NXStream *NXOpenMemory(const char *addr, int size, int mode)
{
NXStream *s;
int newMode = mode;
if ((int)addr % vm_page_size && (mode != NX_READONLY))
return 0;
s = NXStreamCreate(newMode, FALSE);
s->functions = &memory_functions;
s->buf_base = (unsigned char *)addr;
s->buf_size = size;
s->buf_left = size;
s->buf_ptr = (unsigned char *)addr;
s->eof = size;
s->flags |= NX_CANSEEK;
if (addr)
s->flags |= NX_USER_OWNS_BUF;
else
switch(mode) {
case NX_READONLY:
break;
case NX_WRITEONLY:
memory_flush(s); /* get initial buffer */
break;
case NX_READWRITE:
if (s->flags & NX_READFLAG) {
NXChangeBuffer(s);
memory_flush(s); /* get initial buffer */
}
break;
}
return (s);
}
extern int _NXStreamChangeBuffer(NXStream *s, unsigned char ch)
{
int wasReading;
_NXVerifyStream(s);
wasReading = (s->flags & NX_READFLAG);
NXChangeBuffer(s);
if (wasReading)
NXPutc(s, ch);
else
ch = NXGetc(s);
return ((int)(ch));
}
__private_extern__
int NXDefaultWrite(NXStream *s, const void *buf, int count)
{
register int n;
int total = count;
int curPos;
const char * volatile bufPtr = buf;
NXHandler exception;
_NXVerifyStream(s);
/*
* Loop until copying complete.
*/
exception.code = 0;
if (s->flags & NX_READFLAG)
NXChangeBuffer(s);
while (count > 0) {
/*
* Flush buffer if necessary.
*/
if (s->buf_left == 0) {
NX_DURING {
(void)NXFlush(s);
} NX_HANDLER {
exception = NXLocalHandler;
break;
} NX_ENDHANDLER
}
/*
* Figure out how much to copy this time.
*/
n = count;
if (n > s->buf_left)
n = s->buf_left;
bcopy((const char *)bufPtr, s->buf_ptr, n);
/*
* Update all pointers.
*/
s->buf_ptr += n;
s->buf_left -= n;
bufPtr += n;
count -= n;
}
NXStream *NXOpenSmallMemory(int mode){
NXStream *s;
int newMode = mode;
char *addr;
if (mode != NX_WRITEONLY && mode != NX_READWRITE)
return NULL;
addr = malloc(INITIAL_SIZE);
s = NXStreamCreate(newMode, FALSE);
s->functions = &cheap_functions;
s->buf_base = (unsigned char *)addr;
s->buf_size = INITIAL_SIZE;
s->buf_left = INITIAL_SIZE;
s->buf_ptr = (unsigned char *)addr;
s->eof = 0;
s->flags |= NX_CANSEEK;
switch(mode) {
case NX_READWRITE:
if (s->flags & NX_READFLAG) {
NXChangeBuffer(s);
}
break;
}
return (s);
}
