diff options
Diffstat (limited to 'serverboot/bunzip2.c')
| -rw-r--r-- | serverboot/bunzip2.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/serverboot/bunzip2.c b/serverboot/bunzip2.c new file mode 100644 index 00000000..9f79ade5 --- /dev/null +++ b/serverboot/bunzip2.c @@ -0,0 +1,169 @@ +/* Modified by okuji@kuicr.kyoto-u.ac.jp for use in serverboot. */ +/* Decompressing store backend + + Copyright (C) 1997 Free Software Foundation, Inc. + Written by Miles Bader <miles@gnu.ai.mit.edu> + This file is part of the GNU Hurd. + + The GNU Hurd is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2, or (at + your option) any later version. + + The GNU Hurd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */ + +#include <stdio.h> +#include <string.h> +#include <setjmp.h> +#include <cthreads.h> +#include <errno.h> + +#include <file_io.h> + +#define IN_BUFFERING (256*1024) +#define OUT_BUFFERING (512*1024) + +static struct mutex bunzip2_lock = MUTEX_INITIALIZER; + +/* Uncompress the contents of FROM, which should contain a valid bzip2 file, + into memory, returning the result buffer in BUF & BUF_LEN. */ +int +serverboot_bunzip2 (struct file *from, void **buf, size_t *buf_len) +{ + /* Callbacks from do_bunzip2 for I/O and error interface. */ + extern int (*unzip_read) (char *buf, size_t maxread); + extern void (*unzip_write) (const char *buf, size_t nwrite); + extern void (*unzip_read_error) (void); + extern void (*unzip_error) (const char *msg); + + /* How we return errors from our hook functions. */ + jmp_buf zerr_jmp_buf; + int zerr; + + size_t offset = 0; /* Offset of read point in FROM. */ + + /* Read at most MAXREAD (or 0 if eof) bytes into BUF from our current + position in FROM. */ + int zread (char *buf, size_t maxread) + { + vm_size_t resid; + size_t did_read; + + if (from->f_size - offset < maxread) + did_read = from->f_size - offset; + else + did_read = maxread; + + zerr = read_file (from, offset, buf, did_read, &resid); + if (zerr) + longjmp (zerr_jmp_buf, 1); + + did_read -= resid; + offset += did_read; + + return did_read; + } + + size_t out_buf_offs = 0; /* Position in the output buffer. */ + + /* Write uncompress data to our output buffer. */ + void zwrite (const char *wbuf, size_t nwrite) + { + size_t old_buf_len = *buf_len; + + if (out_buf_offs + nwrite > old_buf_len) + /* Have to grow the output buffer. */ + { + void *old_buf = *buf; + void *new_buf = old_buf + old_buf_len; /* First try. */ + size_t new_buf_len = round_page (old_buf_len + old_buf_len + nwrite); + + /* Try to grow the buffer. */ + zerr = + vm_allocate (mach_task_self (), + (vm_address_t *)&new_buf, new_buf_len - old_buf_len, + 0); + if (zerr) + /* Can't do that, try to make a bigger buffer elsewhere. */ + { + new_buf = old_buf; + zerr = + vm_allocate (mach_task_self (), + (vm_address_t *)&new_buf, new_buf_len, 1); + if (zerr) + longjmp (zerr_jmp_buf, 1); + + if (out_buf_offs > 0) + /* Copy the old buffer into the start of the new & free it. */ + bcopy (old_buf, new_buf, out_buf_offs); + + vm_deallocate (mach_task_self (), + (vm_address_t)old_buf, old_buf_len); + + *buf = new_buf; + } + + *buf_len = new_buf_len; + } + + bcopy (wbuf, *buf + out_buf_offs, nwrite); + out_buf_offs += nwrite; + } + + void zreaderr (void) + { + zerr = EIO; + longjmp (zerr_jmp_buf, 1); + } + void zerror (const char *msg) + { + zerr = EINVAL; + longjmp (zerr_jmp_buf, 2); + } + + /* Try to guess a reasonable output buffer size. */ + *buf_len = round_page (from->f_size * 2); + zerr = vm_allocate (mach_task_self (), (vm_address_t *)buf, *buf_len, 1); + if (zerr) + return zerr; + + mutex_lock (&bunzip2_lock); + + unzip_read = zread; + unzip_write = zwrite; + unzip_read_error = zreaderr; + unzip_error = zerror; + + if (! setjmp (zerr_jmp_buf)) + { + /* Call the bunzip2 engine. */ + do_bunzip2 (); + zerr = 0; + } + + mutex_unlock (&bunzip2_lock); + + if (zerr) + { + if (*buf_len > 0) + vm_deallocate (mach_task_self (), (vm_address_t)*buf, *buf_len); + } + else if (out_buf_offs < *buf_len) + /* Trim the output buffer to be the right length. */ + { + size_t end = round_page (out_buf_offs); + if (end < *buf_len) + vm_deallocate (mach_task_self (), + (vm_address_t)(*buf + end), *buf_len - end); + *buf_len = out_buf_offs; + } + + return zerr; +} |