29 @@ Online versions of both books can be found at
 %-----------------------------------------------------------------------------
 \section{Functionality Changes}\label{section:functionality}
 
-\subsection{Compression format (9.5.3)}
+\subsection{Compression format and level (9.5.3)}
 
-The default format for compressed-file writing is now LZ4, while {\tt
+Support for LZ4 compression has been added.
+LZ4 is now the default format when compressing files (including
+object files produced by the compiler) and bytevectors, while {\tt
 gzip} is still supported and can be enabled by setting
-\scheme{compress-format} to \scheme{'gzip}. Reading in compressed mode
+the new \scheme{compress-format} parameter to the symbol \scheme{gzip} instead of the
+default \scheme{lz4}.  Reading in compressed mode
 infers the format, so reading {\tt gzip}-compressed files will still
-work without changing \scheme{compress-format}. Reading LZ4-format
+work without changing \scheme{compress-format}.  Reading LZ4-format
-files tends to be much faster than reading {\tt gzip}-format files, in
+files tends to be much faster than reading {\tt gzip}-format files,
-most cases nearly eliminating the load-time cost of compressing
+while {\tt gzip}-compressed files tend to be smaller.
-compiled files.
+In particular, object files created by the compiler now tend to be
+larger but load more quickly.
+
+The new \scheme{compress-level} parameter can be used to control
+the amount of time spent on file compression (but not
+bytevector compression).
+It can be set to one of the symbols \scheme{low},
+\scheme{medium}, \scheme{high}, and \scheme{maximum}, which are
+listed in order from shortest to longest compression time and least
+to greatest effectiveness.
+The default value is \scheme{medium}.
 
 \subsection{Mutexes and condition variables can have names (9.5.3)}
 

s/Mf-base

@@ -24,15 +24,23 @@ o = 3
 # d is the debug level at which the system should be built
 d = 0
 
-# cl (xcl) determines the commonization level
+# cl determines the commonization level
 cl = (commonization-level)
 
 # i determines whether inspector-information is generated: f for false, t for true
 i = f
 
-# cp0 (xcp0) determines the number of cp0 (source optimizer) iterations run
+# cp0 determines the number of cp0 (source optimizer) iterations run
 cp0 = 2
-xcp0 = 2
+
+# cc determines whether compiled files are compressed
+cc = t
+
+# xf determines the compression foramt
+xf = (compress-format)
+
+# xl determine the compression level
+xl = (compress-level)
 
 # p (xp) determines whether source profiling is enabled: f for false, t for true.
 p = f
@@ -214,6 +222,9 @@ clean: profileclean
              '(optimize-level $o)'\
              '(debug-level $d)'\
              '(commonization-level $(cl))'\
+             '(compile-compressed #$(cc))'\
+             '(compress-format $(xf))'\
+             '(compress-level $(xl))'\
              '(when #$p (compile-profile (quote source)))'\
              '(when #$(bp) (compile-profile (quote block)))'\
              '(when #$(loadspd) (profile-load-data "${ProfileDumpSource}"))'\
@@ -238,6 +249,9 @@ clean: profileclean
              '(optimize-level $o)'\
              '(debug-level $d)'\
              '(commonization-level $(cl))'\
+             '(compile-compressed #$(cc))'\
+             '(compress-format $(xf))'\
+             '(compress-level $(xl))'\
              '(when #$p (compile-profile (quote source)))'\
              '(when #$(bp) (compile-profile (quote block)))'\
              '(when #$(loadspd) (profile-load-data "${ProfileDumpSource}"))'\
@@ -265,6 +279,9 @@ clean: profileclean
              '(optimize-level $o)'\
              '(debug-level $d)'\
              '(commonization-level $(cl))'\
+             '(compile-compressed #$(cc))'\
+             '(compress-format $(xf))'\
+             '(compress-level $(xl))'\
              '(generate-inspector-information #$i)'\
              '(subset-mode (quote system))'\
              '(compile-file "$*.ss" "$*.so")'\
@@ -275,6 +292,9 @@ clean: profileclean
              '(optimize-level $o)'\
              '(debug-level $d)'\
              '(commonization-level $(cl))'\
+             '(compile-compressed #$(cc))'\
+             '(compress-format $(xf))'\
+             '(compress-level $(xl))'\
              '(when #$(xp) (compile-profile (quote source)))'\
              '(when #$(xbp) (compile-profile (quote block)))'\
              '(generate-inspector-information #$i)'\
@@ -344,6 +364,9 @@ cmacros.so: cmacros.ss machine.def layout.ss
              '(optimize-level $o)'\
              '(debug-level $d)'\
              '(commonization-level $(cl))'\
+             '(compile-compressed #$(cc))'\
+             '(compress-format $(xf))'\
+             '(compress-level $(xl))'\
              '(generate-inspector-information #$i)'\
              '(subset-mode (quote system))'\
              '(compile-file "$*.ss" "$*.so")'\
@@ -356,6 +379,9 @@ priminfo.so: priminfo.ss primdata.ss cmacros.so
              '(optimize-level $o)'\
              '(debug-level $d)'\
              '(commonization-level $(cl))'\
+             '(compile-compressed #$(cc))'\
+             '(compress-format $(xf))'\
+             '(compress-level $(xl))'\
              '(generate-inspector-information #$i)'\
              '(subset-mode (quote system))'\
              '(compile-file "$*.ss" "$*.so")'\
@@ -369,6 +395,9 @@ mkheader.so: mkheader.ss cmacros.so primvars.so env.so
              '(optimize-level $o)'\
              '(debug-level $d)'\
              '(commonization-level $(cl))'\
+             '(compile-compressed #$(cc))'\
+             '(compress-format $(xf))'\
+             '(compress-level $(xl))'\
              '(generate-inspector-information #$i)'\
              '(subset-mode (quote system))'\
              '(compile-file "$*.ss" "$*.so")'\
@@ -381,6 +410,9 @@ nanopass.so: $(shell echo ../nanopass/nanopass/*) ../nanopass/nanopass.ss
              '(optimize-level $o)'\
              '(debug-level $d)'\
              '(commonization-level $(cl))'\
+             '(compile-compressed #$(cc))'\
+             '(compress-format $(xf))'\
+             '(compress-level $(xl))'\
              '(generate-inspector-information #$i)'\
              '(collect-trip-bytes (expt 2 24))'\
              '(collect-request-handler (lambda () (collect 0 1)))'\
@@ -404,6 +436,9 @@ script.all makescript:
              '(optimize-level $o)'\
              '(debug-level $d)'\
              '(commonization-level $(cl))'\
+             '(compile-compressed #$(cc))'\
+             '(compress-format $(xf))'\
+             '(compress-level $(xl))'\
              '(when #$p (compile-profile (quote source)))'\
              '(when #$(bp) (compile-profile (quote block)))'\
              '(when #$(loadspd) (profile-load-data "${ProfileDumpSource}"))'\
@@ -440,6 +475,9 @@ script-static.all:
              '(optimize-level $o)'\
              '(debug-level $d)'\
              '(commonization-level $(cl))'\
+             '(compile-compressed #$(cc))'\
+             '(compress-format $(xf))'\
+             '(compress-level $(xl))'\
              '(when #$p (compile-profile (quote source)))'\
              '(when #$(bp) (compile-profile (quote block)))'\
              '(generate-inspector-information #$i)'\
@@ -462,6 +500,9 @@ script-dynamic.all:
              '(optimize-level $o)'\
              '(debug-level $d)'\
              '(commonization-level $(cl))'\
+             '(compile-compressed #$(cc))'\
+             '(compress-format $(xf))'\
+             '(compress-level $(xl))'\
              '(when #$p (compile-profile (quote source)))'\
              '(when #$(bp) (compile-profile (quote block)))'\
              '(generate-inspector-information #$i)'\

s/back.ss

@@ -156,12 +156,38 @@
       x)))
 
 (define-who compress-format
-  ($make-thread-parameter
+  (case-lambda
-    'lz4
+    [()
-    (lambda (x)
+     (let ([x ($tc-field 'compress-format ($tc))])
-      (unless (or (eq? x 'lz4) (eq? x 'gzip))
+       (cond
-        ($oops who "~s is not a supported format" x))
+         [(eqv? x (constant COMPRESS-GZIP)) 'gzip]
-      x)))
+         [(eqv? x (constant COMPRESS-LZ4)) 'lz4]
+         [else ($oops who "unexpected $compress-format value ~s" x)]))]
+    [(x)
+     ($tc-field 'compress-format ($tc)
+       (case x
+         [(gzip) (constant COMPRESS-GZIP)]
+         [(lz4) (constant COMPRESS-LZ4)]
+         [else ($oops who "~s is not a supported format" x)]))]))
+
+(define-who compress-level
+  (case-lambda
+    [()
+     (let ([x ($tc-field 'compress-level ($tc))])
+       (cond
+         [(eqv? x (constant COMPRESS-LOW)) 'low]
+         [(eqv? x (constant COMPRESS-MEDIUM)) 'medium]
+         [(eqv? x (constant COMPRESS-HIGH)) 'high]
+         [(eqv? x (constant COMPRESS-MAX)) 'maximum]
+         [else ($oops who "unexpected $compress-level value ~s" x)]))]
+    [(x)
+     ($tc-field 'compress-level ($tc)
+       (case x
+         [(low) (constant COMPRESS-LOW)]
+         [(medium) (constant COMPRESS-MEDIUM)]
+         [(high) (constant COMPRESS-HIGH)]
+         [(maximum) (constant COMPRESS-MAX)]
+         [else ($oops who "~s is not a supported level" x)]))]))
 
 (define-who debug-level
   ($make-thread-parameter

s/bytevector.ss

@@ -1454,25 +1454,23 @@
   )
 
   (let ()
-    ;; Store uncompressed size as u64, using high bit to indicate LZ4:
+    ;; Store uncompressed size as u64, using low bits to indicate compression format:
     (define uncompressed-length-length (ftype-sizeof integer-64))
     ;; Always big-endian, so that compressed data is portable.
-    ;; It might be useful somehow that valid compressed data always starts
-    ;; with a 0 or 128 byte; otherwise, the expected size would be unrealistically big.
     (define uncompressed-length-endianness (endianness big))
 
     (define $bytevector-compress-size
-      (foreign-procedure "(cs)bytevector_compress_size" (iptr boolean) uptr))
+      (foreign-procedure "(cs)bytevector_compress_size" (iptr int) uptr))
     (define $bytevector-compress
-      (foreign-procedure "(cs)bytevector_compress" (scheme-object iptr iptr scheme-object iptr iptr boolean) scheme-object))
+      (foreign-procedure "(cs)bytevector_compress" (scheme-object iptr iptr scheme-object iptr iptr int) scheme-object))
     (define $bytevector-uncompress
-      (foreign-procedure "(cs)bytevector_uncompress" (scheme-object iptr iptr scheme-object iptr iptr boolean) scheme-object))
+      (foreign-procedure "(cs)bytevector_uncompress" (scheme-object iptr iptr scheme-object iptr iptr int) scheme-object))
 
     (set-who! bytevector-compress
       (lambda (bv)
         (unless (bytevector? bv) (not-a-bytevector who bv))
-        (let* ([as-gz? (eq? 'gzip (compress-format))]
+        (let* ([fmt ($tc-field 'compress-format ($tc))]
-               [dest-max-len ($bytevector-compress-size (bytevector-length bv) as-gz?)]
+               [dest-max-len ($bytevector-compress-size (bytevector-length bv) fmt)]
                [dest-alloc-len (min (+ dest-max-len uncompressed-length-length)
                                     ;; In the unlikely event of a non-fixnum requested size...
                                     (constant maximum-bytevector-length))]
@@ -1483,34 +1481,25 @@
                                          bv
                                          0
                                          (bytevector-length bv)
-                                         as-gz?)])
+                                         fmt)])
             (cond
              [(string? r)
               ($oops who r bv)]
              [else
-              ($bytevector-u64-set! dest-bv 0 (bytevector-length bv) uncompressed-length-endianness who)
+              (let ([tag (bitwise-ior
-              (unless as-gz? (bytevector-u8-set! dest-bv 0 128)) ; set high bit for LZ4
+                           (bitwise-arithmetic-shift-left (bytevector-length bv) (constant COMPRESS-FORMAT-BITS))
-              (bytevector-truncate! dest-bv (fx+ r uncompressed-length-length))])))))
+                           fmt)])
+                ($bytevector-u64-set! dest-bv 0 tag uncompressed-length-endianness who)
+                (bytevector-truncate! dest-bv (fx+ r uncompressed-length-length)))])))))
 
     (set-who! bytevector-uncompress
       (lambda (bv)
         (unless (bytevector? bv) (not-a-bytevector who bv))
         (unless (>= (bytevector-length bv) uncompressed-length-length)
           ($oops who "invalid data in source bytevector ~s" bv))
-        (let* ([as-gz? (not (fx= 128 (bytevector-u8-ref bv 0)))]
+        (let* ([tag ($bytevector-u64-ref bv 0 uncompressed-length-endianness who)]
-               [dest-length (cond
+               [fmt (logand tag (fx- (fxsll 1 (constant COMPRESS-FORMAT-BITS)) 1))]
-                             [as-gz?
+               [dest-length (bitwise-arithmetic-shift-right tag (constant COMPRESS-FORMAT-BITS))])
-                              ($bytevector-u64-ref bv 0 uncompressed-length-endianness who)]
-                             ;; Need to skip high bit; likely can skip first 4 bytes
-                             [(and (fx= 0 (bytevector-u8-ref bv 1))
-                                   (fx= 0 (bytevector-u8-ref bv 2))
-                                   (fx= 0 (bytevector-u8-ref bv 3)))
-                              ($bytevector-u32-ref bv 4 uncompressed-length-endianness who)]
-                             [else
-                              ;; Clear high bit the hard way
-                              (+ ($bytevector-u32-ref bv 4 uncompressed-length-endianness who)
-                                 (let ([v ($bytevector-u32-ref bv 0 uncompressed-length-endianness who)])
-                                   ((bitwise-arithmetic-shift-left (- v #x80000000) 32))))])])
           (unless (and (fixnum? dest-length)
                        ($fxu< dest-length (constant maximum-bytevector-length)))
             ($oops who "bytevector ~s claims invalid uncompressed size ~s" bv dest-length))
@@ -1521,7 +1510,7 @@
                                             bv
                                             uncompressed-length-length
                                             (fx- (bytevector-length bv) uncompressed-length-length)
-                                            as-gz?)])
+                                            fmt)])
             (cond
              [(string? r) ($oops who r bv)]
              [(fx= r dest-length) dest-bv]

s/cmacros.ss

@@ -531,6 +531,15 @@
 
 (define-constant SEOF -1)
 
+(define-constant COMPRESS-GZIP 0)
+(define-constant COMPRESS-LZ4 1)
+(define-constant COMPRESS-FORMAT-BITS 3)
+
+(define-constant COMPRESS-LOW 0)
+(define-constant COMPRESS-MEDIUM 1)
+(define-constant COMPRESS-HIGH 2)
+(define-constant COMPRESS-MAX 3)
+
 (define-constant SICONV-DUNNO 0)
 (define-constant SICONV-INVALID 1)
 (define-constant SICONV-INCOMPLETE 2)
@@ -1371,6 +1380,9 @@
    [ptr suppress-primitive-inlining]
    [ptr default-record-equal-procedure]
    [ptr default-record-hash-procedure]
+   [ptr compress-format]
+   [ptr compress-level]
+   [void* lz4-out-buffer]
    [U64 instr-counter]
    [U64 alloc-counter]
    [ptr parameters]))

s/io.ss

@@ -264,7 +264,7 @@ implementation notes:
     (foreign-procedure "(cs)new_open_output_fd"
       (string int
        boolean boolean boolean
-       boolean boolean boolean boolean boolean)
+       boolean boolean boolean boolean)
       scheme-object))
   (define $open-input/output-fd
     (foreign-procedure "(cs)new_open_input_output_fd"
@@ -310,7 +310,7 @@ implementation notes:
   (define $compress-input-fd
     (foreign-procedure "(cs)compress_input_fd" (int integer-64) scheme-object))
   (define $compress-output-fd
-    (foreign-procedure "(cs)compress_output_fd" (int boolean) scheme-object))
+    (foreign-procedure "(cs)compress_output_fd" (int) scheme-object))
   (module (clear-open-files register-open-file registered-open-file? unregister-open-file)
     (define open-files #f)
     (define file-guardian)
@@ -645,14 +645,17 @@ implementation notes:
 
   (define binary-file-port-close-port
     (lambda (who p)
-      (unregister-open-file p)
-      (let ([msg ($close-fd ($port-info p) (port-gz-mode p))])
-        (unless (eq? #t msg) (port-oops who p msg)))
-      (mark-port-closed! p)
       (when (input-port? p)
         (set-port-eof! p #f)
         (set-binary-port-input-size! p 0))
-      (when (output-port? p) (set-binary-port-output-size! p 0))))
+      (when (output-port? p) (set-binary-port-output-size! p 0))
+      (unregister-open-file p)
+      ; mark port closed before closing fd.  if an interrupt occurs, we'd prefer
+      ; that the fd's resources never be freed than to have an open port floating
+      ; around with fd resources that have already been freed.
+      (mark-port-closed! p)
+      (let ([msg ($close-fd ($port-info p) (port-gz-mode p))])
+        (unless (eq? #t msg) (port-oops who p msg)))))
 
   (define-syntax binary-file-port-port-position
     (syntax-rules ()
@@ -3185,7 +3188,7 @@ implementation notes:
                                   ; reposition to 'unread' any compressed data in the input buffer
                                   (set-port-position! p fp)
                                   ($compress-input-fd fd fp))
-                                ($compress-output-fd fd (eq? (compress-format) 'gzip)))])
+                                ($compress-output-fd fd))])
                   (when (string? gzfd) ($oops who "failed for ~s: ~(~a~)" p gzfd))
                   (unless (eqv? gzfd fd) ; uncompressed input port
                     (assert (box? gzfd))
@@ -4091,8 +4094,7 @@ implementation notes:
           (let ([fd (critical-section
                       ($open-output-fd filename perms
                         no-create no-fail no-truncate
-                        append lock replace compressed
+                        append lock replace compressed))])
-                        (and compressed (eq? (compress-format) 'gzip))))])
             (when (pair? fd) (open-oops who filename options fd))
             (open-binary-fd-output-port who filename fd #t b-mode lock compressed)))))
 

s/primdata.ss

@@ -926,6 +926,7 @@
   (compile-profile [sig [() -> (ptr)] [(ptr) -> (void)]] [flags unrestricted])
   (compile-program-handler [sig [() -> (procedure)] [(procedure) -> (void)]] [flags])
   (compress-format [sig [() -> (symbol)] [(sub-symbol) -> (void)]] [flags])
+  (compress-level [sig [() -> (symbol)] [(sub-symbol) -> (void)]] [flags])
   (console-error-port [sig [() -> (textual-output-port)] [(textual-output-port) -> (void)]] [flags])
   (console-input-port [sig [() -> (textual-input-port)] [(textual-input-port) -> (void)]] [flags])
   (console-output-port [sig [() -> (textual-output-port)] [(textual-output-port) -> (void)]] [flags])