/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2010 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#include "sfhdr.h"
/* Create a temporary stream for read/write.
** The stream is originally created as a memory-resident stream.
** When this memory is exceeded, a real temp file will be created.
** The temp file creation sequence is somewhat convoluted so that
** pool/stack/discipline will work correctly.
**
** Written by David Korn and Kiem-Phong Vo.
*/
#if _tmp_rmfail
/* File not removable while there is an open file descriptor.
** To ensure that temp files are properly removed, we need:
** 1. A discipline to remove a file when the corresponding stream is closed.
** Care must be taken to close the file descriptor before removing the
** file because systems such as NT do not allow file removal while
** there is an open file handle.
** 2. An atexit() function is set up to close temp files when process exits.
** 3. On systems with O_TEMPORARY (e.g., NT), this is used to further ensure
** that temp files will be removed after the last handle is closed.
*/
typedef struct _file_s File_t;
struct _file_s
{ File_t* next; /* link list */
Sfio_t* f; /* associated stream */
char name[1]; /* temp file name */
};
static File_t* File; /* list pf temp files */
#if __STD_C
static int _tmprmfile(Sfio_t* f, int type, Void_t* val, Sfdisc_t* disc)
#else
static int _tmprmfile(f, type, val, disc)
Sfio_t* f;
int type;
Void_t* val;
Sfdisc_t* disc;
#endif
{
reg File_t *ff, *last;
NOTUSED(val);
if(type == SF_DPOP) /* don't allow this to pop */
return -1;
if(type == SF_CLOSING)
{
(void)vtmtxlock(_Sfmutex);
for(last = NIL(File_t*), ff = File; ff; last = ff, ff = ff->next)
if(ff->f == f)
break;
if(ff)
{ if(!last)
File = ff->next;
else last->next = ff->next;
if(_Sfnotify)
(*_Sfnotify)(f,SF_CLOSING,f->file);
CLOSE(f->file);
f->file = -1;
while(sysremovef(ff->name) < 0 && errno == EINTR)
errno = 0;
free((Void_t*)ff);
}
(void)vtmtxunlock(_Sfmutex);
}
return 0;
}
#if __STD_C
static void _rmfiles(void)
#else
static void _rmfiles()
#endif
{ reg File_t *ff, *next;
(void)vtmtxlock(_Sfmutex);
for(ff = File; ff; ff = next)
{ next = ff->next;
_tmprmfile(ff->f, SF_CLOSING, NIL(Void_t*), ff->f->disc);
}
(void)vtmtxunlock(_Sfmutex);
}
static Sfdisc_t Rmdisc =
{ NIL(Sfread_f), NIL(Sfwrite_f), NIL(Sfseek_f), _tmprmfile, NIL(Sfdisc_t*) };
#endif /*_tmp_rmfail*/
#if __STD_C
static int _rmtmp(Sfio_t* f, char* file)
#else
static int _rmtmp(f, file)
Sfio_t* f;
char* file;
#endif
{
#if _tmp_rmfail /* remove only when stream is closed */
reg File_t* ff;
if(!File)
atexit(_rmfiles);
if(!(ff = (File_t*)malloc(sizeof(File_t)+strlen(file))) )
return -1;
(void)vtmtxlock(_Sfmutex);
ff->f = f;
strcpy(ff->name,file);
ff->next = File;
File = ff;
(void)vtmtxunlock(_Sfmutex);
#else /* can remove now */
while(sysremovef(file) < 0 && errno == EINTR)
errno = 0;
#endif
return 0;
}
#if !_PACKAGE_ast
#define TMPDFLT "/tmp"
static char **Tmppath, **Tmpcur;
#if __STD_C
char** _sfgetpath(char* path)
#else
char** _sfgetpath(path)
char* path;
#endif
{ reg char *p, **dirs;
reg int n;
if(!(path = getenv(path)) )
return NIL(char**);
for(p = path, n = 0;;) /* count number of directories */
{ while(*p == ':')
++p;
if(*p == 0)
break;
n += 1;
while(*p && *p != ':') /* skip dir name */
++p;
}
if(n == 0 || !(dirs = (char**)malloc((n+1)*sizeof(char*))) )
return NIL(char**);
if(!(p = (char*)malloc(strlen(path)+1)) )
{ free(dirs);
return NIL(char**);
}
strcpy(p,path);
for(n = 0;; ++n)
{ while(*p == ':')
++p;
if(*p == 0)
break;
dirs[n] = p;
while(*p && *p != ':')
++p;
if(*p == ':')
*p++ = 0;
}
dirs[n] = NIL(char*);
return dirs;
}
#endif /*!_PACKAGE_ast*/
#if __STD_C
static int _tmpfd(Sfio_t* f)
#else
static int _tmpfd(f)
Sfio_t* f;
#endif
{
reg char* file;
int fd;
#if _PACKAGE_ast
if(!(file = pathtemp(NiL,PATH_MAX,NiL,"sf",&fd)))
return -1;
_rmtmp(f, file);
free(file);
#else
int t;
/* set up path of dirs to create temp files */
if(!Tmppath && !(Tmppath = _sfgetpath("TMPPATH")) )
{ if(!(Tmppath = (char**)malloc(2*sizeof(char*))) )
return -1;
if(!(file = getenv("TMPDIR")) )
file = TMPDFLT;
if(!(Tmppath[0] = (char*)malloc(strlen(file)+1)) )
{ free(Tmppath);
Tmppath = NIL(char**);
return -1;
}
strcpy(Tmppath[0],file);
Tmppath[1] = NIL(char*);
}
/* set current directory to create this temp file */
if(Tmpcur)
Tmpcur += 1;
if(!Tmpcur || !Tmpcur[0])
Tmpcur = Tmppath;
fd = -1;
for(t = 0; t < 10; ++t)
{ /* compute a random name */
static ulong Key, A;
if(A == 0 || t > 0) /* get a quasi-random coefficient */
{ reg int r;
A = (ulong)time(NIL(time_t*)) ^ (((ulong)(&t)) >> 3);
if(Key == 0)
Key = (A >> 16) | ((A&0xffff)<<16);
A ^= Key;
if((r = (A-1) & 03) != 0) /* Knuth vol.2, page.16, Thm.A */
A += 4-r;
}
Key = A*Key + 987654321;
file = sfprints("%s/sf%3.3.32lu.%3.3.32lu",
Tmpcur[0], (Key>>15)&0x7fff, Key&0x7fff);
if(!file)
return -1;
#if _has_oflags
if((fd = sysopenf(file,O_RDWR|O_CREAT|O_EXCL|O_TEMPORARY,SF_CREATMODE)) >= 0)
break;
#else
if((fd = sysopenf(file,O_RDONLY)) >= 0)
{ /* file already exists */
CLOSE(fd);
fd = -1;
}
else if((fd = syscreatf(file,SF_CREATMODE)) >= 0)
{ /* reopen for read and write */
CLOSE(fd);
if((fd = sysopenf(file,O_RDWR)) >= 0)
break;
/* don't know what happened but must remove file */
while(sysremovef(file) < 0 && errno == EINTR)
errno = 0;
}
#endif /* _has_oflags */
}
if(fd >= 0)
_rmtmp(f, file);
#endif /* _PACKAGE_ast */
return fd;
}
#if __STD_C
static int _tmpexcept(Sfio_t* f, int type, Void_t* val, Sfdisc_t* disc)
#else
static int _tmpexcept(f,type,val,disc)
Sfio_t* f;
int type;
Void_t* val;
Sfdisc_t* disc;
#endif
{
reg int fd, m;
reg Sfio_t* sf;
Sfio_t newf, savf;
void (*notifyf)_ARG_((Sfio_t*, int, void*));
NOTUSED(val);
/* the discipline needs to change only under the following exceptions */
if(type != SF_WRITE && type != SF_SEEK &&
type != SF_DPUSH && type != SF_DPOP && type != SF_DBUFFER)
return 0;
/* notify function */
notifyf = _Sfnotify;
/* try to create the temp file */
SFCLEAR(&newf,NIL(Vtmutex_t*));
newf.flags = SF_STATIC;
newf.mode = SF_AVAIL;
if((fd = _tmpfd(f)) < 0 )
return -1;
/* make sure that the notify function won't be called here since
we are only interested in creating the file, not the stream */
_Sfnotify = 0;
sf = sfnew(&newf,NIL(Void_t*),(size_t)SF_UNBOUND,fd,SF_READ|SF_WRITE);
_Sfnotify = notifyf;
if(!sf)
return -1;
if(newf.mutex) /* don't need a mutex for this stream */
{ (void)vtmtxclrlock(newf.mutex);
(void)vtmtxclose(newf.mutex);
newf.mutex = NIL(Vtmutex_t*);
}
/* make sure that new stream has the same mode */
if((m = f->flags&(SF_READ|SF_WRITE)) != (SF_READ|SF_WRITE))
sfset(sf, ((~m)&(SF_READ|SF_WRITE)), 0);
sfset(sf, (f->mode&(SF_READ|SF_WRITE)), 1);
/* now remake the old stream into the new image */
memcpy((Void_t*)(&savf), (Void_t*)f, sizeof(Sfio_t));
memcpy((Void_t*)f, (Void_t*)sf, sizeof(Sfio_t));
f->push = savf.push;
f->pool = savf.pool;
f->rsrv = savf.rsrv;
f->proc = savf.proc;
f->mutex = savf.mutex;
f->stdio = savf.stdio;
if(savf.data)
{ SFSTRSIZE(&savf);
if(!(savf.flags&SF_MALLOC) )
(void)sfsetbuf(f,(Void_t*)savf.data,savf.size);
if(savf.extent > 0)
(void)sfwrite(f,(Void_t*)savf.data,(size_t)savf.extent);
(void)sfseek(f,(Sfoff_t)(savf.next - savf.data),SEEK_SET);
if((savf.flags&SF_MALLOC) )
free((Void_t*)savf.data);
}
/* announce change of status */
if(notifyf)
(*notifyf)(f, SF_NEW, (void*)((long)f->file));
f->disc = disc->disc;
/* erase all traces of newf */
newf.data = newf.endb = newf.endr = newf.endw = NIL(uchar*);
newf.file = -1;
sfclose(&newf);
return 1;
}
#if __STD_C
Sfio_t* sftmp(size_t s)
#else
Sfio_t* sftmp(s)
size_t s;
#endif
{
Sfio_t* f;
static Sfdisc_t Tmpdisc =
{ NIL(Sfread_f), NIL(Sfwrite_f), NIL(Sfseek_f), _tmpexcept,
#if _tmp_rmfail
&Rmdisc
#else
NIL(Sfdisc_t*)
#endif
};
/* start with a memory resident stream */
if(!(f = sfnew(NIL(Sfio_t*),NIL(char*),s,-1,SF_STRING|SF_READ|SF_WRITE)) )
return NIL(Sfio_t*);
if(s != (size_t)SF_UNBOUND) /* set up a discipline for out-of-bound, etc. */
f->disc = &Tmpdisc;
/* make the file now */
if(s == 0 && _tmpexcept(f,SF_DPOP,NIL(Void_t*),f->disc) < 0)
{ sfclose(f);
return NIL(Sfio_t*);
}
return f;
}