major stdio overhaul, using readv/writev, plus other changes

[musl] / src / stdio / __stdio_read.c

diff --git a/src/stdio/__stdio_read.c b/src/stdio/__stdio_read.c
index d9bb326..a2e4cd6 100644 (file)
--- a/src/stdio/__stdio_read.c
+++ b/src/stdio/__stdio_read.c
@@ -2,5 +2,21 @@
 
 size_t __stdio_read(FILE *f, unsigned char *buf, size_t len)
 {
-       return syscall(SYS_read, f->fd, buf, len);
+       struct iovec iov[2] = {
+               { .iov_base = buf, .iov_len = len },
+               { .iov_base = f->buf, .iov_len = f->buf_size }
+       };
+       ssize_t cnt;
+
+       cnt = syscall(SYS_readv, f->fd, iov, 2);
+       if (cnt <= 0) {
+               f->flags |= F_EOF ^ ((F_ERR^F_EOF) & cnt);
+               f->rpos = f->rend = 0;
+               return cnt;
+       }
+       if (cnt <= len) return cnt;
+       cnt -= len;
+       f->rpos = f->buf;
+       f->rend = f->buf + cnt;
+       return len;
 }