ref: 10e8e99e07e8bfc3d2fc68efe95a572e8adc65a0
parent: 23e857034070229923a7b3b800d608ab0e14236d
author: Sigrid Solveig Haflínudóttir <sigrid@ftrv.se>
date: Sun Nov 3 13:45:02 EST 2024
add io-wait
--- a/ios.c
+++ b/ios.c
@@ -844,6 +844,32 @@
}
int
+ios_wait(ios_t *s, int us)
+{+ if(s->bpos < s->size)
+ return 1;
+ if(s->_eof)
+ return IOS_EOF;
+#ifdef __plan9__
+ USED(us);
+ return 1; // FIXME(sigrid): wait for input, but not too much
+#else
+ struct timeval t, *pt = nil;
+ if(us >= 0){+ t.tv_sec = us / 1000000;
+ t.tv_usec = us % 1000000;
+ pt = &t;
+ }
+ fd_set f;
+ FD_ZERO(&f);
+ FD_SET(s->fd, &f);
+ int r;
+ while((r = select(s->fd+1, &f, nil, nil, pt)) == EINTR);
+ return r && FD_ISSET(s->fd, &f);
+#endif
+}
+
+int
ios_getutf8(ios_t *s, Rune *r)
{int c;
--- a/ios.h
+++ b/ios.h
@@ -84,6 +84,8 @@
// ensure at least n bytes are buffered if possible. returns # available.
size_t ios_readprep(ios_t *from, size_t n);
+int ios_wait(ios_t *s, int us);
+
/* stream creation */
ios_t *ios_file(ios_t *s, char *fname, int rd, int wr, int create, int trunc);
ios_t *ios_mem(ios_t *s, size_t initsize);
--- a/iostream.c
+++ b/iostream.c
@@ -145,6 +145,20 @@
return mk_rune(r);
}
+BUILTIN("io-wait", io_wait)+{+ if(nargs > 2)
+ argcount(nargs, 2);
+ ios_t *s = toiostream(args[0]);
+ int us = nargs > 0 ? tooffset(args[1]) : -1;
+ int r = ios_wait(s, us);
+ if(r >= 0)
+ return r ? FL_T : FL_F;
+ if(r == IOS_EOF)
+ return FL_EOF;
+ lerrorf(IOError, "i/o error");
+}
+
BUILTIN("io-putc", io_putc) {argcount(nargs, 2);
@@ -198,7 +212,7 @@
ios_t *s = toiostream(args[0]);
size_t pos = toulong(args[1]);
off_t res = ios_seek(s, (off_t)pos);
- if(res == -1)
+ if(res < 0)
return FL_F;
return FL_T;
}
@@ -208,7 +222,7 @@
argcount(nargs, 1);
ios_t *s = toiostream(args[0]);
off_t res = ios_pos(s);
- if(res == -1)
+ if(res < 0)
return FL_F;
return size_wrap((size_t)res);
}